Nitrogen Fixing Tree Associaton
Nitrogen Fixing Tree Association 1994
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The Nitrogen Fixing Tree Association (NFTA) is an international organization of 1600 community groups, development workers, tree breeders, scientists and farmers. Through research, outreach and communications activities, NFTA provides the skills and resources necessary to introduce, improve and manage nitrogen fixing trees for economic and environmental benefits. NFTA is registered as a non-profit organization in the United States of America.
NFTA 94-08 September 1994
Koa (Acacia koa Gray.) is unquestionably Hawaii's most prized tree species culturally, ecologically and economically. Hawaiians have always valued koa for its exceptionally beautiful and durable wood. It remains the premier Hawaiian timber for furniture, cabinetry, interior work and woodcrafts. Equally important, native koa forests provide unique wildlife habitat, critical watershed recharge areas and recreational opportunities. Unfortunately, forest clearing for agriculture, cattle grazing and feral pig activity have much diminished Hawaii's once extensive koa forest. The scarcity of koa wood is reflected in its ever increasing price-high enough now to economically justify helicopter logging.
Botany and Ecology
Acacia koa is a large, evergreen broadleaf tree and the only Acacia native-and endemic-to Hawaii. Trees occurring in dense, wet native forest stands typically reach heights of 25 m and stem diameters (DBH) of 150 cm, while retaining a straight, narrow form.. In the open, trees develop more spreading, branching crowns and shorter, broader trunks. Koa bark is gray, rough, scaly and thick. Observations indicate that koa has one main tap root - and an otherwise shallow, spreading root system.
Koa belongs to the thorn-less, phyllodinous group of the Acacia subgenus Heterophyllum (Whitesell 1990). Like other phyllodial species, mature koa trees do not have true leaves. Instead they produce phyllodes, or flattened leaf petioles. Young seedlings have bipinnate compound true leaves with 12 to 15 pairs of leaflets. Where forest light is sufficient, seedlings stop producing true leaves while they are small less then 2 m tall.. True leaves are retained longer by trees growing in dense shade.
Phyllodes are sickle-shaped and often more than 2.5 cm wide in the middle and blunt pointed on each end. Investigations suggest that true leaves promote more rapid early growth when moisture is adequate, whereas phyllodes are better adapted to drought Phyllodes transpire only 20 percent as much as true leaves, and their stomata close four times faster after dark. Phyllodes typically hang down vertically, a position that enhances their ability to capture light during early morning and late afternoon hours. Seedlings are able to switch back from phyllode to true leave production when the sunlight reaching them is reduced (Walters and Bartholomew 1990). This adaptation allows them to survive and grow under a wide range of light regimes.
Observations suggest koa can flower a]most any time of year, depending upon local weather conditions. The inflorescence of koa is a pale yellow ball averaging 8.5 mm in diameter, one to three on a common stalk. Each inflorescence is composed of many bisexual flowers. Each flower has an indefinite number of stamens and a single elongated style. One known pollinator of koa is the honeybee (Apis mellifera). Koa appears to be fully self-fertile (Brewbaker 1977).
Koa pods are slow to dehisce and about 15 cm long and 2.5 to 4 cm wide. They normally contain between 6 and 12 seeds that vary from dark brown to black. Pods reach maturity at 4 to 6 months, depending on location and weather conditions. Insect larvae of many species typically destroy a large proportion of the mature seeds before they dehisce.
Seed production typically begins when trees are 5 years old. Koa bears seed often and abundantly. Seeds are seldom dispersed far from the tree and remain viable in the soil for up to 25 years. Thus remnant koa stands are capable of dominant regeneration under favorable conditions. Koa seeds do not require sunlight to germinate, but seedling growth is slow in dark understories or in thick grass. The species thus requires large forest gaps, such as those created by storms, to successfully regenerate.
Acacia koa occurs at elevations from 180 to 6000 meters between 19 and 22 latitude on all of the major Hawaiian islands. It prefers an annual rainfall of 1900 to 5100 mm, and well drained acid soils. However, koa adapts to almost any of Hawaii's diverse environments indicating its potential elsewhere in the Pacific. Koa is found on all volcanic soil types of all geologic ages. It grows well in moderately to well-drained, medium to very strongly acid soils on both flatland and steep slopes. On dry, shallow, poorly drained soils koa's growth is slow and its form generally poor.
Occurring in both pure and mixed forest stands, koa is most commonly associated with the native ohia (Metrosideros polymorpha). IL is also a codominant in several other major forest types including: Koa/Mamane (Sophora chrysophylla) Montane Dry Forest and Koa/Ohia/A'e (Sapindus soponaria) Forest (Wagner et al, 1990). Today Acacia koa stands are fragmented and concentrated in areas between 600 and 1800 meters elevation (Whitesell 1990). This distribution is largely the result of land conversion to agriculture and ranching. Cattle avidly graze koa seedlings, preventing regeneration.
Propagation is most successful from seed. One study recommends air-layering as the best vegetative propagation technique (Skolmen 1978). Koa seeds are durable and easy to store. They germinate after many years of storage if kept in a cool, dry place. The most effective method for improving seed germination is mechanical scarification. However, hot water soaking works well and is a more practical method. Boil water and remove it from the heat source. Soak seed in the boiled water for 24 hours. Once treated, seeds are typically sown m nursery beds. One week after germination, seedlings are transplanted into nursery tubes or bags. Seedlings are ready for transplanting into the field when they are approximately 20 cm tall-after 3 to 4 months in the nursery. Observations suggest that heart rot problems may be partially caused by root damage during transplanting. Therefore, establishment by direct seeding or encouragement of natural regeneration is recommended. On favorable sites, planted seedlings typically grow to 9 m m 5 years time (Judd 1920).
Koa's wide branching form is the result of open growth. Trees with long clear boles-called "Canoe trees" by native Hawaiians are now rare, but still found in forest gaps created by fallen trees. Dense stocking of seedlings, which mimics the competitive environment where superior "canoe trees" grow, encourages straight and rapid height growth. Initial spacing of 1.2 x 1.2 meters is currently recommended. Observation indicates that effective self-thinning will result in an adequate number of potential crop trees by age 25.
Where scattered koa cover is adequate, plantation establishment is most easily and successfully accomplished through the stimulation of natural regeneration. Pasture soils are scarified and competition from grasses reduced by the application of a contact herbicide. Gaps in the regeneration are filled with planted seedlings. Fertilizers are applied to give seedlings an initial "boost". Plantation thinning prescriptions should be based on desired products and management capabilities. The most important factors to consider in picking koa crop trees is stem form and height. Research on koa plantation management and various spacing and thinning regimes is direly needed.
Koa heartwood is highly valued by furniture and crafts people throughout Hawaii, and consumers the world-over, for its unique grain, varied color and workability. It seasons well without serious warping or splitting. Curly-grained wood, the result of both stress and genetics, is preferred over straight-grained wood. Wood color ranges from a subtle yellow to a striking dark red-purple. The specific gravity of koa wood averages .40, but with curly-grained wood can be as high as .65. Mature koa boles are commonly forking or fluting and often suffer from heart rot. These characteristics and wide branch angles limit its value as a large timber. Fortunately, these defects may be corrected through silviculture.
Forage and Wildlife Habitat.
Cattle, sheep and pigs browse koa foliage aggressively, especially its juvenile leaves. Koa is spread geographically throughout Hawaii and thus offers a variety of wildlife habitats of diverse moisture regimes, soils and vegetative compositions. An overlay of a koa forest area map onto a forest bird "habitat island" map produced by Walker (1986) shows remarkable correlation.
Most koa plantations in Hawaii have been established to provide vegetative cover on sites degraded by decades of intense grazing. Where scattered koa already exists, seed stored in the soil will likely germinate if the soil is scarified and grass competition controlled.
Acacia koa is nodulated by the slow-growing Bradyrhizobium spp. common in tropical soils. It nodulates heavily in a variety of soils, suggesting it is effective with a wide variety of Bradyrhizobia strains.
Pests and Diseases
Banana poke (Passiflora mollissima) is a fast growing vine that commonly outgrows and smothers young koa trees. Kikuyu grass (Pennisetum clandestinum), a dominant and extremely aggressive highland grass in Hawaii, is a major deterrent to the emergence of koa seedlings on cleared or formerly grazed lands. Successful koa plantation monoculture has historically been difficuIt to achieve due to associated insect and disease problems. Examples include the defoliating koa moth (Scotorythra paludicola) and a lethal "koa blight" first observed in 1988 on the island of Oahu.
Brewbaker, J.L. 1977. Final Report, Acacia koa project.
Unpublished report on file at the Institute of Pacific Islands
Forestry and University of Hawaii, Department of Horticulture, Honolulu, Hawaii.
Judd, C.S. 1920. The koa tree. Hawaii Forester and Agriculturalist 17(2):30-35.
Skolmen, R.G. 1978. Vegetative propagation of Acacia koa Gray. In Proceedings, Second Conference in Natural Sciences, Hawaii Volcanoes National Park, June 1-3, 1978, edited by C.W.
Smith. p. 260-273.
Wagner, W.L., D.R. Herbst and S.H. Sohmer. 1990. Manual of the Flowering Plants of Hawaii. Vol. 1. University of Hawaii Press, Bishop Museum, Honolulu, Hawaii.
Walker, R.L. 1986. Koa and wildlife - An enduring relationship. Unpublished paper on file at the Hawaii Division of Forestry and Wildlife, Honolulu, Hawaii.
Walters, G.A., and D.P. Bartholomew. 1990. Adaptation of Acacia koa leaves and phyllodes to changes in photosynthetic photon flux density. Forest Science 36(4):1050-1060.
Whitesell, C.D. 1990. Acacia koa Gray. In Silvics of North America; 2, Hardwoods. R.M. Burns and B.H. Honkala, Tech Coordinators. Agricultural Handbook No. 654. USDA Forest Service, Washington, D.C.
A Publication of the Nitrogen Fixing Tree Association Winrock International 38 Winrock Drive Morrilton AR 72110-9537
FACT 96-04 June 1996
Native to arid areas in South and Southeast Asia. Acacia Ieucophloea (syn. Mimosa leucophloea) is easily identified by its white bark and large wide spreading limbs. It is most often utilized as shade for livestock and as a source of dry-season fodder. Growing well on alluvial or infertile soils, .4. Ieucophloea also has great potential as a reforestation species for degraded sites. Currently, it is not commonly planted for this purpose. Common names for this species often refer to its light color; white-bark acacia (English), safed kikkar (Hind)), safed babul (Bengali). goira (Oriya). sarai, velvelam (Tamil). Other common names include pilang and besok (Indonesian).
Acacia Ieucophloea (Roxb.) Willd. (Leguminosae Mimosoideae) is a large thorny tree attaining heights of 35 m and diameters at breast height (dbh) of 100 cm (Nielsen 1992, Heyne 1950). It may be deciduous. Mature trees become less thorny and can live to be 100 years old. Trunks are stout, dividing into several large diameter branches. Open-grown specimens have a characteristic wide umbrella-like crown. In India, the trunk is often crooked (Troup 1983), but reported as straight in Indonesia (Heyne 1950). Generally, the bark is white to yellowish gray, smooth and exfoliates in long strips. On old trees. the bark becomes black and rough (Troup 1983. Heyne 1950). In harsh environments and on poor soils this species remains a shrub or small malformed tree.
The feathery green foliage offers a strong contrast to the light-colored bark. Leaves are bipinnately compound having 5-30 pairs of leaflets. Circular glands are found on the rachis below the junction of pairedpinnae (Nielsen 1992, Troup 1983). Spines, 2-5 mm long, occur at the base of leaves. The leaves may fall during the cold or dry seasons and regrow with the rains. The conspicuous flowers are light-yellow to cream in color and are borne in abundance during the rainy season. Flowering occurs July through November in India (Troup 1983) and December through March in Indonesia Djogo 1992). The pods are yellow. green or brown in color. net and fairly straight. They measure 10-20 cm long, 5-10 mm wide and ripen from February to June in India (Troup 1983) and July to September in Timor (Djogo 1992). Pods should be collected before they split and disperse their seed. Healthy pods contain 10-20 smooth oblong seeds of dark brown color and 6x4 mm in size (Kumar and Bhanja 1992).
Acacia Ieucophloea is a component of dry-forests, savannas. bush woodlands. and desert ecosystems from sea level to elevations of 800 m. In these areas. rainfall is only 4001500 mm/year and dry seasons may persist for 9-10 months. Temperatures are extreme. varying from -1° to 49° C.
Acacia Ieucophloea is common on sands. infertile rocky soils. limestone soils. organic clays and alluvial areas. Plant growth is usually slow. On fertile soils, I. Ieucophloea seedlings grow quickly, up to 60 cm a year, but on such sites faster-growing associate species usually dominate. Under irrigation height growth may reach 7-10 meters in 5-6 years. Seedlings are light demanding and sensitive to weed competition. fire and frost. In order to exploit sufficient soil moisture. seedling root growth generally exceeds shoot growth. Once established. trees are very tolerant of drought. fire and frost. Reports concerning . i. Ieucophloea tolerance of saline conditions are contradictory. This question needs future investigation. Pruned or injured trees produce thorny branch and stump sprouts.
Acacia leucophloea's native range through South and Southeast Asia is non-contiguous. Its largest continuous distribution is and India through Sri Lanka, Bangladesh, Burma and much of Thailand. Other populations occur in southern Vietnam; Java and Bali of central Indonesia; and Timor of eastern Indonesia (Nielsen 1992, Troup 1983). This species has not been widely introduced to other regions.
The wood of this species is strong, heavy and hard with a specific gravity of 0.71. It seasons well and takes a good polish (Troup 1983). The brick-red heartwood is very beautiful and is used to make decorative furniture. The pale yellow sapwood is perishable. Commodities produced from the wood include poles, farming implements, carts, wheels, turnery, construction timbers and fuel. The utilization of this species is limited because its wood has irregular interlocked grain, a rough texture, is difficult to work and is not durable.
Fodder and Pasture.
Acacia leucophloea is an important dryseason fodder and pasture tree throughout its range. Leaves, tender shoots and pods are eagerly eaten by goats, sheep and cattle. Singh (1982) reports that leaves contain 15% crude protein and 19% crude fiber. However, due to hydrocyanic acid toxicity A. Ieucophloea should not be used as a sole feed (Bhadoria and Gupta 1981). During dry seasons, this tree protects livestock and understory pasture from excessive temperatures. Grass beneath the trees remains succulent while exposed grass becomes dry and unpalatable. In eastern Indonesia, populations of this species have declined significantly due to heavy use as a dry-season fodder. Farmers do not replants. leucophloea because of its slow growth.
The inner bark of A. Ieucophloea has a foul aroma. It produces a reddish-brown stain used to manufacture dyes and tannins (Heyne 1950). Fibers from the inner bark are used to make fish nets and rough rope. Additionally, a water soluble gum of fair quality can be extracted from the bark. The leaves yield a black dye and the bark produces tannin and dye (Heyne 1950, Troup 1983). Heyne (1950) reports the bark is used to distill liquor in India and seed sprouts are eaten as vegetables in Java. The vivid colors of its leaves, flowers and bark make A. Ieucophloea a beautiful, yet underutilized, ornamental tree.
Seeds of A. Ieucophloea (37,000-50,000/kg) have hard seedcoats. Under natural conditions they germinate unevenly. To encourage uniform germination, seed should be scarified. Two methods are recommended: 1) submerge seeds in boiled water until the water cools - roughly 24 hours, or 2) soak seeds in sulfuric acid for 10-30 minutes followed by a cool water soak for 24 hours (Kumar and Bhanja 1992). The visibly swollen seeds should be removed from the water and sown immediately.
Acacia leucophloea can be established by direct sowing, stump sprouts or seedlings. Direct sowing is preferred because the large roots of seedlings may hamper transplanting. Troup (1983) recommends the following method. Immediately prior to the rainy season, the sowing site should be cleared of weeds and the soil well cultivated. When the rains arrive sow scarified seed at a depth of 1 cm. Germination begins within a week.
Seedlings are sensitive to vegetative competition and browse damage. Weed control must be maintained for a minimum of two years. Livestock must be excluded from plantations until trees are beyond their reach. Annual cultivation around the seedlings improves growth and survival. Interplanting A. leucophloea at low densities with crops or pasture grasses can benefit both crops and trees (Troup 1983, Djogo 1992). Although this species is slow growing it should not be disregarded. Acacia leucophloea is a good reforestation species for poor soils in low rainfall areas. Otherwise underutilized, these sites could become useful fodder and fuel plantations.
Acacia leucophloea fixes atmospheric nitrogen through a symbiotic relationship with Rhizobium bacteria which enables it to survive on infertile sites. Quantitative information concerning the amount of nitrogen fixed in this relationship is lacking.
The wide crown of A. Ieucophloea competes with adjacent crops for sunlight, limiting the trees usefulness on farms. The wood degrades quickly and is difficult to work.
Bhadoria, B.K. and R.K. Gupta. 1981. A note on hydrocynic acid content in Acacia leucophloea Roxb. Willd. Current Science 50: 689-690.
Djogo, A.P.Y. 1992. The possibilities of using local droughtresistant multipupose tree species as alternatives to lamtoro (Leucaena leucocephala) for agroforestry and social forestry in West Timor. Working Paper No. 32. EAPI, East West Center, Honolulu, Hawaii, USA. 41 p.
Heyne, K. 1950. De nuttige planter van Indonesie (The useful plants of Indonesia). N.V. Uitgeverij W. van Hoeve, Bandung, Indonesia. pp 713-715.
Kumar, S.V. and M. Bhanja. 1992. Forestry seed manual of Andhra Pradesh. Research & Development Circle, Andhra Pradesh Forest Department, Hyderabad, India. 100 p.
Nielsen, I.C. 1992. Flora Malesiana: Mimosaceae (Leguminosae-Mimosoideae), vol. 11:45.
Singh, R.V. 1982. Fodder trees of India. Oxford and IBH Publishing, Co. New Delhi, India. pp 367-69.
Troup, R.S. 1983. Troup's Silviculture of Indian Trees, vol. IV Leguminosae. Forest Research Institute and Colleges, Dehra Dun, India. pp 33-38.
NFTA 94-03 April 1994
Alnus acuminata is a fast-growing species valued for its wood, watershed protection and soil improvement. Native from Mexico to Northern Argentina, it is known as alive (Mexico, Argentina, Colombia, Ecuador and Peru); aile, ilite (Mexico); ramrÃ¡m, lambrÃ¡n (Guatemala, Costa Rica and Peru); jaÃºl (Costa Rica); palo de lama (Guatemala) and; cerezo and chequiro (Colombia). Easily propagated from seed or by natural regeneration, A. acuminata is a popular agroforestry species in its native range. It has been successfully introduced into southern Chile and southern New Zealand.
Alnus acuminata ssp. arguta (Schlectendal) Furlow (Betulaceae) grows to 30 m in height and to 50 cm in diameter (after 30 years) in natural conditions. Maximum age may be 60 years (L Fournier,, personal communication). The leaves are simple, alternate, elliptical, 6 to 15 cm long, 3 to 8 cm wide, border double dentate, deciduous or semideciduos. The upper leaf surface is dark green and the lower surface is pale, whitish to light green. The bark is light-gray or silvery with yellowish lenticels. Crown shape is open rounded to pyramidal. Male and female flowers occur in separate catkins on the same branch. Inflorescences are cone-like with lignified scales, dark brown when ripened, and bearing more than 100 fruits per cone. The fruit is a small membranous-winged samara, 2 to 3 mm long that contains one seed. Dispersal is mainly by the wind. Seeds ripen in February,, March and August in South America (NAS, 1980), and from September to January in Costa Rica (Rotas et al., 1991).
There is considerable confusion in the taxonomy of Alnus acuminata. Furlow (1977) reported the species as Alnus acuminata H B.K, but in his last revision (1979) he classified it as Alnus acuminata ssp. arguta. The species also has been described as Alnus jorullensis H.B.K. by Carlson and Dawson (1985). Holdridge (1951) concluded that if subspecies populations exist they apparently intergrade into each other and because of similarities in wood and silvicultural characteristics they may be considered as a single species, at least from a forestry viewpoint.
Distribution and ecology
Alnus acuminata is native to the American contient ranging from Mexico to Northern Argentina in elevations between 1,200 and 3,200 m.a.s.i. where annual rainfall is 1,000 to 3,000 mm or more. The species occurs where mean annual temperature ranges between 4° and 27°C; however it can withstand temperatures dipping briefly below 0°C (NAS, 1980).
Alnus acuminata is a fast-growing pioneer species that regenerates naturally in open, disturbed areas. It grows in moist soil environments' usually along the banks of streams, rivers, ponds, and swamps where it typically forms dense pure stands.
It also can be associated with wet flood plains, or moist mountain slopes, although it may be adapted to somewhat drier conditions. However, it is usual' restricted to zones with extra soil moisture such as cool, tropical highlands, and cool, high-ladtude regions with abundant rainfall where mist and cloud cover can be a source of fog-drip precipitation. In tropical highlands of Central and South America, clouds and mist are important in supporting Alnus acuminata and grass, when associated, through the dry season.
Alnus acuminata prefers deep, well-drained soils with high organic matter content. However, it is commonly found growing on shallow soils, such as landslides. Rojas et al. (1991) report that it will grow in soil with pH as low as 45.
Alnus acuminata wood is light brown-yellow to pink, odorless' and tasteless' without differences between the heartwood and the sapwood. Reports on specific gravity vary from 034 to 039 (Tuk, 1980) and 05 to 0.6 (NAS, 1980). The calorific value is 19,2501kJ/kg (CATIE, 1986). The wood dries easily and preserves well. It has even grain, seasons fairly well, and is easy to work and finish by hand or machine. Despite its light weight it is tough and strong, and is sometimes used for construction. Timber is also used for fuelwood, posts' poles, light lumber, boxes, broom handles, domestic implements, plywood cores, particle board, and musical instruments. A match company in Colombia evaluated more than 20 native species and found Alnus acuminata wood best suited for making stick matches (In". R. Arismendi, Personal Communication).
Farmers in Costa Rica have grown Alnus acuminata in pastures and as a shade tree for coffee crops for more than 90 years. Trees are regenerated naturally or planted from nursery stock at spacings of 8 to 14 m (about 100 trees/ha).
One benefit of including trees in cattle pastures is greater milk production-cows on pastures with Alnus acuminata produce more than cows on pastures without it (Budowski, 1983). Farmers in Costa Rica sometimes construct crude fences around individual seedlings to protect them from livestock-protection is needed until trees grow tall enough that livestock can not browse new growth.
Alnus acuminata is propagated by seeds (more than 2 million pure seeds/kg). Seeds are recalcitrant and must be planted quickly-viability decreases from 70% to 20% in a few months. Seed viability can be extended by storing seed in airtight containers at 5° Cviability is 50% and 31 % after 2 and 3 months, respectively (Rojas et al., 1991).
No seed pre-treatment is necessary. Rojas et al. (1991) recommend broadcasting seed in germination beds (15 to 20 g of seed per m² of bed) and covering them with a very thin layer of mixed soil and sand. The germination bed should be a 1:1:2 mixture of fine soil, sand and organic material. Seeds should be watered twice daily with a very fine mist to maintain soil humidity. Overwatering may cause damping-off. Germination starts 6 to 7 days after sowing and is complete within 15 days. The most vigorous seedlings should be transplanted to pots or back plastic bags 20 days after germination. Seedlings may be planted out when they are 20 cm tall (in about four months). Bare-root seedlings and stump cuttings are possible alternatives to container-grawn seedlings. Seedlings do not compete well with weeds so frequent weeding is important (Rojas et al., 1991).
Alnus acuminata is grown in plantations mainly in Colombia and Costa Rica, but in other countries as well. In Colombia, an initial spacing of 2.6 x 2.6 m (1,480 trees/ha) is common (Sicco Smit, 1971). In Costa Rica, an initial spacing of 3 x 3 m is preferred. At least two thinnings are recommended, the first after the third year and the second after 10 to 15 years, leaving 250 to 350 trees per hectare. Trees are harvested in rotations of about 20 years. Average annual wood production is 15 to 20 m³ per hectare. According to Canet (1985), a stand of 30-year-old trees with a density of 35 trees/ha yielded 70 m³/ha of timber, 183 ton/ha of dry fuelwood, and 3.6 ton/ha of leaves and fine branches. Alnus acuminata resprouts vigorously from the stump after cutting.
Alnus acuminata, like other Alnus species, forms a symbiosis with actinomycetes of the genus Frankia. Rojas et al. (1991) report that nodules begin to grow on 13-day-old nursery seedlings. Estimates of nitrogen fixation for Alnus species vary widely between 62 kg/ha/yr for A. sinuata in Alaska and 125 kg/ha/yr for A. glutinosa, to 320 kg/halyr for A. rubra in Oregon (Carlson and Dawson, 1985). In a 2year-old A. acuminata plantation in the Colombian highlands (1200 trees/ha), Carlson and Dawson (1985) estimate an annual increase in soil nitrogen of 279 kg/ha. Acetylene reduction values for 120-day-old A. acuminata greenhouse seedlings inoculated with a crushed nodule suspension were between 32.5 and 86.4 µmol of ethylens produced per gram of nodule dry weight per hour (Russo and Berlyn, 1988).
Pests and diseases
Alnus acuminata is susceptible to attack by defoliators (Nodonota irazuensis and Nodonota cat parvula, Coleoptera, Chrysomelidae). A stem borer Scolytodes alni, (Coleoptera, Scolytidae) has been observed in Costa Rica during the dry season. Vertebrates such as Sciurus sp. (Rodentia, Sciuridae) may cause debarking and Sylvilagus brasiliensis (Lafomorpha, Leporidae) may destroy seedlings. Fungi such as Fusarium sp. and Trichoderma sp. may damage seeds; Colletotrichum sp. and Phomopsis sp. may affect leaves; and Rosellinia sp. may affect stems and roots in mature trees (CATIE, 1991).
Budowski, G. 1983. An attempt to quantify some current agroforestry practices in Costa Rica. In Huxley, P. A. ed. Plant Research in Agroforestry. Nairobi, Kenya, ICRAF. pp. 43-62.
Canet, G.C. 1985. Caracteristicas del sistema silvo-pastoril jaÃºl (Alnus acuminata) con lecheria de altura en Costa Rica. In R. Salazar ed. TÃ©cnicas de producciÃ³n de leÃ±a en fincas pequenas. Actas de los simposios. CATIE, Turrialba, 2428 de junio, 1985. pp. 241-249.
Carlson, P.J. and J.O. Dawson. 1985. Soil nitrogen changes, early growth, and response to soil internal drainage of a plantation of Alnus jorullensis in the Colombian highlands. Turrialba 35(2):141-150.
CATIE 1986. Silvicultura d e especies promisorias para producciÃ³n de leÃ±a en America Central. CATIE, Turrialba, Costa Rica. p. 51.
CATIE 1991. Plagas y enfermedades forestales en America Central: guÃa de campo. CATIE, Turrialba, Costa Rica.185 p.
Furlow, J.J. 1977. Betulaceae. In Burger, W. Flora Costaricensis. Fieldiana: Botany 40:56-58.
Furlow, J.J. 1979. The systematics of the American species of Alnus (Betulaceae). Rhodora 81(825):1-121.
Holdridge, L.R. 1951. The alder, Alnus acuminata, as a farm timber tree in Costa Rica. Caribbean Forester 12(2):47-57.
National Academy of Sciences. 1980. Firewood crops: shrub and tree species for energy production. Vol. 1. National Academy of Sciences, Washington, D.C.
Rojas, F., G. Torres, E. ArnÃ¡ez and I, Moreira. 1991. JaÃºl cuadernos cientificos y tecnolÃ³gicos, especies forestales tropicales, No. 1. Instituto TecnolÃ³gico de Costa Rica, Cartago, Costa Rica. 9 p.
Russo, R.O. and G.P. Berlyn. 1989. The effect of a new growth biostimulant on acetylene reduction in nodulated seedlings of Alnus acuminata. Nitrogen Fixing Conference Abstracts. Ames, Iowa. July 30-August 3, 1989.
Sicco Smit, G. 1971. Notas silviculturales sobre Alnus jorullensis de Caldas, Colombia. Turrialba 21:83-88.
Tuk, J. 1980. Informe general del proyecto: ClasificaciÃ³n y normalizaciÃ³n de maderas para uso estructural. Instituto TecnolÃ³gico de Costa Rica, Cartago, C.R.
A publication of the Nitrogen Fixing Tree Association Winrock International 38 Winrock Drive Morrilton AR 72110-9537
NFTA 95-02 (Replaces 87-06) January 1995
Albizia saman (Jacq.) F. Muell. (Leguminosae, Subfamily Mimosoideae) is a fast growing tree which obtains a large size. It is most common as a pasture, shade or ornamental tree, but has numerous uses. This New World tree is so widely cultivated and used in Southeast and South Asia it is often mistaken as native to that area. It was formerly classified as Samanea saman, Pithecellobium saman and Enterolobium saman. Common names include saman, monkey pod, raintree, cow tamarind, algarrabo and guango.
Albizias are related to and often mistaken for Acacias-in the Philippines acacia is a common name for A. saman. Albizia saman can obtain a height of 3045 m and diameter breast height (DBH) of 150-250 cm. Open-grown specimens have short stems and stout wide-spreading nearly horizontal branches. The umbrella-shaped crown may be wider than the height of the tree. The brown gray bark is rough and furrowed into ridges and plates (Little and Wadsworth 1989). Limb bark is lighter in color. Twigs are stout and green. The bipinnately compound leaves are 2540 cm long dark green above and light green below. The stalkless leaflets are arranged in pairs numbering from 12 to 32 (Little and Wadsworth 1989). Leaflets are wider towards the apex. Both leaves and leaflets are progressively larger towards their terminal ends.
The showy flower heads, composed of many narrow pink flowers, are found near the end of twigs and appear from March to September (Hensleigh and Holaway 1988). The dark-brown to black pods are hard and thick with a raised seam. They are 8-20 cm long and about 2 cm wide. The pods do not readily open and remain on trees for long periods. Seeds are red-brown oblong and squarish. There are 5000-8000 seed/kg.
Albizia saman is found in the tropics from sea-level to 1000 meters where the temperature is 20-35° Celsius. It is a common component of dry forests and grass savannas. Annual rainfall in these areas is 600-3000 mm/year. Albizia saman easily survives dry seasons of 24 months. While more common on drier sites, this species grows best in moist, well-drained fertile soils (Hensleigh and Holaway 1988). It tolerates heavy clays and infertile or waterlogged soils. Although normally found in neutral to moderately acid soils, it will grow in soil with pH as low as 4.6 (Franco et al. 1995).
This species is native from Southern Mexico and Guatemala south to Peru, Bolivia and Brazil. It is naturalized throughout the tropics and has been introduced to sub-tropical areas.
Shade and ornamental.
Albizia saman is planted along roads throughout the tropics. In parks and commons, its high arching branches provide welcome protection from the heat of the tropical sun. Having crowns of great diameter, trees furnish ample shade. Trees serve as windbreaks and are cultivated for their beautiful pink flowers.
The wood of Albizia saman is highly valued for the manufacture of furniture, cabinets, decorative veneers, bowls and other handicrafts. The chocolate heartwood and yellow sapwood form a beautiful contrast. The light-weight wood (specific gravity 0.48) is strong, durable, works easily and takes a good finish (Chudnoff 1984). It shrinks so little that products made from green wood dry without warping (NAS 1979). Albizia saman is a good quality fuel and charcoal, producing 5200-5600 kcal/kg (F/FRED 1994). Other uses of the wood include fencing, construction timbers, plywood and the manufacture of crates, wheels and boats.
Pasture and fodder.
Albizia saman is a valuable component of pasture systems. Its shade protects livestock from the hot tropical sun. Its nutritious pods contain 12-18% crude protein and are 40% digestible (F/FRED 1994). Relished by livestock, pods are an important dry-season fodder. Tree leaves are also nutritious, but are not an important fodder. The shade and nitrogen-rich leaf-litter of A. saman improve the nutritional value of understory grass (Allen and Allen 1981). During the dryseason, grass beneath trees remains green and succulent while exposed grass becomes dry and unpalatable. Leaves fold inward at night which may increase the amount of moisture, rain and dew, reaching the understory. In the morning leaves unfold giving full shade and conserving soil moisture.
This species is used as shade for tea, coffee, cacao, nutmeg and vanilla. Performance has been fair in alley-and hedgerow-cropping studies. Initial growth is slower than other woody perennials, but A. saman coppices well and yields nitrogen-rich green manure. However, shallow roots and large branch size compete heavily with companion crops, especially in dry areas. In these systems, A. saman must be heavily pruned. In most areas, other species will be more appropriate for alley-and hedgerow-cropping studies. Albizia saman is appropriate in home gardens where it provides a service role and multiple products simultaneously.
Children eat the pods which contain a sticky sweetflavored pulp. A fruit drink is also made from the pulp. Honey is produced from the flowers. The bark yields gums and resins. In Thailand, A. saman is an important host plant for lac production (Subansenee 1994).
Seeds of A. saman have hard, impermeable seedcoats. Two methods of seed scarification are recommended. For small quantities of seed, cut through the seedcoat opposite the micropyle, or pointed-end of the seed, taking care not to damage the seed embryo. For large quantities of seed, pour boiled water over the seeds, soak and stir for two minutes. Drain off the hot water. The hot water should equal five times the volume of seeds. With either method of scarification, the seed should be soaked in cool water overnight before sowing (NFTA 1989). Seed should be sown at a depth equal to its width in large nursery bags, 10cm x 20cm. The recommended nursery mixture is 3 parts soil: 1 part sand: 1 part compost. Seedlings should receive partial shade for 2-4 weeks and then be exposed to full sunlight. After 3-5 months seedlings will be 20-30 cm tall and ready for field planting. Direct sowing is possible, but success depends on rigorous weed control. Albizia saman can be propagated by cutting or stump cutting.
Open-grown A. saman have short trunks and spreading limbs which are considered poor form for timber production. Close spacing, 1.5-2 meters, does produce straighter trees with less branching, but boles retain a spiral form. For this reason, A. saman is not commonly planted in single-purpose timber plantations. In pastures, home gardens or other multiplepurpose plantings, tree spacing will depend on companion plants and management strategy.
A light-demanding species, A. saman grows fast and is tolerant of heavy weed competition. However, survival and growth can be improved through vigorous weed control until trees achieve dominance over competing vegetation. Wood production varies by site and management system. A good site can produce 10-25 m³/hectare/year under a 10-15 year rotation (F/FRED 1994).
Albizia saman forms nitrogen fixing symbiosis with many strains of Rhizobium. In the field it readily forms root nodules.
Heterophylla cabana, Psylla acacia-baileyanae and other defoliators are common pests (Braze 1990) but do not cause serious stress problems. Wide spreading branches and shallow roots make A. saman susceptible to damage during intense storms. The destruction of natural forests threatens the genetic diversity of this species. In response to this threat, the Oxford Forestry Institute has included A. saman in its gene conservation program (Hughes 1989).
Allen, O.N. and E.K. Allen. 1981. The Leguminosae: a source book of characteristics, uses and nodulation. Wisconsin Press. Madison, Wisconsin, USA. pp. 590-92.
Braza, R.D. 1990. Psyllids on nitrogen fixing trees in the Philippines. NFTRR 8:62-63.
Chudnoff, M. 1984. Tropical timbers of the world. Agriculture Handbook 607. USDA Forest Service. Washington, DC.p. 134.
F/FRED. 1994. Growing Multipurpose Trees on Small Farms (2nd ed.). Module 9. Species fact heets. Bangkok, Thailand. Winrock International, pp. 22-23.
Franco, A., E.F.C. Campello, LE. Dias and S.M. de Faria. 1995. Revegetation of acidic residues from bauxite mining using nodulated and mycorrhizal legume trees. In: D. Evans and L. Szott (eds.), Nitrogen fixing trees for acid soils. Nitrogen Fixing Tree Research Reports (Special Issue). Morrilton, Arkansas, USA. In press.
Hensleigh, T.E. and B.K. Holaway. 1988. Agroforestry species for the Philippines. US Peace Corps. Washington, DC. pp. 281-84.
Hughes, C.E. 1989. Intensive study of multipurpose tree genetic resources. Oxford Forestry Institute, University of Oxford, UK. pp. 66-79.
Little, E.L. and F.H. Wadsworth. 1989. Common trees of Puerto Rico and the Virgin Islands. Agriculture Handbook No. 249.USDA Forest Service. Washington, DC. pp. 164-66.
NAS. 1979. Tropical legumes: Resources for the future. National Academy of Sciences, National Research Council. Washington, DC. pp. 202-03.
Macklin, B., N. Glover, J. Chamberlain and M. Treacy. 1989. NFTA cooperative planting program establishment guide. Nitrogen Fixing Tree Association. Morrilton, Arkansas, USA. 36 p.
Subansenee, W. 1994. Economic value of Albizia saman. In: JB Raintree and HA Francisco (eds.). Marketing of Multipurpose Tree Products in Asia Bangkok, Thailand. Winrock International, pp. 229-35.
NFTA 90-04 July 1990
Casuarina junghuhniana Miq. occurs naturally in Indonesia where its common names are jemara or cemara (Java), and adjaob and kasuari (Timor). It is an environmentally important nitrogen-fxing tree, hosting the actinorhiza Frankia. C. junghuhniana is a tall forest tree 15-25 m tall and 30-50 cm diameter, that can grow up to 35 m in height and 1 m in diameter. A putative hybrid with C. equisetifolia is commercially cultivated in Thailand (Chittachumnonk 1983). C. junghuhniana is locally important in Indonesia for fuelwood, poles and soil conservation. With domestication its utility could be enhanced.
The crown of jemara is reasonably open and consists of numerous long deciduous branchlets bearing reduced scale leaves. It is dioecious; individual trees are carry either male or female flowers. Male flowers are borne on the tips of deciduous branchlets and female "cones " in the axils of scale "leaves " on permanent shoots. This species grows rapidly with a strong apical dominance. It has the capacity to produce vigorous root suckers and female trees seed abundantly.
The taxonomy of C junghuhniana is very confused and requires revision. Currently the species is considered to consist of two subspecies. Subspecies junghuhniana is found on the islands of Java, Bali, Lombok, Sumbawa and Flores. A subspecies tentatively called timorensis occurs on Timor, Wetar, Sumba and perhaps Sumbawa, Indonesia. Variation within each subspecies funkier complicates the subgroupings. The subspecies junghuhniana consists of discrete populations having coarse, fine, and intermediate textured deciduous branchlets but the patterns of variation are currently unresolved. The coarse forms may be related to tree growth on exposed sites. The coarse form is notable for its rugged, deeply furrowed, corky bark which is unusual for a casuarina. Subspecies timorensis on Timor is also thought to consist of two forms which the locals term "white" and "black" casuarinas. The hillside form has long, robust deciduous branchlets which in the riverine form are short and thin. Provenance trials of this casuarina have not been conducted. Environmental variation in natural habitat, however, suggests that considerable genetic variation is present.
Casuarina junghuhniana is wholely tropical in distribution, and is a native of highlands in Indonesia where it pioneers deforested lands such as screes (rocky slopes) and grasslands, and in disturbed areas it replaces mixed mountain forest plant communities (NAS 1984). Subspecies junghuhniana typically grows in extensive pure stands on volcanic slopes between altitudes of 1500 to 3100 m but can also occur below 100 m. Subspecies timorensis is normally found at lower altitudes, especially in Timor where it grows from near sea level to 300 m. Rainfall in its natural habitat is monsoonal with a well-defined summer maximum and a range of 700-1500 mm (NAS 1984). C jungilahniana often forms pure stands in dry and periodically burnedover areas. It is also found along gravelly stream beds in Timor. Once trees reach a few meters in height they are fire resistant and have good sprouting ability if fire damaged. C junghuhniana grows in a wide range of soils from volcanic, sandy to compact clay soil and including very acidic sites, pH 2.8 (Chittachumnonk 1983). It also appears well-adapted to growing on alkaline soils in Timor (Turnbull 1989 pers. comm.). It can tolerate waterlogging up to 104 days (Verhoef 1943). It is considered moderate (NAS 1984) to very (Djogo 1989) drought resistant and is especially good as a pioneer on landslide-prone soils (Djogo 1989). In Timor it commonly grows on limestonederived soils.
As with other casuarinas, wood of C junghuhniana is highly suitable for fuelwood and charcoal production. Its calorific value in charcoal form is 7180 kcal/kg, among the highest for a firewood species. Its wood is very heavy having an air-dry density of 900, kg/m³ (Chomcharn et al. 1986).
C junghuhniana is especially suitable for wind breaks and for ornamental plantings. It is not used as fodder. In Timor C. junghuhniana is used for soil improvement, live fencing, building material and firewood, and branches and foliage are burnt and the ashes spread in village gardens (Djogo 1989). It has been used in revegetation and land rehabilitation projects in Java for nearly a century. In Thailand its straight-stemmed character makes it a popular underground pile for construction work as well as for fishtrap stakes. It is grown on farm boundaries for pole production in Kenya and Tanzania.
Seed from C. junghuhniana is small with approximately 1-1.6 million seeds per kg. No special pretreatment is needed to germinate seed. Like most casuarinas, seed probably loses viability quickly unless kept in dry, cold storage.
In Indonesia, Kenya and Tanzania all C. junghuhniana are raised from seed. In Thailand and India planting stock is raised by vegetative propagation because only male trees were originally introduced. Airlayering has been tried but with little success. The most successful method for production on a large scale was developed in Thailand. Stem cuttings of young shoots are placed in small pots filled with soil and river sand. Several pots are enclosed in polyethylene bags with tops supported by a stake. Rooting hormone (IBA) is necessary to promote rooting. The rooting process takes 3-4 weeks under 70% shade. Mahmood and Possuswam (1980) also report successful root cuttings of shoots and root suckers of this casuarina in India.
C junghuhniana has the potential to grow very quickly. In irrigated plantations in Thailand it can attain 21 m height and 15 cm diameter at 5 years. Growth is normally slower without irrigation. In Markhanam, Madras, India trees reach 5 m tall at 20 months after planting (Thirawat 1953). Well-maintained plantations can produce 30-35 m³/ha/y (Boontawee and Wasuwanich 1980).
PESTS AND DISEASES:
There appear to be no serious insect pests of C junghuhniana. In East lava forests of C junghuhniana have been attacked by caterpillars but the trees recovered even after repeated defoliations. Defoliation of C junghuhniana plantations by a locust Aulaches miliaris) during rainy season has also been reported in Thailand. Young trees died but older trees suffered only a temporary setback. Also reported from Thailand was minor damage to young shoots by an insect identified as Aristobia approxirmator in plantations Chittachumnonk 1983). In dry areas subterranean termites can destroy young plants by attacking their roots.
Boontawee, B. and Wasuwanich P. 1980. Casuarina junghuhniana. Forestry review, Silvicultural Research Subdivision, Royal Forest Department, Thailand.
Chittachumnonk, P. 1983. Silviculture of Casuarina junghuhniana in Thailand. In S.J. Midgley, J.W. Turnbull and R.D. Johnston (eds), Casuarina ecology, management and utilization. CSIRO, Canberra. p. 102-106.
Chomcharn, A., S. Visuthideppakul and P. Hortrakul. 1986. Wood property and potential uses of 14 fast-growing tree species. Report, Division of Forest Products Research, Royal Forest Department, Thailand.
Djogo, A.P.Y. 1989. The possibilities of using local drought resistant and multipurpose tree species as alternatives to lamtoro (Leucaena leucocephala) for agroforestry and social forestry in West Timor. Working paper, Env. and Policy Inst., East West Center, Hawaii. (in press)
Mahmood, AM. and P.K Possuswam. 1980. Propagation of Casuarina junghuhniana by planting shoots and root suckers. Indian Forester 106(4):298-299.
NAS (National Academy of Science). 1984. Casuarinas: Nitrogen fixing trees for adverse sites. National Academy Press, Washington, D.C.
Thirawat, S. 1953. Note on Casuarina junghuhniana with special reference to its experimental introduction into India. Indian Forester 79(12):636442.
Verhoef, L. 1943. Root studies in the tropics. VI. Further data about the oxygen requirements of the root system. Korte Meded. B.P.S. 81:1-65.
NFTA 90-05 November 1990
Enterolobium cycloca, pum (Jacq.) Griseb. is one of the largest trees in the dry forest formation of Mexico and Central America, reaching up to 3 m diameter and 40 m in height with a huge spreading crown. It is a conspicuous and well-known tree in its native range. Large crowned trees scattered in pastures are a common sight and a distinctive feature of the landscape in many parts of Central America. Such is its fame that Enterolobium has been adopted as the national tree of Costa Rica. The province of Guanacaste in Costa Rica is named after Enterolobium which occurs abundantly in that area.
Enterolobiant cyclocarpum is also well-known for its distinctive, thickened, contorted, indehiscent pods which resemble an ear in form. Most of the common names for Enterolobium refer to this resemblance, including ear fruit, ear pod, orejon (from Spanish oreja an ear) and guanacaste (conacaste, a NahuatI derivation signifying ear tree).
The nitrogen ftxing tree Enterolobium cvclocarpum belongs to the subfamily Mimosoideae of the Leguminosae and is placed in the tribe lngeae. The ,genus Enterolobium is closely related to Albizia and Samanea and is probably only maintained as a separate genus due to its widespread cultivation. Enterolobium contains only five species, all from Central and South America, and only E. cyclocarpum is widely cullivated. Closely related species, such as E. schomburgkii Benth., remain untested to date.
Enterolobium leaves are bipinnately compound with opposite leaflets. Small white flowers occur in compact round heads. In Central America E. cyclocarpum is sometimes confused with Albizia niopoides (Guanacaste blanco) due to similarity in tree form but may be readily distinguished by the different bark which is pale golden yellow in A. niopoides.
Enterolobium cyclocarpum occurs from latitude 23°N in central Mexico, south through Central America, to TN in northern South America. It has been widely introduced throughout the tropics where it is cultivated mainly as a roadside or garden tree. In its native range, Enterolobium occurs in a wide range of different forest types from tropical, dry deciduous forest to tropical moist forest. It becomes a climax tree only in the dry forest, being restricted to disturbed areas in wetter forest types. Enterolobium cyclocarpum is a lowland species occurring from sea level to 1200 m elevation and has only very limited tolerance of frost.
Annual rainfall varies between 750-2500 mm through most of its native range with a dry season that lasts 1-7 months. Trees are generally deciduous, losing their leaves during the dry season and flushing out again about two months before the onset of the rainy season. Flowering starts while the trees are leafless (March-April in Central America), and the pods take a year to mature, ripening in April-May.
The wide spreading canopy of a mature Enterolobium makes it an ideal shade tree, whether for livestock in pasture lands, for perennial crops such as coffee, or in roadside and urban plantings. Its value to livestock is further enhanced by production of large quantities of highly palatable and nutritious pods containing a sugary dry pulp. Pods are generally shed at the end of the dry season in Central America when livestock feed is particularly short. Pods fall from the trees gradually over a period of two months thus spreading the availability of pods for livestock. Data from Puerto Rico suggests that pod production may be delayed as much as 25 years after planting. The foliage is also palatable, though to a lesser extent than the pods, which results in high mortality of natural regeneration in pasture lands and may explain why the tree occurs naturally only as scattered individuals.
Enterolobium heartwood is reddish-brown, coarse-textured and moderately durable, with a straight interlocking grain and an appearance somewhat similar to walnut. Specific gravity is variable, ranging from 0.40.6. The wood is resistant to attack by dry-wood termites and Lyctus, and can be used in house construction as well as for nonstructural interior elements including panelling. The white sapwood, by contrast, is highly susceptible to insect attack. Enterolobium wood may also be used for boat-building because of its durability in water; it has been used in the past for water-troughs and dug-out canoes. The dust from sawmilling can produce allergic reactions in workers.
Other uses include food (the immature pods as a cooked vegetable, or the seeds toasted and ground), soapmaking (using tannins from the pods and bark), and medicinal use of bark extracts against colds and bronchitis. The ability of Enterolobium to fix nitrogen, and to resprout vigorously when coppiced, suggest it could also have a role in alley-cropping systems as a hedgerow species, though this is an area requiring further research.
Enterolobium is a light-demanding species at all stages in its development. It is susceptible to weed competition during early, growth. Enterolobium resprouts vigorously after coppicing or lopping; indeed, it is difficult to kill Enterolobium by girdling because of its tendency to resprout below the girdle line. Little information is available, however, on its response to repeated cutting. With no silvicultural intervention it usually occurs as a single, large, open-grown tree, though pruning can improve the length and form of the bole.
Enterolobium can tolerate a wide range of soil types, from alkaline and calcareous to somewhat acidic (pH as low as 5), provided that aluminum saturation is not a problem. Best growth is on deep, medium-textured soils but sandy and clay soils also allow good development provided drainage is unimpeded. The trees will not thrive on sites prone to waterlogging.
The combination of large nutritious pods and seeds with hard coats is ideal for seed dispersal of Enterolobium by animals. Seeds are most easily collected by waiting for pods to fall. An adult tree produces an average of 2000 pods, each with 10-16 seeds (9001200/kg). Trees produce seed crops in most years in Central America. Seed extraction from the indehiscent pods is usually carried out by manual threshing, milling or maceration of the pods followed by winnowing and screening.
Enterolobium seed is naturally scarified by passage through the gut of large herbivores. It is likely that the original consumers of Enterolobium pods are now extinct and their role as seed dispersal agents has been assumed by horses and cattle. Collected seed requires pretreatment before sowing to allow water to penetrate the seed coat. Manual scarification is effective, as is treatment with hot water or concentrated sulfuric acid. A suitable hot water treatment is a brief (30 second) soak in water close to boiling point, followed by 24 hours in water at room temperature. Enterolobium seeds remain viable for several years under cool, dry conditions and can be easily stored under normal conditions.
Seed supplies are currently dependent on collections from natural populations in Latin America and scattered cultivated trees in areas where Enterolobium has been introduced. Most early introductions of E. cyclocarpum were undocumented, casual and collected from a narrow genetic base. A broader range of representative germplasm should be tested to evaluate the potential of the species. Seed is available from OFI and NFTA for the establishment of field trials.
The seed should be sown 1-2 cm deep with the micropyle pointing downwards; the emerging root is not strongly geotropic and may come up out of the soil if the seed is planted upside down. Early seedling growth is rapid and vigorous. This early advantage over smaller-seeded species can continue several months after outplanting, but thereafter growth rate, though still vigorous, is no longer exceptional relative to other fast growing species.
PESTS AND DISEASES:
Enterolobium has no serious or widespread disease and insect problems, although attack by a Fusarium fungus, with associated damage by wood-boring insects, can cause affected limbs to fall from mature trees. Branches may also be broken off by storm damage. Both factors reduce the desirability of Enterolobium for urban and roadside planting. Although no bruchid seed predators are found on E. cyclocarpum, the green pods are often preyed upon by parrots and fruiting may be further disrupted by the gall forming moth Asphondylia enterolobii.
Echenique-Manrique, R. and R.A. Plumptre. 199.0. A guide to the use of Mexican and Belizean timbers. Tropical Forestry Paper 20. Oxford Forestry Institute, UK. 175 p.
Francis, J.K. 1988. Enterolobium cyclocarpum (Jacq.) Griseb. Guanacaste, Earpod-tree. Leguminosae. Legume Family. USDA Forest Service. Southern Forest Experiment Starion. SO-ITF-SM-15.
Janzen, D.H. 1983. Enterolobium cyclocarpurn. In D.H. Janzen (ed), Costa Rican Natural History. Univ. Chicago Press. Chicago, IL. 816 p.
Little, E.L., R.O. Woodbury, and F.H. Wadsworth. 1974. Trees of Puerto Rico and the Virgin Islands, Vol. 2. USDA Agric. Handbook No. 449. p. 258-259.
Standley, P.C. and J.A. Steyermark. 1946. Enterolobium.. In Flora of Guatemala. Fieldiana: Botany 24(V):32-34.
NFTA 94-02 January 1994
Erythrina variegata is a showy, spreading tree legume with brilliant red blossoms. Commonly known as the 'Indian coral tree' in Asia or 'tropical coral' in the Pacific, this highly valued ornamental has been described as one of the gems of the floral world. It has also proven valuable for fodder production and as a sturdy component of windbreaks. It is a useful species for soil enrichment because it nodulates readily and prolifically in both acid and alkaline soils. Farmers in India appreciate E. variegata as fodder, light timber and, more recently. pulp for the paper industry.
Erythrina variegata is a medium to large tree, commonly reaching 15 to 20 m in height in 20 to 25 years. It has an erect, spreading form, typically with several vertically oriented branches emerging from the lower stem. On favorable sites, the stem can reach a diameter at breast height (dbh) of 50 to 60 cm in just 15 to 20 years.
The smooth bark is streaked with vertical lines of green, buff, grey and white. Small black prickles cover the stem and branches. These become longer if the tree suffers moisture stress. They typically drop off as the girth of the stem expands (Hegde, 1993). The leaves are trifoliate. The leaflets are commonly variegated, medium to light green, heart shaped. 7 to 12 cm wide and 12 to 18 cm long. The trees are deciduous. typically losing their leaves before flowering except under very humid conditions.
Brilliant orange-red flowers emerge in dense, conical inflorescences 5 to 7 cm long and 2 to 3 cm wide, usually after the leaves have dropped. Flowering is normally followed by a lavish production of seed. The pods are thick and black-1.5 to 2 cm wide and 15 to 20 cm long. Each contains 5 to 10 egg-shaped seeds. These are glossy brown, red or purple and are 6 to 10 mm in diameter and 12 to 17 mm long.
A column-shaped cultivar, 'Tropic Coral' or 'Tall Erythrina', is used extensively in windbreaks and as an ornamental in parks and gardens. Through cultivation, it has spread from New Caledonia to Australia, Hawaii and southern Florida. Unlike other cultivars. the leaves of 'Tropic Canal' remain on the tree through flowering.
Erythrina variegata is well adapted to the humid and semiarid tropics and subtropics, occurring in zones with annual rainfall of 800 to 1500 mm distributed over a five- to six-month rainy season. The species is most commonly found in warm coastal areas up to an elevation of 1500 m. The trees prefer a deep. well-drained, sandy loam, but they tolerate a wide range of soil conditions-from sands to clays of pH 4.5 to 8.0. They can withstand waterlogging for up to two weeks and are fairly tolerant of fire. Erythrina variegata is bird-pollinated, outcrossed and sometimes genetically incompatible.
Erythrina variegata is native to the coast of India and Malaysia. It has been widely introduced in coastal areas of the Old World tropics, extending from East Africa and Madagascar through India, Indochina, Malaysia, northern Australia and Polynesia. The seeds can float on salt water for months, facilitating the spread of the species. Introduced to the Americas, it was so well established by 1825 that Candolle described two new species based on trees considered to be native to the New World (McClintock, 1982). It is now a very popular hedge species in southern Florida.
Support for vine crops.
Farmers in India use E. variegata to support climbing plants such as betel (Piper belle), black pepper (Piper nigrum), vanilla (Vanilla planifolia) and yam (Dioscorea spp.) (Hegde, 1993). Trees established to support vines are usually planted at a spacing of 2 x 2 to 2 x 3 m. Vines are planted three to four months after establishment of the tree seedlings or during the following rainy season. During the hottest months. foliage from the closely spaced trees shades the vines and keeps them moist. When the days become cooler, the leaves fall and the vines receive more direct sunlight, which matches their requirements at this time.
Coffee and cacao growers establish E. variegata shade trees from large cuttings (2 to 3 m long and 2 to 5 cm in diameter) at a spacing of 8 x 10 m. The trees are pollarded once a year to a height of 2 to 3 m to produce a spreading crown. The pruned leaves are usually spread in the plantation as mulch. The branches may be used as fuelwood.
Erythrina variegata, particularly the columnar variety, is widely used as a windbreak for soil and water conservation. The trees have a strong, vertical root system that does not seem to compete too severely with adjacent crops (Rotar et al., 1986). Windbreaks are normally established from large cuttings planted in lines at a spacing of about 2 m.
Erythrina variegata makes excellent live fenceposts. Farmers commonly establish fenceposts from three-yearold upright branches about 15 cm in diameter and 2.5 m long. These are normally stacked in the shade in an upright position and left to cure for one week before planting.
The foliage of E. variegata makes an excellent feed for most livestock. Leaves normally contain 16 to 18% crude protein and have an in-vitro dry-matter digestibility of 50% A tree of average size, pruned three or four times a year, produces from 15 to 50 kg of green fodder annually depending on growing conditions. Trees maintained in coffee plantations benefit from associated cultivation practices-they can produce up to 100 kg of fodder from one annual harvest. The leaves have no known toxicity to cattle.
The wood of E variegata is light and sott. with a specific gravity of 0.2 to 0.3. Each shade tree in a coffee plantation can yield from 25 to 40 kg of wood from annual pollarding. The wood is used to construct floats, packing boxes, picture frames and toys, and, in India, it is increasingly used for pulp production. The timber requires careful seasoning, preferably kiln drying. It does not split on nailing, but holds nails poorly.
Erythrina variegata has a reputation for medicinal properties in India, China and Southeast Asia. The bark and leaves are used in many traditional medicines, including paribhadra, an Indian preparation said to destroy pathogenic parasites and relieve joint pain. Juice from the leaves is mixed with honey and ingested to kill tapeworm, roundworm and threadworm (Hegde, 1993). Women take this juice to stimulate lactation and menstruation. It is also commonly mixed with castor oil to cure dysentery. A warm poultice of the leaves is applied externally to relieve rheumatic joints. The bark is used as a laxative, diuretic and expectorant.
With their rapid growth and prolific nodulation, all erythrinas are a good source of organic matter for green manure. The nitrogen-rich litterfall decomposes rapidly, making nutrients available for plant uptake. The dry foliage of E. variegata normally contains from 1 to 3% nitrogen.
Aqueous leaf extracts of E. variegata have also proven highly toxic to certain nematodes (Mohanty and Das, 1988).
Erythrina variegata is successfully propagated from seed or large stem cuttings. Seed should be scarified by soaking in hot water (80°C) for 10 minutes and then in tepid water overnight. Treated seeds normally germinate within 8 to 10 days. Well-watered seedlings are normally ready for planting at 10 weeks.
Woody cuttings establish best under dry conditions. They should always be held for at least 24 hours before planting to prevent attack by soil fungi. Cuttings establish quickly, producing axillary shoots in three to four weeks and then rooting. To produce tall trees with straight stems, it is important to retain the terminal bud of branch cuttings. The columnshaped form, 'Tropic Coral', may not reproduce true to form from seed and should thus be propagated from cuttings.
Erythrina variegata generally requires little maintenance. Once established, seedlings grow rapidly, usually to 3 m in one year. Cuttings typically produce more and larger side branches than seedlings; they should be pruned when young if upward growth and a clear bole are desired.
This species is a host to the fruit-piercing moth Othreis fullonia, a destructive insect pest in the Pacific region. The larvae feed on the tree and the adults 'pierce' important commercial fruits such as oranges, guava, papaya. banana and grapes. causmg serious economic losses (Muniappan, 1993). The light wood. with 60 to 65% moisture content, is not useful as a fuel. Even when dry, it produces smoke when burned.
Hegde, N. 1993. Cultivation and uses of Erythrina variegata in Western India. In S.B. Westley and M.H. Powell, eds. Erythrina in the New and Old Worlds. Paia, HI (USA): NFTA, pp. 77-84.
Little, E.L. and Skolmen, R.G. 1989. Common forest trees of Hawaii (native and introduced). Agricultural Handbook 679. Washington, DC: USDA Forest Service, pp. 142-44.
McClintock, E. 1982. Erythrinas cultivated in California. Erythrina Symposium IV. Allertonia. 3 (1): 139-54.
Mohanty, K.C. and Das, S.N. 1988. Nematicidal properties of Erythrina indica against Meloidogyne incognita and Tylenchorhynchus rnashhoodi. Indian Journal of NernatolOgy.18(1):138.
Muniappan, R. 1993. Status of Erythrina species and the fruitpiercing moth in the Pacific. In S.B. Westley and M.H. Powell, eds. Erythrina in the New and Old Worlds. Paia, HI (USA): NFTA, pp.340-44.
Raven, P.H. 1974. Erythrina (Fabaceae): achievements and opportunities. LLOYDIA (Journal of Natural Pruducts). 37:321-31.
Rotar, P.P., Joy, R.J. and Weissich, P.R. 1986. 'Tropic Coral': tall erythrina (Erythrina variegate L.). Research Extension 072. Honolulu, HI (USA): University of Hawaii.
A Publication of the Nitrogen Fixing Tree Association Winrock International 38 Winrock Drive Morrilton Ar 72110-9537
NFTA 93-04 September 1993
Inga is a large genus of leguminous trees native to the American humid tropics. Inga edulis, the best known of the Inga species, is popular with agroforesters for its rapid growth, tolerance of acid soils and high production of leafy biomass to control weeds and erosion.
Inga edulis Mart. is one of about 250 species of Inga of the Mimosoideae subfamily of the Leguminosae. It reaches a height of 30 m and a stem diameter (dbh) of 60 cm. and usually branches from below 3 m. The branches form a broad, flat, moderately dense canopy. The bark is pale grey and smooth, with pale elongated lenticels. The young twigs are angular in cross-section and covered in fine short brown hair.
The leaves are once pinnate, up to 24 cm long, with 4 to 6 pairs of opposite leaflets. The terminal pair of leaflets is larger than the basal pair and can be up to 18 cm long and 11 cm wide. Between each leaflet there is a nectary gland on the leaf rhachis; in 1. edulis these are large (2 to 3 mm) and squashed transversely, an important character for identifying the species. The leaflets and rhachis are covered in dense, short, rough brown hair. The seedlings have a characteristic grayish sheen on the upper leaf surface.
The inflorescences are dense axillary spikes of flowers, each consisting of a calyx tube with 5 lobes (4 to 9 mm long), a corolla tube with 5 lobes (13 to 25 mm long), and a large number of white stamens up to 4.5 cm long, united in a tube in the lower half. In humid climates 1. edulis may flower throughout the year, but in regions with a short dry season it is most likely to flower at the beginning of the wet season. The inflorescences may not have many flowers open at the same time, but they are usually conspicuous.
The fruits are ribbed, cylindrical pods, straight or often spirally twisted, up to I m long (occasionally even longer), and 3 to 5 cm in diameter. They contain fleshy green seeds (3 cm long) in a sweet, white, cottony pulp. They are produced during the wet season, and monkeys and birds eat the sweet pulp and scatter the soft seeds (Castro and King, 1950). These are recalcitrant and sometimes begin to germinate in the pod, often within a few days of reaching the ground where they need humidity to survive.
Distribution and ecology
The native range of Inga edulis is in Amazonian Brazil, Bolivia, Peru, Ecuador and Colombia. The species has also been introduced across most of tropical South America, Panama and Costa Rica. It grows in hot, humid climates between 26°S and 10°N, and up to 1600 m elevation. It is most widespread in areas without a dry season (Andean South America. western Brazil) or with a dry season of three to four months and minimum annual rainfall of around 1200 mm. It can tolerate short droughts, although in its natural range some rain falls every month.
Inga edulis is particularly tolerant of acid soils (Smythe, 1993; M. Hands, Department of Geography, Cambridge University, personal communication; Salazar and Palm, 1991), outgrowing many other leguminous trees in trials under such conditions. It is a forest gap regenerator: although seedlings often establish themselves in the shade of other trees, it needs light to grow and flower. In the forest it becomes a canopy tree. but it is also common in secondary forest.
Shade and litter.
Inga edulis has been used as a shade tree for perennial crops-mainly coffee and cacao-since the beginning of the nineteenth century. Many farmers value it as much for soil protection as for shade. The leaf litter protects the soil surface and roots of other plants, helps retain nutrients in the topsoil, and (most importantly for farmers in the humid tropics) controls weeds.
In Amazonian Peru, Szott and MelÃ©ndez (1991) grew crops on land cleared and burnt after seven different fallow treatments. Land where Inga edulis had been planted gave the highest crop yields-34% higher than crops following natural forest fallow.
In species trials in Costa Rica, Peru and Brazil, 1. edulis was outstanding in terms of growth. Coppice regrowth was also good after pruning. In four out of five trials, crop yields were higher under alley cropping with 1. edulis than in control plots (Smythe, 1993; Fernandes et al., 1991; Salazar et al., 1991; Salazar and Palm, 1991; M. Hands, personal communication). In two of these trials, crops performed better with 1. edulis than with other species (Salazar and Palm, 1991; M. Hands, personal communication).
The litter is high in nitrogen, lignins and polyphenols. It is slow to decompose, but provides a long-term build up of organic nitrogen (Palm and Sanchez, 1990) and effective weed control. Weed biomass decreased considerably in all agroforestry trials with 1. edulis, much more than with other leguminous species (Salazar and Palm, 1991). On cultivated slopes, 1. edulis mulch reduced soil erosion to levels almost equal to those under secondary forest (Alegre and Fernandes, 1991). Existing trials are still too new to ascertain whether 1. edulis can maintain or improve soil fertility on acid sites in the long term, but results so far are promising.
The large fruit is popular throughout the region where 1. edulis is distributed. Fruits are sold in local markets in Bolivia, Peru, Ecuador, Brazil and Costa Rica. The branches are a popular source of fuelwood, with a high calorific content and little smoke, but the trees are not cultivated specifically for fuelwood.
Inga edulis seed can only be stored up to two weeks. Best results have been achieved by removing the pulp and storing the seed in impermeable bags. Normally. only one seed should be sown in a plastic bag. no more than 2 cm below the soil surface. Semi-shade should be provided if possible. The seeds germinate readily (95 to 100% germination rate) within 2 to 3 days. Seedlings are normally kept for two months in the nursery. They should be watered regularly and the shade should be removed one month before transplanting.
Farmers sometimes sow 1. edulis seed directly in the field. This must be done during a season of regular rainfall to avoid seed desiccation. Direct seeding has not yet proven to be a reliable method for establishing a trial. Bare-rooted seedlings can be transplanted successfully from the nursery (Fernandes et al., 1991). Inga edulis has not been reproduced by cuttings.
Management and symbiosis.
An area of I m diameter should be kept clear around the trees during the first six months as they become established. Inga edulis grows back well after pruning, but not if cut too low (below 0.75 m). It responds better if pruning height is varied and a few branches are left uncut (Salazar et al., 1991). The cut should be made carefully, at least 3 cm above a node from which the shoots can grow again (M. Hands, personal communication).
Fernandes and others (1991) observed Rhizobium nodules on the roots of 1. edulis, both in the field and in the nursery. They also showed that vesicular-arbuscular (VA) mycorrhizal infection occurs in acid tropical soils and that nodulation rates increase when mycorrhizae have infected the root. In their trial, plant biomass correlated positively with length of root infection by VA mycorrhizae.
Inga edulis pods are heavy and bulky to transport. This, combined with short seed viability, means that I. edulis seed must normally be collected near the planting site.
Decomposing slowly, the leaves do not provide fast-cycling green manure. In Ecuador, Inga edulis is particularly susceptible to infestation with mistletoe.
In Central America, 1. edulis is replaced by the closely related 1. oerstediana Benth., a popular species for coffee shade from sea level to elevations of 2000 m. The flowers are smaller than those of 1. edulis and the fruits are much shorter. In ongoing trials in Honduras and Costa Rica, 1. oerstediana has shown fast growth and abundant production of leafy biomass. Another promising species from the same section of the genus is the Amazonian 1. ingoides (Rich.) Willd., which has grown well for four years on a periodically flooded site in lowland Bolivia.
Inga edulis has been introduced throughout the neotropics, but seed is usually collected from a few trees already estabfished in plantations and transported over very short distances. Population studies in the species's native range could help identify diversity in growth rate, fruit size, soil tolerance and litter-decomposition rates. Methods to prolong seed viability would also improve the usefulness of this species.
Alegre, J.C. and Fernandes, E.C.M. 1991. Runoff and erosion losses under forest low-input and alley-cropping on slopes: Y-433B. In TropSoils technical report 1988-89. Raleigh, NC (USA): North Carolina State University, pp. 227-28.
Castro, Y.G.P. and Krug, P. 1950. Experiments on germination and storage of seeds of Inga edulis. a species used in shading coffee trees. [In Portuguese.] Sao Paulo (Brazil): Office of the Secretary of State for Agriculture, Forestry Service.
Fernandes, E.C.M., Davey, C.B. and Sanchez, J.A. 199]. Alleycropping on an Ultisol in the Peruvian Amazon: mulch, fertilizer and hedgerow root-pruning effects: Y-433A. In TropSoils technical report 1988-89. Raleigh, NC (USA): North Carolina State University, pp. 223-26.
Palm, C.A. and Sanchez, P.A. 1990. Decomposition and nutrient release patterns of the leaves of three tropical legumes. Biotropica. 22(4):330-38.
Salazar, A.A. and Palm, C.A. 1991. Alley-cropping on Ultisols: Y-425. In TropSoils technical report 1988-89. Raleigh, NC (USA): North Carolina State University, pp. 221-22.
Salazar, A.A., Palm, C.A. and Szott, L.T. 1991. Alleycropping on alluvial soils: Y-417. In TropSoils technical report 1988-89. Raleigh, NC (USA): North Carolina State University, pp. 218-20.
Smythe, S. 1993. The role of trees in tropical agroforestry. Ph.D. thesis. Cambridge (UK): Cambridge University, Department of Plant Sciences, 215 pp.
Szott, L.T. and MelÃ©ndez, G. 1991. Crop yields, soil nitrogen mineralization, and soil chemical properties following 4.5 years of managed leguminous fallows. In TropSoils technical report 1988-89. Raleigh. NC (USA): North Carolina State University, pp. 234-36.
A Publication of the Nitrogen Fixing Tree Association Winrock International 38 Winrock Drive Morrilton Ar 72110-9537
NFTA 92-01 March 1992
Many N-fixing trees are alternately praised and cursed. Hardy, tenacious, seedy, and able to provide their own nitrogen, they often colonize soils and sites that are difficult or impossible for other trees. Pithecellobium dulce is such a tree.
Pithecellobium dulce is a thorny tree which can become weedy. In Hawaii it has a reputation as a pest in grass pastures, but normally only when fields have been left nitrogen-starved. It is a tree with many uses; food (sweet pods), firewood, honey, fodder, soap oil, tannin, hedges and shade-and it can survive hostile climates. The generic name refers to the curly pod, that mimics an ape's earring (pithekos ellobium), and the species name "dulce" refers to the sweet pod.
This hardy American tree is native along coasts from California through Mexico to South America. but is now found throughout the tropics. Pithecellobium dulce followed the Spanish galleon route (with leucaenas, gliricidias and other nitrogen fixing trees) through the Pacific and Asia to Africa.
It is now common and naturalized in India and tropical Africa, especiaIly along coasts. It is notably weedy in the Caribbean islands (including Cuba, Jamaica, Puerto Rico, and St. Croix), and in Florida and Hawaii, USA, but less so where population and animal pressure keep it contained.
Pithecellobium dulce (Roxb.) Benth. (family Leguminosae, subfamily Mimosoideae) is one of 100-200 species in this genus. Pithecellobian. dulce is the only species that has become widespread outside its origin.
The height of P. dulce is commonly 10-15 meters, but ranges from 5 to 18 m. They are broad-spreading with irregular branches. The bark is grey, becoming rough, furrowed, and then peeling. Leaves are bipinnate, and leaflets oblong to 4 cm in length. Thin spines are in pairs at the base of leaves, and range from 2 to 15 mm in length. Leaves are deciduous. However, new leaf growth coincides with the loss of old leaves, giving the tree an evergreen appearance.
The flowers are in small white heads 1 cm in diameter. Each flower has a hairy corolla and calyx surrounding about 50 thin stamens united in a tube at the base. Flowering begins in 3-4 years and is seasonal (April in Hawaii). The pods are pinkish, 1-1.5 cm wide, about 12 cm long, and become spiral as they mature. Seeds are about 10 per pod (9,000 to 26,00.0/kg), black and shiny, hanging on a reddish thread from the pod. The pod splits along both margins.
Pithecellobium dulce thrives in dry warm climates where annual rainfall is 400 to 1650 mm. It is typical of lowlands, but can be found at elevations above 1,500 m in Mexico and East Africa. This species is found on most soil types, including clay, limestone, and sands. Pithecellobium species are noted for their tolerance of heat, salinity, and impoverished soils. They are also tolerant of drought conditions.
FOOD AND FODDER:
Names like "dulce" (sweet) and "Manila tamarind" reflect the wide use of the pods as food. Pods contain a pulp that is variously sweet and acid. commonly white but also red. The seed and pulp are made into a sweet drink and eaten roasted or fresh. In India. the seeds are used fresh or in curries. The pods are relished by monkeys and livestock. The flowers are attractive to bees as source of pollen. The resulting honey is of high quality. Although the pods are attractive fodder to most animals, the leaves are browsed but not considered an important animal fodder.
The wood of P. dulce is strong and durable yet soft and flexible. It can be used in construction and for posts. The reddish-brown heartwood is dense and difficult to cut. It is commonly used as fuel. although due to smokiness and low calorific values (5,500 kcal/kg) it is not of high quality. The short spines and irregular crooked growth make it less attractive for wood uses.
The tree is used extensively as a shade or shelterbelt tree with a great tolerance of arid and harsh sites. It coppices readily and can be managed as a hedge. Coppicing often increases the occurrence of thorns. This characteristic makes hedges of P. dulce excellent for livestock fences, but problematic for other uses.
Pithecellobium dulce is also very popular as an ornamental and is used in topiary (plant sculpturing). Trees with variegated leaflets are available as ornamentals in HawaÃ¯i. When wounded, the bark exudes a reddish-brown gum similar to gum arabic that dissolves in water to make a mucilage. The bark can also be used for tanning and produces a yellow dye. Seeds contain an oil that can be used in soapmaking or as food, and the residue can be used as animal feed. Medicinal uses are known but not common.
SILVICULTURE AND GROWTH:
Seed viability is long under dry cool storage. No pretreatment is necessary for seeds to germinate, although nicking may improve and hasten the process. Germination occurs quickly, normally in 1-2 days. Application of Rhizobium inoculum to seeds is suggested prior to sowing. Successful propagation by cuttings has also been reported.
Pithecellobium dulce normally competes successfully with other vegetation. It often establishes in grass ecosystems without the benefit of weed and grass control. Few data are available on its relative growth rate, but it appears to be intermediate in growth to the slower Prosopis spp. and the faster Leucaena spp. Height growth can reach 10 meters in 5-6 years under good environmental conditions.
Pithecellobium dulce forms root nodules with Rhizobium bacteria. Nodulation is common in all types of soil, but quantitative data on fixation has not been reported.
PESTS AND PROBLEMS:
The sharp thin spines can be fierce on young shoots and often limit plant utilization. Spines are reportedly absent in some trees; a pure spineless variety would be welcomed. In pastures and cropland. P. dulce can be a tenacious weed. Coppice regrowth is rapid. and the tree is not easily killed once established.
The tree is evidently not deeply rooted and is subject to blowdown. Superficial rooting is not common in drier soils, thus blow-down is less of a problem under such conditions. The sap is said to cause irritating skin welts and severe eye irritation (the latter is common to sap or juice from many legume trees and their fruits). The heavy smoke created by burning limits its usefulness as fuelwood. Pests include the thornbug and several boring and defoliating insects.
OTHER SPECIES OF PlTHECELLOBlUM:
The genus includes several other important species-P. arboreum, P. unguiscati, P. flexicaule. P. jiringa, and P. parviflorum. Common names include "Manila Tamarind", "Madras thorn", "bread-and-cheese". "blackboard" (English), "guamuchil", "quamachil" (Spanish), "kamachile" (Phillipines), "macamtet" (Thailand), and "opiuma" (Hawaii).
Allen, O.N. and E.K. Allen. 1981. The leguminosae: a source book of characteristics, uses and nodulation. Wisconsin Press, Wisconsin. 812 p.
Ambasta, Shri S.P. (ed). 1986. The useful plants of India. Publ. and Info. Directorate, CSIR. New Delhi, India.
National Academy of Sciences. 1980. Firewood crops shrub and tree species for energy production. NAS/NRC, Washington D.C. pp. 141-145.
Little, E.L. 1985. Common fuelwood crops. Communi-Tech Assoc., Morgantown, W. Va. pp.
Little, E.L. Jr. and F.H. Wadsworth. 1964. Common trees of Puerto Rico and the Virgin Islands. Ag. Hand. No. 249. USDA Forest Service, Washington D.C.
NFTA 92-02 March 1992
Pterocarpus indicus is one of the best known trees in southeast Asia. It is known as narra in the Philippines, sonokembang in Indonesia, angsana or sena in Malaysia and Singapore, and pradoo in Thailand. In the Philippines, it is the national tree and the favorite timber for the manufacture of fine furhiture (Duaresma et al. 1977). In Singapore, it is practically the symbol of that country's garden city planting program; many avenues are graced by this attractive species. In Malaysia, it has been planted as a shade tree for at least 200 years.
Pterocarpus indicus Willd. (Leguminosae, subfamily Papilionoideae) is a big tree, growing to 33 m in height and 2 m diameter. The trunks are usually fluted and buttressed to 7 m diameter at the base. The crowns are large and bear many long branches that are at first ascending, but eventually arch over and sometimes droop at the ends. Trees with long willowy, drooping branches are particularly conspicuous and attractive in Singapore and some parts of Malaysia and Hawaii. Elsewhere the drooping habit may not develop.
The leaves are compound-pinnate, bearing 6-12 alternate leaflets. The leaflets are rather large, 7 x 3.5 to 11 x 5.5 cm and ovate to elliptic in shape, with a pronounced acuminate tip. The flowers are yellow, fragrant, and borne in large axillary panicles. When flowering, the buds do not open in daily sequence. Instead, as buds come to full size, they are kept waiting, to be triggered into opening. The opened flowers last for one day. After that, several days may pass before another batch of accumulated 'ready' buds open. The nature of the trigger is unknown. Whole avenues of such trees blooming in unpredictable synchrony making a splendid display. Local drivers have learned to slow down on the flower-carpeted roads to avoid skidding. The fruits, which take four months to mature, are discshaped, flat, and have winged margins. About 5 cm across, the fruit have a central woody-corky bulge containing several seeds (ptero-carpus means winged fruit). Unlike most legumes, the Pterocarpus fruit is indehiscent and dispersed by wind. It also floats in water and can be water-dispersed.
There are 1-3 seeds in each fruit. The seeds are difficult to extract, but will germinate readily through built-in weaknesses in the fruit wall; hence each fruit is able to function like a seed, but produces 1-3 seedlings. There is no advantage to extracting the seeds because the germination time and percentage are practically the same between whole fruits and extracted seeds.
In a non-seasonal humid tropical climate such as in Kuala Lumpur and Singapore, the trees are generally evergreen, but in regions with seasonal rainfall, the trees are deciduous.
The genus Pterocarpus consists of 20 species distributed throughout the tropics (Rojo 1977). P. indicus has a wide range from southern Burma to the Philippines and throughout the Malay Archipelago to New Guinea and the Solomon Islands. There is considerable morphological and ecological variation when viewed throughout its range, but because of extensive clonal propagation, the trees planted in any given locality tend to be uniform. In Malaysia, its natural habitat is by the sea and along tidal creeks and rivers. Elsewhere (e.g., Papua New Guinea), it occurs in inland forests. In the Moluccas (Manupatty 19721973), four varieties are locally recognized, which occupy a range of habitats from the coast to submontane forests and seasonal swamps.
P. indicus may be propagated by seed, which germinate in 8-100 days, but the initial growth of seedlings and saplings is relatively slow. Propagation by cuttings is preferred, especially for ornamental planting (Wong 1982). P. indicus is unique among big timber trees in that the capacity for rooting of stem cuttings is not lost with age. Stem cuttings can be taken from trees of any age and size. Indeed, cuttings of diameter 6 cm or larger will root better than cuttings of smaller diameter. Young leafbearing stems will not root at all. For roadside planting, the cuttings used are in the form of stakes 1.5-3 m long and as much as 10 cm diameter. Such stakes produce up to 10 radiating shoots at the top, making a symmetrical crown, very quickly, above pedestrian height. Few species can match P. indicus in the ability to produce wellcrowned instant trees within one or two years. If large stakes fail to root, it is usually because of water-logging or accidental movement of the stakes during the tender rooting period. These problems can be avoided by rooting the stakes in loamy soil in large well-drained containers, while tied securely to a simple supporting framework. The stakes root in about 3 months and can be reduced to as short as 10 cm length, but such cuttings would take longer to develop into trees.
The timbers of all species of Pterocarpus are highly valued. P. indicus timber is moderately hard (.52 specific gravity), moderately heavy, easy to work, pleasantly rose-scented, takes a fine polish, develops a range of rich colors from yellow to red, and has conspicuous growth rings, which impart a fine figure to the wood. Remarkably, such growth rings are developed even in the non-seasonal humid tropics. In Java and the Moluccas, giant burrs on the stem give rise to finely figured gnarl wood (also called wavy or curly wood). In the Moluccas, P. indicus is also the source of linggua kasturi, a highly valued red wood with the scent of sandalwood (Burkill 1935); this is perhaps a pathological condition. Traditionally, Pterocarpus has been so much in demand for cabinet class furniture that nearly everywhere its existence in the wild is precarious.
P. indicus behaves like a pioneer and grows best in the open. Seedlings are slower growing than cuttings and exhibit considerable variation in vigor. A strict culling program would be necessary to ensure that only the best stocks are planted out. Rooted cuttings can be established readily on nearly all kinds of soils, from coastal sands to inland clays, in urban and garden situations, and even in guise small planting holes dug into pavements. However, establishment trials in forest areas have had mixed results and some have failed. The reasons are not clear.
With a little practice, it is easy to distinguish a healthy tree by its luxuiant foliage from one that is thinly leafed and stressed. Under favorable conditions, trees in Singapore have been known to grow an average of 13.3 m in height and 1.55 m in girth in 11 years, or an average annual increment of 1.2 m height and 14 cm girth. Urban trees in Singapore are fertilized with compound fertilizer at the rate of 0.5, 1, and 1.5 kg per tree per annum in the first, second, and third years of growth. Subsequently, they get 3-5 kg per tree per annum depending on their size. The fertilizer is spread evenly on the soil under the tree crown and is applied once a year. Where the area of the soil is smaller than the crown (e.g., for trees planted in pavements and road dividers), the fertilizer is divided into two or more smaller applications (Wong 1982). As an urban tree, P. indicus is relatively wind-firm and seldom suffers branch breakage.
Trees of all sizes and ages easily regenerate new shoots when lopped or pollarded. In Papua New Guinea, logged forest trees readily regenerate new plants from the roots (Saulei 1988).
The seedlings nodulate readily.
Pests and diseases.
P. indicus trees in Singapore and Malaysia suffered extensively from an unknown disease between 1875 and 1925. The leaves of affected trees withered, the branches died back, and after 2-3 months the whole tree would die (Corner 1940). Sometimes, whole avenues were wiped out. Strangely, the disease then disappeared and has not recurred. There are at present no serious pests and diseases.
Other species of Pteroarpus.
Other well-known species are P. dalbergioides of the Andamans Islands in the Bay of Bengal, P. marsupium of India and Sri Lanka, P. macrocarpus of Burma, Thailand, and Indo-China, P. Officinalis of tropical America, and P. soyauxii of Africa. The silviculture of some of these has been described by NAS (1979).
Burkill, I.H. 1935. Dictionary of the Economic Products of the Malay Penisula. p. 1826-1833.
Corner, E.J.H. 1940. Wayside Trees of Malaya. 3rd Edition by Malayan Nature Society (1988). p. 416-417.
National Academy of Sciences. 1979. Tropical Legumes: Resources for the future.National Academy Press, Washington D.C. USA. 332 p.
Saulei S.M. 1988. Early secondary succession of a tropical lowland rainforest following clear-fell logging in Papua New Guinea. In F.S.P. Ng (ed) Trees and Mycorrhiza.Forest Research Institute Malaysia. p.261290.
Troup, R.S. 1921. The Silviculture of Indian Trees 1:265294.
Wong, Y.K. 1982. Horticultural notes on the angsana (Pterocarpus indicus Willd.). Gardens' Bulletin Singapore 34(2):189-202.
A complete list of references is available from NFTA.
NFTA 91-03 July 1991
Very few nitrogen fixing trees are temperate, and very few of these are legumes. The genus Robinia, with four species native to temperate regions of North America, is noteworthy for an ability to tolerate severe frosts.
Robinia pseudoacacia L., or black locust (family Leguminosae, subfamily Papilionoideae), is among the few leguminous NFTs adapted to frost-prone areas. It is also adaptable to environmental extremes such as drought, air pollutants, and high light intensities (Hanover 1989). Rapid growth, dense wood, and N fixing ability make it ideal for colonizing degraded sites.
Black locust is a medium-sized tree reaching 1535 m in height and 0.3-1.0 m in diameter. Long (2045 cm) pinnate leaves consist of 5-33 small, oval, alternate leaflets. Sharp spines are found at the nodes of young branches but are rare on mature wood. The smooth bark becomes reddishbrown and deeply furrowed with age. White to pink, fragrant flowers in 10-25 cm long, hanging racemes appear in early summer soon after the leaves. The closed flowers require bees to force petals open for cross-pollination. The small pods contain 4-8 hard-coated seeds which can persist in the soil for many years. Seed crops occur every 1-2 years beginning at age 3; pods open on the tree in winter and early spring. Although it can occur as a polyploid, it is primarily diploid (N= 10).
Black locust is native to regions with 1,0001,500 mm annual rainfall, yet it is drought-tolerant and survives on as little as 400 mm. Its natural distribution includes the Appalachian and Ozark mountains of the eastern US between 35°-43° N latitudes. It occurs on upland sites in hardwood forests with black oak, red oak, chestnut oak, pignut hickory, yellow poplar, maple, and with ash along streams. In the northern part of its range at 800 m elevation it occurs with Picea rubra and Acer saccharum (Keresztezi 1988b).
First introduced to France and England in 1600, black locust has become increasingly important throughout Europe and in parts of Asia (Keresztesi 1988a). It now covers 18% of Hungary's forested areas. It is grown in temperate and subtropical regions in the US, Europe, New Zealand, India, China, and Korea. It has even been grown at higher, cooler elevations in the tropics (e.g. in Java). Trees tolerate temperatures from 40°C to -35°C. It is found on a variety of soils with pHs of 4.6 to 8.2, but grows best in calcareous. well-drained loams. Trees do not tolerate water-logging. Extremely intolerant of shade, the trees are pioneers on disturbed soils or burned sites. often reproducing prolifically from root sprouts (Fowells 1965). Black locust dominates early forest regeneration in many native forest stands where it occurs (Boring and Swank 1984).
Black locust seeds (35,000-50,000 seeds/kg) require scarification for good germination. Treatment with concentrated sulfuric acid for 20-50 min is most effective. Seeds can also be nicked, soaked in boiling water for several minutes, or washed in aerated cold water for 2-3 days.
Trees sucker readily from roots and also graft easily. They can be propagated, with difficulty, from hardwood cuttings (15-30 cm long and 1-2 cm diameter) collected in winter or early spring. Treatment with indole acetic acid improves rooting. The tree responds well to tissue culture and has been mass propagated by this method. In nursery culture black locust is either direct seeded or root sections (5-8 cm long) planted. Robinia pseudoacacia seed is available from NFTA; improved seed is available from James Hanover (MSU).
Growth and yield:
The species has one of the highest net photosynthetic rates among woody plants. Black locust grows rapidly, especially when young. Trees can reach 3 m tall in one growing season and average 0.5-1.5 m height and 0.2-2 cm diameter growth per year. Trees attained 12 m ht in 10 yrs and 20 m ht in 25 yrs in Kashmir (Singh 1982), and 26 m ht and 27 cm diameter in 40 yrs in the US. Intensive management combined with genetic selection gave experimental dry weight yields up to 40 t/ha/yr under short rotation. On fertile sites it can yield more than 14 m³/ha/yr (9.5 t/ha/yr) on a 40-yr rotation with only moderate management. On poor sites, such as strip mines in the US, oven-dry biomass yields range from 3.1 to 3.7 t/ha/yr. Timber volume in a 20-yr-old stand ranged from 63 to 144 t/ha (Keresztesi 1988a), and aboveground biomass in a 38yr-old native mixed forest stand in N. Carolina, US, was 330 t/ha (Boring and Swank 1984). Fuelwood plantations in S. Korea coppice readily and are lopped annually for fuel (NAS 1983).
R. pseudoacacia has been cultivated for over 350 years. Natural variation in numerous traits has often been observed and many cultivars described. Surles et al. (1989) showed a high degree of polymorphism (71%) for 18 enzyme systems in black locust. Most of the diversity resided within seed sources with low geographic variation. Cultivars vary in crown and stem form, growth rate, growth habit (upright vs. prostrate), leaf shape, thorniness, flowering characteristics, and phenology. Clonal selection, early pruning, and close spacing have been effective means of producing straight-stemmed black locust in plantations especially in Eastern Europe. Comprehensive germplasm collections and plantings for provenance tests were begun in 1982 at Mich. State Univ. Efforts in crossbreeding are under way to improve the tree for growth rate, borer resistance, stem form, thorn-lessness, or other traits (Hanover et al. 1989). In Hungary, a large array of tall clones is in commercial use (Keresztesi 1983), based on seeds from trees of "shipmast locust" originating from Long Island in New York State.
Black locust wood is strong and hard with a specific gravity of 0.68, yet it has the lowest shrinkage value of US domestic woods. The wood makes a good charcoal. Wood energy yield is typical of temperate broadleaf trees, about 19.44 x 10 6 J/kg (Stringer and Carpenter 1986). The beautiful light to dark brown wood is used to make paneling, siding, flooring, furniture, boat building (substitute for teak), decking, vineyard or nursery props, fruit boxes, and pallets. It is also a preferred wood for pulp production. Black locust wood is highly resistant to rot (Smith et al. 1989).
Black locust has become an important tree in the Himalayas where it is heavily lopped for fodder (Singh 1982). Leaves have a crude protein content of 24%. However, tannins and lectin proteins found in leaves and inner bark can interfere with digestion in ruminants and in nonruminants (Harris et al. 1984). Tannin levels are high in young leaves but decrease as leaves mature.
Bees harvest Robinia nectar to produce a honey regarded as one of the world's finest. Tree improvement specifically for late flowering and high nectar sugar content is ongoing in Hungary and the US.
The tree is used extensively to rehabilitate surface mine tailings in the US. In Hungary, black locust is often grown for wood on small private farms (Keresztesi 1986). A dense growth habit makes black locust suitable for windbreaks, a use most common in China. Black locust may even prove useful for alley cropping in temperate climates. Researchers at the Rodale Research Center in Pennsylvania are experimenting with intercropping black locust with vegetables. Numerous reports indicate the beneficial effect of this NFT to associated plants through improved soil fertility. Mixed plantings of black locust and conifers, however, can lead to reduced growth or death of the slower growing conifers because of shading and over-topping.
PESTS AND PROBLEMS.
The most serious pest to black locust in the US is the locust borer, Megacyllene robiniae (Forster). There is some evidence for genetic resistance to the borer. Another insect confined to trees in the US is the locust twig borer, Ecdytolopha insiticiana (Zeller). Aphids, Nectria cankers, leaf miners, and Rimosus heart rot also affect the tree (Hoffard and Anderson 1982). Its propensity to root spout aggressively can also cause problems.
Robinia is fairly specific in its Rhizabium requirements. Although it will form nodules with a variety of exotic strains, for effective N-fixation, strains from native trees work best. Newly introduced trees require inoculation; inoculum may be gotten from the soil of black locust stands, or from NFTA. The tree's fine roots are also colonized by VA mycorrhizae.
Boring, L.R. and W.T. Swank. 1984. The role of black locust (Robinia pseudoacacia) in forest succession. J. Ecol. 72:749766.
Fowells, H.A. (ed). 1965. Silvics of Forest Trees of the United States. USDA, Forest Service, Agric. Handbook No. 271.
Hanover, J.W. 1989. Physiological genetics of black locust (Robinia pseudoacacia L.): A model multipurpose tree species. Proc. Conf. on Fast Growing Nitrogen Fixing Trees, 1989, Marburg, W. Germany.
Hanover, J.W., T. Mebrahtu, and P. Bloese. 1989. Genetic improvement of black locust: A prime agroforestry species. Proc. First Conf. on Agroforestry in N. America, Aug. 1989 Guelph, Ontario, Canada.
Hoffard, W.H. and R.L. Anderson. 1982. A guide to common insects, diseases, and other problems of black locust. USDA Dept. Agric. Forestry- Rep. SA-FR-19.
Keresztesi, B. (ed). 1988a. The Black Locust. Akademiai Kiado Budapest, Hungary.
Keresztesi, B. 1988b. Black locust: The tree of agriculture Outlook on Agric. (Great Britain) 17(2):77-85.
Singh, R.V. 1982. Fodder Trees of India. Oxford and IBA Public. Co., 66 Janpath, New Delhi 110001, India.
Stringer, J.W. and S.B. Carpenter. 1986. Energy yield of black locust biomass fuel. For. Sci. 32:1049-1057.
Surles, S.E., J.L. Hamrick, and B.C. Bongarten. 1989. Allozyme variation in black locust (Robinia pseudoacacia). Can. J. For Res. 19:471-479.
A full list of highlight references is available from NFTA.
NFTA 92-04 June 1992
Acacia nilotica (L.) Willd. ex Del. (Leguminosae, subfamily Mimosoideae) is one of about 135 thorny African Acacia species. Variation is considerable with nine subspecies presently recognized, three occurring in the Indian subcontinent and six throughout Africa (Brenan 1983.) They are distinguished by the shape and pubescense of pods and the habit of the tree.
In habit A. nilotica varies from a shrubby tree with wide spreading crowns in savanna habitats (ssp. subalata, leiocarpa, adstringens, hemispherica and kraussiana), to a 20 meter tree (ssp. nilotica, tomentosa, and indica) in riverine situations. Ssp. cupressiformis has ascending branches like a poplar.
Acacia nilotica is easy to recognize by its bright yellow flowers in round heads, straight stipular spines often slightly deflexed, and dark indehiscent pods compressed over the seeds. Flowering is prolific, and can occur a number of times in a season. Often only about 0.1% of flowers set pods (Tybirk 1989.) The taxa form a polyploid complex: most are tetraploids (2n=4x=52); but higher numbers have been found in ssp. nilotica (2n = 8x= 104) & ssp. tomentosa (2n = 16x= 208) (Nongonierma 1976.)
There are two very distinct ecological preferences in the African subspecies. Subspecies subalata. leiocarpa and adstringens occur in wooded grassland, savanna and dry scrub forests. Subspecies nilotica and tomentosa are restricted to riverine habitats and seasonally flooded areas. Subspecies kraussiana prefers dry grasslands and savannas, especially on compacted sandy loam, shallow granite or clay soils along drainages and rivers, but away from flooding.
On the subcontinent, ssp. indica forms low altitude dry forests usually on alluvium and black cotton soils. It has been widely planted on farms throughout the plains of the subcontinent. The species grows on saline, alkaline soils, and on those with calcareous pans. Subspecies hemispherica is restricted to dry sandy streams beds near Karchi, ssp. cupressiformis has similar preferences to ssp. indica though is less resilient to weed competition.
A. nilotica occurs from sea level to over 2000 m. It withstands extremes of temperature (-1 to 50 C), but is frost tender when young. Annual rainfall varies from 250 1500 mm. Trees are generally deciduous during the dry season, though riverine ssp. can be almost evergreen.
The species is naturally widespread in the drier areas of Africa, from Senegal to Egypt and down to South Africa, and in Asia from Arabia eastwards to India, Burma and Sri Lanka. It has also been cultivated elsewhere, including Australia, Cape Verde islands, Indonesia, Iran, Iraq, Nepal, Vietnam' and the West Indies.
Since the time of the Pharoahs, large timber trees have been exploited from the riverine forests of the Nile. At present the Sudan forests are managed on a 20-30 year rotation producing termite resistant timber especially suitable for railway sleepers. In India and Pakistan riverine plantations are managed on a 15-20 year rotation for fuelwood and timber.
The dark brown wood is strong, durable, nearly twice as hard as teak, very shock resistant, and is used for construction, mine props, tool handles and carts. It is best carved in a green state. It has a high calorific value of 4950 kcal/kg, making excellent fuelwood and quality charcoal. It burns slow with little smoke when dry.
The pods and leaves contain 8% digestible protein [12.4% crude protein], 7.2 MJ/kg energy, and are rich in minerals (Le Houerou 1980). In part of its range smallstock mainly consume it, but elsewhere it is also very popular with cattle. Pods are used as a supplement to poultry rations in India. Dried pods are particularly sought out by animals on rangeiands. In India branches are commonly lopped for fodder. Pods are best fed dry as a supplement, not as a green fodder.
Babul (ssp. indica) is a popular farm tree of the central plains of India. More recently interest has centred on the fastigiate form (ssp. cupressiformis). This subspecies makes an ideal windbreak surrounding fields; its narrow crown shades less than other windbreak species.
In India this species is used extensively on degraded saline/alkaline soils, growing on soils up to pH 9, with a soluble salt content below 3%. It also grows well when irrigated with tannery effluent, and colonises waste heaps from coal mines. Over 50,000 hectares of the Indian Chambal ravines have been rehabilitated with A. nilotica by aerial seeding (it is one of the 3 most frequently used trees for this purpose).
The bark of ssp. indica has high levels of tannin (12-20%) which are used for tanning leathers. Ten year old trees yield 35-40 kg of bark. The pods of ssp. nilotica have been used for tanning in Egypt for 6,000 years. Subspecies adstringens is used for both tanning and dye making. Deseeded pods from ssp. indica have 18-27% tannin levels, whereas ssp. tomentosa and nilotica reach up to 50%.
The tannin also contributes to its medicinal use as a powerful astringent. It is also a powerful molluscicide and algicide. Fruits added to ponds in Sudan kill snail species which carry schistosomiasis without affecting the fish.
There are many other reported uses (Fagg & Greaves 1990). The tree makes effective live fencing, a good host plant for growing sandalwood, and an important source shellac in the Sind. The gum is used in paints and medicines and has been collected for a millennia. It has similar properties to gum arabic (from A. senegal) and is frequently used in calico printing in India.
It is a pioneer species, easily regenerated from seed. The nutritious indehiscent pods have evolved for animal dispersal. A mature tree can produce 2,000-3,000 pods in a good fruiting season, each with 8-16 seeds, yielding 5,000 - 16,000 seed/kg depending on the subspecies.
Hard coated seeds can be extracted by pounding the pods or collected from animal pens after the pods have been eaten (Sheikh 1989). Pretreatment is needed. Mechanical scarification works best for small seed lots. Acid scarification from 60 - 120 minutes (depending on seed provenance or age), or pouring boiling water over the seeds and allowing them to cool are also effective.
Seed from natural populations of some subspecies are available from India and some Sahelian countries. A broader range of germplasm and Rhizobium inoculum is available from the Oxford Forestry Institute (Oxford OX1 3RB UK) for field triels.
The species can be direct seeded or established by seedlings. In the nursery long poly tubes (20 x 7 cm) should be used so as not to restrict rapid tap root growth. Frequent root pruning is advised. Nursery grown seedlings are usually outplanted after 6 months, but in some cases stay in the nursery up to a year.
Establishment varies depending on the site. Seedlings are shade intolerant. In irrigated plantations in the Sind and Punjab, 10-15 seeds are spot sown at 2x3 m spacing on the tops of trenches. They are thinned to 3-4 seedlings after 34 months. Further thinning occurs at 5 year intervals. Rotations are 20-25 years. In the Thal desert, Pakistan (250 mm of rain), promising growth resulted from irrigation on a 10 day interval. Growth rates varied considerably depending on the sites, with maximum mean annual increment of 13 m³/ha at 20 yrs old and 10.5 m³/ha at 30 years recorded.
A wide range of pests and diseases affect this species. Of economic importance is the stem borer Cerostema scabrator on young plantations in India. Euproctis lunata & E. subnotata occasionally defoliate patches of forest in Sukkur and Hyderabad. Bruchid beetles attack the seeds, destroying up to 70 %. Buprestid beetles cause a dieback disease in Sudan. Fungal rots (Fomes papianus & F. badius) attack unhealthy trees, and powder post beetles (Sibixylon anale & Lyctus africanus) attack the sapwood of felled timber.
Acacia nilotica can become weedy when introduced out of its native range, particularly in more humid zones. Thorniness can be a problem when introduced to areas where people do not traditionally use thorn trees.
Brenan, J.P.M. 1983. Manual on the taxonomy of Acacia species: Present taxonomy of four species of Acacia (A. albida, A. senegal, A. nilotica, A. tortilis). FAO, Rome, Italy. 47 p.
Fagg, C.W. and A. Greaves. 1990. Acacia nilotica 18691988. CABI/OFI Annotated bibliography No. F42. CAB International, Wallingford, Oxon, UK 77 p.
Le Houerou, H.N. 1980. Chemical composition and nutritional value of browse in tropical West Africa. In H.N. Le Houerou (ed), Browse in Africa, the Current State of Knowledge. ILCA, Ethiopia. p 261-289.
Nongonierma, A. 1976. Contribution a l'etude du genre Acacia Miller en Afrique occidentale. II. Caracteres des inflorescences et des fleurs. Bulletin de l'IFAN
Serie A. 38 (3) 487-657.
Tybirk, K. 1989. Flowering, pollination, seed production of Acacia nilotica. Nordic Journal of Botany 9 (4) 375-381.
Sheik, M.I. 1989. Acacia nilotica (L.) Willd. ex Del. Its production, Management and Utilization. Pakistan. Regional wood energy development programme in Asia, GCP/RAS/111/NET Field document no. 20, FAO, Bankok 10200, Thailand. 45 p.
NFTA 92-03 June 1992
Acacia saligna is a small nitrogen fixing tree native to the southwest of Western Australia. It is commonly known as golden wreath, orange wattle, or blue-leafed wattle and was formerly known as A. cyanophylla. It is fast growing and tolerant of a wide range of soils, including calcareous and slightly saline types in temperate climates. Acacia saligna is planted in North Africa and the Middle East for fodder, fuelwood, sand stabilization, and as a wind break. In Australia it is most commonly used as an ornamental, but is being increasingly planted in agroforestry systems for fodder production and soil conservation.
A. saligna (Labill.) H. Wendl. is a dense and multistemmed, thornless, spreading shrub or singlestemmed small tree up to 9 m in height. The bark is smooth and grey to red-brown on branchlets. Young plants become dark grey and fissured with age. Dark green to blue-green phyllodes with conspicuous midribs are long and narrow to lanceolate and 8-25 cm long. Flower heads are globular and contain 2555 (up to 78) bright yellow, five-parted flowers. The pods are narrow, 4-6 mm wide and usually 8-12 cm long. The seed is 5-6 mm long x 3-3.5 mm wide, dark brown to black and shiny (Maslin 1974); there are 14,000-25,000/kg. Acacia saligna is 2n=26 and outcrossing.
In its native range A. saligna is confined to southwest Western Australia. It has become naturalized in parts of eastern Australia, from Victoria to southeast Queensland. In its natural habitat, A. saligna occurs where the mean annual rainfall is 300 to 1,000 mm. In drier areas it normally receives additional run-on water.
Mean maximum temperature of the hottest month is 23 to 36°C and mean minimum of the coldest month is 4 to 9°C. Much of the area of natural distribution is frostfree but occasional light frosts occur in inland areas (Hall and Turnbull 1976). A. saligna is sensitive to frosts and damage is likely to be severe if the temperature falls below -4°C. The tree ranges from sea level to about 325 m elevation.
Trees are common on alkaline, infertile sandy soils. In many places A. saligna is more or less restricted to creeks and rivers and disturbed roadsides. It is moderately common along the south coast of Western Australia, but is best developed in the deep sands and loams along the water courses throughout the area. Further inland, in the wheatbelt, populations occur at the base of many of the large, granitic rock outcrops.
On coastal dune systems it often forms dense thickets in the hollows between sand hills (Maslin 1974).
A. saligna wood is used as fuel and charcoal, and for vine stakes and small agricultural implements (Michaelides 1979). It has been successfully processed into particle board in Tunisia (El-Lakany in Turnbull 1987).
The phyllodes, young shoots, pods and seeds, whether fresh or dry, are protein rich and non-toxic and palatable to both sheep and goats (Michaelides 1979). According to Woodward and Reed (1989), however, the phyllodes are not suitable for ruminants. This feed is especially valuable seasonally when other forage is scarce. The chemical composition shows the following ranges: dry matter (50-55%), crude protein (12-16%), crude fiber (2024%), crude fat (6-9%), and ash (1012%) (El-Lakany in Turnbull 1987). Analysis of phyllodes from trial plantings in southeast Queensland indicate a moderately low digestibility (36.5% predicted in vivo) but high levels of crude protein (18.3%) (Vercoe in Boland 1989). The low Ca/P ratio of 4.1 should enable efficient use of phosphorus supplements.
The tree is used extensively for coastal sand dune fixation in North Africa, the Middle East, and South Africa and for gully erosion control in Uruguay. In Australia it has been used in the rehabilitation of sand mining areas (Hall and Turnbull 1976).
Trees were planted in the past for tannin production from the bark (Hall and Turnbull 1976). The damaged bark exudes copious amounts of gum that is very acidic. Such acid-stable gum has promise for use for pickles and other acidic foodstuffs (Michaelides 1979). A. saligna is also widely planted as an ornamental.
Prior to sowing, seed should be immersed in boiling water for 1 min to remove seedcoat dormancy. Seed coats can also be scratched or nicked with a file or nail clipper. Seeds are available from NFTA. Treated seed should be planted to a depth of 0.5 cm. Seedlings can be produced either by direct seeding or in a nursery. A nursery phase of 10-12 weeks is recommended. Soil should not be allowed to dry between sowing and germination. Young plants require protection from grazing animals.
In trials in southeast Queensland, A. saligna attained an average height of 6.2 m after only 41 months (Ryan and Bell in Boland 1989). The tree is tolerant of drought, light frost, alkalinity, and salt (Simmons 1981). Successful irrigation trials (6 liters/tree every 2nd day) have been undertaken at the Desert Development Center, The American University in Cairo. A. saligna coppices well and fodder biomass production is optimized by regular, annual harvesting (El-Lakany in Turnbull 1987). Trees grow poorly in tropical areas, except at high altitudes. In such areas the species A. ampliceps, a valuable alkaline soil fodder tree, may prove a more acceptable alternative.
The tree nodulates with certain strains of Rhizobium (Roughley in Turnbull 1987). In common with many other acacias, it forms associations with VA mycorrhizal fungi (Reddell and Warren in Turnbull 1987).
PESTS AND DISEASES:
Older plants are susceptible to gall rust, Uromycladium tepperianum, and various gallexploiting insects. In parts of Western Australia more than 90 percent of A. saligna trees bear conspicuous woody galls (Van den Berg 1978). Trees are susceptible to white scale insects (Coccidae) which attack the leaves and stems. Rodents sometimes attack the roots. Termites may cause serious problems in tropical countries (Michaelides 1979).
Caution is advised using A. saligna. The tree has become a major weed in South Africa by invading and displacing the indigenous vegetation (Roux and Middlemiss 1963). The species was introduced to South Africa in the first half of the nineteenth century. It has spread to waterways and irrigation channels. The seed has also spread in river sand transported for road and dam construction. Its hardiness and ability to coppice rapidly after fires or from trunks has also led to widespread establishment (Stirton 1980).
Boland, D.J. (ed). 1989. Trees for the Tropics. ACIAR Monograph No. 10. ACIAR, Canberra, Australia.
Hall, N. and J.W. Turnbull. 1976. Acacia saligna (Labill.) H. Wendl. formerly known as A. cyanophylla Lindl. Australian Acacias No. 4. CSIRO Division of Forest Research Canberra.
Maslin. B.R. 1974. Studies in the Genus Acacia, 3: The taxonomy of A. saligna (Labill.) H. Wendl. Nuytsia 1(4), 332-340.
Michaelides, E.D. 1979. Mini-monograph on Acacia cyanophylla. Technical Consultation on Fast-Growing Plantation Broadleaved Trees for Mediterranean and Temperate Zones. Lisbon, Portugal, 16-20 October 1979. FAO, Rome.
Roux, E.R. and E. Middlemiss. 1963. Studies in the autecology of Australian acacias in South Africa. The occurrence and distribution of Acacia cyanophylla and A. cyclops in the Cape Province. South Africa J. Science 59:286-294.
Simmons, M. 1981. Acacias of Australia. Thomas Nelson, Melbourne.
Stirton, C.H. (ed). 1980. Plant Invaders: Beautiful, but Dangerous. The Department of Nature and Environmental Conservation of the Provincial Administration, Cape Town, South Africa.
Turnbull, J.W. (ed). 1987. Australian Acacias in Developing Countries. ACIAR Proceedings No. 16. ACIAR, Canberra, Australia.
Van den Berg, M A. 1978. Natural enemies of certain acacias in Australia. Proc. 2nd Nat. Weeds Conf. S. Afr. 75-82.
Woodward, A. and J.D. Reed. 1989. The influence of polyphenolics on the nutritive value of browse: A summary of research conducted at ILCA. ILCA Bulletin 1989. No. 35, p 2-11.
NFTA 91-02 April 1991
Acacia senegal is a multipurpose African tree (subfamily Mimosoideae, family Leguminosae), highly valued for centuries for gum arabic production. Today, A. senegal is grown primarily for gum, but plays a secondary role in agricultural systems, restoring soil fertility and providing fuel and fodder.
A deciduous shrub or small tree, Acacia senegal (L.) Willd. grows to 2-6 m (occasionally to 15 m) tall, with a flat to rounded crown. The tree has many branches and erect twigs spreading within the upright part. The bark is typically yellow/brown and smooth on younger trees, changing to dark grey, gnarled, and cracked on older trees. The branchlets have thorns just below the nodes: either three thorns with the central one hooked downwards and laterals curved upwards, or a single thorn with laterals absent. Leaves are small, gray-green, alternate, and bipinnate. Pinnae occur in (2-)3-8(-12) pairs, and leaflets in 7-25 pairs. The rachis sometimes have prickles. The white or cream colored flowers occur on 2-12 cm long spikes. Pods are dehiscent (open by splitting at maturity), yellowish to brown, flat, papery, and oblong (2-19 cm long by 1-3.4 cm wide). Seeds are nearly round to flat, olive brown, and 8-12 mm in diameter. The tree flowers during the rainy season.
Varietal differences in Acacia senegal are based on variation in natural distribution as well as differences in morphological characteristics such as: presence or absence of hair on the axis of the flower spike, color of the axis, shape of pod tips, number of pinnae pairs, occurrence of a distinct trunk, and shape of the crown. Four different varieties of Acacia senegal are recognized: var. senegal, var. kerensis Schweinf., var. rostrata Brenan, and var. Ieiorhachis Brenan.
Acacia senegal var. senegal is found in Mauritania, Senegal, Gambia, Ghana, Burkina Faso, Cote d'Ivoire, Mali, Niger, Nigeria, Cameroon, Zaire, Central African Republic, Rwanda, Chad, Sudan, Ethiopia, Somalia, Uganda, Kenya, Tanzania, Mozambique, Oman, Pakistan, and India. It has been introduced into Egypt, Australia, Puerto Rico, and the Virgin Islands. Var. kerensis is found in Ethiopia, Somalia, Uganda, Kenya, and Tanzania. Var. rostrata occurs in Somalia, Uganda, Kenya, Mozambique, south to Zimbabwe, Botswana, Angola, Namibia, and South Africa. Var. Ieiorhachis occurs in Ethiopia, Somalia, Kenya, Tanzania, southern Zambia, Zimbabwe, Mozambique, Botswana, and South Africa (Transvaal).
Acacia senegal is very drought resistant. It grows on sites with annual rainfall between 100-950 mm, mainly between 300-400 mm, and 5-11 month dry periods. It tolerates high daily temperatures (mean maximum temperatures of up to 45°C or more), dry wind, and sandstorms. Generally it cannot withstand frost. Acacia senegal prefers coarse-textured soils such as fossil dunes, but it will also grow on slightly loamy sands and skeletal soils such as Lithosols. Although generally soils are welldrained, there are exceptions: in the Kayers region, SouthKordofan, East Sudan, A. senegal grows on heavy clay soils with approximately 800 mm annual precipitation. The best sites have pH of 5 to 8. The tree ranges from 100-1700 m elevation in the Sudan to 1950 m around Nakuru in Kenya.
Acacia senegal and its close relatives are the defined source of commercial gum arabic for food purposes. A. senegal produces the only acacia gum evaluated toxicologically as a safe food additive (Anderson 1989). The gum from other Acacia species (A. seyal etc.) is available commercially as gum tahla (approx. 10% of all acacia gum marketed) for technological applications. Gum arabic has been used for at least 4,000 years by local people for preparation in food, in human and veterinary medicine, in crafts, and as a cosmetic. Today, gum arabic's applications are manifold. Formerly the international trade market largely absorbed all gum available, though recently international demand has declined together with gum prices.
Gum arabic is used in the food industry as ;m:avor fixative and emulsifier, to prevent crystallization of sugar in confections, as a stabilizer in frozen dairy products, for its viscosity and adhesive properties in bakery products, and as a foam stabilizer and clouding agent in beer. In pharmaceutics, it is used as a stabilizer for emulsions, binder and coating for tablets, and as an ingredient in cough drops and syrups. A soothing and softening agent, gum arabic is extensively employed in folk medicines. Among many other uses, it is used internally for coughs, diarrhea, dysentery, hemorrhage, and externally to cover inflammed areas. Gum arabic is used in cosmetics as an adhesive for facial masks and powders, and to give a smooth feel to lotions. Industrially, gum arabic is applied as an a&esive, as a protective colloid and safeguarding agent for inks, sensitizer for lithographic plates, coating for special papers, sizing agent for cloth to give body to certain fabrics, and coating to prevent metal corrosion. Gum arabic is also used in the manufacture of matches and ceramic pottery.
Acacia senegal wood is locally valued for fuelwood and charcoal, although biomass yield per unit land area is not sufficient to plant A. senegal purely for fuelwood. Wood is used in local construction for poles and fenceposts, the lightcolored wood for tool handles and dark heartwood for weaver's shuttles. Strong ropes are made from the bark fibers of the tree's long surface roots.
Food and fodder:
Dried and preserved seeds of A. senegal are used by people as vegetables. The foliage and pods are browsed by sheep, goats, camels, impala, and giraffe. Leaves contain 10%-13% digestible protein and 0.12%-0.15% phosphorus, while the pods contain 15% digestible protein and 0.12%-0.14% phosphorus.
Acacia senegal is important for desertification control through sand dune stabilization and wind breaks.
Acacia senegal is grown in agroforestry systems especially in the Sudan in "gum gardens" for gum as well as to restore soil fertility. Five-year-old trees are ready for tapping, and production peaks between 7 and 15 years. In Sudan, a traditional bush-fallow system is followed with a 20year rotation during which time Acacia senegal is grown for 15 years. Agricultural crops are grown for five years (millet, sesame, sorghum, groundnuts), followed by five years with young, unproductive A. senegal trees, which later produce gum during the last 10 years of the rotation. Corresponding to this rotation, 1/4 of the land is kept in agricultural crops, 1/4 in young unproductive trees, and 1/2 in productive trees. Controlled grazing is practiced after the trees have reached age four and under productive trees after the gum has been harvested. Wild trees are harvested during the dry season for gum exuded from cracks in the bark.
Seed should be harvested before pods have dried for easy collection and to avoid insect attack. Seed is easily extracted by hand. Freshly extracted seed should immediately be dusted with an insecticide. Seed will remain viable for 3-4 years if kept in opaque, airtight containers. There are 10,000-30,000 seeds/kg. Fresh seed requires no pretreatment if sown immediately after harvest. Seed collected in previous seasons, however, requires pretreatment to break seed dormancy. Soaking seed in water for 12-24 hours gives good results and is simple to apply. Seeds can also be nicked.
A. senegal is usually raised in the nursery in polyethylene pots, 2-4 seeds per pot, thinned to one seedling after 4-6 weeks. Direct seeding (5-8 seeds in 30 x 30 x 30 cm pits or larger) can also be used. Strict protection from fire and livestock grazing, and efficient control of weed competition during at least the first two years is important to seedling survival. Minimum spacing for block planting is 4 x 4 m. At 10 x 10 m spacing, agricultural intercropping is possible, for example, interplanting with millet, beans, or groundnuts.
PESTS AND DISEASES.
The buffalo treehopper (Stictocephala bubalus) may destroy seed crops. Spiders (Cyclops sp.) can smother young growing apices. Larval stage of Coleoptera (bruchids), Lepidoptera, and Hyrnenoptera damage the seed. Locusts (Acridium melanorhodon) can defoliate vast areas overnight. Acacia senegal is also attacked by the fungi Cladosporium herbarium, Fusarium sp., Ravenelia acaciae-senegalae and R acaciocola.
Anderson, D.M.W. 1989. NFT gums: Ancient and modern commercial products. NFTA Highlight 89-01.
Booth, F.E.M. and G.E. Wickens. 1988. Non-timber uses of selected arid zone trees and shrubs in Africa. FAO Conservation Guide 19. Rome, FAO.
Brenan, J.P.M. 1983. Manual on Taxonomy of Acacia Species. Rome, FAO Forestry Division.
Depierre, D. 1969. Les experiences de gommeraie cultivÃ©e Ã leurs enseignements au Tchad. Bois et Forets des Tropiques 125:27-34.
Doran, J.C., J.W. Turnbull, D.J. Boland and B.V. Gunn. 1983. Handbook on Seeds of Dry-Zone Acacias. FAO, Forestry Division, Rome.
Duke, J.A. 1981. Handbook of Legumes of World Economic Importance. Plenum Press, New York.
FAO and UNEP. 1983. Notes on trees and shrubs in arid and semiarid regions. EMASAR Phase II. FAO, Rome, Italy.
Giffard, P.L. 1966. Les gommiers Acacia senegal Willd. Acacia laeta R. Br. Bois et Forets des Tropiques 105:22-32.
Giffard, P.L. 1975. Les gommiers, essences de reboisement pour les regions saheliennes. Bois et Forets des Tropiques 161:320.
Little, E.L. 1983. Common Fuelwood Crops. Communi-Tech Assoc., Morgantown, West Virginia.
Maydell, H.J. von. 1983. Arbres et arbustes du Sahel. Leurs caracteristiques et leurs utilizations. Eschborn, GTZ.
Southgate, B.J. 1983. Handbook on Seed Insects of Acacia Species. FAO, Forestry Division, Rome.
Vassal, J. 1983. Dommiers et production gommiere. In Acquisitions Recentes dans les Domaines des Hydrocolloides Vegetaux Naturels. Pub. I.I.E.R.C.N. Presses Univ. AixMarseille, France. p. 5-17.
NFTA 94-07 September 1994
One of few strongly gregarious Sahelian tree species, Acacia seyal combines tolerance of periodically inundated heavy clays with major roles in fuel and fodder production in countries at the southern edge of the Sahara desert, especially Mali, Chad and Sudan. A gum (gum talha) is collected from the tree and a proportion enters international trade. The epithet seyal derives from an Arabic word for "torrent" used for the species in Egypt and denotes association with water courses.
Acacia seyal Delile (family Leguminosae, subfamily Mimosoideae) is one of over 60 African acacias referred to the Uniseriae group of subgenus Acacia. The species usually reaches 9-10 m in height at maturity and in well-formed individuals a flat-topped crown develops. There arc two varieties, differing primarily in whether or not pseudogalls ("ant galls") develop and in bark color. In var. seyal there are no pseudogalls and a reddish bark color prevails, although periodic bark exfoliation exposes a pale powdery surface which darkens slowly. In var. fistula pseudo-galls arc present and the powdery bark typically remains whitish or greenish-yellow. Both varieties have paired, straight, strong, pale-colored, stipular spines up to 8 cm long which in var. fistula are often fused at the base into the inflated pseudo-galL The leaves arc bipinnate - usually with 48 pairs of pinnae, each of which bears 10-20 pairs of close-set, obscurely veined leaflets. Individual leaflets are 1-15. mm wide and about 5-8 mm long. Small bundles of up to 5 pedunculate capitate inflorescences arise in axillary positions on the young parts of shoots. Each inflorescence is vivid yellow in color, about 15 mm in diameter, and is borne on a peduncle 34 mm long. The dehiscent pods arc flat and somewhat curved, brown and up to about 20 cm long and 5-10 mm wide when ripe, with slight constrictions between the seeds. In a well-developed pod 6-10 seeds arc present, each 69 mm long, 4-5 mm wide and about 2 mm thick - in 1 kg there arc 20,00025,000 seeds. The chromosome number of 2n = 52 suggests tetraploidy.
The range of A. seyal extends from Senegal eastwards to western Somalia and the coastal lowlands east of the Red Sea, and from the Nile valley of southern Egypt to southern Zambia. The two varieties differ markedly in their ranges-var. seyal extends westwards from central Sudan and north of latitude 18°N and var. fistula extends south of latitude 10°S. The ranges overlap mainly in the upper Nile catchment, the Lake Victoria basin and the Ethiopian and East African rift valleys. Occurrence beyond the natural range is limited to arboreta (e.g. Iraq, Portugal) and experimental studies (e.g. India).
Given suitable climatic and edaphic conditions closed, and essentially pure, stands of A. seyal develop but admit sufficient light for grass to grow in the understory.
Through the greater part of the range of A. seyal mean annual rainfall is 500-1200 mm and there is a well-defined 6-8 month dry season with mean annual rainfall less than 50 mm. Occurrences in more arid climates arc associated with the presence of water in addition to direct rainfall The phenological cycle relates closely to the rainfall regime. Where there is a well defined unimodal rainfall pattern, leaf fall takes place by the middle of the dry period and trees remain leafless for 4-7 months, depending on when the subsequent wet season begins. Leafless periods are briefer in bimodal equatorial rainfall regimes. Flowering is concentrated in the middle of the dry season and ripe fruits arc present about 4 months later.
Temperature regimes vary through the range, particularly for var. seyal which is subject to mean annual temperatures of 18-25°C. Var. fistula occurs mostly where mean annual temperatures are 20-25°C, but also in cooler climates in Ethiopia, at the upper elevation limit (1700-2000 m). Relationships with extreme temperatures follow a similar pattern - in parts of West Africa where var. seyal is present, absolute temperature maxima are 50-55°C. Absolute minima through the range of the species are generally 5-10°C but below Sac at the northern limit and at altitudes >1800 m. The distribution pattern overall is indicative of a frost-sensitive species.
Relationships with soil are well-defined. There is an unusual degree of adaptation for deep, heavy soils (pH 6-8) accumulated a, low points in a landscape or formed directly from fine-grouned rocks, such as shales, and readily weathered volcanic materials. In communities containing both varieties, var. fistula displays greater tolerance of waterlogging and occupies lower positions in depressions and along drainage lines. Saline soils are not suitable.
Var. seyal, especially, is an important source of rural energy as both fuelwood and charcoal. Stands managed on a 10-15 year rotation yield 10-35 m³ ha-1 of fuelwood.
Both varieties of A. seyal are viewed favorable as forage. Dry matter net energy contents are high: 6-8 MJ kg- 1 (foliage) and 4-7 MJ kg1 (fruits). The associated digestible protein levels are also :gh: 100-150 g kg1 in the foliage, and higher in the fruits. For both foliage and fruits, analyses indicate a well balanced supply of minerals and very favorable qualities in terms of proximate fractions (e.g. crude fiber 10-20%; ether extract <7%). The foliage of var. seyal has been shown to contain secondary metabolites but experience suggests that levels are not a matter of serious concern.
Gum talha has not been toxicologically evaluated and is not listed as an approved food additive. It contrasts with gum arabic in several significant respects, being strongly dextrorotatory, of high molecular weight and low in nitrogen (0.06-0.24%) and rhamnose (<4% sugar composition). Ash contents of cobalt, copper, iron, nickel and, especially, aluminum (>6000 ppm) are high and tannin is present (2%), restricting acceptable use to such applications as a binder for foundry molding and a sizing agent in the textile industry.
Management of natural stands
Both varieties of A. seyal are noteworthy for occurrence in the undisturbed state in seral, even-aged stands. Reconstitution of an exploited var. seyal stand depends not on coppice shoots but on the presence of abundant seed and its exposure to a mild fire which enhances the germination of var. seyal but checks the regeneration of competing species. Stands 15 years old when harvested are likely to have produced a seed reserve sufficient to regenerate the stand. However, individual trees or uncut patches of the original cover should be left as seed sources to insure abundant regeneration. Where management for fodder production is concerned, evaluation of responses to lopping and cutting of var. seyal indicate limited recovery capacity in mature trees. Beating branches to detach leaves and fruits without damage to axillary buds is therefore preferred to exploit these as dry season resources.
Unopened, full-sized fruits are gathered off the trees and allowed to release seed. After cleaning, seed stores well in cool, dry conditions, remaining viable for up to 8 years. Pretreatment in the nursery is advantageous, although not essential, to accelerate the germination rate. Scarification and acid treatments have proved favorable. However, germination rates have rarely exceeded 30% in 7 days. Seeds can be pregerminated in contact with moist cotton wool or filter paper to allow rapid identification of viable non-dormant seed. Transfer to containers filled with a silt-rich medium. Seedlings require shade until the second leaf expands and watering at intervals of 1-3 days as necessary to keep the medium moist but not waterlogged.
Stands of var. seyal have been established in Sudan, often by direct sowing of pretreated seeds to prepared planting spots. Sowing seed in batches ensures a high proportion of spots become occupied. Competition from weed growth is overcome by using taungya, with mechanized site preparation and sowing. Sesamum or Sorghum is intercropped among widely spaced (ca 4 m) rows of trees. For poles and fuelwood a 20 year rotation is projected. Initial stocking is 1000 stems ha -1. Thinnings after 10 and 14 years reduce stocking to 675 and 450 stems ha -1, respectively.
Nodulation occurs in natural populations. In artificial regeneration it has been achieved by pelleting seed with culture of bacterial isolates, sowing into an infected medium or germinating in unsterilized soil. Uninfected seedlings have been inoculated successfully by treatment with a suspension of a symbiont. Rhizobium strains from A. mellifera and A. senegal and Bradyrhizobium from the latter have proved to be effective symbionts.
Over 40 species of insects are reported associated with A. seyal. These include 10 species of bruchid beetles which may damage high proportions of stored seeds. Beetles of various other families attack the wood, the postrychid Sinoxylon senegalense being the most notorious and swiftly locating and infesting freshly cut wood, especially if lying on the ground. Attacks are much reduced if the bark is removed and the cut stems stacked upright Subsequent creosote treatment ensures extended durability.
Adams, M.E. 1967. A study of the ecology of Acacia mellifera, A. seyal and Balanites aegyptiaca in relation to land clearing. Journal of Applied Ecology, 4: 221-237.
Booth, F.E.M. & Wickens, G.E. 1988. Non-timber uses of selected arid zone trees and shrubs in Africa FAO Conservation Guide, 19: 8-12.
Hall, J.B. & McAllan, A. 1993. Acacia seyal: a monograph. School of Agricultural and Forest Sciences, University of Wales, Bangor.
Le HouÃ©rou, H. N. 1980. Browse in Africa the current state of knowledge. International Livestock Centre for Africa Addis Ababa. 491 pp.
Tybirk, K. 1991. Regeneration of woody legumes in the sahel. Aarhus University Botanical Institute. AAU Report, 27: 1-81.
For a complete set of references contact the author or NFTA.
A Publication of the Nitrogen Fixing Tree Association c/o Winrock International Rt. 3, Box 376 Morrilton, Arkansas 72110 USA Tel: 501-727-5435; Fax: 501-727-5417
NFTA 91-01 April 1991
Acacia tortilis, often called the "umbrella thorn" for its distinctive spreading crown, is one of the most widespread trees in seasonally dry areas of Africa and the Middle East. The umbrella thorn is the dominant tree in many savanna communities and provides an important source of browse for both wild and domesticated animals.
Acacia tortilis (Forsk.) Hayne (subfamily Mimosoideae, family Leguminosae) is one of about 135 African acacia species. Unlike the Australian acacias, African acacias are armed with thorns and produce highly palatable pods. A. tortilis is a variable species, with six infraspecific taxa including four recognized subspecies: tortilis, spirocarpa, heteracantha, and raddiana (Brenan 1983). Although some French and Israeli authors consider ssp. raddiana a separate species (A. raddiana), recent revisions treat it as a subspecies (Brenan 1983, Ross 1979). As with other African acacias, A. tortilis is a polyploid complex most are tetraploids (2n=4x=52); ssp. raddiana is an octoploid (2n=8x=104).
Acacia tortilis varies from multi-stemmed shrubs (ssp. tortilis), to trees up to 20 m tall with rounded (ssp. raddiana) or flat-topped (ssp. heteracantha and spirocarpa) crowns. The presence of very long thorns and two thorn types, longstraight and shorter-hooked, distinguishAcacia tortilis from other acacia species in Africa. The alternate leaflets (usually < 1 mm wide) are smaller than those of most bipinnate acacias. White or pale-yellow fragrant flowers cluster in 1 cm diameter round heads. Flowering is prolific with up to 400 flowers/meter twig. Flowers later develop into bunches of spirally twisted, indehiscent pods. Straight pods also occur, though rarely (Somalia and Kenya). Pods vary considerably in size depending on provenance but range from 8 to 12 cm long.
Acacia tortilis occurs throughout dry Africa, ranging from Senegal to Somalia and down into South Africa. In Asia, trees occur in Israel, southern Arabia, and Iran. A. tortilis is found in all countries fringing the Sahara and is often the tree that extends furthest into the desert. Young A. tortilis forms natural thickets in heavily overgrazed savanna in southern Africa. The tree was introduced from Israel in 1958 into the district of Rajasthan, India, where it showed the greatest promise of 277 tested species. It is now widely planted in Rajasthan and has also been planted in Pakistan and on the Cape Verde Islands.
Acacia tortilis occurs from sand dunes and rocky scarps to alluvial valley bottoms, avoiding seasonally waterlogged sites. A very drought resistant species, the umbrella thorn grows in areas with annual rainfall as low as 40 mm and as much as 1200 mm, with dry seasons of 1-12 months. The tree favors alkaline soils but will colonize saline and gypseous soils. A. tortilis forms a deep tap root in sandy soils; the solitary landmark Tenere tree in the southern Sahara had roots reaching 35 m deep. On shallower soils and in arid sites, it can develop hose-pipe subsurface roots extending over twice the width of the crown. The umbrella thorn ranges from 390->2000 m elevation. It survives sites where temperatures regularly reach 50 °C at mid-day and fall to near freezing at night. Older trees (>3 m tall) can withstand frosts and light grass fires.
A. tortilis nodulates frequently over its natural range. Considerable variation in nodulation levels has been found under controlled environmental conditions. Fastgrowing Rhizobium strains have been isolated at Dundee University.
In semi-arid areas,Acacia tortilis provides a staple browse especially for camels and goats. Forage is available throughout most of the dry season when other sources are scarce. In the Turkana region of Kenya, large riverine trees (called ekwar) are individually owned. Pods are collected for sale in markets, such as in Lodwar (Turkana) and Msinga (South Africa), both as animal and human food. Pods are also fed to lactating animals to increase milk yields. Pods and leaves have a good level of digestible protein (mean = 12%) and energy 6.1 Ml/kg DM (Le Houerou 1980), as well as being rich in minerals. Seeds are high in crude protein (38%) and phosphorus, an element usually scarce in grasslands. The pods require milling to increase digestion in cattle. Over 90% of the tree's flowers abort and drop from the trees, providing an additional important forage (Kayongo Male and Field 1983).
Few studies have quantified A. tortilis fodder production but an estimated 1 dry ton/ha/yr shoot and leaf growth was available in semi-deciduous bushland in the Tugela Dry Valley, South Africa (Milton 1983). Yields from young plantations in India indicate similar productiviry: 2.5 kg/tree/yr (at 400 trees/ha), discounting pod (1 kg/tree/yr by age 7) and fuelwood production (Gupta and Mohan 1982).
A. tortilis provides shade for animals. Some of the most palatable grass species grow beneath its canopy (Walker 1979). In Turkana, Kenya, soil nutrients and herbaceous plant productivity and diversity were significantly greater under than away from the tree canopy (Weltzin and Coughenour 1990).
Sand dune stabilization and shelterbelts:
A. tortilis has been used with some success to stabilize sand dunes in Somalia, United Arab Emirates, and Rajasthan, India. In India it has been grown successfully in shelterbelts with Azadirachta indica.
The dense, red wood of A. tortilis makes very good charcoal and fuelwood (4360 Cal/kg) (BOSTID). It burns slowly and produces little smoke when dry. Poles are commonly used in hut construction and for tools. The wood of ssp. heteracantha is durable if water-seasoned. The tree resprouts vigorously when coppiced and is managed for fuelwood in natural woodlands in Sudan. In plantations in India, trees are planted at 3 x 3 m spacing and coppiced for fuelwood. After 10-12 years over 50 tons/ha wood can be harvested. In other areas the trees are not cut, to avoid reducing pod yields.
In traditional, pastoral societies every part of Acacia tortilis is used. The high value held by local people for the tree is reflected in the detailed nomenclature given to its cycles of development. In Oman, for example, local people call A. tortilis by more than a dozen different names in Dhofari arable.
Flowers provide a major source of good quality honey in some regions. Fruits are eaten in Kenya, the Turkana make porridge from pods after extracting the seed, and the Masai eat the immature seeds. The bark yields tannin and the inner bark cordage. Thorny branches are used for enclosures and livestock pens; roots are used for construction of nomad huts (Somali and Fulani). Leaves, bark, seeds, and a red gum are used in many local medicines. Two pharmacologically active compounds for treating asthma have been isolated from the bark (Hagos et al. 1987).
A. tortilis is a pioneer species easily regenerated from seed. Pods are best collected by shaking them from the canopy. In East Africa, a mature tree can produce over 6000 pods in a good year, each with 8-16 seeds (10,000 - 50,000/kg depending on the subspecies).
Seeds are often extracted by pounding pods in a mortar followed by winnowing and cleaning. The hard-coated seeds remain viable for several years under cool, dry conditions. They require pretreatment for good germination. Mechanical scarification works best for small seed lots. Soaking seeds either in sulfuric acid for 20-30 minutes. or in poured. boiled water allowed to cool. are both effective treatments (Fag" and Greaves 1990).
Seed are planted in the ground in 1 cm deep holes or in the nursery in 30 cm long tubes. Rapid tap root growth requires frequent root pruning. Seedlings are ready to be planted out after 3-8 months. On marginal sites, initial seedling growth is often slow but quickens once roots have reached a water source. For best growth, plants should be weeded and protected from browsing animals for the first three years. At Jodhpur, India (320 mm annual rainfall) average height of 20 selected 2.5-yr-old plants was 3.8 m.
Limited seed supplies are available from natural populations in a number of countries, primarily in Sahelian Africa, and from landraces in India. A broader range of germplasm is available from the Oxford Forestry Institute (South Parks Road, Oxford OX1 3RB, UK) for establishment of field trials. Small quantities of seed from Kenyan provenances are also available from NFTA.
PESTS AND LIMITATIONS.
A large number of insects have been recorded to attack living trees. but only bruchid beetles are of economic importance. They can destroy over 90% of seeds produced in any year. The buprestid beetle (Julodisy sp.) defoliated over 50% of a plantation in Rajasthan. Acacia tortilis is also susceptible to nematodes, mistletoes (Loranthaceae), and galls. Large numbers of insects and mammals feed on the flowers. In India, powder post beetles (Sinoxylor. spp.) can reduce the wood of felled timber to dust over a period of weeks. A further consideration is in humid to subhumid areas where A. tortilis can become weedy if it is not being used (BOSTID 1979).
BOSTID. 1979. Tropical legumes: Resources for the Future. National Academy of Sciences. Washington, D.C.
Brenan, J.P.M. 1983. Manual on taxonomy of Acacia species: Present taxonomy of four species of Acacia (A. albida A. senegal, A. nilotica, A. tortilis). FAO, Rome, Italy. 47 p.
Fagg, C.W. and A. Greaves. 1990. Acacia tortilis 1922-1988. CABI/OFI annotated bibliography. No. F41. CAB International, Wallingford, Oxon, UK
Gupta, T. and D. Mohan. 1982. Economics of trees versus annual crops on marginal lands. Centre for Management in Agriculture (CMA), Monogr. No. 81. 139 p.
Hagos, M., G. Samuelsson, L. Kenne and B.M. Modawi. 1987. Isolation of smooth muscle relaxing 1,3-diaryl-propan-2-ol derivatives from Acacia tortilis. Planta MÃ©dica 53(1):27-31.
Kayongo Male, H. and C.R. Field. 1983. Feed quality and utilization by cattle grazing natural pasture in the range areas of northern Kenya. In W. Lusingi (ed), IPAL Report A5. p. 230-245.
Le Houerou, H.N. 1980. Chemical composition and nutritional value of browse in tropical West Africa. In H.N. Le Houerou (ed), Browse in Africa. the Current State of Knowledge. ILCA, Ethiopia. p. 261-289.
Milton. S.J. 1983. Acacia tortilis ssp. heteracantha productivity in the Tugela dry valley bushveld: Preliminary results. Bothalia 14(34):767-772.
Ross, J.H. 1979. A conspectus of the African Acacia species. Memoirs of the Botanical Survey of S. Africa No. 44. 155 p. Walker, B.H. 1979. Game ranching in Africa. In B.H. Walker (ed), Management of Semi-Arid Ecosystems. Elsevier, Amsterdam. p. 55-81.
Weltzin J.F. and M.B. Coughenour. 1990. Savanna tree influence on understory vegetation and soil nutrients in northwestern Kenya. J. Veg. Sci. 1:325-334.
NFTA 90-06 November 1990
Alnus nepalensis D. Don. (Betulaceae) called utis in Nepal, maibau in Burma, and Indian or Nepalese alder in English, is one of 35 species of alder worldwide. Alnus is one of 15 genera of trees that fix nitrogen but are not in the legume family.
Utis is a deciduous or semideciduous tree with a straight trunk that reaches up to 30 m in height and 60 cm (rarely to 2 m) in diameter. The bark is dark green or grey, often with yellowish patches and short, raised lenticels. The leaves, which are frequently damaged by insects, are alternate, elliptical, 6-20 cm long, 5-10 cm wide, entire, denticulate or sinuate. The upper leaf surface is dull or shiny dark green, the lower is pale with dot-like, yellowbrown scales.
The narrowly cylindrical clusters of tiny flowers, or catkins, occur as male or female separately on the same or different twigs in autumn. Male catkins are yellow, 10-25 cm long, and hang in clusters at the end of twigs. Female catkins are much shorter, erect and woody, and occur on branching side twigs. The fruits, which superficially resemble cones of the pine family, are dark brown, upright on short stalks, elliptical, composed of many spreading, hard woody scales. Empty cones may persist on the tree. The seeds are light brown, circular and net with two broad membranous wings, more than 2 mm across. Seeds ripen from November to March depending on geographical locality.
A. nepalensis occurs throughout the Himalaya at 500-3000 m elevation from Pakistan through Nepal, northern India, Bhutan and Upper Burma to southwest China and Indochina. It is found naturally in moist, cool or subtropical mountain monsoon climates, with an average annual rainfall of 500-2500 mm and a 4-8 month dry season. Mean annual temperatures range from 13-26°C. Soils tend to be moist and well-drained, varying from loam and loamy sand to gravel, sand, and clay. At lower altitudes particularly, utis occurs on moist sites, such as near rivers and in ravines, but it will colonize rocky sites exposed by landslips, or lands abandoned following cultivation. It occurs naturally in both pure and mixed stands.
Alnus nepalensis is a pioneer species and grows well in full light although it will also tolerate shade. It does not require high soil fertility, but prefers permeable soils and should not be planted on compacted or eroded soils. Utis grows well on soils with high water content, but not on waterlogged soils. It grows poorly on dry, exposed ridgetops.
Utis wood is moderately soft with densities of 320370 kg/m³ (NAS 1980) to 480-590 kg/m³ (Lamichhaney 1984). Wood calorific value is low (18,230 kJ/kg - Hawkins 1982, or 20,480 kJ/kg - Webb et al. 1984), but utis wood, like that of other alders dries rapidly and burns easily. Although not among the best construction timbers, utis has an even grain, seasons fairly well, and is easy to saw and finish by hand or machine. The wood preserves fairly well, but is perishable if subject to alternately wet and dry conditions. The wood is also subject to discoloration by oxidation and fungal sap stain. It is suitable for boxes, splints and matches (Dey and Ramaswami 1960) and for newsprint (Guha 1965).
The foliage is of low to moderate value as fodder. Mature leaves are eaten by sheep and goats. but not cattle (Panday 1982, Singh 1982). Leaves are also used as animal bedding. The tree's bark is occasionally used for tanning and dyeing (Little 1983).
Utis is well known as a species that gives some stability to slopes that tend to slip and erode. Seed has been broadcast to stabilize landslides. In Burma, A. nepalensis has been effectively used to reforest abandoned taungya areas (Troup 1921, NAS 1980).
Cardamom is planted under utis in eastern Nepal (including about 80% of cardamom plantations in Ilam District Ghimire 1985). On terraced slopes in Nagaland State, India, A. nepalensis is commonly pollarded for poles and interplanted with crops such as maize, barley, chili and pumpkin (Zeliang et al. 1985). The trees provide fuelwood, green leaf manure, and help in soil conservation. Farmers in India cultivate utis on the berms (mounded earth borders) of crop fields (Kavasha 1985).
Alnus nepalensis forms symbiosis with N-fixing actinomycetes of the genus Frankia. Although the biochemistry and physiology of the "alder-type" symbiosis with Frankia are not fully understood, cell-free preparations of nitrogenase have been obtained from Alnus nodules (Postgate 1979). Studies in West Bengal indicated that nitrogenase activity was highest in young nodules irrespective of tree age and concluded that A. nepalensis is capable of fixing significant amounts of nitrogen (Sharma and Ambast 1984). Sharma et al. (1985) investigating soil properties under five stands in the Eastern Himalaya found that total soil N increased with increasing stand age.
The species is readily propagated from seed (1.6 to 23 million seeds/kg, if pure). It is orthodox and will retain viability for at least a year if properly dried and stored in sealed containers. No pretreatment is needed. Germination starts 1-2 weeks after sowing and is completed 2 weeks later. Transplanting into containers can begin 4-5 weeks after germination. Below 1200 m elevation seedlings should reach planting size (25-35 cm) in 4-5 months, but above this altitude they may take as long as 11 months (Napier and Robbins 1989). Young seedlings are liable to damage by ants and defoliation by frost and are very often killed.
Most planting is done with containerized seedlings, although bare-rooted seedlings have proven successful given proper lifting and handling and moist site conditions. Wildings (natural seedlings) have also been used successfully, especially on north-facing slopes. Direct sowing is an alternative. The seed must be fresh and have a high germination capacity. Ample quantities should be used, and the seed sown on exposed mineral soils. Good results are obtained when soil from under old trees is mixed with seed to facilitate even broadcasting and to introduce Frankia. Vegetative propagation has been unsuccessful (Lohani et al. 1980).
Alnus nepalensis has a wider range of site tolerance than its natural distribution would suggest. It has been successfully established in plantations in a number of countries, mostly within its natural range, but also in Hawaii and Costa Rica. A spacing of 2.5 x 2.5 m is commonly used for plantations in Nepal, although a closer spacing is desirable for fuelwood crops. Poles and fuelwood can be harvested after five years on good sites.
Utis will coppice after cutting, but successful regrowth seems to depend on season and locality - wet season felling and moist localities being best. Small diameter timber can be harvested in less than 10 years. Longer rotations are needed for ordinary saw timber.
Actual growth rates of A. nepalensis vary considerably, particularly in response to differences in soil moisture. Recorded growth in Nepal's middle mountains compares favorably with figures from West Bengal and Hawaii. A 9year-old stand in Nepal had a mean annual increment in height of 2.7 m and in diameter at breast height of 2.9 cm. Corresponding figures for 10-year-old stands in West Bengal and 8.5-year-old trees in Hawaii were 1.7 m and 1.6 cm (Homfray 1937) and 0.7 m and 1.2 cm (Whitesell 1976), respectively. In Costa Rica a 3-year-old stand had a mean annual icrement in height of 2.3 m and in diameter of 3.6 cm (Palmer, cited in Lamichhaney 1984). Biomass and volume tables have been produced in Nepal.
Research in Nepal has shown local provenances to perform best at any given site. No provenances have proven to be of overall superiority (Lamichhaney 1984, Jackson 1987).
PESTS AND DISEASES.
Utis is very susceptible to attack by defoliators (Oreina sp., Anomala sp.). The stem borers Batocera spp. (Webb et al. 1984) and possibly Zeuzera sp. (Jackson 1987) may also become pests. An aphid, Eutrichosiphum alnifoliae, is a pest of economic importance (Des and Raychaudhari 1983).
Ghimire, M.P. 1985. Growing Alnus trees over cardamom plantations for fuelwood in Ilam District. Community Forestry Development Project, Occasional Paper No. 9, FAO/UNDP/HMG, Nepal.
Jackson, J.K. 1987. Manual of afforestation for Nepal. Nepal-UK Forestry Research Project, Kathmandu, Nepal.
Lamichhaney, B.P. 1984. Variation of Alnus nepalensis D. Don in Nepal. Unpublished M.Sc. thesis, Oxford University, UK.
Little, E.L. Jr. 1983. Common fuelwood crops. A handbook for their identification. Communi-Tech Associates, McClain Printing Company, USA.
Napier 1. and M. Robbins. 1989. Forest seed and nursery practice in Nepal. Nepal-UK Forestry Research Project, Kathmandu, Nepal.
NAS. 1980. Firewood crops. Shrub and tree species for energy production. National Academy of Sciences, Washington, D.C. p. 78-79.
Postgate, J. 1979. Nitrogen fixation. The Institute of Biology, Studies in Biology No. 92. Arnold, London.
NFTA 90-02 May 1990
Casuarina equisetifolia Forst. & Forst. (syn. C litorea L), is the most widespread ant well-known member of the family Casuarinaceae, ant has many names: casuarina, ironwood, coast she-oak, horsetail, Australian pine, whistling pine, beefwood, agoho (Philippines), ru (Malaysia), filao (Vietnam, West Africa, West lndies) ant nokonoko (Fiji). All the casuarinas are nitrogen-fixing. Casuarinas support an actinorhiza symbiont in their root nodules, as opposes to the rhizabium symbiont found in the root nodules of leguminous trees that fix N2.
C equisetifolia has two variants. C equisetifolia var. incana is a small (6-10 m) tree that grows exclusively alone the coast of Queensland and northern New South Wales. Var. equisetifolia is a tall (10-40 m) tree fount on seacoasts from Malaysia to subtropical Australia, Melanesia, Micronesia, the Philippines ant Polynesia.
Like other Casuarinaceae, C equisetifolia has a conifer-like appearance which is increased by hanging green branchlets ant cone-iike fruits. Casuarinas are actually typical angiosperms with simplified and reduces unisexual flowers. They are dioecious or monoecious, the proportion of male, female and monoecious trees varying widely from one site to another. The stem of Casuarinaceae is composed of two parts indeterminate persistent branches which after secondary thickening, form the permanent above-growt plant body; ant determinate deciduous branchlets (incorrectly called cladodes), about 15-25 mm in diameter. These branchlets are the major photosynthetic organs of the plant (Torrey ant Berg 1988). The leaves are reduced to white or brown scales fuses laterally at the base in whorls that define notes on the branchlets.
Individual plants have striking phenotypic variations in the crown shape, branch angle, length of branchlets ant size ant shape of cones C equisetifolia is known to hybridize with other casuarinas, such as C junghuhniana and C glauca..
Casuarina cquisetifolia is intolerant of frost. Var. incana thrives in the warm subhumid zone while var. equisetifolia is a heat-loving plant of the hot subhumid zone. Although C equisetifolia is generally a lowland tree, it grows at altitudes up to about 600 m in Hawaii.
C equisetifolia tolerates a wide range of moisture availability. C equisetifolia grows best along the coast, where sea spray supplements moisture from the water table in arid ant semiarid climates with average annual rainfall <300 mm. C equisetifolia's N2-fixing ability seems to depend wholly on the availability of adequate soil moisture.
C equisetifolia tolerates both calcareous ant slightly alkaline soils, but withstands salinity less well than C glauca and C obesa. It thrives in sandy soils ant grows poorly on clay soils, with some exceptions. It cannot stand to be waterlogget long.
The wood of C equisetifolia is dark brown, very hart (density 1000 kg/m3), ant resistant to decomposition in soil or saltwater. It is often used as round wood for making piles, poles and fences, but splits too severely during drying to be popular as lumber; although in areas with acute wood shortages, such as southeastern China, C equsetifolia is used for house beams ant simple furniture (Midgley et al. 1983).
Because of its high calorific value (ca. 5000 kcal/kg), C. equisetifolia wood is an excellent source of fuel and charcoal. People in China and India use stumps and even litter for fuel. use which also draws heavily on soil phosphorus and potassium reserves.
Because of its resistance to salt-laden winds. C equisetifolia is widely used to stabiles coastal sand dunes. It is also extensively planted as windbreaks to protect crops. In some tropical lowland agroforestry systems it is associated with crops such as coffee, cashew nut, coconut, groundnut, sesame and various grain legumes.
C. equisetifolia and its hybrids are often used as ornamental plants for urban beautification, parks and seaside resorts. There is also potential for incorporating C. equisetifolia into mixed-species tree plantations.
Root nodules are prolific on C. equisetifolia when they occur. Effective strains of Frankia are now available to inoculate C. equisetifolia on sites where the same Frankia-compatible group of trees (in principle any species of the Casuarina genus) have not been previously planted.
When there are no limiting factors, the response to inoculation is spectacular. Inoculation with Frankia entrapped in alginate beads is the most convenient system (Sougoufara et se. 1989). Inoculation with crushed nodules, which is sometimes practiced, should be discouraged because of the risk of introducing nonnodulating or poorly effective strains and disseminating soil-borne pathogens like Pseudomonas solanacearurn, a bacterium that causes casuarina wilt. Prolonged waterlogging inhibits nodule development.
As in other actinorhizal plants, spontaneous endomycorrhizal (YAM) infection occurs easily in C equisetifolia True ectomycorrhizae have, however, been seldom reported, except in certain coastal areas of northern Australia where a wide range of fungi are involved (Paul Reddell, pers. comm.). Proteoid roots have also been observed on their root systems. These are unique structures made of tightly packed rows of rootless which may increase the ability of the host plant to absorb nutrients and thereby better tolerate nutrient deficient soils.
Ripe green cones are collected from branches lopped from mature trees and dried in the sun. One kg of green cones yields 20-60 g of seeds. There are 300,000-700,000 cleaned seeds/kg. The seeds have a relatively low viability of 80-90% for fresh seeds and 3040% for seeds after 3 years storage. Germination is usually complete within 2 weeks after planting.
At 6-10 weeks the 10-15 cm high seedlings are transplanted into containers where they are grown for 5-8 months to a height of 50-70 cm, at which time they are transplanted to the field. Another procedure is to transplant the 10-15 cm seedlings in a new bed at a 10 x 10 cm spacing to obtain plants ready to be planted bare rooted in the field. Cuttings and microcuttings can be used when working with clones.
C. equisetifolia does not sucker as vigorously as C. glauca. Plantation planting density is usually around 2,000 plants/ha but private farmers can plant up to 8,000 to 10,000 trees/ha (Midgley et al. 1983).
C. equisetifolia can be improved by exploiting the large phenotypic variation of its populations. There are essentially two approaches to increase both wood production and N2-fixation potential: conventional plant breeding and screening of elite individuals followed by vegetative propagation.
The N2-fixing potential of C equisetifolia can be greatly enhanced through the use of selected clones inoculated with effective Frankia strains. Clone beta of C equisetifolia inoculated with strain ORS021001 and irrigated throughout the dry season in Senegal, fixed 45 g N2/yr/tree during the two first years of growth (Dommergues. unpublished data). Extrapolating this result gives a figure of 90 kg of N2 fixed annually/ha at a planting density of 2,000 trees/ha.
Compared to some of the other casuarinas, C equisetifolia is relatively short-lived, surviving only 40-50 years. Its growth is rapid during the first 7 years (15-25 m/yr), then gradually declines. In general, the volume yield reaches a maximum at age 15-20 years (7-10 m /ha yr-1). The yield could probably be greatly increased by using selected clones and applying proper management practices, including irrigation and inoculation with effective Frankia strains. C. equisetifolia plantations are generally managed on a rotation of 7-15 years.
PESTS AND DISEASES:
C equisetifolia is not prone to any serious pest and diseases, except when grown in unfavorable conditions. Pests that attack the tree include crickets and grasshoppers (Chondracis rosea, Schistocerca gregaria), defoliators (Lymantria xylina), stem borers (spate monachus) and sap feeders (Icerya spp.). The major root diseases are caused by Pseudomonas solanacearum, Trichosporium vesiculorum and Rhizoctonia spp.
Midgley, S.J., J.W. Turnbull and R.D. Johnston (eds). 1983. Casuarina Ecology, Management and
Utilization. CSIRO, Melbourne.
Sougoufara, B., H.G. Diem and Y.R. Dommergues. 1989. Response of field-grown Casuarina equisetifolia to inoculation with Frankia strain ORS021001 entrapped in alginate beads. Plant and Soil 118:133-137.
Torrey, J.G. and R.H. Berg. 1988. Some morphological features for generic characterization among the Casuarinaceae. Amer. J. Bot. 75:864-874.
NFTA 91-05 July 1991
Known as swamp she-oak in its native Australia, Casuarina glauca grows in difficult, saline sites inhospitable to many other trees. This casuarina has been planted in agroforestry systems primarily as a windbreak but also in woodlots for fuelwood and reserve fodder.
Casuarina glauca Sieb. ex Spreng. (family Casuarinaceae) is a medium-sized tree 10-15 m tall, occasionally reaching 25 m, with an often buttressed and fluted main stem. The dense crowns of plantationgrown trees become sparse to narrow in free-growing trees (Midgley et al. 1983). The jointed, green. cylindrical branchlets, which serve as leaves for casuarinas, are much coarser, thicker, and longer (1 mm diameter, 30-60 cm long) than those of C. equisetifolia or C. cunninghamiana The length of the internodes on branchlets averages 15 mm. The reduced, true leaves appear as teeth at the nodes and vary in number from 12-16, occasionally to 20.
C. glauca is dioecious; male and female trees occur in approximately 1:1 ratios in natural stands. Male flowers appear as 4-7 cm long, light-green spikes. Female flowers are small, dark red, and inconspicuous. Males trees flower at 2-3 years of age and female trees produce fruits one year later. Trees fruit mainly in autumn, except in plantations (for example, in Egypt), where trees produce crops in both autumn and spring.
The cone-like woody fruits vary in size with provenance, ranging from 12 to 16 mm long and 11.5 to 14 mm wide (ElLakany and Youness 1985). Fruit bracteoles are relatively thin compared to other casuarinas. C glauca is a prolific cone producer and averages 70 seeds/cone and 1,300,000 seeds/kg (El-Lakany et al. 1989). Closed cones may persist on the tree for more than a year.
Casuarina glauca hybridizes with other Casuarina species through open, wind pollination. A hybrid with C cunninghamiana has been reported in Australia and identified in Egypt (Badran et al. 1976), and a hybrid with C equisetifolia is recognized in USA and Egypt.
Natural distribution is limited to a narrow coastal belt of southeast Australia (23-37° S latitude) with an insular occurrence on Fraser Island. Trees occasionally extend 50-80 km inland. Trees often occur along the edges of tidal reaches and estuaries, intermediary between mangrove swamps and open woodland, and sometimes on or near beach fronts. On swampy sites water tables may be only 30 cm from the surface. Trees usually occur close to sea level but are also found on seasonally moist hillsides near the sea, and up to 900 m elevation in Hawaii. In its native range annual precipitation averages 500 mm; in Hawaii rainfall is as much as 4,000 mm (NAS 1984). Annual temperatures range from 5 to 33°C.
C glauca is more salt tolerant than other casuarinas (ElLakany and Luard 1983). Seedlings outgrew eight species in nutrient solutions containing increasing concentrations of NaCl. In these tests both C glauca and the closely related C obesa survived 500 mM/l NaCl-a level close to 3/4 the total salinity of seawater.
C glauca has proven widely adaptable. In Egypt, trees grow on clay to coarse sand, saline to calcareous, and dry to waterlogged soils. Trees grow on very dry sites with saline soils in Israel and flourish on limestone soils in Florida USA. In Hawaii, trees have been planted on parent basalt. C glauca has also been successfully planted in Kenya India Malawi. and South Africa.
No seed pretreatment is required. Turnbull and Martensz(1982) recommend temperatures of 20-25°C and El-Lakany and Shepherd (1983) recommend 30°C to germinate C. glauca seed. Seed stores well up to eight months at room temperature (El-Lakany et al. 1990). Seed for experimental purposes is available from the Australian Tree Seed Centre, (Div. Forestry and Forest Products, CSIRO, Canberra Australia), the Desert Development Center (AUC, P.O. Box 2511, Cairo, Egypt), and NFTA.
Wide intraspecific variation for certain characteristics has been reported for C. glauca (El-Lakany and Shepherd 1983). Early results of provenance trials in Egypt and elsewhere suggest substantial growth gains are possible through use of proper seed sources. In an irrigated plantation on the desert fringes in Egypt, height growth varied by a factor of two among nine provenances (ElLakany and Youness 1985). Biomass productivity of 12year-old irrigated plantations was estimated at 496 t/ha of which wood volume was 294 m³/ha (Megahed and ElLakany 1986). Provenance testing is underway in California, USA for frost colerance (Merwin 1990). Irrigation is required to establish trees in desert areas.
C glauca forms a symbiosis with actinomycetes of the genus Frankia. Spherical woody nodules, some exceeding 20 cm in diameter, are found in large masses near the base of the trunk and as deep as 10 m. Root nodules have been observed on trees in natural stands and on trees in plantations growing on very saline or waterlogged sites. The greatest number of nodules are found in soils with pH ranging from 6-8.
For Casuarina species, N-fixation is greatest when species are inoculated and when inoculated with nodules from the same species (Reddell and Bowen 1985, Reddell 1990). Crushed nodules or soil from beneath mature trees can be used to inoculate nursery seedlings. Under conditions of high soil salinity, drought or waterlogging, C. glauca exhibited more efficient N-fixation than C cunninghamiana (El-Lakany 1987). Inoculum is available from CSIRO, Davies Lab, PMB, Aikenvale, QLD 4814, Australia.
C glauca finds its best use in shelterbelts, windbreaks, and amenity plantings around settlements. The trees are wind-firm and show rapid early growth. In parts of North Africa and the Middle East, especially in water-scarce areas, they are preferred to eucalypts for plantings. Windbreaks are planted 2-3 rows wide. Like other casuarinas, trees can be coppiced to form dense hedges. The low branching habit and extensive litter production help reduce soil erosion. Trees have also been used successfully to stabilize stream banks and shifting sand dunes.
The most universal use of casuarina is for fuel. The wood has a high calorific value (about 5,000 Kcal/kg) and tends to burn slowly with little smoke or ash. Branches, branchlets, and other litter also burn well. Casuarina wood makes excellent charcoal. Wood is reddish-brown, tough, and fissile with a density ranging from 662 El-Lakany 1983) to 980 (Midgley et se. 1983) kg/m³. Timber is used for handles, fence rails, rafters, shingles, stakes, small sea-water piles, for flooring and turnery, and in Egypt, with some technical difficulty, for particle board. The timber does not season readily and has a tendency to warp.
Cattle, sheep and goats will graze C glauca seedlings, suckers. and branchlets. The ground foliage has been included as an ingredient in chicken feed (El-Deek et al. 1988). Foliage contains 9% crude protein, 37% crude fiber, and 37% total digestible nutrients (Omran and Nour 1980).
C glauca has potential for use in wide-row intercropping and, contrary to common belief, has been found to increase yields of crops sheltered (El-Sayed et se. 1983). Farmers usually dig a ditch between the crop and trees to minimize competition for water and nutrients. An excellent shade tree, it is planted along streets in many arid zone cities. Like other casuarinas, the dense canopy and slow-todecompose litter severely inhibit understory plant growth.
PROBLEMS AND PESTS.
Prolific production of root suckers lends C glauca a serious potential for weediness, especially in humid areas. It is considered a pest in Florida and the Hawaiian isles (NAS 1984). In arid areas such as Egypt it has generally not become a weed, although it can spread along water courses. The tree itself is almost pestfree except for Stromatium fulvum, a wood borer which makes the stem susceptible to wind-damage and rot.
El-Lakany, M.H. and K.R. Shepherd. 1983. Variation in seed germinability, seedling growth, and biomass between provenances of Casuarina cunninghamiana Miq. and C. glauca Siev. Forest Management and Ecology 6:201-216.
El-Lakany M.H., J.W. Turnbull, and J.L. Brewbaker (eds). 1990. Advances in Casuarina research and utilization. Proc. 2nd Internal. Casuarina Workshop, Jan. 15-20, 1990, Desert Development Ctr., Cairo, Egypt.
El-Sayad, A..B., T.A. Omran, and A.E. Khalil. 1983. Influence of windbreaks on crop yields in West Nubariah region. Alex. Sci. Exch. 4:57-71.
Megahed, M.H. and M.H. El-Lakany 1986. Biomass charac teristics of young Casuarina plantations in northwestern region of Egypt. Alex J. Agric. Res. 31:411422.
Midgley, S.J., J.W. Turnbull, and R.D. Johnston (eds). 1983. Casuarina ecology, management, and utilization. Proceedings of an international workshop, Canberra, Australia. CSIRO, Melbourne. 286 p.
NAS (National Academy of Sciences). 1984. Casuarinas: Nitrogen-fixing trees for adverse sites. Innovations in tropical reforestation. National Academy Press, Washington, D.C. 118 p.
Reddell, P. and G.D. Bowen. 1985. Frankia source affects growth, nodulation and nitrogen fixation in Casuarina species. New Phytol. 100:115-122.
Turnbull, J.W. and P.N. Marten=. 1982. Seed production, collection and germination in Casuarinaceae. Austr. For. Res. 12:281-294.
A full list of references is available from NFTA.
NFTA 93-03 June 1993
Chamaecytisus palmensis is a fast-growing shrub or small tree adapted to temperate regions with winter rains and prolonged, dry summers. In addition to producing high yields of palatable. nutritious fodder, the shrubs provide welcome shelter for livestock. help control soil erosion and salinization, increase soil fertility through nitrogen fixation. and produce nectar for bees. If allowed to develop, thick branches provide fuelwood that burns with intense heat.
Called "tagasaste" on the island of La Palma in the Canaries, where it originates. the species was formerly known as Cytisus proliferus. After its introduction to Australia. it was given the misleading common name of "tree lucerne" (Webb. 1982).
Chamaecytisus palmensis is a member of the Papilionoideae subfamily of legumes. If managed as a single-stemmed tree. it reaches heights of 7 to 8 m. but its common growth form is a multi-stemmed. spreading shrub of 5 to 7 m. The branches droop, the leaves are on short petioles, and the single lanceolate leaflets are pubescent below. Seed pods are 4 to 5 cm tong. They become black on ripening, and contain 8 to 12 black seeds. About 35,000 to 40,000 seeds weigh 1 kg.
The shrubs have no thorns and produce profuse masses of fragrant white pea-like flowers in early spring, making them attractive ornamental plants. The white flowers distinguish C. palmensis from related. unpalatable species that have yellow flowers.
To date, successful growth has been restricted to temperate regions with wet winters and dry summers. with annual rainfall ranging from 350 to 1600 mm (Douglas. 1987). The shrubs tolerate a wide range of temperatures: They grow vigorously to the southern tip of New Zealand (46°S) and are naturalized in Australia as far north as Toowoomba (27 S). They are found from seal level to elevations of 1000 m and are reported to survive at 3000 m in Ethiopia (ILCA, 1987).
Cultivars develop that are suited for specific environments. In Australia. seedlings proliferate vigorously along roadsides near Orange, New South Wales. despite annual frosts down to -15°C. Seedlings survive with equal vigor in deep coastal sands in the hot and arid climate of Geraldton. Western Australia.
Chamaecytisus palmensis establishes most easily on sandysurfaced soils. but tolerates a wide range of soil types including gravels. loams. acid laterites and limestones. The shrubs tolerate a pH range of 5.0 to 7.0. but require soils that are free draining. Under waterlogged conditions. they are susceptible to root rot and mortality is high.
Seedlings are remarkably drought resistant and can survive six months of hot weather without rain or irrigation. Of more importance. established shrubs have a remarkable capacity to recover from defoliation. Regrowth occurs even in the prolonged absence of rain.
Chamaecytisus palmensis is endemic to the arid volcanic slopes of La Palma in the Canary Islands. The shrub was introduced to Australia in 1879. It is now also common in New Zealand and has been introduced to parts of Africa.
For centuries. farmers in the Canaries depended on C. palmensis to maintain their livestock through the long dry summers. However. the species did not gain international recognition until the 1980s.
In Australia. the apparent need for manual or mechanical harvesting was initially a serious deterrent to farmers. Subsequently, the demonstration that sheep and cattle can browse the shrubs directly without detriment to the plants has led to greatly increased use. Well-managed plantations remain fully productive without irrigation for many years (Snook, 1952; 1982). They require little attention beyond annual application of fertilizer and periodic lopping.
The foliage has a composition similar to bestquality alfalfa. Material eaten by grazing animals can be expected to contain 17 to 22% crude protein, depending on the stage of growth and severity of grazing. The leaves and fine stems of fresh regrowth may contain 25 to 29% crude protein (dry matter) and only 16 to 19% crude fiber. The foliage is free from toxic substances.
A well-managed three-year-old plantation of C. palmensis in Western Australia, growing on deep sand otherwise useless for crop or pasture production. The shrubs have been grazed by sheep and mown regularly to keep them low and bushy.
Nutrient composition varies according to soil fertility. In particular. minerals such as calcium and phosphorus are reduced in foliage grown on mineral-deficient soils. Leaves have high in-vitro dry-matter digestibility (0.77 to 0.82). Stem digestibility is lower (0.59). but still adequate for feeding (Borers and Poppi, 1986). The fodder contains protein. vitamins and minerals that are lacking in poor-quality roughage. Used as a supplement. it increases consumption of dry mature grass and improves roughage utilization. Normally C. palmensis foliage is readily consumed by ail grazing animals-including rabbits. pigs and poultry-but there may be some hesitation when it is first introduced.
In regions with annual winter rains of 600 to 1000 mm. established shrubs planted in rows 5 m apart can produce 15 to 20 kg of edible dry matter/plant when harvested once a year. In-row spacing can vary from 25 cm to 2 m. At a planting density of 1.000 trees/ha. annual yields of 15 to 20 t/ha can be expected (Snook. 1986). Under current systems of dryland farming in Western Australia. plantations should produce at least 10 t/ha of edible dry matter from a single annual grazing or cutting. This is equivalent to 1.5 kg each for 18 sheep every day of the year. If plantations are harvested three or four times a year, or subjected to rotational or continuous grazing, yields can be even higher.
The small black seeds are extremely hard and must be scarified or treated with boiling water to ensure quick germination. Hot-water treatment consists of dropping the seeds into boiling water and immediately lifting them out. They should not remain in the water for more than one minute.
In Australia. most plantations are established by direct seeding. Contractors have developed special machinery to do this in one operation. A blade or "scalper" removes a strip of surface soil to clear away weed growth. This is followed by a ripper which opens the soil so that fertilizer and seed can be placed in lines. Finally, a following wheel compacts the soil over the seeds.
In most situations. C. palmensis readily makes use of mizobia present in the soil. However. to insure nodulation, seed should be treated with cowpea inoculum or an inoculum specific for the species.
It is important to apply adequate fertilizer with the seed. This will encourage deep rooting and the development of robust plants that can withstand the first summer. Fertilizer should be applied as recommended for other legumes at each specific site. In most cases soluble phosphate will be the main requirement, but if additional essential plant minerals are lacking, these must be supplied. In Western Australia, for example, superphosphate with copper and zinc should be applied at seeding at a rate of 200 kg/ha.
Seedlings transplant very well and are commonly used for establishment in small areas. on steep slopes or where stones prevent the use of machinery. Animal-proof fences are essential for the first two to three years to protect young seedlings from grazing animals. Rabbits and hares are particularly fond of the seedlings and must be excluded. Mature plants recover remarkably well, even from severe overgrazing, if early regrowth is protected.
Most plantations consist of shrubs planted in parallel rows about 5 m apart. although distance between rows can be varied. Interplanted crops grow well because the shrubs provide protection from cold and drying winds.
Experience shows that shrubs in plantations must be kept short and bushy. When seedlings are about 10 months old. they should be cut with a mower or grazed. This encourages the formation of bushes with multiple stems. The time and frequency of further harvests or grazing will be determined by the rate of growth. Until recently, the common practice was to graze or cut the shrubs once a year. Even when grazing is severe. vigorous leaders remain. and it is essential to lop these annually.
The need for annual lopping can be reduced or eliminated by grazing the shrubs three or tour times a year or on a continuous basis. Under such management, vigorous, upright shoots are eaten before they become too robust.
Obviously, the shrubs must not be overgrazed to the extent that regrowth is eaten before root vigor is restored. When grazing pressure is too high, the animals may inflict serious damage by eating the bark. This problem is rare with good management: It is difficult for the animals to tear off bark from shrubs with a bushy growth habit and multiple stems.
For continued high yields of nutritious fodder. regular application of the appropriate fertilizer is essential. In Western Australia. superphosphate and potash (3:2) should be applied annually at a rate of 200 kg/ha. Application of micronutrients. such as calcium. may also be necessary. The shrubs may continue to grow despite a lack of essential minerals. but the quality and palatability of the foliage will decline steadily.
In Australia, C. palmensis is remarkably free of pests and there is no evidence of viral infection. Slugs, cutworms and grasshoppers eat emerging seedlings, but one application of insecticide at seeding appears to give adequate protection. Mature shrubs are the last crop plants to be attacked by grasshoppers or locusts, and even when all the foliage is eaten, the plants make a rapid recovery when the swarms pass on. The species's requirement for fertilization to maintain high levels of productivity and nutrient content poses a management limitation for resource-poor farmers.
Borens. F. and Poppi, D.P. 1986. Feeding value of tagasaste. New Zealand Journal of Agricultural Science. 20: 149-51.
International Livestock Center for Africa (ILCA). 1987. Forage Network in Ethiopia Newsletter. Addis Ababa: ILCA, pp. 21-23.
Snook. L.C. 1952. Tree Lucerne: a fodder crop which has been overlooked. Journal of the Department of Agriculture of Western Australia. (3):587-93.
Snook, L.C. 1982. Tagasaste (tree lucerne): a shrub with high potential as a productive fodder crop. Journal of the Australian Institute of Agricultural Science. 48:209-14.
Snook, L.C. 1986. Tagasaste (tree lucerne): high production fodder crop. Shepparton (Australia): Night Own Publishers. 102 pp.
Webb. C.L. 1982. Tree lucerne: its taxonomic status and naturalization in New Zealand. In Tree lucerne in New Zealand. Christchurch (New Zealand): Division of Scientific and Industrial Research. pp. 2-5.
A publication of the Nitrogen Fixing Tree Association 1010 Holomua Road. Paia. Hawaii 96779-6744. USA Tel: (808) 579-9568; FAX: (808) 579-8516 Telex: 510100 4385
NFTA 94-04 April 1994
Dalbergia latifolia is a premium-quality timber species internationally known as "Indian Rosewood". It is used to manufacture furniture, paneling, and other ornamental products Medicines and an appetizer are made from tannins in the bark. The tree is commonly called sitsal, beete, shisham or Bombay blackwood in India, and sonokeling or sonobrits in Indonesia.
Dalbergia latifolia Roxb. (Leguminosae, subfamily Papilionoideae) is predominantly a single-stem deciduous tree with a dome shaped crown of lush green foliage. On wet sites it may remain evergreen. The trees reach a height of 20-40 meters with a girth of 1.5 - 2.0 meters (Prasad et al, 1993). Leaves are alternate, odd-pinnate with 5-7 unequal-sized leaflets originating from the same rachis. Leaflets are broadly obtuse, dark green above and pale below. Flowers are white in axillary panicles, 0.5-1.0 cm long. The brown pods are oblong-lanceolate and pointed at both ends. They contain 1-4 smooth brown seeds and do not open at maturity. The bark is grey, thin with irregular short cracks, exfoliating in fibrous longitudinal flakes (Troup, 1921; Kadambi, 1954). The root system is well developed, consisting of deep tap roots and long lateral roots When near the soil surface, roots produce suckers.
The annual rainfall in D. Iatifolia's native habitat ranges from 750-5000 mm. As a seedling D. latifolia is shade tolerant but sensitive to drought and fire. In maturity, it is tolerant of drought and ground fire, but susceptible to crown fire. It is classified as a moderate light demander (Troup, 1921). Establishment is restricted by frost. It survives maximum temperatures of 37°-50° C, minimum temperature of 15° - 0° C, and relative humidity of 40-100 percent. Dalbergia latifolia occurs from the low plains to roughly 1500 m (Kadambi, 1954). It commonly grows with Tectona grandis, Terminalia sp., Anogeissus latifolia and bamboos.
This species grows on a variety of soil formations including; gneiss, trap, laterite, alluvial, and boulder deposits. It grows best on welldrained, deep, moist soils. Dalbergia latifolia is common on deep loams or clays containing lime. It also grows well on black cotton soils. Shallow dry soils and poor drainage stunt tree growth.
The natural range of Dalbergia latifolia stretches from the sub-Himalayan tract to the southern tip of India and the island of Java in Indonesia (Kadambi, 1954). Its best growth occurs in the Western Ghat forests of Karnataka, Kerala, and Tamil Nadu. It has been introduced to Burma, Sri Lanka, Nepal, Nigeria, and Kenya (Kadambi, 1954).
The sapwood of D. Iatifolia is pale yellowish-white often with a tinge of purple. Heartwood varies in color from light golden brown to shades of light purple with dark streaks, or deep purple with distant black lines. The heartwood darkens with age and weighs about 850 kg per cubic meter. The wood is very hard with no distinct annual rings. It is difficult to work because of its high density. The wood is fragrant and commands a high price. It is used to make premium-grade furniture, panelling, veneers, and interior and exterior joinery Secondary uses of the wood include; knife handles, musical instruments, calico-printing blocks, mathematical instruments, agricultural implements, and boats keels and screws.
Dalbergia latifolia is a popular agroforestry species in Indonesia. Trees are spaced widely, 3 x 1 to 6 x 2 m, with intercrops of upland rice, maize, beans, or cassava during the first three years. In other systems D. latifolia is planted with mango, annona, jackfruit, and guava. When the tree canopies begin to close, shade tolerant crops, like turmeric and ginger, are underplanted (Sukandi, 1993). Farmers use the nitrogenrich foliage of D. latifolia as a green manure and fodder.
Tannins from the bark are used to produce medicines for the treatment of diarrhoea, worms, indigestion, and leprosy. These tannins also produce an appetizer.
Under natural conditions, D. Iatifolia reproduces by seed, root sucker or coppice. Artificial reproduction is common by seed, root cutting, and stump sprout. Direct seeding is possible under moist conditions with good weed control. Root cuttings can be planted directly in the field or raised in a nursery for future transplanting.
Fresh seed germinates at 50-75% within 7-21 days of sowing. Stored in gunny sacks or earthen pots, seed remains viable for six months (Kadambi, 1954). Seed viability can be extended to 9-12 months by drying seeds to 8% moisture content and storing them in airtight containers, however, germination will decrease to 30-40%. One kilogram contains 21,000 seeds (DITSI, 1980).
Although no seed treatment is necessary, soaking seed in coot water for 12-24 hours will hasten germination. Nursery grown seedlings are transplanted to the field after 6 months in Java (DITSI, 1980) or 12 months in India (Kadambi, 1954).
Root cuttings should be taken from trees that are at least 5 years old. Recommended length of cuttings is 20 cm with a diameter of 1-2 cm. Keep cuttings at room temperature for three days before planting them in either nursery beds or polyethylene bags (Soekeri, 1979). Eighteen cm of the cutting should be planted below the soil surface with 2 cm above. Transplant cuttings to the field after 6 months in the nursery (DITSI, 1980).
Dalbergia Iatifolia can be quickly established by stump sprouts. Stumps are made from seedlings of seed or cutting origin. Stump roots and shoots should be 4.5 cm and 2.5-4.0 cm long, respectively. Rootcollar diameter should be 05-15 cm (Deshmukh, 1975). Planting must coincide with heavy rains or survival will be low.
As pure stands, D. Iatifolia is spaced at 1.2 x 1.2 to 1.8 x 1.8 m (Deshmukh, 1975) or 2 x 1 to 25 x 1 m (Japing, 1936 in Kadambi, 1954). Wider spacing may produce crooked stems. For agroforestry systems spacings of 3 x 1 to 6 x 2 m are common (Sukandi, 1993). Trees are usually harvested in 30 40 years. In Java, to obtain 30 cm of heartwood a 50 year cutting cycle is recommended (DITSI, 1980). Dalbergia latifolia is generally managed by clear felling followed by artificial regeneration. After planting or direct sowing, regular weeding is necessary until trees dominate weed competition. Loosening soil around seedlings also improves growth. Weeding and soil loosening should be done before weeds become dense. The sudden removal of heavy weed growth from around seedlings may cause death from exposure (Kadambi, 1954).
Growth and Yield.
Fertilization, soil moisture conservation and weed control enhance the typically slow growth of this species. In a 25 year old plantation in Purwakarta, West Java average diameter breast at height (1.30 m above the ground) was 26.1 cm and tree height 203 m (Sukandi, 1993). A maximum diameter growth of 3 meters has been reported in Karnataka, India (Prasad et al., 1993).
Dalbergia Iatifolia is known to be a nitrogen fixing tree. However, studies on the symbiosis of this species with Rhizobium bacteria have not been made.
In Java, two varieties of D. Iatifolia are recognized. The native variety, called sonokeling, seldom produces seeds. The naturalized variety of Indian-origin, called sonobrits, produces seed yearly.
Dalbergia Iatifolia is very susceptible to crown fires, a common danger throughout the dry ecosystems it occupies. Trees are commonly attacked by fungi (Fusarium. spp.) termites and browsing wild animals (Kadambi, 1954; Suharti and Hadi, 1974). Unfortunately, little is known concerning management options for these pests.
Tree improvement programs for D. Iatifolia should involve the selection and breeding of specimens with excellent timber/furniture characteristics. Selection of superior genotypes have been made and an experimental seed orchard established in Karnataka. In-situ conservation has been initiated at Nagarahole, Coorg, India. For more information contact the lead author.
Dalbergia sissoides, another endemic species to the western Ghats of India, is closely related to D. Iatifolia. Its wood is not distinguished from that of D. Iatifolia in trade; but it is stronger, harder, and lighter in color with more streaks The wood of D. sissoides does not take as high a polish as the wood of D. Iatifolia, but it commands a high market price for use in premium-grade furniture and cabinets (Prasad and Shilalingadaradhya, 1988).
Deshmukh, D.K 1975. Regeneration of Rosewood (Dalbergia latifolia, Raxb.) Myforest 11 (2):87-93.
Direktorat Reboisasi den Rehabilitasi (DlTSI). 1980. Pedoman Pembuatan Tanaman. Jakarta: DITSI, Ditjen Kehutanan. pp. 75-84.
Kadambi, K. 1954. The silviculture of Dalbergia latifolia. Monograph of Indian trees, No. 1. Government of India, Manager of Publications, Delhi.
Prasad, A G.D. and M.V. Shilalingadaradhya. 1988; Distribution and economic potential of Dalbergia in Karnataka. Myforest 24 (4): 241-47.
Prasad, A G.D., K.S.J.. Chandra and A N.Y. Reddy. 1993. Initiation of a genetic improvement program for Dalbergia Iatifolia in Kamataka India. Paper presented at the International Dalbergia Workshop, 31 May - 4 June, 1993. Hetauda, Nepal.
Soekeri. 1979. A possibility on modification of the sonokeling planting technique. Duta Rirnba 5 (35): 20-26.
Suharti, M. and S. Hadi. 1974. Wilt diseases of Dalbergia Iatifolia in KPH Malang, East Java. Lembaga Penelitian Hutan Report No. 194 (In Indonesian with English summary). Lembaga Penelitian Hutan, Bogor, Indonesia.
Sukandi, T. 1993. Agroforestry-based plantations of Dalbergia latifolia, Roxb. in Java, Indonesia Paper presented at the International Dalbergia Workshop, 31 May - 4 June, 1993. Hetauda, Nepal.
Troup, R.S. 1921. The silviculture of Indian trees, Vol. I. Oxford, Clarendon. pp.318-325.
Financial support for this NFT Highlight was provided by the USDA Forest Service Forestry Support and Tropical Forestry Programs (USDA/FS/FSP & TFP)
A publication of the Nitrogen Fixing Tree Association 1010 Holomua Road, Paia, Hawaii 9677-9744, USA Tel: (808) 579-9568; FAX (808) 579-8516.
NFTA 93-05 September 1993
Dalbergia melanoxylon produces one of the finest timbers in the world. Known in Tanzania as African ironwood, African ebony, mpingo, poyi or mugembe (Brenan and Greenway, 1949; Gillet et al., 1971; Noad and Birnie. 1989), round logs of this species fetch up to US$18,000/m . Yet the trees are seldom planted and little is known about their silviculture.
Dalbergia melanoxylon Guill. & Perr. (Leguminosae subfamily Papilionoidae) is a small, heavily branched tree, typically 4.5 to 7.5 m tall but occasionally reaching 15 m. The bole is fluted with high narrow ribs separated by deep indentations. Bole length occasionally reaches up to 3.6 m, but normally ranges from 1.2 to 1.8 m. Average diameter at breast height (dbh) at maturity is less than 38 cm, although trees have been found with a dbh of more than 60 cm. The bark is pale gray to grayish-brown, papery, fairly smooth, and flaking in long narrow strips (Bryce, 1967). The stems are often crooked.
Branchlets are clustered at the nodes. Some grow out, while others are short and spine tipped. They are covered at first with short crisp hairs, and are usually glabrous. Leaves are alternate, pinnately compound and 6 to 22 cm long. The fragrant white flowers are 6 to 9 cm long, occurring in dense clusters. There are usually nine stamens, united or variously divided. Pods are elliptic oblong or irregularly oblong, bluntly pointed, flat and thin. They range from 3 to 7 cm long and 0.8 to 1.4 cm wide. They tend to be papery, glabrous, and laxly and rather diffusely veined, with one or two seeds.
Dalbergia melanoxylon grows under a wide range of conditions including semi-arid, subhumid and tropical lowland areas. It is often found on dry, rocky sites at elevations from sea level to 1200 m, but is most frequent in the mixed deciduous forests and savannas of the coastal region. The mean minimum temperature in its native range is 18°C and the maximum is 35°C, with no frost. Annual rainfall averages 700 to 1200 mm, often distributed in a bimodal pattern of three to six months. Soils vary from loamy sands to clayey vertisols ("black cotton soils"). The species is water and light demanding; it is common near water and will not regenerate under heavy cover. Mature trees are fire tolerant.
Dalbergia melanoxylon is widely distributed in Africa, from Senegal across to Sudan, Eritrea and northern Ethiopia, Uganda and Kenya. To the south, it ranges from Angola to Zambia, Tanzania and Mozambique, as far south as the Transvaal (Gillett et al., 1971; Redhead and Temu, 1981).
Traditional uses include fuelwood and charcoal, as well as pestles, combs, knife shafts, cups and farming implements.
The sapwood is white or yellowish-white, often 12 cm wide, and sharply differentiated. The heartwood is purplish black, sometimes darker towards the outside, with light streaks and not always uniform in color. The timber is slightly oily, exceptionally hard and heavy, brittle and somewhat fissile. The heartwood is extremely durable (specific gravity not yet determined) and resistant to all forms of biodeterioration. The sapwood, however, is susceptible to fungal or insect attack (Bryce, 1967). The dry wood is difficult to saw or plane. It blunts saws and cutters and cannot be nailed or screwed without drilling. It is, however, the finest of all turnery timbers, cutting exactly and finishing to a brilliantly polished, lustrous surface, dry and cold to the touch.
The calorific value of the sapwood and heartwood is more than 49,000 Kcal/kg. Heat generation is so high that fires of D. melanoxylon have been reported to melt cooking utensils.
The wood of D. melanoxylon is used in carving, turnery and marquetry to produce sculptures, musical instruments, ornaments, inlays, chess pieces. walking sticks, gearings and many other products. The main industrial use, long supporting an export trade from East Africa and Mozambique, is the manufacture of musical instruments, especially woodwinds. With its high density and fine texture. D. melanoxylon wood produces a beautiful musical tone. It is stable, stands up to metal-working processes, and takes an excellent finish (Bryce. 1967).
The roots are used in traditional medicines to treat abdominal pain, diarrhea and syphilis. The smoke is inhaled to treat headaches and bronchitis. The pods and leaves can be used as animal fodder.
Seeds (about 42,000/kg) generally remain viable for only a few months, although viability could probably be increased by storage in sealed containers. Seed extracted from pods germinates readily without treatment. However. few seedlings attain maturity under natural conditions due to fire and drought (Mugasha. 1978).
In Tanzania. D. melanoxylon has not yet been planted extensively. Experimental work suggests that survival and growth are improved by planting two-year-old stumps that are 14 cm long, comprising 12 cm of root and 2 cm of shoot. These should be planted in the early or middle rainy season, followed by intensive weeding. Potted seedlings may also be used, but they tend to grow more slowly (Mugasha, 1983). When seedlings are raised in pots, frequent root pruning is mandatory. Delayed pruning leads to seedling shock. Advanced plant-production techniques, such as tissue culture or use of growth hormones, have not been tested.
Field trials are currently exploring suitable spacing for D. melanoxylon plantations. An initial spacing of 2 x 2 m results in good branching characteristics, while later thinning improves growth. Stem form is improved by raising the trees under medium shade provided by Pinus caribaea Morelet (Nshubemuki, 1983).
Thorough weeding is important at the initial phase of establishment. After 7.5 years, trees planted early in the rainy season on thoroughly weeded plots averaged about 30% taller than trees planted at the same time but only lightly weeded. Trees planted in the middle of the rainy season and thoroughly weeded were taller still-about 45% taller than those planted at the beginning of the rains and lightly weeded (Mugasha, 1983). Intensive weeding is crucial until root-collar diameters measure about 5 cm. Alternatively, the area around the trees should be slashed until root-collar diameters measure 8 to 10 cm. The species is extremely slow growing: trees obtain timber size in 70 to 100 years. Studies on mycorrhizal associations have not been initiated.
Pests and diseases.
Heart rot is observed on some logs, apparently associated with fungal infection following fire damage. Small game may feed on young shoots and leaves.
Dalbergia melanoxylon is not gregarious and may be difficult to establish in pure plantations. Rapid loss of seed variability might also make it difficult to establish plantations in new areas. Difficulties in working the wood call for specialized techniques. perhaps not feasible for cottage industries.
Logs are almost invariably defective and the wastage is considerable in conversion to top-grade dimension stock. End checks appear soon after felling and star shakes develop unless end coatings are applied immediately. Seasoning may take as long as two to three years after pieces are rough sawn.
Future research needs
Dalbergia melanoxylon occurs in three of the four drainage basins found in Tanzania. Observed differences in growth habits suggest the existence of clinal variation resulting from genetic, topographic and ecological influences. Selections for characters such as fast growth. wood quality, volume production and stem straightness have considerable potential. Studies of provenance variation related to end use should form the basis for in-situ and ex-situ conservation.
Research would be useful on improved methods to increase seed viability and shorten the seasoning period. Symbiotic relationships also need to be explored and quantified. HybridCation with related species, such as D. sissoo, should be initiated.
Brenan, J.P.M. and Greenway, P.J. 1949. Check lists of the forest trees and shrubs of the British Empire. Part 5: Tanganyika Territory. Oxford (UK): Imperial Forestry Institute. p 418.
Bryce, J.M. 1967. The commercial timbers of Tanzania. Moshi (Tanzania): Tanzania Forest Division, Utilization Section, p. 139.
Gillet, J.B., Polhill, R.M. and Verdourt, B. 1971. Flora of tropical East Africa. Part 3: Leguminosae, sub-family Papilionoidae.
Mugasha, A.G. 1978. Tanzania natural forests' silvicultural research: review report. Tanzania Silviculture Technical Note (New Series) 39, p. 41.
Mugasha, A.G. 1978. The effects of planting season, different planting materials and weeding methods on early performance of Dalbergia melanoxylon at Kwamarukanga, Korogwe, Tanzania. Tanzania Silviculture Research Note 43,p. 14.
Noad, T. and Birnie, A. 1989. Trees of Kenya. Nairobi: General Printers, p. 219.
Nshubemuki, L. 1993. Recent research progress in the silviculture of Dalbergia melanoxylon in Tanzania. Paper presented to the International Workshop on Dalbergia species, 31 May to 4 June, Hetauda, Nepal.
Redhead, J.F. and Temu, A.B. 1981. Valued timber but neglected tree: mpingo (Dalbergia melanoxylon). Tanzania Association of Foresters Newsletter. 2:8-9.
Tack, C.H. 1962. Nomenclature of East African timbers. Nairobi: East African Timber Advisory Board, p. 16.
Financial support for this NFT Highlight was provided by the United States Forest Service Forestry Support Program (USFS/FSP) and the Danish International Development Agency (DANIDA).
A publication of the Nitrogen Fixing Tree Association 1010 Holomua Road, Paia, Hawaii 96779-6744. USA Tel: (808) 579-9568; FAX: (808) 579-8516 Telex:510100 4385.
NFTA 94-01 January 1994
Cultivated for centuries, Erythrina edulis is an important food source for humans and animals in the tropical highlands of South America. The seed is a component of many diets, and the trees also provide shade in coffee and cacao plantations, support for vine crops, green manure, live fenceposts' wood for construction and fuel, and medicinal preparations.
Erythrina edulis Triana ex M. Micheli is one of about 115 Erythrina species in the subfamily Papilionoideae of the Leguminosae (syn. Fabaceae) family. Over a normal life span of 30 to 40 years, the leafy trees grow up to 14 m tall with stem diameters up to 37 cm and crown diameters up to 7 m. The stem and branches are covered with stout prickles. The alternate leaves are trifoliate with long petioles and two nectar-producing glands at the base of each leaflet. The flower cluster (raceme), 'supported on a stout stalk, consists of 180 to 200 short-stalked flowers arranged in threes around the axis. The flowers have a reddish-green calyx and a crimson corolla with an upper petal (standard) and two lateral petals forming the keel. The pistil is surrounded by 10 stamens. The two-petaled flowers face upward. forming a large cup in which nectar gathers (Ruskin, 1989).
Erythrina edulis is cross pollinated by sucking insects, bees, wasps and birds. Seeds mature 65 days after flowering. Fruits hang in bunches of 9 and 18 cylindrical pods. Pod size varies widely, but averages 32 cm long and 3 cm in diameter with six seeds. The seed coat is generally brownish-red but is sometimes yellow or black (Acero, 1989).
Erythrina edulis is distributed from MÃ©rida in Venezuela, to the mountain ranges of Colombia and the Andes mountains of Ecuador, Peru and Bolivia. It is commonly known as chachafruto, balÃº, basul or sachaporoto in Colombia, guato in Ecuador, and pashuro, pajuro, basul sachaporoto or sacha purutu in Argentina and Bolivia (Ruskin, 1989).
Erythrina edulis is a pioneer species that grows best in full sunlight, but trees can tolerate some shade in the early stages of growth. In Colombia the species occurs from elevations of 1200 to 2600 m, with an optimum range from 1600 to 2200 m. In Peru, E. edulis grows from 900 to 3200 m (Martel, 1989). In the species's native range, annual rainfall varies from 450 to 1800 mm and temperatures are between 5 and 25 C. The trees grow well in loose-textured sandy loams and in heavy clay soils. They do not tolerate frequent frosts.
The seeds contain 23% protein, 1% fat, 8% crude fiber and 84% moisture. They have a good balance of amino acids and a digestibility after cooking of about 50%. Seeds must be boiled at least 45 minutes or fried thoroughly before being eaten. As a paste, they provide a nutritious base for tortillas, desserts, pies, soups and food for infants. They are also boiled. sun dried, ground and added to flour. Research indicates that uncooked E. edulis seeds can be toxic if consumed over a long period (Perez et al., 1979). Seeds of all other Erythrina species are highly toxic.
The leaves and tender branches can be fed to cattle, goats, horses, pigs, guinea pigs and rabbits. Leaves contain 24% protein. 29% crude fiber (dry weight) and 21% total carbohydrates. They are rich in potassium but low in calcium (Surco, 1987). Seeds and pods can be fed fresh to cattle and goats, but should be cooked before feeding to pigs, chickens, rabbits or fish. The pods contain 21% protein, 23% crude fiber (dry weight), 24% carbohydrates and 91% moisture. Cooked seed can replace up to 60% of the concentrate fed to chickens and fish (Martin and Falla, 1991).
For maximum fodder production, the trees can be planted in protein banks at a close spacing (1.0 x 0.5 m). They are first pruned at 10 months and then at six- or four-month intervals. A two-year-old protein bank can produce up to 80 tons of leaves and tender branches per ha, or the leaves can be dried and ground to produce 6 tons of chicken feed rich in carotene (Vargas and Ocarnpo, 1991).
Shade and support.
Erythrina edulis is widely used as a shade tree for coffee or as a support for vine crops such as pepper, betel and grape. In Colombia, trees are spaced at 6 x 6 to 8 x 8 m in coffee plantations or 5 x 5 m with vine crops (Vargas and Ocampo, 1991). Annual pod production from three- to four-year-old trees at a 6 x 6 m spacing can average 30 kg/tree or 8 tons/ha (green weight); annual pod production from 20-year-old trees can average 177 to 211 kg/tree.
In Colombia, live fenceposts are established from stakes at 2-m intervals and allowed to grow for 30 months before pruning or attaching barbed wire. Stakes should be at least 4 to 6 cm in diameter and 2 m long. Pruned at fourmonth intervals, leafy branches from I km of fencing can provide up to 30 tons of fodder per year; unpruned, the same fenceposts can provide up to 85 tons of fruit (Vargas and Ocampo, 1991).
In Colombia, a soap made from the bark, branches and leaves of E. edulis is used to wash dogs with skin disease. In Peru, the seed is mixed in a liquid concoction to treat inflammation of the bladder. The flowers are used to treat eye irritations (Acero, 1989).
Erythrina edulis is easily propagated from seed or cuttings, but seedlings tend to root deeper and live longer than cuttings. Seed should be removed from pods immediately and stored in paper bags in a cool, dark place. They lose viability quickly and should be planted within eight days of harvesting. Viability can be extended up to 20 days by dipping seeds for a moment in molten paraffin so that a thin layer of paraffin coats the entire seed. Seed size varies widely: Acero (1989) reports 60 fresh seeds per kg in Colombia, while Martel (1989) reports 146 fresh seeds per kg in Peru.
Larger seeds tend to produce more vigorous seedlings. Plant seeds in l-kg polyethylene bags with the convex side facing upwards and slightly exposed. Leave room between planting bags to allow space for leaf development (Vargas and Ocampo, 1991). Germination begins in 5 to 10 days. Shade the seedlings in the nursery and reduce shade partially in the last two weeks before outplanting. At 60 days, seedlings may be planted out in holes 30 cm deep.
Erythrina edulis can also be direct seeded. Cultivate the soil thoroughly to a depth of 30 cm and plant two seeds per hole. Thin to one seedling after four or five weeks. Weed periodically in a 1-m circle around the plants. Seedlings grow rapidly (2.5 m in the first year) and begin producing fruit in approximately 24 to 27 months.
Cuttings of 4 to 6 cm diameter, and usually 1 m in length, should be planted to a depth of 30 to 50 cm within three days of harvesting (Vargas and Ocampo, 1991). Cuts should be made with well-sharpened tools to avoid damage that can lead to rotting; the top cut should be at a 45 angle. Sealing the cuts with paraffin, plastic, mud or other material can increase survival rates. Cuttings begin producing fruit about 18 months after planting.
Erythrina edulis forms a nitrogen-fixing symbiosis with Rhizobium in the cowpea miscellany (Acero, 1989). Large nodules form in the upper soil surface and decrease in size with increasing soil depth.
Erythrina edulis does not tolerate long periods of drought, especially during early stages of establishment. It does not grow well in strongly acidic soils (pH below 4.5). Stem borers damage terminal shoots and cause lateral branching. Butterfly larvae (Terastia meticulosalis) bore into seeds. Trees are also susceptible to nematodes (Helicotylenchus sp., Hoplotylus sp. and Meloidogyne sp.) (Francia Varon de Agudelo, personal communication).
Future research needs
The large differences observed in seed size suggest the existence of genetic variation. Rangewide provenance collection and testing is needed to determine differences in fruit yield, biomass production, nutrient content and adaptability. Research would also be useful on improved methods to increase seed viability. Symbiotic relationships need to be explored and quantified. Finally, traditional agroforestry uses of E. edulis and pest and disease management need further documentation.
Acero, E. 1989. Informe final silvicultura y productividad del chachafruto Erythrina edulis. Part 1. Bogota: Universidad Distrital-CIID-CONIF.
Krukoff, B.A. and Barneby, R.C. 1974. Conspectus of species of the genus Erythrina. LLOYDlA (Journal of Natural Products).37:359.
Martel, A. 1989. Erythrina edulis Triana, especie de gran potencial Papa asociaciones agrofrestales: advances de su propagatiÃ³n. Technical Note 01. FAO/Holland/DGFF Project, 30 pp.
MartÃn, D. and Falla, J.A. 1991. EvaluaciÃ³n de los efectos biolÃ³gicos de la sustituciÃ³n de concentrado por harina de chachafruto Erythrina edulis (15 y 30%) en la alimentaciÃ³n de pollos de engorde bajo un esquema de producciÃ³n de economÃa campesina. Thesis in Zootechnology. Valle (Colombia): Universidad Nacional de Colombia-Palmira.
PatiÃ±o, J.E.. 1992. SuplementaciÃ³n de cabras con chachafrutoErythrina edulis. Thesis in Zootechnology. Valle (Colombia): Universidad Nacional de ColombiaPaimira.
PÃ©rez, G., de Martinez, C. and DÃaz, E. 1979. EvaluaciÃ³n de la calidad de la proteÃna del chachafruto Erythrina edulis. BogotÃ¡: Universidad Nacional de Colombia.
Ruskin, F.R. 1989. Basul. In Lost crops of the Incas. Washington, DC: National Academy Press, pp. 164 71.
Surco, J. 1987. EvaluaciÃ³n de minerales nutricios en las semilla de Erythrina edulis. Cuzco (Peru): Universidad Nacional San Antonio Abad del Cuzco.
Vargas, L.R. and Ocampo, M.P., eds. 1991. El chachafruto o balÃº protector de aguas y suelos superalimento humano, forraje para el ganado. Extension Bulletin 7. BogotÃ¡: FederaciÃ³n Nacional de Cafeteros de Colombia, p. 22.
A Publication of the Nitrogen Fixing Tree Association Winrock International 38 Winrock Drive Morrilton AR 72110-9537
NFTA 92-06 October 1992
Erythrina sandwicensis, commonly known as wiliwili is the only Erythrina endemic to the Hawaiian Islands. The wood, seed and flowers were traditionally used in Hawaii and the tree is integral to many Hawaiian legends and proverbs. A unique characteristic of the species is the flower color variation within natural populations. Wiliwili is adapted to arid lowland environments and has potential for revegetation of degraded sites.
Erythrina sandwicensis Degener (syn. E. monosperma Gaud) is closely related to both the E. tahitensis and E. velutina (Neill 1990). Erythrina sandwicensis is a small deciduous tree 5-15 m tall, with a short, stout, crooked or gnarled trunk 30-90 cm in diameter. Spreading branches are stiff, and the broad thin crown is wider than it is high. A champion tree measured on the Island of Hawaii in 1968 was 16.8 m tall with a trunk circumference (cbh) of 3.8 m.
The bark is smooth, light to reddish brown, and has scattered stout grey or black spines up to 1 cm long. With age, it becomes slightly fissured and thin. Twigs are stout, green with yellow hairs when young and have scattered blackish spines. Leaves are alternate, compound, 13-30 cm long, with a long slender leafstalk. The three leaflets are short-stalked. The end leaflet is larger than the other two. Leaflets are 4-10 cm long and 6-15 cm wide (Little and Skolmen 1989).
Flower clusters (racemes) are on hairy yellow stalks of 7.4 cm or less. Flowers are crowded in a mass and are 7.515 cm long and short stalked. Flower color within natural populations can include orange, yellow, salmon, green and white (Little and Skolmen 1989). This striking color variation is probably unique within the genus (Neill 1990).
Reports vary on flowering and leaf falL Rock (1913) reported that wiliwili loses its leaves in the late summer or early fall (August to October), and leaves appear again during early spring to mid-summer (March to July), usually after flowering has occurred. Observations on Maui indicate that leaves drop during the dry periods of late spring or early summer (May to June). The tree flowers during the fall (September to November). Leaves reappear after the first southerly storms in the late fall (November)(B. Hobdy, Hawaii Department of Land and Natural Resources, personal observation). Differences in observations may be tied to variation of annual soil moisture, and the considerable heterogeneity of flowering, leaf loss, and seed set within a single stand.
Fruits (pods) are approximately 10 cm long and 13 cm broad, flattened, and pointed at both ends. They are blackish and slightly narrowed between seeds. Mature pods are found on the trees during winter months (December to February). Pods contain 1-4 elliptical, shiny red orange seeds 13-15 mm long (Little and Skolmen 1989).
Wiliwili occurs near sea level to 610 m altitude in arid regions (Little and Skolmen 1989). Annual rainfall in these areas ranges from 500 to 1250 mm and is usually concentrated between November and March. Once an important component of ancient endemic Hawaiian dryland forests (Rock 1913), wiliwili has been replaced by Prosopis pallida in many areas (Little and Skolmen 1989). However, the species is not in danger of extinction.
Wiliwili is endemic to the leeward side of the Hawaiian Islands (Little and Skolmen 1989). It is not known to have been introduced elsewhere.
The wood is reported to be the lightest of Hawaiian woods. It was used for surfboards (Neal 1965), canoe outriggers, and fish net floats, (Degener 1973, Neal 1965). Degener (1973) reports that the practice of using Wiliwili wood for outriggers was abandoned because Hawaiians believed that sharks followed such canoes. They also believed that trees bearing orange-red flowers possessed more durable wood than those bearing lighter colored flowers (Degener 1940).
The bright red seeds were used for making leis (Rock 1913). Captain Cook was reportedly given a lei made of Wiliwili seed when he visited the islands in 1778 (Little and Skolmen 1989). Wiliwili has been planted as living fences (Degener 1940). The species is strongly naked to Hawaiian culture through legends and proverbs. One legend refers to the different appearances of this species in the transformation of three sisters into Wiliwili trees. A bald sister becomes a tree with no leaves, a sister with wind-tossed hair becomes a tree with fluttering leaves, and a hunchbacked sister becomes a gnarled tree (Neal 1965).
Wiliwili is now being used in revegetation programs using endemic species to rehabilitate highly eroded areas in Hawaii. It survives extended drought and high winds, but growth is slow under such harsh conditions.
Wiliwili can be easily propagated by seed or vegetative cuttings. To improve germination, the seeds should be mechanically scarified by nicking the seed coat, and soaked in water (at room temperature) overnight. For nursery propagation 1 liter containers with a 1:1:1 mixture of perlite, vermiculite, and potting soil are suggested. A small amount of 14-14-14 NP-K slow release fertilizer can be added to the potting mix (Chapin 1990). If vesicular arbuscular mycorrhizal (YAM) inoculant is available, it should be mixed in the potting media as well. Plant seeds 4 cm deep. Inoculate with rhizobia by irrigating the seedlings with a suspension of peat inoculant in water. Keep seedlings in a shady area until the first 2 or 4 true leaves appear. Water as needed. Overwatering may cause damping-off. After two weeks, place plants in the full sun. Water with a liquid fertilizer solution containing N-P-K plus micro-nutrients. Moderate fertilizer use will not adversely affect the microsymbionts .
Methods for vegetative propagation of Erythrina variegata (Rotar et al. 1986) may be used for wiliwili. Rotar recommends that cuttings be a minimum of 2.5 cm in diameter and 30 cm long. Before planting, cuttings should air dry, or cure, for at least 24 hours. The base of the cuttings can be coated with rooting hormone. The cuttings should be placed in the ground to a depth of at least 15 cm, and the soil kept moist. Sealing the top surface of the cuttings with wax or tree-wound dressing will help to prevent drying out.
Wiliwili should be planted on sites similar to its natural environment. Sites are recommended that have well-drained soil and receive full sun. Seedlings are ready for outplanting when stems are sturdy and well hardened, after approximately four months in the nursery. Planting holes should contain slow-release fertilizers as recommended by soil nutrient analysis. If possible, water once a week for the first month. If watering is not possible or if conditions are particularly harsh, the leaves of the seedlings may be trimmed or the tops cut off entirely.
Wiliwili forms a nitrogen fixing symbioses with Bradyrhizobium species. Highly effective strains have been identified (van Kessel et al. 1988). Rhizobial inoculants are available from NifTAL, 1000 Holomua Rd., Paia, HI, 96779 USA.
In highly eroded soils in Hawaii, inoculation of Wiliwili with VAM species Glomus fasciculatus resulted in significantly increased plant growth and decreased requirements for phosphorus amendments. This indicates VAM symbioses is critical to plant success in phosphorus infertile soils.
Wiliwili seedlings may be susceptible to damping-off problems. Powdery mildew fungi will attack the leaves in humid environments. Stem boring caterpillars have caused seedling mortality. Red spider mites are commonly associated with wiliwili. The tree is not suited for areas with high rainfall.
Chapin, M.H. 1990. April plant of the month - Hawaiian 1990. Kauai, Hawaii (USA): Hawaii Plant Conservation Center of the National Tropical Botanical Garden.
Degener, O. 1940. Flora Hawaiiensis: Leguminosae. Honolulu, Hawaii (USA): O. Degener.
Degener, O. 1973. Plants of Hawaii national parks illustrative of plants and customs of the South Seas. Ann Arbor, Michigan: Braun-Brumfield.
Little, E.L. and R.G. Skolmen. 1989. Common forest trees of Hawaii (native and introduced). Agricultural Handbook 679. Washington, D.C.: USDA.
Neal, M.C. 1965. In Gardens of Hawaii. Special Publication 50. Honolulu: Bishop Museum Press.
Neill, D A. 1990. Erythrina. pp 671-2. In: W.L. Wagner, D.R. Herbst and S.H. Sohmer (eds). Manual of the flowering plants of Hawaii, Vol 1. Special Publication 83. Honolulu, Hawaii: Bishop Museum Press.
Rock, J.H. 1913. The indigenous trees of the Hawaiian Islands [USA]. Reprinted in Tokyo: Charles E. Tuttle.
Rotar, P.R., R.J. Joy and P.R. Weissich. 1986. "Tropic Coral ": tall Erythrina (Erythrina variegate L.). Research Extensions Series 072. Hawaii Institute of Tropical Agriculture & Human Resources. University of Hawaii. Honolulu, Wawaii.
van Kessel, C., J.P. Roskoski and K Keane. 1988. Ureide production by N2-fixing leguminous trees. Soil Biology and Biochemistry 20:891-7.
NFTA 93-02 June 1993
HippophaÃ« rhamnoides L., commonly known as sea buckthorn, is an arborescent shrub of wide adaptability distributed throughout more than 20 countries of Europe and Asia. The species has a history of utilization that goes back at least 12 centuries. An actinorhizal plant, sea buckthorn has the capacity to fix atmospheric nitrogen and thus enrich the soil. It is used successfully as a windbreak and to stabilize sand dunes, and several of its products have high value.
Sea buckthorn is a deciduous shrub or small tree, with thorns and unisexual flowers. It is dioecious and wind pollinated. Its fruit is a drupe, reddish orange, varying in length from 5 to 12 mm, with a tart, bittersweet taste. Each fruit has one bonehard seed. Shrubs usually begin to bear fruit after three years and give maximum yields after seven to eight years.
The trees have an extensive, shallow root system and rootsuckering is common. Plants degenerate after approximately 15 years and then reproduce by suckering.
Rousi (1971) divided the genus HippophaÃ« into three species. More recently, Lian (1988) revised the taxonomy, dividing the genus into five species. HippophaÃ« rhamnoides is by far the most common and references to HippophaÃ« are usually to this species.
Sea buckthorn grows anywhere in temperate latitudes, from sand dunes near the sea to the Eurasian plateau at 5200 m above sea level. Plant characteristics vary considerably according to this wide range of climatic conditions. For instance, these "shrubs" can reach 18 m in height in certain zones.
This is a light-demanding species. Trees growing in forested areas will die if the canopy density exceeds 50%. However, they are extremely drought tolerant, with extensive root systems that scavenge soil humidity and groundwater aggressively. They grow readily in areas that receive as little as 250 to 800 mm of rainfall annually. For example, there is a large area of natural HippophaÃ« forest on the loess plateau of China, including the semi-arid regions of Shanxi, Shaanxi and Gansu Provinces.
The species is also well adapted to cold climates. There are 18,000 ha of natural HippophaÃ« forest in Siberia where the temperature commonly drops well below 0°C. Sea buckthorn is also tolerant of alkaline and saline soils. It is reported to grow in the Qaidam Basin of China where the salt content of the soil ranges from 0.6 to 1.1% and the pH is 9.5.
Sea buckthorn is native to the temperate zones of Asia and Europe, where it is widely distributed. It is also well represented at higher altitudes in the sub-tropical zones of Asia. Russia has approximately 200,000 ha of natural HippophaÃ« forest plus more than 6,000 ha in plantations. With 920,000 ha, China has the largest area under HippophaÃ« of any country, and also the largest variety of HippophaÃ« species.
Sea buckthorn fruit is rich in vitamins C, E, K, B1 and B2, as well as niacinamide, pantothenic acid. carotenoids and other substances such as oil, sugar, malic acid, amino acids and pectin. The vitamin C content of the Chinese sea buckthorn HippophaÃ« rhamnoides subsp. sinensis Rousi) fruit can be as high as 1253 mg/100 g.
Numerous food products are made from the fruit of this species. For instance, sea buckthorn wine is well known in Russia. In that country, a new variety has been bred by hybridizing geographically distant plants: it produces as much as 10.000 kg/ha of fresh fruits. In China, poor peasants have become prosperous by collecting and processing the fruit.
HippophaÃ« leaves also contain various nutritious substances and minerals. They are commonly used as tea.
There are records of the medicinal use of sea buckthorn as early as the eighth century A.D. The Tibetan medical classic. Four Books of Pharmacopeia, lists 84 prescriptions for the preparation of sea buckthorn medicines. According to one account, a Tibetan lame considered this plant as a general panacea and made extensive use of its roots, stems, leaves, flowers, fruits and seed. The plant was widely used as a folk medicine in ancient Greece, the Roman Empire, Mongolia and Russia. Oil from the fruit acts as an antioxidant and may thus be used to treat wounds, frost bite and pathological problems of the alimentary mucous membranes. Serotonin (5-hydroxy-tryptamine) extracted from sea buckthorn possesses antitumor capabilities.
The ancient Greeks named the genus HippophaÃ« or "glittering horse," because they believed that horses became plump and healthy when maintained on pastures with these trees. Today, herdsmen in northwest China often feed sea buckthorn leaves to their animals. In Russia, fodder supplements of sea buckthorn by-products are reported to improve liveweights and coat condition. Feeding poultry with meal made from sea buckthorn fruit and fruit oil has been observed to increase the pigmentation of egg yolks and body fat. The oil also increases flesh pigmentation in rainbow trout.
HippophaÃ« possesses a strong capacity to fix atmospheric nitrogen in its root nodules when associated with the actinomycete, Frankia. Most soils possess enough Frankia to support nodulation. In one stand on the east coast of England, annual nitrogen fixation was estimated as high as 179 kg/ha (Stewart and Pearson, 1967).
All of the plant's characteristics, especially its strong nitrogen-fixing ability and rapid growth, make it a good species for improving soil fertility, controlling erosion, conserving water. and stabilizing sand dunes. In mixed plantings, it can promote the growth and development of adjacent plants. Sea buckthorn also shows a strong tolerance for toxic pollutants in the soil and air. It can thus be used to revegetate heavily industrialized areas or to reclaim mining sites.
Cosmetics derived from sea buckthorn are widely used in Romania, Russia and China. Massage creams, day creams and a shampoo developed in Romania have received international patents. In addition, the trees yield good-quality fuelwood. In China's western Liaoning Province, a six-year-old sea buckthorn plantation can produce 6.32 t/ha of wood. Sea buckthorn is also useful as an ornamental shrub.
Management varies according to objectives and environment factors. The species propagates well asexually because lignified branches of any age possess a strong ability to form adventitious roots. HippophaÃ« rhamnoides can also be propagated from softwood cuttings under mist. For introduction or breeding trials, seed propagation is the most suitable treatment.
The seeds retain their viability after indoor storage for three to four years. Under suitable conditions,they will germinate during any season of the year. In 1977, a large plantation was successfully established on the loess plateau of China by broadcasting seed from aircraft.
The wide adaptability and varied reproductive strategies of HippophaÃ« rhamnoides indicate that it could be a serious weed in some environments. Its extensive, suckering root system may make it unsuitable for agroforestry technologies that include close tree/crop associations. In addition, thorns on the stem and branches often make it difficult to harvest the fruits.
Lian Yongshan. 1988. New discoveries of the genus HippophaÃ« L. (Elaeagnaceae). Acta Phytotaxonomica Sinica. 26(3):235-37.
Rousi, A. 1971. The genus HippophaÃ« L: a taxonomic study. Annales Botanica Fennici. 8(3): 177-277.
Stewart, W.D.P. and Pearson, M.C. 1967. Nodulation and nitrogen fixation by HippophaÃ« rhamnoides in the field. Plant and Soil. 26(2):348 - 60.
A publication of the Nitrogen Fixing Tree Association 1010 Holomua Road, Paia, Hawaii 967796744, USA Tel: (808) 579-9568; FAX: (808) 5798516 Telex: 510100 4385
NFTA 92-05 October 1992
Leucaena diversifolia is the second-best known species in the genus Leucaena. Through numerous international tree trials, it has gained a reputation for aggressive growth at cool or high elevation sites where L. Ieucocephala performs poorly. It is a common companion tree to coffee in much of Indonesia and Mexico. L. diversifolia has moderate or high resistance to both psyllids and seed beetles, and is low in mimosine. Its forage digestibility is somewhat lower than L. Ieucocephala. It produces straight boles, and is desirable for paper and charcoal production.
L. diversifolia (Schlecht.) Bentham (Leguminosae, subfamily Mimosoideae) is a mediumsized tree, often growing 10 to 20 m in height and 10 to 40 cm in diameter. L. diversifolia typically grows as a single stem tree with a long straight bole and slender uplifted branches that terminate in horizontal twigs. Some diploids produce branches at 180 degrees to each other, giving the trees a planar or two-dimensional appearance.
The leaves of L. diversifolia are easily distinguished from L. Ieucocephala by high numbers of small leaflets. The leaflets are 1 to 2 mm wide and nearly 1 cm long. The apex of the leaflet is usually off-center and pointed Flower heads are borne in clusters at leaf axils and average under 1 cm diameter (0.51.8 cm) on the day before flowering. Unlike L. Ieucocephala flowers, the styles of L. diversifolia extend past the anther halo. Flowering is profuse, beginning in late spring and continuing until mid-fall. Flower color ranges from bright red to light pink. Young pods can turn bright red in the sun, accounting for the Mexican name "guaje rojo" or red leucaena (Brewbaker 1987b).
L diversifolia contains two subspecies. The most widely cultivated, L. diversifolia ssp. diversifolia, is line L Ieucocephala being self-fertile and "tetraploid" (2n=104). It is often abbreviated DIV4. The other subspecies, L. diversifolia ssp. trichandra (syn. L d ssp. stenocarpa) is outcrossing and has half as many chromosomes ("diploid"). It is abbreviated DIV2. The subspecific division is important as the breeding methods used to improve each subspecies are very different.
DIV4 pods mature in about 90 days, while those of DIV2 mature in 80 to 160 days. L. diversifolia seed weigh about one third (about 20 seeds/gram) of L. Ieucocephala seed. Seeds of the DIV2 are commonly smaller than those of DIV4.
Unlike L. Ieucocephala, which frequents hot mesic lowlands (sea level to 1000 m), L. diversifolia colonizes higher (700 to 2500 m), cooler, and seasonally wetter sites. Its performance in highland trials is predictably good. Biomass yields of L. diversifolia (DIV4) were five times that of L. Ieucocephala at Mealani, Hawaii 850 m elevation, mean average temperature 18°C (Brewbaker et al. 1988). An Indonesian L. diversifolia diploid performed better than several L. Ieucocephala in Papua, New Guinea (Bray et al. 1988)
L. diversifolia is not frost tolerant. Early indications suggest that L. diversifolia is drought-sensitive. It performs best on fertile (maize-growing) soils, but also colonizes infertile ones. The species is not normally found on acid soils but some can tolerate moderate acidity (Hutton 1984). Some diploids have been discovered growing among pines near Siguatepeque, Honduras. The species does not appear to be tolerant of saline or sodic soils. It tolerates partial shade and seasonally heavy rain.
The native distribution extends from Eastern and Central Mexico (Veracruz and Puebla) south through Guatemala, Honduras and into Nicaragua. The tetraploid is native only in a small region of central Veracruz, Mexico near Jalapa. No diploids grow in this area, although they probably occur in southern Veracruz. The center of diversity of the diploids is Guatemala. Oaxacan (Mexico) diploids are different in tree form (shrubby), pollen (large) and pubescence heavier) from their Guatemalan kin, and may withstand periodic drought.
The naturalized distribution of the species includes the Caribbean, Africa and S.E. Asia. The tetraploid was probably established in Jamaica early in this century. Diploids (probably Guatemalan) were brought into the Ivory Coast, Cameroon and Java, Indonesia in the late 1800s. The Indonesian populations appear to be agronomically superior and may be partially inbred; if so they could be invaluable in hybrid seed production.
L. diversifolia does not have a history of cropping and much of the information on its value remains anecdotal. The primary uses of L. diversifolia are fuelwood, posts, pulpwood, shade and reforestation. It is also used for soil improvement and stabilization, alley cropping and agroforestry, pasture improvement and forage.
In one study, foliar digestibility of L. diversifolia lines were 10-20% less than that of L. Ieucocephala. The higher tannin content of the foliage may increase bypass protein levels in ruminants. Bypass protein is important to ruminants because the protein is protected from degradation in the rumen, but available for absorption in the small intestine, which is metabolically efficient. Mimosine content (1.5-2.5%) is about half that of L. Ieucocephala (4%). Levels of more than 50% of the forage in animal diets are not recommended.
Seed can be scarified by, a 5-7 minute soak in concentrated sulfuric acid, a 3 minute soak in 75°C hot water, or mechanical scarification. L. diversifolia fixes nitrogen with Rhizabium, and has a specificity comparable to that of L. Ieucocephala. Little is known about its mycorrhizal needs; these are also assumed to be comparable to that of L. Ieucocephala.
Seedling vigor of L. diversifolia is poor, especially of the tetraploids and small-seeded diploids (Sorensson et al. in submission?. Seeds may take a week to fully vigorous leucaenas. Seedlings are typically transplanted into the field eight to twelve weeks after germination, when they should be 15 to 30 cm tall. Vegetative propagation from cuttings and grafts has generally failed although tissue culture is successful.
PESTS & DISEASES.
L. diversifolia are generally resistant to insect pests in the field. Tetraploids show moderate psyllid resistance, but defoliate during heavy pest outbreaks (Brewbaker 1987a, Bray and Woodroffe 1988). Some diploids are extremely resistant to psyllids.
Both tetraploids and diploids show high resistance to seed beetles Araecerus levipennis and A. fasciculatus (Braze 1988). Damage to unprotected seed from A. Ievipennis in Hawaii is often one-quarter that to seed of other susceptible leucaenas.
Most interspecific combinations between and within L. diversifolia and other species are successful (Pan 1985, Sorensson and Brewbaker in submission). The best known hybrid is that between tetraploid L. diversifolia and L. Ieucocephala. It is called 'KX3'. It has a broader genetic base than either parent and often outyields them. Like the parents, the hybrid is self-fertile and seedy.
Bray, R.A. and T.D. Woodroffe. 1988. Resistance of some Leucaena species to the leucaena psyllid. Tropical Grasslands 22:11-16.
Bray, R. A., D.G. Cooksley, T.J. Hall and D. Ratcliff. 1988. Performance of fourteen Leucaena lines at five sites in Queensland. Australian J. of Experimental Agriculture 28:69-72.
Braza, R.D. 1988. Two insect pests of L. diversifolia seeds in Surigao del Sur, Philippines. Leucaena Research Reports 9:88-89.
Brewbaker, J.L. 1987a. Leucaena: A multipurpose tree genus for tropical agroforestry. pp 289-324. In: Agroforestry A decade of development. Editors: HA. Steppler and P.K.R. Nair. ICRAFT. Nairobi, Kenya.
Brewbaker, J.L. 1987b. Guide to the systematics of the genus Leucaena (Mimosoideae). Leucaena Research Reports 7(2):6-20.
Brewbaker, J.L., R.W. Wheeler and C.T. Sorensson. 1988. Psyllid-tolerant highland leucaena yields. Leucaena Research Reports 9:11-13.
Hutton, E.M. 1984. Breeding and selecting Leucaena for acid tropical soils. Pesquisa Agropecuaria Brasilia 19 (special issue):263-274.
Pan, F.J. 1985. Relationships within the L. diversifolia complex Dissertation, Univ. of Hawaii. 297pp.
Sorensson, C.T. and J.L. Brewbaker. Interspecific compatibility among fifteen Leucaena species. Submitted to American J. of Botany.
Sorensson, C.T., H.M. Shelton, M.T. Austin and J.L. Brewbaker. Seedling vigor of Leucaena leucocephala, L. diversifolia, L. pallida and their hybrids. Submitted to Tropical Grasslands.
NFTA 90-01 May 1990
In the early years of its planting, leucaenas were often called "miracles frees" for their success as fast-growing, multipurpose, nitrogen fixing trees in the tropics. Several leucaena species are characterized by rapid growth, are highly palatable to animals, and produce dense firewood. Today, a more balanced view exists of this versatile group of trees. A major pest, the psyllid, has infested leucaena stands around the world with particular susceptibility expressed by varieties of Leucaena leucocephala. Research, however, has identified psyllid-tolerant varieties and hybrids, and psyllid populations in leucaena stands are declining over time, apparently due to natural agents.
Few countries lack their own names for Leucaena. "Guaje" in Latin America, subabul" or "kubabul" in India, "ipil-ipil" in Philippines, "lamtoro" in Indonesia and "yin hue when. in China are among those better known. The Hawaiians named it "koa haole" (the "foreign koa" (the native Hawaiian koa is Acacia koa), and leucaena varieties developed in Hawaii are named K8, K636, etc., "K" for koa.
Leucaena leucocephala (Lam.) de Wit, formerly known as L glauca, became pantropical in the 17th century from its native region in Central America and Mexico. Not until the 20th century did other species attract interest. Today we recognize 13 species in the genus, and expect others to be validated. In addition to L. Ieucocephala (abbreviated here as LEUC), these are L. collinsii (COLL), L diversifolia (DIVE), L esculenta (ESCU), L. greggii (GREG), L. Ianceolata (LANC), L. macrophylla (MACR), L palIida (PALL), L pulverulenta (PULV), L. retusa (RETU), L. salvadorensis (SALV), L shannoni (SHAN) and L trichodes (TRIC). LEUC, PALL and one subspecies of DIVE are polyploid (104 chromosomes), while the other species are diploid (52 or 56 chromosomes).
Leucaenas vary widely in leaf and tree shape, ranging from shrubs to stately trees. Leaves are alternate and bipinnately compound. Flowers range from bright yellow (RETU, GREG) and pink (DIVE, PALL) to white (all others). Clustered vertical brown pods, 8-25 cm in length, are a distinguishing mark. LEUC and tetraploid varieties of DIVE are self-pollinating, while all others are outcrossing.
The species range naturally from Peru (TRIC) to Texas (RETU), from sea level to over 2000 m elevation, and in areas with annual rainfalls between 500 and 2000 mm. Leucaenas are associated with soils of pH 5-8, and are not found on waterlogged soils. The leucaenas fail on highly acid soils, where aluminum competes with calcium and other cations for exchange sites in the soils.
The genus is considered an interbreeding complex, and breeding efforts are concentrated on producing interspecific hybrids. LEUC has been crossed successfully with all other species except GREG. Over 50 species hybrids are now under study in Hawaii for growth, form, psyllid resistance, cold tolerance and fodder quality. Many hybrids have high commercial potential notably in cooler climates and on certain acid soils where LEUC is an economic failure. New varieties are increasingly available from breeding programs in Hawaii Australia, Taiwan and Indonesia.
Depending on species, leucaenas have 10-80,000 seeds/kg. Leucaena seeds have hard coats that need pretreatment to enhance germination. Seeds can be mechanically scarified, either by nicking the seed coat or treating with boiled water. Leucaena can be direct seeded, or planted as container grown seedlings, stump cuttings or bare root seedlings. In areas where they have not grown before, leucaenas require inoculation with specific Rhizobium in order to nodulate and grow well.
Under suitable conditions, leucaenas have produced wood yields similar to the best of tropical trees. Mean annual wood increments fall in the range of 20-60 m³/yr in short rotation (3-5 yr) trials. Wood of a 4-yr-old tree has about 46% moisture and a specific gravity of 0.52. This medium hard wood serves well for posts, housebuilding, utensils and parquet flooring. It is an excellent pulpwood (Hu 1987), and a preferred fuelwood that burns with little smoke or ash. Charcoal is of high yield and quality.
Leucaena is perhaps best known as a fodder plant for ruminant animals, with high acceptability and dry matter digestibility (55-70%). Some of the newer species undergoing testing (DIVE, PALL) may have lower digestibilities. Goats and cattle make superior gains on grass supplemented with 20-30% leucaena, which can be fed solely when necessary.
Mimosine is a toxic amino acid in leucaena foliage (2-6% dry matter) that causes hair loss and other damage in nonruminant animals. A breakdown product of mimosine, DHP, can cause problems in ruminant animals. A bacterium found in the gut of ruminants in areas where LEUC is native or naturalized can detoxify DHP. The bacteria can now be obtained from Australian scientists at CSIRO and used for rumen inoculation. Leucaena can be used to color the egg yolks of poultry, due to its high content of vitamin A precursor carotenoids. However, it is not a nutritional supplement to poultry without pre-preparation.
Alley farming, shade and species mixtures.
The leucaenas have been model trees for alley farming, a system in which trees are planted in crop fields and managed as hedgerows. Crops grown in the "alleys" formed by the trees benefit from the nitrogen-rich leucaena leaves applied as green manure. Fresh litter has higher nitrogen (3-4%) than dried leaves (1%). Leucaenas coppice readily; best results are realized from cutting heights of 50 cm or above. The leaves defoliate from cut branches and wilt rapidly after harvest. Leucaena has soil and rainfall preferences similar to most annual food crops, making a good hedge for maize, sorghum, cassava and the taller grain legumes (Kang et al. 1984).
Leucaena is used to shade crop plants such as coffee and cacao in Indonesia and Costa Rica. It has also been planted in species mixtures in tree plantations in Brazil and Hawaii to increase wood production of non fixing species such as Eucalyptus (Schubert et al. 1988).
Foods, gums and other products.
Green pods of several leucaenas (ESCU, MACR, LEUC) are marketed for food in Mexico, but little eaten elsewhere. Tender young vegetative shoots are often sold as a vegetable in S. E. Asia. Seeds are made into tempeh in Indonesia. More should be known of the goiter-causing DHP before food uses are widely recommended. Gums from leucaena bark have been the subject of extensive study for their similarity to gum arable; gum yields appear high in certain species hybrids. The seed gum of leucaena is also a unique galactomannan with potential medical uses. The production of liquid protein extracts from leucaena leaves is, however, complicated by gumprecipitation problems.
THE LEUCAENA PSYLLID:
Heteropsylla cabana Crawford is a tiny jumping plant louse that attacks leucaenas. It is the subject of a previous NFT Highlight (8805). The psyllid is travelling around the tropics from its home in Latin America, where it does little significant damage to LEUC, probably from control of the psyllid by native insect predators. Useful predators being deployed abroad include the beetle Curinus coeruleus and the parasitic wasp Psyllaephagus nr. rotundifomis.
Management practices influence psyllid resistance. In some species, repeated cuttings can result in higher damage to juvenile leaves; weather patterns can also affect the degree of damage. Species exhibiting a relatively higher degree of resistance to psyllid damage than LEUC include COLL, DIVE, ESCU, GREG, PALL RETU and SALV. Interspecific hybrids such as KX1 and KX2 have shown high psyllid resistance in Asia and the Pacific.
LITERATURE AND SEEDS:
Serious students of leucaena should peruse Leucaena Research Reports (LRR), published annually by NFTA. Seed sources are listed annually in LRR; seeds for ILTs (International Leucaena Trials) are available from NFTA.
Brewbaker J.L. 1986. Guide to the systematics of the genus Leucaena (Mimosoideae: Leguminosae). LRR 7(2):6-20.
Brewbaker, J.L. 1987. Leucaena: a multipurpose tree genus for tropical agroforestry. In Agroforestry A decade of Development. HA. Steppler and P.K.R. Nair (eds). ICRAF, Nairobi Kenya. pp. 289-323.
Brewbaker, J.L. and EM. Hutton. 1979. Leucaena - Versatile tree legume. In New Agricultural Crops, GA. Ritchie, (ed). AAAS Selected Symposium. Westview Press' Boulder, Colorado.
Hu, Ta Wei. 1987. Use of Nitrogen Fixing Trees for Pulpwood. NFTA, Waimanalo, Hawaii.
Hutton, EM. 1984. Breeding and selecting leucaena for acid tropical soils. Pesq. Agropec. Bras. 19:263-274.
Kang, B.T., G.F. Wilson and T.L. Lawson. 1984. Alley Cropping - A Stable Alternative to Shifting Cultivation. IITA, Ibadan, Nigeria.
NFTA. 1985. Leucaena Forage Production and Use; Leucaena Wood Production and Use. NFTA, Waimanalo, Hawaii.
NRC. 1984. Leucaena: Promising forage and tree crop for the tropics. 2nd ed. U.S. National Research Council, USNAS, Washington, D.C.
Oakes, A.J. 1982-1984. Leucaena Bibliography. 3 vols. Germplasm Resources Lab., USDA, Beltsville, Maryland.
Pound, B. and L.M. Cairo. 1983. Leucaena: Its cultivation and use. Overseas Development Administration, London.
Schubert, T.H., D.S. DeBell and C.D. Whitesell. 1988. Eucalyptus/legume mixtures for biomass production in Hawaii. Nitrogen Fixing Tree Research Reports 6:26 27.
NFTA 92-08 December 1992
Olneya tesota, called Desert Ironwood, Tesota or Palo fierro, is a conspicuous tree in much of the Sonoran Desert of southwestern North America. Valued for its wood, this long-lived desert tree has potential for development as a tree food crop for hot arid climates.
Olneya tesota A. Gray (Leguminosae, subfamily Papilionoideae) is the sole member of the genus Olneya. It grows as a small tree to 10 m in height and spread, commonly with several trunks. The trunks can attain a diameter up to 60 cm on very old individuals. Young twigs up to 10 or 15 mm thick are green. The bark of limbs is gray and smooth, becoming fissured and eventually shredding on older limbs and trunks. Painfully sharp, paired spines, 3-11 mm long occur at each node.
The foliage is cold and drought deciduous but trees in favorable locations may remain nearly evergreen. The oncepinnate leaves are up to 6 cm long with 6 to 20 grayish green leaflets. Leaflets are 7 to 20 mm long. Pink to lavender pea-like flowers, 15 mm long, appear in short, dense racemes or panicles in the late spring. In some years they cover the trees with dense masses of color. While most individual trees flower each year, flowering appears to be heavy only about two years in five. The pods ripen in the summer and contain one to several round seeds 5-6 mm in diameter. Mature pods rapidly dehisce.
Olneya tesota is adapted to hot arid climates. Average rainfall over its range varies from 75400 mm. The tree occurs from below sea level to approximately 900 m elevation, most often in sandy and rocky soils of plains, slopes and along dry washes. Its Ph limits are unknown, but it grows well in soils with a range of 7 to 8.5.
Along its range, O. tesota is a dominant component of many plant communities. In the more arid portions of its range it is restricted to dry desert watercourses where storm runoff increases the available moisture. The largest individuals are found in these habitats, often forming woodlands with other desert trees including Cercidium floridum, Prosopis glandulosa var. torreyana, P. velutina, Acacia greggii, and others (Felger 1992). Seeds require rainfall or storm runoff during the hot season to germinate. Few seedlings which germinate away from the protective cover of other plants survive rodent predation.
Olneya tesota tolerates some freezing but generally sustains stem damage below -6° C. Prolonged exposure to lower temperatures may cause severe damage or death. It tolerates summer temperatures of 45° C. Because of its preference for warmer sites, O. tesota has been used as an indicator plant in choosing locations for citrus plantations (Little 1950). The trees are long-lived, perhaps attaining 200 years of age. Dead stumps can persist for decades. The trees serve as a source of food and shelter for many species of wildlife. Other desert plants, including shrubs, vines, cacti, and annuals, often grow in the microclimate beneath the canopy of O. tesota.
Olneya tesota is endemic to the Sonoran Desert Region. It is found in central and southwest Arizona and southeast California, USA, much of the Baja California peninsula, western Sonoran and extreme northwest Sinaloa, Mexico (Hastings et. al 1972).
The seeds of O. tesota have been used for food by native Americans. Fresh, uncooked seeds have a taste similar to soybeans (Glycine max). Felger and Moser (1985) report that the Seri Indians of Sonora, Mexico, cooked the seeds in water, emptied the water and then cooked the seeds a second time in fresh water to remove an unpleasant smell. The cooked seeds were eaten whole, or ground and salted. The seeds contain Canavalin, a mild toxin (Rosenthal 1977). Roasted seeds have been used as a substitute for coffee.
The wood is very hard, dense and durable. It will not float in water. Olneya tesota is cut for fuelwood, charcoal and carvings. The heartwood is dark brown and takes a beautiful polish. The trees do not respond well to coppicing. Larger trees are usually killed by this practice and recovery of younger plants is slow. Widespread cutting of O. tesota has seriously reduced the numbers of these trees in areas of Mexico.
Wildlife and domestic livestock browse the foliage to some extent (Allen and Allen 1981). Olneya tesota is cultivated as a landscape tree in hot arid regions of southwestern United States. The nearly evergreen foliage, dense shade, showy flowers and attractive form make it well suited for a variety of landscape functions. Trees up to 8 m tall have been successfully transplanted by side-boxine.
Olneya tesota is propagated from seeds. Scarification of the seeds enhances uniform germination but fresh seeds will germinate without scarification. Optimum temperature for germination appears to be 25-30° C. Fresh seeds often have 80-90% germination. Emergence usually occurs in 412 days. Seedlings can reach 25 cm tall in their first season.
Olneya tesota thrives in well-drained soils with infrequent. deep irrigation. Established trees will survive on 200 mm of annual rainfall. Typically slow growing in the wild' established plants can grow up to 6(; cm per year under favorable conditions in cultivation. Olneya tesota shows no tendency to become weedy.
Optimum conditions for fruit production are not fully documented. Unless supplemental irrigation is available in arid regions, O. tesota grows slowly, prolonging the time it tales for the tree to reach flowering size.
Felker and Clark (1981) report that O. tesota seedlings grown in nitrogen free media produced nodules when inoculated with soil taken from beneath wild trees. Allen and Allen (1981) indicate that nodulation has been reported from cultivated trees of O. tesota in Zimbabwe.
Desert Mistletoe (Phorodendron califomicum) can be a serious problem on O. tesota in its natural range. Heavy infestations can weaken and even kill mature trees. Control can be achieved by periodically removing the clumps of mistletoe.
Young plants may be severely damaged by browsing, particularly by rodents. No significant disease problems have been reported. The plants do not appear to be fire resistant. The spiny stems can be a nuisance to people working around the plants.
Methods of vegetative propagation should be investigated to provide a convenient method of propagating selected cultivars. Trial plantings are needed to determine how this species may perform under field conditions.
Allen O. N. and E. K Allen. 1981. The Leguminosae: a source book of characteristics, uses and nodulation. The University of Wisconsin Press, Madison. 812 pp.
Felger R. S. 1992. Reflections on a desert legume trinity. Aridus 4(4):1-4, 7.
Felger R. S. and M. B. Moser. 1985. People of the desert and sea - ethnobotany of the Seri Indians. The University of Arizona Press, Tucson. 435 pp.
Felker P. and P. R. Clark. 1981. Nodulation and nitrogen fixation (acetylene reduction) in desert ironwood (Olneya tesota). Oecologia 48:292-293.
Hastings, J.R., R.M. Turner and D.K Warren. 1972. An atlas of some plant distributions in the Sonoran Desert. The University of Arizona, Institute of Atmospheric Physics, UA-IAP-TR-72-21, Tucson, Arizona.
Little, E.L. 1950. Southwestern trees - a guide to the native species of New Mexico and Arizona. USDA Handbook No. 9, Government Printing Office, Washington, DC.
Rosenthal G. A. 1977. The biological effects and mode of action of L-canavaline, a structural analogue of Larginine. Quarterly Review of Biology 52:155-178.
NFTA 90-07 December 1990
Native to North America, Prosopis glandulosa Torrey is a small to medium-sized tree, 3-7 m tale with two recognized varieties. Prosopis glandulosa var. torreyana grows primarily in the deserts and drylands of the southwestern United States and northern Mexico (Hilu et al. 1982). P. glandulosa var. glandulosa is found from Mexico north to Kansas and east to Louisiana (Burkhart 1976). Commonly called mesquite, or honey mesquite, this nitrogen fixing tree was a key resource of the native people, providing food drink, alcohol fuel, medicine, and fertilizer.
Mesquite has spiny branches and leaves with 7-18 sets of paired leaflets. Its seed pod resembles the common pea or bean, 10-30 cm long and 5-10 mm diameter. The flower is a yellow inflorescence with many spikes. Hybridization is common and the taxonomy of mesquite is difficult (Hilu et al. 1982). Genetic variability is high with good potential for selection of individuals and ecotypes and plant breeding. The trees are self-fertile.
Honey mesquite will grow in a wide range of soils and is moderately salt and frost tolerant. It thrives under very high temperatures (>38°C) and survives in areas with very low precipitation ( < 200 mm annually), but it is usually found in areas with groundwater reserves. This tree has been found to occur in Death Valley with only 50 mm annual rainfall (Hilu et al. 1982). In its drier, western range it occurs along streams and in low-lying areas; in areas with more rainfall it occurs on open range or in chaparral.
Honey mesquite pods were a primary food of the residents of the SW North American deserts (Felger 1977). Pods are quite sweet and whole pod composition is 80% carbohydrate, 13% protein, 25% fiber, and 3% fat (Zolfaghari et al. 1982). The pods are easy to collect and store and, unlike most beans, are edible without cooking. Mesquite pods are still used as a food and beverage in Mexico. Processing and use is described in Meyer 1984 and Meyer et al. 1986. Pods could prove useful for production of flour, wine, tempe, and tofu products. R.S. Felger has proposed that the pods of this dryland-adapted tree will one day become as important as corn, rice, and wheat to the world food system. Bees favor the Sowers, and mesquite honey is highly valued for its flavor.
Grinding improves the use of honey mesquite pods for fodder. Sheep, goats, and pigs are able to use a higher percentage of mesquite pods in their diet than are cattle and horses. In 1965, 40,000 tons of pods were used as feed in Mexico (Lorence 1970). Leaves of mature honey mesquite are browsed by cattle only on deteriorated rangeland.
Mesquite wood (17,000 BTU/kg), chips, and charcoal are excellent fuels, and the wood smoke lends a pleasant flavor to cooked foods. Annual production on dry, low quality sites may be < 1 t/ha, but with sufficient water (even though slightly saline) trees can grow rapidly and yield >5 t/ha/yr (Felker et al. 1983).
Mesquite wood is very dense, specific gravity 0.7+, and has very balanced shrinkage on drying (Rodgers 1986). These properties make it excellent for woodworking. Mesquite is also used for fencing.
Mesquite has been used for a variety of medicinal purposes, including lice control, treatment of sore throats, and treatment of skin sores and ulcers (Felger 1977). Mesquite produces quality gums which may be economically valuable (Meyer 1984).
The refinement of a modern management system of intercropping with mesquite based on traditional practices (Lawson and Bean 1968) should receive high priority. The deeply-rooted, open-canopied trees may provide little competition for field crops and can fix 30 40 kg N/ha with 30% canopy cover (Jarrell et al. 1982). Soils under honey mesquite are enriched with nitrogen (Abrams et al. 1990). Mesquite may be established as tree crops for alley cropping, windbreaks, or timber belts.
Mesquite pods ripen simultaneously. They should be picked when the seed rattles in the pod, and stored in a dry place. Bruchid beetles can be killed by freezing or fumigating the pods. Mesquite seeds store well, maintaining excellent viability for years or even decades. There are about 30,000 seeds/kg. A modified commercial meat grinder with a plate with holes 1 cm in diameter is recommended for cleaning. The seeds have a very tough coating which must be scarified for germination by chipping or cutting, acid treatment, or exposure to boiling water. Acid, however, will damage seeds if cuts in the seed coat are made by mechanical cleaning. Seeds germinate best at temperatures between 20-40°C and can germinate within six hours of wetting at 34°C (Bainbridge and Virginia 1989). Preliminary studies of honey mesquite propagation from cuttings, tissue culture, and air layering suggest that these vegetative reproduction techniques are possible Bainbridge and Virginia 1989).
Scarified or sprouted seed should be planted in a welldrained soil mix. If small containers are used. transplant seedlings 2-3 weeks after germination to avoid disturbing the dominant tap root. Young seedlings can have root to shoot ratios as high as 10:1 (Mooney et al. 1977). Larger transplants can be grown in deep containers (7.5 cm wide by 100 cm deep) or in plant bands (4 cm x 40 cm).
Although mesquite is very drought tolerant, best growth is achieved in areas where the root system can reach groundwater. In areas with low rainfall, especially in fast-draining soils, irrigation may be required during establishment. Buried clay pot and deep pipe irrigation have considerable potential for establishing mesquite in hot desert regions (Bainbridge and Virginia 1989). Soils with compacted or hard pan layers should be deep ripped or worked with an auger to 1-3 m and planting strips cleared of competing vegetation. Direct seeding is also possible, if adequate soil moisture can be maintained for germination.
Mesquite forms symbioses with rhizobia and VA mycorrhizae. The active root nodules can occur many meters deep (Virginia et al. 1984, 1986: Jenkins et al. 1989). Nitrogen levels in the soil under plantationgrown mesquite were much higher than same-aged P. chilensis or P. alba (Abrams et al. 1990). Seedling rhizobial inoculation can be done with a liquid culture, clay or peat based inoculum, or with small amounts of soil from the active root zone under healthy, established trees nearby (Bainbridge and Virginia 1989). Fertilizer (especially phosphorus) may increase mesquite growth on poor soils, but both P and N can depress microbial symbionts and fertilization may be detrimental in the long term.
PESTS AND PROBLEMS.
Pods are commonly damaged by bruchid beetles. Mesquite hosts mistletoe and infection may be extensive on older trees. Trees rarely suffer significantly from other diseases and pests. although psyllids may be a problem in some areas, and spider mites have been a problem in glasshouse studies. When planted in southern Texas, var. torreyana from California, but not var. glandulosa, is subject to stem fungal diseases (P. Felker, pers. comm. 1990). Fencing or seedling protectors will usually be needed to protect young, transplanted mesquite seedlings from rabbits or other grazing animals. To ensure good tree form, the leader should be protected against grazing. As with other Prosopis species. mesquite can become a serious invader on disturbed lands or overgrazed rangelands.
Abrams, MM, W. M. Jarrell, HA. Smith and P.R. Clark 1990. Nitrogen accretion in soil and biomass production by three Prosopis species. Agrofor. Systems 10:93-97.
Bainbridge, DA. and R.A. Virginia. 1989. Mesquite, Species Notes 1. Systems Ecology Research Group, San Diego State University, San Diego, CA. 14 p
Burkhart, A. 1976. A monograph of the genus Prosopis. J. Arnold Arboretum 57:450-525.
Felger, R.S. 1977. Mesquite in Indian cultures of the Southwestern North America. In B.B. Simpson (cd). Mesquite: Its biology in two desert scrub ecosystems Dowden, Hutchinson & Ross. Stroudsburg, PA. p. 150-176
Felker, P. 1979. Mesquite: An all-purpose leguminous arid land tree. In GA. Ritchie (ed), New Agricultural Crops. American Association for the Advancement of Science, Westview Press, Golden, CO. p. 89-132.
Hilu, K.W., S. Boyd, and P. Felker. 1982. Morphological diversity and taxonomy of California mesquites (Prosopis, Leguminosae). Madrono 29(45):237-254.
Lawton, H.W. and L.J. Bean. 1968. A preliminary reconstruction of aboriginal agricultural technology among the Cahuilla Indian Historian 1(5):18-24,29.
Meyer, D., B. Becker.. M.R. Gumbmann, P. Vohra, H. Neukom, and R. Saunders. 1986. Processing composition, nutritional evaluation and utilization of mesquite (Prosopis spp) pods as a raw material for the food industry. I. Agric. Food Chem. 34(5):914-919.
Mooney, HA., B.B. Simpson. and O.T. Solbrig. 1977. Phenology, morphology, physiology. In B.B. Simpson (ed). Mesquite: Its biology in two desert scrub ecosystems. Dowden, Hutchinson & Ross, Stroudsburg, PA. p. 2443.
Virginia, R.A. and W.M. Jarrell. 1983. Soil properties in a mesquite dominated Sonoran desert ecosystem. Soil Sci. Soc. Amer. 1. 47:138-144.
FACT 97-03 June 1997
Pongamia pinnata (L.) Pierre has also been called Derris indica (Lam.) Bennet and Pongamia glabra Vent., all three of these names are still commonly found in literature. Pongamia pinnate is one of the few nitrogen fixing trees (NFTs) to produce seeds containing 30-40% oil. It is often planted as an ornamental and shade tree. This species is commonly called pongam, karanga, or a derivation of these names.
Pongam (Leguminosae subfamily Papilionoideae) is a mediumsized tree that generally attains a height of about 8 m and a trunk diameter of more than 50 cm. However, Troup (GOI 1983) reports trees attaining heights of 18 m. The trunk is generally short, with thick branches spreading into a dense hemispherical crown of dark green leaves. The bark is thin, gray to grayishbrown, and yellow on the inside (GOI 1983). The taproot is thick and long, lateral roots are numerous and well developed.
The alternate, compound pinnate leaves consist of 5 or 7 leaflets which are arranged in 2 or 3 pairs, and a single terminal leaflet.
Leaflets are 5-10 cm long, 4-6 cm wide, and pointed at the tip. Flowers, borne on racemes, are pink, light purple, or white. Pods are elliptical 3-6 cm long and 2-3 cm wide, thick walled, and family contain a single seed. Seeds are 10-20 cm long, flat, oblong, and light brown in color.
Native to humid and subtropical environments, pongam thrives in areas having an annual rainfall ranging from 500 to 2500 mm In its natural habitat, the maximum temperature ranges from 27 to 38°C and the minimum 1 to 16°C. Mature trees can withstand waterlogging and slight frost. This species grows to elevations of 1200 m, but in the Himalayan foothills is not found above 600 m (GOI 1983).
Pongam can grow on most soil types ranging from stony to sandy to clayey, including Verticals. It does not do well on dry sands. It is highly tolerant of salinity. It is common along waterways or seashores. with its roots in fresh or salt water. Highest growth rates are observed on well drained soils with assured moisture. Natural reproduction is profuse by seed and common by root suckers.
Distribution The natural distribution of pongam is along coasts and river banks in India and Burma. Native to the Asian subcontinent this species has been introduced to humid tropical lowlands in the Philippines, Malaysia, Australia, the Seychelles, the United States (Little undated), and Indonesia.
With a calorific value of 4600 kcal per kg, pongam is commonly used as fuelwood. Its wood is beautifully grained and medium to coarse textured However, it is not durable, is susceptible to insect attack, and tends to split when sawn. Thus the wood is not considered a quality timber. The wood is used for cabinet making, cart wheels, posts (NAS 1980), agricultural implements, tool handles and combs (GOI 1983).
A thick yellow-orange to brown oil is extracted from seeds. Yields of 25% of volume are possible using a mechanical expeller. However, village crushers average a yield of 20% (ICFRE, undated). The oil has a bitter taste and a disagreeable aroma. thus it is not considered edible. In India, the oil is used as a fuel for cooking and lamps. The oil is also used as a lubricant, water-paint binder, pesticide, and in soap making and tanning industries. The oil is known to have value in folk medicine for the treatment of rheumatism, as well as human and animal skin diseases. It is effective in enhancing the pigmentation of skin affected by leucoderma or scabies (ICFRE undated).
Fodder and feed.
Opinions vary on the usefulness of this species as a fodder. Troup (GOI 1983) reports that the leaves are eaten by cattle and readily consumed by goats. However, in many areas it is not commonly eaten by farm animals. Its fodder value is greatest in arid regions. According to Singh (1982) the leaves contain 43% dry matter, 18% crude protein, 62% neutral detergent fiber, 40% acid detergent fiber, and in vitro dry matter digestibility of 50%. The presscake, remaining when oil is extracted from the seeds, is used as a poultry feed
Incorporation of leaves and the presscake into soils improves fertility. Dried leaves are used as an insect repellent in stored grains. The presscake, when applied to the soil has pesticidal value, particularly against nematodes. String and rope can be made from the bark fiber.
Pongam is often planted in homesteads as a shade or ornamental tree and in avenue plantings along roadsides and canals. When planted as a shade or ornamental tree' branch pruning may be necessary to obtain a trunk of appropriate height. It is a preferred species for controlling soil erosion and binding sand dunes because of its dense network of lateral roots. Its root, bark, leaf, sap, and flower also have medicinal properties.
Pongam is easily established by direct seeding or by planting nursery-raised seedlings or stump cuttings of 1-2 cm rootcollar diameter. Propagation by branch cuttings and root suckers is also possible. In peninsular India, the seeding season is April to June, and the seed yield per tree ranges from about 10 kg to more than 50 kg. There are 1500-1700 seeds per kg Seeds, which require no treatment before sowing, remain viable for about a year when stored in air-tight containers.
Seed germinates within two weeks of sowing. Seedlings attain a height of 25-30 cm in their first growing season. Transplanting to the field should occur at the beginning of the next rainy season when seedlings are 60 cm in height (GOI 1983). Seedlings have large root systems. Soil should be retained around the roots during transplanting. Seedling survival and growth benefit from annual weed control for the first three years after transplanting.
The spacing adopted in avenue plantings is about 8 m between plants. In block plantings, the spacing can range from 2 x 2 to 5 x 5 m. Pongam seedlings withstand shade very well and can be interplanted in existing tree stands. This species can be regenerated by coppice management Information on management practices to maximize seed or biomass production is not available and should be investigated Because it tolerates moderate levels of salinity, Pongam is an ideal candidate for saline soil reclamation.
Nodulation is reported in Pongam (Dayama, 1985). In nurseries and in the field the presence of nodules on uninoculated pongam seedlings is common. Therefore, this species may not be specific in its Rhizabium strain requirement
Pongam attracts many pests and diseases. Some of the important pests are Parnara mathias, Gracillaria sp., Indarbela quadrinotata Myllocerus curvicornis, and Acrocercops sp. (Anon. 1994). Attacks by these insects cause whitish streaks and the formation of galls on affected leaves. The lateral spread of roots of this species. about 9 m in 18 years, is greater than most other tree species (Misra and Singh 1987). Moreover, it produces root suckers profusely. Because of these characteristics, pongam is unsuitable for agroforestry and has the potential to become a weed if not managed carefully.
Anon. 1994. Biological control agents of social forestry insects. Entomology Research Institute, Loyola College, Madras India 11 p.
Beddome, R.H. 1869-74. The flora sylvatica for Southern India 2 volumes, illustrated Madras India.
Dayama, O. P. 1985. Effect of sucrose on the growth, nodulation and nitrogen content of Pongamia pinnata Nitrogen Fixing Tree Research Reports 3: 9.
GOI (Government of India). 1983. Troup's The Silviculture of Indian Trees, Volume IV, Leguminosae. Government of India Press, Nasik, India. 345 p.
ICFRE (Indian Council of Forestry Research and Education). Undated. Pongamia pinnata Forest Research Institute, Dehra Dun, India 12 p.
Lewis, G. P. 1988. Notes on NFT nomenclature. Nitrogen Fixing Tree Research Reports 6: 23.
Little, E. L. Jr. Undated. Common fuelwood crops. Communi Tech Associates Morgantown, West Virginia. 354 p.
Misra, C. M. and Singh, S. L. 1987. Ecological evaluation of certain leguminous trees for agroforestry. Nitrogen Fixing Tree Research Reports 5: 5.
NAS, 1980. Firewood crops: shrub and tree species for energy production, volume 1. National Academy of Sciences Washington, D.C. 237 p.
Singh, R.V. 1982. Fodder trees of India Oxford and IBH Publishing Co. New Delhi, India 663 p.
FACT 97-02 January 1997
A small to medium-sized tree, Guazuma ulmifolia is widely distributed throughout the Caribbean, Mexico, and Central andSouth America The wood is used for posts, general carpentry, light construction and charcoal. It is an important source of livestock fodder in many areas, particularly during the dry season when pasture grasses are unavailable.
Common names include guÃ¡cima guÃ¡cimo (Spanish); tablote, majagua de toro (Mexico); tapaculo (Guatemala, El Salvador); cualote (Guatemala Honduras, El Salvador, Colombia); contamal (Guatemala); chicharrÃ³n (El Salvador); kamba aka guasa (Paraguay); iumanasi papayillo (Peru); coco (Bolivia); cambÃ¡-acÃ¡ guazuma (Argentina); bacedar, bastard cedar (Jamaica, Trinidad); bois d'orme, West Indian Elm (Trinidad); pigeon wood (Tobago); bay cedar, caulote, pixoy (Belize); bois d'orme. orme d'AmÃ©rique (French); mutamba fruta-de-macaco. embira pojÃ³ (Brazil) (Little and Wadsworth 1964, Lopez et al. 1987, Lorenzi 1992).
Synonyms include Guazuma guazuma (L.) Cockerell, G. tomentosa H.B.K., G. polybotrya Cav., and Theobroma guazuma (L.) Poveda.
Guazuma ulmifolia Lam, family Sterculiaceae, grows to 30 m in height and 30 40 cm in diameter with a round-shaped crown. The alternate. ovate to lance-shaped leaves are 5-7 cm long and 2-5 cm wide. with finely saw-toothed margins. The flowers are brownish-yellow and form in clusters at the base of the leaves. The seeds are black, round to elliptic, 1.5-3 cm long, and hard. Seed capsules contain 5 cells which open at the apex and contain many seeds, 3-5 mm in diameter (Little and Wadsworth 1964, Lopez et al. 1987).
Young twigs are covered with rust-brown or light-gray starshaped hairs. The bark is gray or gray-brown and becomes furrowed and rough or slightly shaggy (Little and Wadsworth 1964).
Guazuma ulmifolia is widely adapted, growing in alluvial and clay soils, and in humid and dry climates. A pioneer species that grows best in full sunlight, it colonizes recently disturbed areas and is also found growing along stream banks and in pastures. It is a common species in secondary forest growth.
Guazuma ulmifolia grows mainly at elevations below 400 m with mean annual temperatures often above 24°C (Dunsdon et al. 1991). It is occasionally found growing up to 800 m in Brazil (Lorenzi 1992), 1000 m in Costa Rica (Vallejo and Oviedo 1994) and 1200 m in Guatemala (Witsberger et al. 1982). In its natural habitat annual rainfall is 600-1500 mm, but it grows well in areas with annual rainfall as high as 2500 mm (Dunsdon et al. 1991).
Leaves remain on the tree all year except in very dry areas where the leaves drop at the end of the dry season. In Puerto Rico, G. ulmifolia flowers from March to October and produces seed all year (Little and Wadsworth 1964). In Paraguay, it flowers in January and produces seed from July to August (Lopez et al. 1987). In Brazil, it flowers from January to September and produces seed in August and September (Lorenzi 1992).
Guazuma ulmifolia is found in the Caribbean, Mexico, Central America and Colombia Ecuador, Peru, Bolivia Paraguay, Argentina and Brazil. It has been cultivated in India for over 100 years. It has been introduced recently to Indonesia.
The wood is used for posts, interior carpentry, light construction, boxes and crates, shoe horns, tool handles, fuelwood. and charcoal. The sapwood is light brown and the heartwood is pinkish to brownish. The wood is easy to work. with a specific gravity of 550-570 km/m³ (Little and Wadsworth 1964,Lopezetal. 1987).
In dry areas throughout its native range, G. ulmifolia is an important source of fodder for livestock, particularly at the end of the dry season when pasture grasses are not available. Naturally regenerated trees are left scattered in pastures to provide shade. Trees are also planted as live posts for fences around pastures. In Puerto Rico, immature fruits and leaves are fed to horses and cattle, and fruits are fed to hogs (Little and Wadsworth 1964). Guazuma ulmifolia is a preferred fodder tree in Jamaica Farmers feed the leaves and fruit to cattle, usually during the dry season (Morrison et al. 1996). Crude protein content of young leaves and stems ranges from 16-23% and 7-8%, respectively. In vitro dry matter digestibility for young leaves and stems ranges from 56-58% and 31-36%, respectively (Araya et al. 1994, Medina et al. 1994). Basal leaves contain 2.4% tannins (dry matter) (Araya et al. 1994).
In a study in Honduras. G. ulmifolia pruned four times in one year produced 10 kg/tree dry matter (leaves and young stems). Of the dry matter, 38% was edible (Medina et al. 1994).
A study in Guatemala compared the weight gain of young goats fed fodder of G. ulmifolia, Cordia dentata, and Panicum maximum. The average weight gain with G. ulmifolia was 71 g/day, compared to 60 g/day with C. dentata, and 42 g/day with P. maximum (Medina 1994).
A beverage of crushed seeds soaked in water is used to treat diarrhea, dysentery, colds, coughs, contusions, and venereal disease. It is also used as a diuretic and astringent (Vallejo and Oviedo 1994).
The seeds are edible, fresh or cooked. The tough, fibrous bark and young stems are used to make rope and twine. Honey bees forage on the flowers (Little and Wadsworth 1964).
Guazuma ulmifolia can be established by direct seeding or by planting cuttings, root-stumps or bare-root seedlings. Seeds require scarification before planting. Pour boiling water over seeds, let them soak for 30 seconds and then drain the water (Dunsdon et al. 1991). For fresh seeds, germination occurs in 7-14 days at a rate of 60-80%. Seedlings are ready for outplanting when they reach a height of 30-40 cm (about 15 weeks). For root stumps, plants are left in the nursery for 5-8 months or until they reach a stem diameter of 1.5-2.5 cm. There are between 100,000 and 225,000 seeds per kilogram (Vallejo and Oviedo 1994, Lorenzi 1992. Dunsdon et al. 1991).
Hilje et al. (1991) reviews pests of G. ulmifolia in Central America Phelyypera distigma is a common defoliating insect. Arsenura armida and Epitragus sp. are defoliators that cause problems occasionally. Automeris rubrescens. Hylesia lineata, Lirimiris truncata and Periphoba arcaei are
defoliating insects that have been observed at least once. A stem borer Aepytus sp. is an occasional problem.
Araya, J., J. Benavides, R. Arias. and A. Ruiz. 1994. IndentificaciÃ³n y caracterizaciÃ³n de Ã¡rboles y arbustos con potential forrajero en Puriscal, Costa Rica. In: J. E. Benavides (ed), Arboles y arbustos forrajeros en America Central. Volumen 1. Serie TÃ©cnica Informe TÃ©cnico N° 236. Centro AgronÃ³mico Tropical de InvestigaciÃ³n y EnsenaÃ±za (CATLE) . Turrialba, Costa Rica p. 31-63.
Dunsdon, A.J., J.L. Stewart, and C.E. Hughes. 1991. International trial of Central American dry zone hardwood species. Species descriptions and biomass tables. Oxford Forestry Institute. UK. p. 39-41.
Hilje, L., C. Araya and F. Scorza 1991. Plagas y enfermedades forestales en America Central: guia de campo. Serie TÃ©cnica, Manual TÃ©cnico N°4., CATIE. Turrialba, Costa Rica p. 185.
Little, E.L., and F.H. Wadsworth. 1964. Common trees of Puerto Rico and the Virgen Islands. Agricultural Handbook No. 249. USDA Forest Service. Washington, D.C., USA. p. 338-340.
Lopez J.A., E.L. Little, G.F. Ritz J.S. Rombold, and W.J. Hahn. 1987. Arboles comunes del Paraguay. Peace Corps. Washington, D.C., USA. p. 364-365.
Lorenzi. H. 1992. Ãrvores Brasileiras. Manual de identificaÃ§Ã£o e cultivo de plantas arbÃ³reas nativas do Brasil. Editora Plantarum LTDA. Nova Odessa, SP, Brasil. p.327.
Medina, J.M. 1994. Observaciones sobre el consumo de follaje de guÃ¡cimo (Guazuma ulmifolia), Tiguilote (Cordia dentata), y Pasto Guinea (Panicum maximum) por cabras semi-estabuladas. In: Arboles y arbustos forrajeros en America Central. Volumen 1. p. 249-256. See Araya et al. 1994.
Medina J.M., B. Rouyer, M. Tejada M. Layus, and B. Boiron. 1994. EvaluatiÃ³n preliminar de la producciÃ³n de biomasa de especies leÃ±osas bajo crecimiento natural en la zone Sur de Honduras. In: Arboles y arbustos forrajeros en America Central. Volumen 1. p. 181 -188. See Araya et al. 1994.
Morrison, B.J., M.A. Gold., and D.O. Lantagne. 1996. Incorporating indigenous knowledge of fodder trees into small-scale silvopastoral systems in Jamaica. Agroforestry Systems 34: 101-117.
Witsberger, D., D. Current, and E. Archer. 1982. Arboles del Parque Deininger. DirecciÃ³n de Publicaciones, Ministerio de EducatiÃ³n. San Salvador, El Salvador. p. 248-249.
Vallejo, M.A., and F.J. Oveido. 1994. Caracteristicas botanical, usos y distribuciÃ³n de los principales arboles y arbustos con potencial forrajero de America Central. In: Arboles y arbustos forrajeros en America Central. Volumen 2. Serie TÃ©cnica. Informe TÃ©chnico N° 236. Centro AgronÃ³mico Tropical de InvestigaciÃ³n y Ensenanza (CATIE). Turrialba, Costa Rica p. 676-677.
NFTA 95-06 September 1995
The African winterthorn is famous for its unusual phenology It sheds its leaves with the rains and is green during the dry season, favoring crop production beneath its canopy and reducing the need for a fallow period on poorer soils.
Faidherbia albida (Del.) A. Chev. (syn. Acacia albida Del.) is a monotypic genus in the legume subfamily Mimosoidae. Normally a deciduous tree to 15 m it can reach 25 m or more in southern Africa. with a large rounded crown and spreading branches. and trunk diameters of 1 m or more. It is distinguished by its phenology, whitish twigs and paired thorns. blue green bipinnate leaves lacking a petiolar gland, but with glands between nearly all its 2-12 pinnate pairs. The inverted phenology, does not occur in seedlings until their tap roots are well into the water table.
Flower buds appear soon after leaves on current season's growth. About 100 creamy white flowers occur on spikes up to 16 cm long, but most abort and normally 5 or less mature into pods 3-4 months later (Zen-Nlo & Joly in Van Den Beldt 1992). Pods (11-30 cm long x 1.4-6.7 cm wide) are orange to reddish brown, often coiled or twisted, and contain up to 30 seeds. Seeds are dispersed by herbivores eating the indehiscent pods or by the pods floating down rivers. Populations in Cameroon show levels of outcrossing from 50-100%, with variation in a population throughout the flowering season. It is a diploid species (2n = 26) over most of its range; a polyploid (2n = 52) has been recorded from Israel (Halevy 1971).
Distribution and Ecology
Its natural range extends throughout dry tropical Africa into the Middle East and Arabia, from 270 m below sea level in Palestine up to 2500 m in Sudan (Wickens 1969). It has been introduced into India, Pakistan, Nepal, Peru, Cyprus, Cape Verde and the Ascension Islands. It grows in a wide range of climates and habitats, either scattered or gregarious. in closed canopy woodland or open savanna and in cultivated lands. It is usually a pioneer on alluvial flats but can form part of a fire climax vegetation in the west African savannas, where optimal conditions are between 500-800 mm annual rainfall. In east Africa it grows well with 1800 to 8 mm or less, provided it taps underground water. It is susceptible to frost damage.
The species develops into large populations on deep sands and alluvia in the Sahelian belt heavy vertisols in the Ethiopian highlands, and around many of the rift valley lakes or riverine and valley bottoms in east and southern Africa. It withstands flooding for a number of months along the Zambesi and Nile rivers and in paddy fields.
The mulch created by falling leaf litter and the canopy shade at planting time creates as improved microclimate (better rainfall infiltration, reduced evapotranspiration and temperature extremes) resulting in increased crop yields (Charreau & Vidal 1965 and Poschen 1986 in CTFT 1988). Geiger et al. (in Vandenbelt 1992) argue that the fertility effect may in part be due to the tree developing on more fertile microsites rather than creating them. Animal dung and urine commonly accumulate under these shade trees.
In Zimbabwe, average leaf fall was calculated at 0.73 t/ha/yr at 11 trees/ha (Dunham 1989) compared with 0.580.97 t/ha/yr at 10 trees/ha in Senegal. Small leaflets rapidly decompose and increase the soil organic matter. In sandy Senegalese soils. mineralized carbon increased by 73%, and total N and available P almost doubled under the canopy compared with open fields (Charreau & Vidal 1965 in CTFT 1988). The species is well suited to subsistence farming when the crop is a cereal (millet. sorghum and maize). Groundnuts yields can be depressed under the canopy from increased vegetative growth due to excess N in relation to P & K. Trees also integrate well in the rice paddy fields and are used as shade for coffee. Analysis of economic returns from cereal cropping under F. albida in the eastern highlands of Ethiopia showed an income gain of 82% was possible where cropping was under 65 trees/ha compared to treeless fields (Poschen 1986 in CTFT 1988).
The nutritional value of leaves and fruit is well documented. Pods fall towards the end of the dry season when fodder is scarce; leaves and branchlets are lopped around this time. Fruit production is highly variable between trees and between years. Average pod production ranges from 6 to 135 kg/tree/yr in the Sudanian zone. In Zimbabwe (Mane pools) 2 trees averaged 161 kg/tree/yr (Dunham 1990). and a single tree varied from 40-339 kg/yr. Average pod production in the Mana woodland was 590 kg/ha/yr at 11 tree/ha. The pods fall over a period of months. In west Africa pods are sometimes shaken down, collected, and fed to animals or sold in markets or at roadsides.
Trees are lopped in a number of countries for leaves and fuelwood, but this in turn affects the pod production and can extend foliage retention into the rainy season. Leaves, pods and seeds contain 200, 150 and 260 g total protein/kg of dry matter; total protein digestibility can reach 73%. Tannins limit digestibility, but incorporating pods into low quality fodder enhances ingestion without reducing digestibility. Milling the pods increases digestion of seeds.
While the wood is used for fuel. it is lighter (specific gravity 0.6-0.7) and less suitable than many African acacias. Because of its size, the wood is locally used for dugout canoes, mortars, doors and some light carpentry but it is susceptible to borers. Cooked seeds are eaten as a human famine food both in Ghana. Nambia. Zambia and Zimbabwe. Flowering later than most plants, it is a useful source of pollen and nectar for honey bees. and log beehives are made from its bark. Widely used for local medicines. Ovambo Namibians use its bark for toothbrushes and is reputed to contain Fluorine. Thorny branches are used for fencing.
Establishment and Growth
Hard coated seeds store well under dry conditions, and are often extracted by pounding the pods in a mortar. Pretreatment is needed for rapid uniform germination. Mechanical scarification works best for small lots. Dipping seed for 5-15 minutes in cone. sulphuric acid or covering the seed with boiling water then allowing to cool for 24 hours are also effective. There are 7,000-20,000 seeds/kg, the seeds are smaller in west Africa than those from the east and south. Seeds can be sown directly or nursery planted, ideally using long poly tubes (30x8 cm), with regular watering and freqent mechanical root or air root pruning (CTFT 1988). Seedlings can be transplanted 3-6 months later. Spacing at 10x10 m is common, but varies with moisture availability and local farming traditions. Establishment in farmers' fields affords protection and weeding as the species is vulnerable to competition. Tractor ploughing between mature trees can promote coppicing from damaged roots.
Extremely variable growth rates have been recorded because of genetic and site variation. Isozyme studies at OFI & CIRAD-FÃ´ret indicate a large genetic diversity within the species, distributed into 3 major areas, west, southern and northeastern Africa with the latter being a key area of diversity. Larger seeded east and southern African provenances initially grow faster than the west African provenances and have a higher shoot/root ratio, but can collapse after a couple of years in the more arid west Africa where water tables are deep. On average 1-1.5 m annual height growth has been recorded on favourable sites in Africa. Clonal propagation from shoot and root cuttings and from callus has been developed although elite stock needs to be identified. Seed from a broad range of provenances is available from members of the African Acacia trials network (OFI, CIRAD-FÃ´ret, DFSC, FAO).
Faidherbia albida nodulates with Bradvrhizobium bacteria common in tropical soils, and has VA mycorrhizal associations. It develops both surface and deep tap roots and in sandy Sahelian soils the highest densities of Bradyrhizobium were found at the water table 30-35 m below the surface. In moister sites abundant nodules can be found near the surface (Dupuy & Dreyfus in Van Den Beldt 1992).
Apart from damage from foraging animals and rodents, the principal pests and diseases are insects and nematodes. Bruchid beetles can destroy up to 50% of the seeds. Seedlings are attacked by sap sucking insects or cochineal bugs, and nematodes (Meloidogyne javanica, M. icognita) favored by the moist nursery conditions. Caterpillars of the moth Crypsotindia conifera can defoliate adult trees by up to 50% in Nigeria and Zimbabwe. For control methods see CTFT (1988). Insect galls (leaf and flower) and parasitic plants occur sporadically in its native range. It is less susceptible to fungal diseases due to its inverted phenology, but leaf blight (Rhizoctonia solani) has been recorded on nursery plants in India Felled timber is susceptible to a variety of wood borers. It is vulnerable to competition in establishment. The thorns can be a deterrent to farmers not used to them.
Centre Technique Forestier Tropical (1988) Faidherbia albida A. Chev. (syn. Acacia albida Del.) Monographie. CTFT/CIRAD. Nogent-sur-Marne, France. 72pp. (English version 1989).
Dunham, K. M. (1989) Litterfall, nutrient-fall and production in an Acacia albida woodland in Zimbabwe. Jour. of Trop. Ecol. 5, 227-238
Dunham, K. M. (1990) Fruit production by Acacia albida trees in Zambezi riverine woodlands. Jour. of Trop. Ecol. 6, 445-457
Halevy, G. (1971) A study of Acacia albida in Israel. LaYaaran 21 (3/3) 97-89, 52-63
Van Den Beldt, R.J. (Ed.) (1992) Faidherbia albida in the West African Semi-arid Tropics Proceedings of a Workshop, 22-26 April 1991, Niamey, Niger. ICRISAT & ICRAF, Patancheru, A.P. 502324, India 206pp.
Wickens G.E. (1969). A study of Acacia albida Del. (Mimosoidae). Kew Bulletin, 23 (2): 181-202.
FACT 97-04 June 1997
Well known as an ornamental street tree, honey locust was widely advocated as a livestock feed early in the 20th century. Silvopastoral cultivar development began in the 1930's at the Tennessee Valley Authority in the United States. Because it can provide a source of fodder, protein, energy, and erosion control, honey locust is being tested in many temperate, Mediterranean and highland tropic regions of the world.
Gleditsia triacanthos L., family Leguminosae (subfamily Caesalpinioideae), attains a normal height of 15-25 m and 0.51.0 m diameter (maximum height 50 m, diameter 1.8 m). Trees have a short bole and open, narrow or spreading crown with reddish brown to black scaly ridged bark, often covered in clusters of large, branched thorns. Leaves are 10-20 cm long, deciduous, pinnate or bi-pinnate with 15-30 leaflets, 1-3 cm long (Harrow et al, 1996). Flowers are a pale-yellow to greenish-yellow color and appear from early May in the southern United States to late June in the north. Seeds are 0.5 to 1.5 cm long, dark brown in color, smooth, with a hard, impermeable seedcoat. Seeds ripen from mid-September to late October in the United States. Mature pods begin to drop by mid-September and continue to drop throughout the winter.
Within the natural range, a large amount of variation exists in both climate and soil conditions. Honeylocust occurs naturally in humid and subhumid climate regions. Average annual precipitation varies from 510 mm to 1520 mm, the frost-free period varies from a minimum of 150 to 300 days (Blair, 1990). Honeylocust grows naturally to 760 m but has been planted from sea level to 1,500 meters in temperate latitudes and will grow above 2,500 m in subtropical highlands.
Honeylocust is a shade intolerant tree, and will only become established in openings. It has a strong taproot and profusely branched root system. Its best growth in the United States is found on deep soils (pH 6.0 to 8.0) in moist, alluvial floodplains between 35° and 40° N. latitude. It generally grows poorly on gravely or heavy clay soils and often fails on shallow soils (Blair, 1990). Honeylocust is resistant to both drought and salinity, and coppices vigorously when cut.
Honeylocust grows naturally in the eastern half of the United States (Blair, 1990). It has become naturalized east of the Appalachian mountains from Georgia to New England in the East, and north to South Dakota in the West (Harrow et al, 1996). As a fodder tree, Honeylocust is being tested in France, Spain, Germany, Greece, Algeria New Zealand, Australia South Africa India Bhutan, Nepal and Guatemala (Wilson, 1993).
Honeylocust pods have long been recognized for their animal fodder value in silvopastoral systems (Scanlon, 1980). Widely spaced overstory fodder trees (fodder orchard), can be planted for on-farm silvopastoral systems, providing light shade, soil enrichment and stabilization, and should be compatible with a variety of forage, grain, vegetable, woody perennials or animals in the understory. In addition to yields from understory enterprises, the pods function primarily as a late fall/winter animal feed supplement (Wilson, 1993). In France, results from sheep feeding trials using pods as a feed supplement indicate that selected grafted clones produce high quality fodder and good weight gain (Dupraz and Baldy, 1993). Sheep are able to digest the majority of seeds within the pods. However, for complete utilization by sheep, cattle, horses or swine, pods and seeds must be machine processed.
Honeylocust leaves are an excellent source of fodder, contain 20 percent crude protein, low lignin and ensile well. Coppice regrowth retains high protein and low lignin levels (Baertsche et al, 1986). However, limited studies indicate very low biomass yield response when planted from seed and harvested with a forage harvester during the first year's growth (Gold. 1984) or when 1-year-old seedlings were coppiced (at age 2) after a full year for establishment and growth (Addlestone, 1996).
Strong, hard and durable. resistant to shock, with attractive figure and reddish-brown color, it is used locally for fence posts, pallets, crating, general construction, railroad ties (Panshin and De Zeeuw, 1970) and by woodworkers for making guitars (A. Wilson, pers. comm). Wood specific gravity is 0.60 green, 0.67 ovendry (Panshin and De Zeeuw, 1970), and is considered an excellent source of fuelwood.
It has been widely planted as an ornamental replacement for American elm in the United States and Canada with over fifty recognized cultivars (Santamour and McArdle, 1983). Thornless trees can be produced by budding with scionwood taken from the thornless upper branches of selected cultivars. However, seedlings from such trees are thorny. Thornless seedlings can be selected at a very early age (within ten weeks of germination) for use as ornamental cultivars.
Honeylocust is hardy and drought tolerant, and can be-grown in windbreaks with the added benefit of pod production.
Mature pods can be collected after they drop off, by hitting branches to jar the pods loose, or by clipping pods from the branches. After harvest, pods should be stored at 0° C to prevent fermentation of the pods and. if bruchid seed weevils (Amblycerus robiniae) are present in the pods, it will prevent them from spreading within the pods. A good pod crop can exceed 20 kg of cleaned seed per tree. Results from a rangewide provenance/progeny test show that seed yield averages 5,200 seeds/kg (varying from 3,300 to 14,300 depending on the seed source) with high purity and soundness.
To prepare pods for mechanical seed extraction, place them in a convection/seed drying oven for at least 2 hours at 35° C. Honeylocust seed will remain viable for many years if stored dry at 1-4° C. Successful germination requires seed scarification via immersion in concentrated sulfuric acid (60 120 minutes followed by thorough rinsing), hot water (82°C), or by mechanical means. Germination of sound seed should be in the range of 75-95 percent. Seeds should be sown .5 to 1.5 cm deep and if properly scarified, complete germination will occur within 21 days of sowing.
For successful in propagation of honeylocust, chip budding with green wood in August works best, and June budding is also satisfactory. Dormant scionwood results in a low percentage of successful grafts (pers. comm. A. Wilson).
One-year-old seedlings (or budded/grafted material) can be outplanted the following spring. Dormant, nursery grown seedlings can be stored, barerooted, at about 0° C for several weeks before outplanting. Due to large variation in pod production from different parent trees, and the presence of both male and female trees, only grafted seedlings are recommended for planting in order to secure consistently high production at an early age. Grafted seedlings begin to bear pods at age three and by age eight will produce 20-75 kg dry weight per tree (Wilson, 1993).
Male trees (about 10%) must be included in or adjacent to fodder orchards to ensure pollination of female trees. When established in working pastures,young trees need protection via plastic tree shelters or electric fencing (Wilson, 1993).
Appropriately managed, average annual pod production at age 10 of 40 kg/tree appears feasible. Planting 75 trees/ha (excluding male trees) would yield 3,000 kg/ha, sufficient to provide 100 sheep a 1.5 kg ration of pods for 20 days. Using conservative yield estimates from grafted trees, economic analyses indicate internal rates of return varied from 9 - 13% (Wilson, 1991).
Typical of many caesalpinioid genera. Gleditsia triacanthos do not nodulate and lack an ability for symbiotic fixation of atmospheric nitrogen (Allen and Allen, 1981).
Thorns on mature trees (twigs, branches and bark) are extremely dangerous as they can puncture tractor tires and injure livestock and increase the difficulty of orchard/windbreak management. Volunteer reproduction of thorny seedlings, usually derived from seeds eaten and not digested by wild and domestic animals. is also a concern. The mimosa webworm, Homadaula anisocentra is a serious defoliant and heavy infestations of spider mites (Eotetranychus multidigituli) occur during dry weather and can also defoliate a tree (Blair, 1990).
Research needs include additional production data from silvopastoral systems, development of consistent, heavy bearing, genetically thomless, high protein cultivars for a range of sites and end uses; and development of high sugar varieties for ethanol production (Gold and Hanover, 1993).
Baertsche, S.R., M.T. Yokoyama, and J.W. Hanover. 1986. Short rotation, hardwood tree biomass as potential ruminant feed-chemical composition, nylon bag ruminal degradation and ensilement of selected species. I. Anim. Sci. 63:20282043.
Blair, R.M. 1990. Gleditsia triacanthos L. Honeylocust. ln: R.M. Burns and B.H. Honkala, Tech. Coordinators. Silvics of North American Trees, vol. 2 Hardwoods. USDA Handbook 654. pp. 358-364.
Dupraz, C. and C. Baldy. 1993. Temperate agroforestry research at INRA, Montpellier, France. In R.C. Schultz and J.P. Colletti, eds. Opportunities for Agroforestry in the Temperate Zone Worldwide: Proceedings of the Third North American Agroforestry Conference. August 15-18, 1993. Ames, lowa U.S.A. pp. 445-449.
Gold, M.A. and J.W. Hanover. 1993. Honeylocust (Gleditsia triacanthos L.): Multipurpose Tree for the temperate zone. International Tree Crops Journal 7(4): 189-207.
Harlow, W.M., E.S. Harrar, J.W. Hardin and F.M. White. 1996. Textbook of Dendrology. Eighth Edition. McGrawHill, Inc. New York. 534 p.
Wilson, A.A. 1993. Silvopastoral agroforestry using honeylocust (Gleditsia triacanthos L.). In R.C. Schultz and J.P. Colletti, eds. Opportunities for Agroforestry in the Temperate Zone Worldwide: Proceedings of the Third North American Agroforestry Conference. August 15-18,1993. Ames, lowa U.S.A. pp. 265-269.
A complete set of references is available from FACTNet
FACT 96-02 January 1996
Andira inermis (Sw.) Kunth ex DC (Berendsohn 1989) is a nitrogen fixing tree that is commonly grown as an ornamental. It has a handsome spreading crown, evergreen foliage, showy pink flowers and responds easily to management. In El Salvador it is known as almendro de rio or river almond because its fruits are similar to the fruits of Terminalia catappa (beach almond). Andira inermis is a multiple use tree that has not been extensively used in agroforestry or other reforestation programs because of relatively slow growth rates; however, it offers refuge for wildlife year-round and could be used as fodder for ruminants and other domestic animals.
This tree is a legume that belongs to the Papilionoideae subamily. It grows to 35 m in height and more than 90 cm in diameter (Allen and Allen 1981, personal observations). It has pink flowers in racemes that are self-incompatible and outcrossers (Bawa 1974). It has a dense and spreading crown with bright tan young leaves and shiny green mature leaves with entire margins. Leaves are pinnately compound with 7 to 17 leaflets. The stem has a rough outer surface. It has a drupelike fruit with one seed that does not open at maturity, an exception among the legumes (Witsberger et al. 1982, Little and Wadsworth 1964). In the Pacific plains of Guatemala, the trunk frequently forms buttresses up to 3 m tall (Standley and Steyermark 1964).
Synonyms include Andira jamaicensis (W. Wright) Urban and Geoffroya inermis W. Wright (Little and Wadsworth 1964).
The number of common names that Andira inermis has is related to its widespread distribution, many uses and botanical characteristics. Names include Almendro de rio (river almond) and amendro macho in El Salvador, Guacamayo in Honduras, came asada in Costa Rica, moca blanca in Puerto Rico, and cabbage angelic, partridge wood or cabbage bark in the United States (Witsberger et al. 1982, Little and Wadsworth 1964).
Andira inermis is found in riparian zones, along rivers and in areas with a high water table. It grows in alluvial forests in Central America but may be found in drier areas. It is found along roadsides, river banks, woodlands and pastures, from sea level to 900 m above sea level (Witsberger et al. 1982,
Little and Wadsworth 1964). It requires low light for establishment and high light for development. It is an evergreen tree with the foliage continually being replaced throughout the year, especially before flowering (personal observations). In Puerto Rico, two flowering seasons are observed, one between January and February and the second one, between May and September (Little and Wadsworth 1964). In Barro Colorado Island, PanamÃ¡, trees may flower for nine months under suitable moist conditions (Croat 1978). This pattern is also observed in trees growing in urban areas in El Salvador where trees flower between December and July (personal observations).
Andira inermis is native from southern Mexico to Peru, Bolivia and Brazil. It has been introduced in the Antilles, Caribbean islands, Florida and Africa (Witsberger et al. 1982).
Planted in parks and yards Andira inermis is a very attractive tree with a dense, spreading crown. showy pink flowers and bright colored leaves.
It is used as a shade tree in coffee plantations because it has a spreading crown and responds well to pruning (Witsberger et al. 1982).
Bats eat the fruits. Flowers are visited by bees, birds, and butterflies (Allen and Allen 1981; Janzen 1976; Little and Wadsworth 1964).
Preliminary studies by scientists at the University of El Salvador showed that the foliage is edible and palatable for ruminants. Research is now being done with rabbits (Jacob Palacios, personal communication).
The wood is very hard, heavy (0.77g/cm³), and very resistant to attack by fungi and termites (GuzmÃ¡n 1947; Little and Wadsworth 1964; Behrendt et al. 1968; Allen and Allen 1981). Andira inermis lumber has been used for bridges, railroad tracks and waterfront docks and also to make furniture, billiard-cues, umbrella handles and boats (Little and Wadsworth 1964).
The bark is reported to have vermifuge, purgative and narcotic properties (GuzmÃ¡n 1947). Prunings from shade trees in coffee plantations are good firewood. In the wild, this tree also offers a suitable environment for some plant epiphytes like orchids, bromeliads, mosses and ferns. In conservation programs, it has been used to restore degraded watersheds where moist conditions are prevalent (El Salvador Forest Service, personal communication).
Mature fruits are collected and kept under cool conditions. The hard seeds need to be scarified before planting. The El Salvador Forest Service recommends making a cut on the hard fruit endocarp with a file and then planting them in seed beds or plastic bags.
A recent seed treatment study for A. inermis compared seeds that were scarified with a file; placed in hot water at two temperatures (70°C and 80°C) for 5, 10, and 15 seconds; or non-treated (Navarrete and Orellana, unpublished).
Seeds started to germinate at week five. Maximum germination for all treatments was observed at week 16. Germination was 43% to 56% for all treatments. The lowest germination recorded was 43% and 46% from seeds at 80°C for 15 seconds and non-treated control, respectively.
One-year-old plants, 50 cm tall or more, can be transplanted during the rainy season. Andira inermis can also be direct seeded. Two or three seeds, per site, are planted directly in the field (El Salvador Forest Service, personal communication).
In the field, little or no management is done. Occasionally lower branches are pruned to induce faster growth and a straight trunk. In landscaping, top branches are pruned to control height growth.
Allen and Allen (1981) reported nodulation of A. inermis in Hawaii. In Brazil, Faria et al. (1987b, 1986) found that A. inermis and six more Andira species showed nitrogenase activity with the acetylene reduction assay. They also report that isolated rhizobial strains showed an infective-host range within the cowpea miscellany.
Andira inermis does not grow well in areas with a marked dry season. It grows very slowly even with suitable moist conditions (Little and Wadsworth 1964). Bark and seeds are reported to be poisonous (GuzmÃ¡n 1947).
Processed wood is attacked by borer insects when used under saltwater (Behrendt et al. 1968). Fruits are attacked by the weevil, Cleogonis sp. (Janzen 1976) with possible effects on seed germination.
There are approximately 30 Andira species distributed in Tropical America and one in Africa (Pennington 1995). Some important species in Brazil are A. racemosa Lam., A. fraxinifolia, A. nitida Mart, A. frondosa, A. legalis and A. anthelmia (Vell.) Macbr. (Faria et al. 1987a, 1987b, 1986). Andira galeothiana Standl. and A. vermifuga Mart. are used as fish poison, vermifuge, narcotic or vomiting agents. Andira retusa HBK and A. inermis yield the alkaloids berberine and angelin. Andira araroba, is the source of a fungicide (chrysarobin) used to treat skin diseases (Allen and Allen 1981).
Studies are needed to determine the amount of nitrogen Andira inermis provides to crops in agroforestry systems. Provenance and propagation studies are also needed.
Behrendt, G., J.D. Brazier., and G.L. Franklin. 1968. Maderas nicaraguenses CaracterÃsticas y uses potenciales. FAO y Min. de Ag. y Ganaderia Honduras. pp 21-22.
Berendsohn, W.G. 1989. Listado bÃ¡sico de la flora salvadorensis. Dicotoyledonae. Familia 118:Leguminosae. Cuscatlania (El Salvador) 1(2): 118-8.
Faria S.M.,J. Sutherland, and J. Sprent. 1986. A new type of infected cell in root nodules of Andira spp. (Leguminosae). Plant Science 45:143-147.
GuzmÃ¡n, D.J.1947. Especies Ãºtiles de la flora salvadoreÃ±a MÃ©dico-agricola-industrial. Imprenta Nacional. San Salvador, El Salvador. p.506.
Little, E.L. and F.H. Wadsworth. 1964. Common trees of Puerto Rico and the Virgin Islands. Agriculture Handbook No.249.
USDA Forest Service. p.l88-190.
Witsberger, D., D. Current, and E. Archer.1982. Arboles del Parque Deininger. Ministerio de EducatiÃ³n, El Salvador. p. 146-147.
For a complete set of references write to the FACTNet. The author acknowledges the assistance of the FacuItad de Ciencias AgronÃ³micas, Universidad de El Salvador.
FACT 96-06 September 1996
Erythrina poeppigiana (Warpers) O.F. Cook is a leguminous tree used in several agroforestry systems in Tropical America including shade for coffee, cacao and pastures, living fence posts, forage and fuel wood. It is also a promising species for alley cropping and mulching. Ease of management, high biomass production, nitrogen fixation and multiple uses make E. poeppigiana a suitable tree for farm and community forestry. It is known as "cÃ¡mbulo" or "barbatusco" in Colombia, "bucare" or "cachimbo" in Venezuela, "amasisa" in Peru, "porÃ³ gigante", "porÃ³ de sombra" or simply "porÃ³ in Costa Rica, "pito" in Guatemala and Honduras, and "immortelle" or "mountain immortelle" in the West Indies; the more formal English name is "coral tree". (Holdridge and Poveda 1975; Russo 1993).
Erythrina poeppigiana belongs to the family Leguminosae, subfamily Papilionoideae, tribe Phaseoleae (Neill 1993). It is a large tree, growing to 35 m in height and 2 m in diameter. The crown is moderately spreading and the bole of large trees tends to be branchless below 10 - 20 m. The bark is grayish brown or gray, with thorn-like protuberances. Leaves are alternate, trifoliolate. The rhomboid-oval or oval foliates are 15 - 25 cm long and generally larger in saplings than in big trees. Glandular stiples below the paired lateral folioles are large and cupshaped. Orange or reddish flowers are produced in racimes. The upper petal is wide and open. Erythrina poeppigiana is pollinated by perching passerine birds. The pods are 10 - 25 cm long. Seeds are brown, about 2 cm long and slightly curved. There are about 4,500 seeds per kg.
Erythrina poeppigiana is native to humid and subhumid tropical lowlands, but cultivated and naturalized trees now are found to 2,000 m elevation (Holdridge and Poveda 1975). The average annual rainfall in its native and naturalized range is between 1,000 and 4,000 mm. In subhumid areas, it tolerates a 5 - 6 month dry season. Erythrina poeppigiana tolerates low soil fertility and relatively high acidity (down to pH 4.3), however tolerance varies by genotype (Perez CastellÃ³n 1990).
In Costa Rica, the phenology of unpruned E. poeppigiana shifts from evergreen to deciduous along a rainfall gradient from the humid lowlands to the sub-humid mountains. The leafless period is quite short, and possibly caused by flowering rather than drought (Borchert 1980). A visible reduction of foliage during the flowering (December - January) also occurs under humid conditions. Pruning trees periodically will prevent complete leaf fall, and pruning trees once-a-year is enough to impede flowering (P. Nygren, pers. obs.).
Erythrina poeppigiana is native to riverine and upland forests of the Amazon and Orinoco basins from Venezuela to Bolivia, and the moist Pacific forests of Ecuador and Colombia It was introduced to Central America and a number of Caribbean Islands in the 19th century, and it has been widely naturalized in some areas like Costa Rica and Trinidad (Neill 1993).
Planted as a shade tree in cacao plantations in the humid tropics, E. poeppigiana conserves soil and contributes to high and sustainable cacao yields (Beer et al. 1990). Shade trees are partially pruned or not pruned at all. Production of Nrich litter (2.3 - 2.6%, Nygren 1995) is abundant, and the N supply in litterfall exceeds several times the export of N in the cacao harvest (Escalante et al. 1984).
In coffee plantations in Costa Rica, E. poeppigiana is usually pruned completely and lopped to a height of 2 - 3 m twice-a-year to promote coffee flowering and ripening of berries. The N supplied through pruning residues left on the ground fulfills the recommended N application rate for Coffee in Costa Rica (Beer 1988). Farmers plant E. poeppigiana at spacings of 8 x 8 m and 6 x 6 m for unpruned and pruned trees. respectively.
Mulching alley cropping.
The green leaves of E. poeppigiana contain 4.1 - 4.9% nitrogen (Perez CastellÃ³n 1990), which makes it an excellent species for green manure production. A ten-year experiment in Costa Rica measured the effects of cutand-carry mulching with 20 tons/ha of E. poeppigiana fresh matter on maize and bean yields in a sequential cropping system. Crops were harvested once-a-year and production was good compared to local on-farm production. Crop production also increased each year of the experiment. The same experiment in Costa Rica evaluated alley cropping E. poeppigiana with maize and beans. Although satisfactory and sustainable for 10 years, the maize yield in this experiment was lower than the maize yield in the mulching experiment. The bean yield in the alley cropping system was both high and sustainable (Haggar et al. 1993). In a separate experiment in Costa Rica, E. poeppigiana alley cropping also sustained two maize crops per year over eight years without fertilization. Soil carbon and nitrogen pools creased, but 50% less than in fertilized control plots Dominique 1994).
For alley cropping, E. poeppigiana should be planted in dense hedgerows (I - 2 m between trees), with wide alleys (6 8 m) between tree rows (Kass et al. 1993a; Nygren and JimÃ©nez 1993).
The green leaves of E. poeppigiana have a good nutritive value (20 - 22% of dry matter), are high in crude protein (27 - 34%) and have a good range of in vitro digestibility (49 - 57%). However, due to the high cell wall content (55 - 58%), they should be supplemented with energy sources, e.g. tropical grass, which are readily degradable in the rumen (Kass et al. 1993b). The presence of potentially toxic alkaloids in the leaves of E. poeppigiana has not affected the health of cattle or goats, but feeding leaves to non-ruminants may be risky (Kass 1994).
The wood is light, with low calorific value but it is sometimes used as fuel wood (Russo 1993).
The seeds of E. poeppigiana may be stored for several years in tightly closed containers in a cool, dry place (ca. 5 °C, 30 - 40% relative humidity). Immersion in water at room temperature for 24 h enhances germination. The germination rate is about 70%. Germination takes 5 - 15 days. The seedlings may be planted in the field when they are 20 - 30 cm high (3 - 4 months), preferably at the beginning of rainy season. The seedling survival is generally good, but weed control may be necessary during the first year to enhance growth (VÃquez and Camacho 1993; P. Nygren pers. obs.).
Air-layering to establish rooted cuttings yields a survival rate of 83% in vegetative propagation of E. poeppigiana. The roots appear about 6 weeks after air-layering. The leaves must be removed before planting, and the top cut made at a 45° angle and sealed with paraffin. Unrooted cuttings should be long (> 1.5 m). Stakes from lower and middle sections of one-and twoyear-old branches give best results. Cuttings are planted at a depth of 30 cm. Inoculation of seeds or cuttings with Bradyrhizobium bacteria is not generally required in and Camacho 199,: P. Nygren pers. obs.). However. inoculation is recommended when introducing the species to new areas.
A formation pruning is recommended about 4 - 6 months after planting to remove the lowest branches. Normal pruning management may start 9- 12 months after planting. Tall crops should not be associated with E. poeppigiana before the first complete pruning, but low crops may be planted at the time of the formation pruning. Coffee and cacao may be planted together with the trees. Due to the slow recovery of carbohydrate reserves, pruning of E. poeppigiana more often than twice-a-year causes the risk of debilitation and turnover of trees within a few years (Nygren et al. 1996).
E. poeppigiana nodulates abundantly with nitrogen fixing bacteria of genus Bradyrhizobium; peak values exceeding 1,000 kg/ha of nodules were reported for unpruned cacao shade trees, but during the driest season nodulation dropped to nil (Escalante et al. 1984). Globular nodules are formed in the site of lateral root emergence. and they have never been observed deeper than 10 cm. (Holdridge and Poveda 1975; Neill 1993; VÃquez and Camacho 1993; P. Nygren, pers. obs.). Soil acidity does not impede nodulation, but differences in the efficiency of bacterial strains were detected in a soil with 50% aluminum saturation (Gross et al. 1993). Pruning causes a complete turnover of nodules, and renodulation initiates about 2.5 months after pruning. After initiation, 66-180 kg/ha of nodules may be produced in a month (Nygren and RamÃrez 1995).
Vesicular-arbuscular mycorrhizae improve nitrate uptake efficiency of unnodulated seedlings (Cuenca and AzcÃ³n 1994).
Adult June beetles (Phyllophaga menetriesi, Coleoptera: Scarabaeidae) teed on young leaves of E poeppigiana. Because June beetles lay eggs close to foraging areas, the root-eating larvae are a potential risk for associated crops (Hilje et al. 1993). Only minor damage to maize alley cropped with E. poeppigiana has been observed (D. Kass. pers. obs.). but the pest problem requires further investigation.
Beer, I. 1988. Litter production and nutrient cycling in coffee (Coffea arabica) or cacao (Theobroma cacao) plantations with shade trees. Agroforestry Systems 7: 103 - 114.
Kass, D.C.L. 1994. Erythrina species - pantropical multipurpose tree legumes. In Gutteridge, R.C. and H.M. Shelton (eds). Forage tree legumes in tropical agriculture. CAB International. Wallingford, U.K. pp: 84 - 96.
Nygren, P. and C. RamÃrez 1995. Production and turnover of N. fixing nodules in relation to foliage development in periodically pruned Erythrina poeppigiana (Leguminosae) trees. Forest Ecology and Management 73: 59 - 73.
Westley, S.B. and M.H. Powell (eds) 1993. Erythrina in the New and Old Worlds. Nitrogen Fixing Tree Research Reports, Special Issue 1993.358p.
For a complete set of references contact the authors or FACT Net.
FACT 97-01 January 1997
Albizia procera is a large, fast-growing tree that occurs on many different sites. Like other Asian Albizias, it occurs in forests and savanna woodlands but prefers moister sites than its relatives. This species provides wood for a variety of purpose nutritious fodder for livestock and shade for tea plantations. It is an important reforestation and agroforestry species. It is commonly called white sins or tall albizia and has many regional names.
Albizia procera (Roxb.) Benth is usually 60-70 cm in diameter and 25 meters in height. Troup (1921) reports trees as large as 95 cm in diameter and 36 meters in height. Mature individuals are characterized by a tall clear, erect, so curved trunk and large branches which form a thin, spreading crown The bark is nearly smooth, whitish to light-greenish gray or light brown It exfoliates in thin flakes with red undersides (Troup 1921). Lateral roots are wide-spreading and the taproot stout The bipinnate leaves, reddish when juvenile, mature to a length of 12-25 cm; leaflets are 2 4 cm long and 8-16 mm wide.
Flowering varies by geographic location; January to March in Indonesia (Djogo 1992), June to September in India (Troup 1921) September in Manila (Hensleigh and Holaway 1988) and August to October in Puerto Rico (Parrotta 1987). Flowers are borne on racemes 8-25 cm long near the end of a twing.
Numerous greenish-yellow flowers form whitish heads 20-24 mm in diameter. Individual flowers, 6-7 mm long, have long white threadlike spreading stamens about 10 mm long (Little and Wadsworth 1964). The reddish-brown flat pods, 10-20 cm long and 18-25 cm wide, are produced in large numbers and ripen 35 months after flowering The mature brown pods, each containing 6-12 seeds, usually remain on the tree until the twig bearing the pods is steed (Troup 1921, Little and Wadsworth 1964). The natural regeneration of white siris is generally good. Following the beginning of the rainy season large numbers of seedlings are common near mature trees. Seedlings, saplings and mature trees coppice vigorously from stumps and roots (Parrotta 1987).
White siris is a component of tropical and subtropical moist and wet forest type-c where rainfall is 1000-5000 mm/yr. It develops best when rainfall is above 2500 mrn/yr. Growing to elevations of 1200 meters, the species is also common on moisture savannas and swamp forests. In its natural habitat, maximum vary from 37-46° C and minimum temperatures from 1-18° C. Once established white siris is drought tolerant. It is susceptible to frost (Troup 1921, Djogo 1992).
Like many nitrogen fixing trees, white siris survives on a variety of soils. It grows best on moist alluvial soils, welldrained loams or clay soils (Brandis 1906, Venkataramany 1968). Its ability to grow on dry, sandy, stony, and shallow soils makes it a useful species for reforestation of difficult sites. Good survival and rapid early growth have been reported in afforestation trials on both saline and alkaline soils (Ghosh 1976). It doe not tolerate suppression, but will survive moderate shade between the seedling and small tree stage Venkataramany 1968).
In India, white siris is dominant to co-dominant in mixed deciduous forest or fauna as scattered individuals or in small groups in savanna woodlands (Benthall 1933, Bor 1953). In Puerto Rico, white siris is an aggressive pioneer, forming pure stands on abandoned farms and other disturbed sites It is also common in pastures at elevations below 600 meters, including areas receiving as little as 800 mm of annual rainfall.
The native range of A. procera is South and Southeast Asia between latitudes 30 degrees N to 15 degrees S. The tree occurs naturally in India, Nepal, the the Adaman Burma, southern China, Laos, Thailand, Cambodia, Vietnam, Malaysia, the Philippines, Indonesia, Papua New Guinea, Melanesia and northern Australia (Nielsen 1979). It is naturalized in the Virgin Islands and Puerto Rico.
Agroforestry. Natural regeneration of A. procera is often encouraged on farms to provide small timber, fuelwood, charcoal, fodder or shade. Seedlings are planted in family forests or home gardens for the same purposes. Albizia procera can be cultivated as shade for tea plantations. However, Albizia odoratissima is preferred for this purpose because of its rapid early growth, fuller crown and resistance to red spidermites. The protein-rich fodder of A. procera is eaten by cattle, buffaloes, goats, camels and elephants in South Asia and the Philippines. However, the fodder is not utilized in Nusa Tenggara, Indonesia.
Durable, strong and resistant to termites, the wood is fight- to cnocolate-brown with light and dark bands. It is difficult to saw due to interlocking grain and has a specific gravity of 0.60.9. The wood is used to produce wheels, carts, boats, furniture, flooring, posts, agriculture irnplements , boxes and carvings. This species is considered a promising source of pulp for high quality paper (Parrotta 1987).
Trees are often planted for shade or beautification along roads Albizia procera is commonly used in traditional medicines Venkalarammany 1968). The bark contains tannins and a reddish gum Also, it can be used to make a poison. The leaves are used to treat ulcers and have insecticidal properties (Parrotta 1987). In the Philippines, the cooked leaves are eaten as a vegetable (Hensleigh and Holaway 1988).
Seeds are small, greenish-brown, elliptical to round, flat and have a hard, smooth seedcoat. There are 20,00024,000 seeds per kilogram (Rosbetho 1997). Insect damage to seed is common in Indonesia (Djogo 1992) but not in India (Troup 1921). Fresh seed germinates readily without treatment (Parrotta 1987). Clean seed can be stored at room temperature for 10 months with minimal loss of viability (Roshetko 1997). Seed that has been stored should be treated before sowing; cut through the seedcoat with a knife or file, or soak seeds in boiled water for 3 minutes. After either treatment soak seed in cool water for 12-24 hour and sow immediately (Roshetko 1997).
In the nursery, seed should be sown in containers or beds Seedling growth is favored by loose soil sufficient soil moisture, full sunlight and the absence of weeds. Healthy seedlings produce a thick, long taproot After two months in the nursery containerized or bare-root seedlings should be transplanted to the field. Direct sowing of white sins is successful given abundant soil moisture and regular weed control (Troup 1921). Propagation is also possible by stem or root cutting and stump sprouts. Plantations should be weeded twice in the first year and once during the second. During weeding, soil should not be unduly exposed; only weeds directly interfering with seedlings should be removed (Venkataramany 1968).
Growth and Management.
In Bangladesh plantation trees have reached heights of 0.3 and 4.5 m in 1 and 5 years. In Burma 6-year-old trees average heights and diameters of 12.8 m and 16 cm, respectively. In Indonesia, 17-year-old trees average heights and diameters of 24.3 m and 22.4 cm, respectively. Total standing volumes of 87 m³/ha have been reported in 8-year-old plantations Burma end of 151 m³/ha in 17-year-old plantations in Indonesia Natural forests are managed for timber production by coppicing on a 40-year rotation. Fuelwood plantations are managed on a 20-year rotation (Venkataramany 1968).
Albizia procera forms symbiotic association with Rhizobium bacteria enabling it to fix nitrogen and thrive on infertile soils. The application of phosphorus fertilizer can improve nodulation and nitrogen fixation. particularly on infertile soils.
Because of its aggressive growth white siris may be a potential weed This is panicularly true in the Caribbean where white siris grows faster than many native species.
Benthall A P.1933. The tea of Calcutta and its neighborhood.Thacker Spink and Co., Calcutta, India. 513 p.
Bar, N.L. 1953. Manual of Indian forest botany. Oxford University Press, London , UK 441 p.
Brandis D. 1906. Indian trees Bishen Singh Mahendra Pal Singh, Dehra Dun, India
Djogo, A.P.Y. 1992. The possibilities of using local drought-resistant multipupose tree species as alternatives to lamtoro (Leucaena leucocephala) for agroforestry and social forestry in West Timor. Working Paper No. 32. EARI East West Center, Honolulu, Hawaii, USA. 41 p.
Ghosh, R.C. 1976. Afforestation problems of saline and alkaline soils in India Van Vigyan 14(1): 1-17.
Hensleigh, T.E. end B.K Holaway. 1988. Agroforestry species for the Philippines. Washington DC: US Peace Corps, 404 p.
Little, E.L., F.H. Wadsworth 1964. Common trees of Puerto Rico and the Vrgin Islands. Agric. Handbook 249. US Department of Agriculture, Washington DC. 548 p.
Nielsen, L 1979. Notes on the genus Albizia Durazz. (Leguminosae-Mimosaceae) in mainland SE. Asia. Adansonia 19(2): 199-229.
Parr otta, IA 1987. Albizia procera (Roxb. )Benth. Silvics of Forest Trees of the American Tropics. Rio Piedras Puerto Rico USA USDA Forest Service, international institute of Tropical Forestry. 4 p.
Roshetko, J.M. 1997. Seed treatment for Albizia species. In: N.Q. Zabala (ed ) Albizia & Paraserianthesis. Proceedings of an international workshop. Morrilton, Arkansas, USA Winrok International in press.
Troup, R.S. 1921. The silviculture of Indian trees Clarendon Press, Oxford, UK 1195 p.
Vankataramany P. 1968. Silvicuture of genusAlbizia and species Silviculture of Indian trees., No. 22. Government of India, Delhi, India 54 p.
NFTA 95-01 January 1995
Albizia odoratissima, Benth (Syn. Mimosa odoratissima, Roxb.) is a medium sized tree highly valued for shade and soil improvement in tea plantations of the Asian subcontinent. It is particularly popular in North-east India and Bangladesh. About 75% of total tea shade trees in Bangladesh are of this species (Sane 1989). On the subcontinent it is known as karuvagai, karmaru, bansa bilkumbi (Troup 1921), chamkoroi (Hasan 1963), tetua-koroi (Kamaluddin 1984), and kalasiris (Sane 1=989).
Albizia odoratissima Leguminosae, Subfamily Mimosoideae) is a multipurpose woody legume which btains a height of 22-26 m and diameter of 120-150 cm. On good sites five-year-old trees can be 5 in height and 14 cm in diameter. A mean annual diameter increment of 1.3 cm has been recorded for this species (Troup 1921). The bark is dark grey to light brown in color with horizontal lenticels The crown is relatively dense.
The dark green leaves are bipinnately compound, downy, with 6-9 pinnae and 16-20 pointed asymmetrical leaflets.
Flowers are corymbs, pale yellowish white, fragrant, and generally appear from March to June. Fruits appear in early August and start ripening at the end of October. The thin flat pods are 13-20 cm long and brown when ripe Hasan 1963, Sana 1989). Trees produce large amounts of pods each containing 8-12 seeds. Albizia odoratissima is deciduous, with a short leafless period from December to February. New leaves normally appear before the old ones have completely fallen Branching habit is uniform, but irregularities occur when the tree is damaged.
Albizia odoratissima tolerates a wide range of temperatures an rainfall. In its natural range the maximum shade temperature varies from 37°-50°C and the minimum from 0°-15°C. Normal rainfall varies from 650-3000 mm with a dry season from November to March. It occurs from sea level to 1500 mete' (Troup 1921) and grows sporadically in both dry and moist deciduous forest zones.
Growth of A. odoratissima is best in deep, well drained sand soils (Sane 1989). The especies prefers soils with large amounts of organic matter. It tolerates hot humid conditions, but dot not tolerate water-logging. On poor soils growth ifs stunted Young plants are susceptible to frost. Albizia odoratissima i classified as moderately light demanding
Juvenile trees require shade. Trees coppice wed, shoots react ing a height of 3 meters in two years. It is susceptible to fire, but resistant to weed competition and drought. It degenerates naturally in sheltered areas with good soil.
Albizia odoratissima occurs naturally in Southern Chin' Burma, Peninsula India, and Tropical Africa. Under tropical conditions the species is not gregarious. It is frequently found on hill slopes and sometimes in valleys.
Albizia odoratissima has been extensively planted as shade tree in tea and coffee e pantations The shade extends the productive life of crop plants and increases annual yield! Recommended spacing vanes from 6x6 to 12x12 m. Albizia odoratissima benefits tea and coffee production in many way' Its well developed mot system decreases erosion and utilizes the subsoil moisture and nutrients not available to tea and coffee plants. Through leaf litter, A. odoratissima provides organic matter and soil nutrients to the rhizophere of understory plants Tree canopies decrease soil desiccation, suppress weed growth and protect plants from hail and rain stones. Albizia odoratissima's presence in the tea monoculture reduces incidence of tea pests, particularly red spider mites and scalet mites. The shade also provides plantation laborers a comfortable working environment under otherwise hot tropical conditions.
Albizia odoratissima produces valuable fuelwood Dead and defective branches from shade trees are a major source of fuel for plantation laborers. The heartwood of mature trees is a beautiful dark brown color. The premium quality wood ifs suitable panelling and furniture. It is also used for carts, wheels, farm implements and construction timbers. Wood weight at 12% moisture content is 735 kg/cubic meter. The wood is 2040% stronger than teak (Anon. undated).
The pods of Albizia odoratissima are eaten by monkeys. The leaves are an excellent green manure and cattle fodder. Sana (1989) reports Albizia odoratissima contributed 16 kgs of nitrogen per hectare from 655 kgs of dry weight leaf liter.
Seed collection and handling.
Pods should be collected while on the tree immediately after they turn brown. Half-opened pods are also collected from beneath trees. Following collection, pods are dried in the sun for 5-7 days. Pods are then lightly pounded with a hammer to extract seeds. Extracted seeds are dried again in the sun for 3 4 days and then stored in bags under well ventilated dry conditions. If seeds are to be stored for a long period, they should be treated with a DDT or Heptachlor dust at the rate of 100 grams per kg of seeds (Anon. 1988). There are approximately 21,000 seeds per kg To break dormancy seed can be soaked; a) in cool water for one hour, b) in 80°C water for two minutes, or c) in boiling water for 30 seconds. Removed from the water, moist seed is stored overnight and sown the following morning. Seedlings emerge within a week Fresh seed may have a germination rue of 99%. Germination of year-old seed decreases to 55-65%.
HDL 2.0 CD-ROM editor's note : (October 1998)
Pesticides are dangerous. Use them rationally and appropriately. Do not use the Dirty Dozen (Parathion, 2, 4, 5-T, Paraquat, DDT, Aldrin/ Dieldrin/ Endrin, Chlordimeform, Dibromochloropropane (DBCP), Chlordane/ Heptachlor, HCH/ Lindane, Ethylene dibromide, Camphechlor and Pentachlorophenyl (PCP). Endosulfan (Thiodan) and Organotins (Brestan and Aquatin) were also banned from the market recently. On selecting a pesticide please be sure to inform for the safest product and application procedures first. Thank you.
Nursery production should be initiated in November or December 4-5 months before the planting season. Well drained sandy loam soil from beneath A. odoratissima trees is recommended far nursery use. If available, well decomposed compost should be mixed with the soil at a ratio of 1:3. Additionally, 500 grams each of triple super phosphate (TSP) and lime should be added to every cubic meter of nursery soil The use of large nursery bags ifs recommended to encourage growth of a deep taproot. In each nursery bag 2-3 seeds should be sown at a depth 5-20 mm and covered with a thin layer of sand Every two weeks seedlings should be fertilized with a well decomposed liquid compost or a standard phosphorus and potassium fertilizer. In large nurseries, 4-10 cm seedlings are sprayed every two wears for protection from insects and fungal diseases. Recommended spray contains 300 ml of malathion and 300 grams of copper oxychloride in 200 liters of water (Anon. 1988).
Albizia odoratissima is also established by direct seeding or stump cuttings. Far quick establishment, stump cuttings give the best results. Stumps are prepared in the late dormant season immediately before buds swell. Trees with stem diameters of 57 cm are appropriate far stumps. Selected trees are cut at a height of 1.5-2 meters and all the lateral branches are removed. It is best to select trees with few lateral branches below the 1 5-2 meter cutting height. Trees should have well developed roots. Carefully, expose the mot system to a depth of 90 cm. Sever the taproot at 80-90 cm and prune all lateral roots. Stumps should be planted immediately in pits 90 cm deep and 75 cm wide.
Planting and fertilization.
At the beginning of the spring rains seedlings are ready far field planting. Seedlings are planted in pits 90 cm deep and 45 cm wide. They should be fertilized during planting. Recommended fertilization rates per seedling are 10 kgs of rotted cattle manure, 200 g TSP, 25 kg wood ash and 1 kg slaked lime. Components should be well mixed with the soil from the planting pit and replaced.
Fertilization of young shade trees improves tree growth and plantation production. For trees under 2.5 m height broadcast 300 grams TSP in a 1.5 meter diameter-circle around the tree. For trees up to 4 m height 333 grams TSP is applied to a 3 meter diameter-circle. Fertilization should be repeated three times per year, April, June and August (Anon. 1988).
Through a symbiotic relationship with Rhizabium bacteria, Albizia odoratissima fixes atmospheric nitrogen. Under natural conditions seedlings generally bear abundant root nodules. For nursery production it is wise to use soil from under a stand of A. odoratissima. No quantitative data is available on the Rhizabium specificity of this species.
Albizia odoratissima is prone to attack by caterpillars, root bares, and root diseases, particularly as a young tree (Barua 1989). Dieback, branch canker, and red rust are also problems for young trees. Damping-off, a fungus infection, is common in poorly managed nurseries. In India, heart-rot of this species is caused by Ganoderma applanatum (tonne 1992). Albizia odoratissima sometimes produces uneven shade (Barua 1989) which causes management problems under plantation conditions.
Tree improvement programs for superior canopy characteristics and resistance to insects and disease should be initiated. In Bangladesh improved planting stock is obtained from root suckers of select varieties Root cuttings of 1-2 cm diameter and 15-20 cm length are placed under heavy shade in a moist rooting bed. One-third of the root is exposed and two-thirds buried in the soil. Spacing between cuttings is approximate 2030 cm. Within a few weeks the stock is ready far transplanting (Anon. 1988).
Anon., 1988. Guide line on management of shade trees. GL No. 5. The Consolidated Tea and Lands Company (BD) Ltd. The Baraoora (Sylhet) Tea Company Ltd. (Incorporated in Great Britan) 14.
Anon,undated. Indian forest utilization. vol. II 925 pp.
Barua, D.N. 1989. Science and practice in tea culture. Tea Research Association, India 402-436.
Hasan, K.A. 1963. Shade trees for tea-their functions and behaviour. Tea Journal of Pakistan 1(2):14 pp.
Kamaluddin, M, 1984. Forest Ecology,Institute of Forestry, Universty of Chittagong. Chitangong, Bangladesh.164 pp.
LeneÃ©, J.M. 1992. Disease of multipurpose woody legumes in the tropics, a review. Nitrogen Fixing Tree Research Reports 10:13-29.
Sana, D.L. 1989. Tea Science. BTRI, Moulvibazar, Bangladesh, 45-51.
Troups, R.S. 1921. Silviculture of Indian Trees. II:466-484.
FACT 96-01 January 1996
Adenanthera pavonina (L.) (family Leguminosae, subfamily Mimosoideae) has long been an important tree in Southeast Asia and the Pacific Islands. Cultivated in home gardens and often protected in forest clearings and village common areas, this useful tree provides quality fuelwood, wood for furniture, food, and shade for economic crops like coffee and spices. The tree has been planted extensively throughout the tropics as- an ornamental and has become naturalized in many countries. The scientific name is derived from a combination of the Greek aden, "a gland," and anthers, "anther"; alluding to the aCircassianbeananthers being tipped with a deciduous gland The tree is known by a host of common names, including red-bead tree, red sandalwood, and Circassian-bean in English; raktakambal (India); saga (Malaysia); lope (Samoa and Tonga); coralitos, peronias, and jumble-bead (Caribbean).
A medium- to large-sized deciduous tree, A. pavonina ranges in height from 6-15 m with diameters up to 45 cm, depending upon location. The tree is generally erect, having dark brown to grayish bark, and a spreading crown. Multiple stems are common, as are slightly buttressed trunks in older trees. The leaves are bipinnate with 2-6 opposite pairs of pinnae, each having 8-21 leaflets on short stalks. The alternate leaflets, 2.02.5 crn wide and 3 cm long, are oval-oblong with an asymmetric base and a blunt apex, being a dull green color on top and a bluegreen beneath. The leaves yellow with age.
Flowers are borne in narrow spike-like racemes, 12-15 cm long, at branch ends. They are small creamy-yellow in color, and fragrant. Each flower is star-shaped with five petals, connate at the base' and having 10 prominent stamens bearing anthers tipped with minute glands.
The curved pods are long and narrow, 15-22 cm by 2 cm, with slight constrictions between seeds, and dark brown in color turning black upon ripening. The leathery pods curve and twist upon dehiscence to reveal the 8-12 showy seeds characteristic of this species. The hard-coated seeds, 7.5-9.0 mm in diameter, are lens-shaped, vivid scarlet in color, and adhere to the pods. The ripened pods remain on the tree for long periods and may persist until the following spring. There are reportedly 1600 seeds per pound (Little and Wadsworth 1964).
This species is common throughout the lowland tropics up to 300-400 m. Adenanthera pavonina is a secondary forest tree favoring precipitation ranging between 3000-5000 mm for optimal growth. Found on a variety of soils from deep, welldrained to shallow and rocky, this tree prefers neutral to slightly acidic soils. Initial seedling growth is slow, but rapid height and diameter increment occur from the second year onward. The tree is susceptible to breakage in high winds, with the majority of damage occurring in the crown. Rapid resprouting and growth following storm damage has been recorded in the Samoan Islands (Adkins 1994).
Adenanthera pavonina is endemic to Southeast China and India, with first reports being recorded in India The tree has been introduced throughout the humid tropics. It has become naturalized in Malaysia, Western and Eastern Africa and most island nations of both the Pacific and the Caribbean.
There are historical accounts from Southeast Asia and Africa of using all parts of tree for traditional medicines (Burkill1966, Watt and Breyer-Brandwijk 1962). Adenanthera pavonina is extensively cultivated as an ornamental for planting along roadsides and in common areas. The fast growth and spreading crown of light, feathery foliage offer attractive shade. Interplanted field and tree crops (spices, coffee, coconuts), along field borders as part of a windbreak or in plantation, A. pavonina is a valuable agroforestry species (Adkins 1994, Clark and Thaman 1993).
Adenanthera pavonina is esteemed for fuelwood in the Pacific Islands, often being sold in local markets. The wood bums readily producing significant heat, and is used in both above- and below-ground ovens. Good sized fuelwood, larger than 11 cm in diameter, can be produced in five years. The wood is hard and durable having red-colored heartwood with light-gray sapwood. It is close-and evengrained, making it useful for constructing furniture, cabinets, and decorative wood products (Benthall 1946, Clark and Thaman 1993). It is also valued for home building.
Known as "food trees" in Melanesia and Polynesia, the seeds of this tree are roasted over a fire and eaten by children and adults alike. Nutritional studies have shown one quarter of the seed weight to be oil with a high percentage of protein, and a fatty acid composition favoring high digestibility for both humans and livestock (Balogun and Fetuga 1985, Burkill 1966). Historically, the seeds were used as weight measures for jewelry and goldsmithing due to their small variation in weight (Benthall 1946, Burkill 1966). The bright red seeds are still used today in fashioning necklaces and decorative ornaments.
The small leaves breakdown easily making for good use as a green manure. As a supplemental source of fodder, the leaves are fairly high in digestible crude protein (1722%), but low in mineral content (Rajaguru 1990).
The tree is cultivated from seed. The seed coat is extremely hard and requires scarification if even germination is to occur. Untreated seeds can be stored up to 18 months without losing viability (Basu and Chakraverty 1986). Manual scarification, immersing the seeds in boiling water for one minute, or treatment with sulfuric acid has shown to significantly increase germination percentage. Following treatment, seed can be directly sown in the field or in a nursery. Germination occurs within 7-10 days with young seedlings obtaining a height of 8-15 cm in approximately three months. Seedling maturity occurs two to three months later at 20-30 cm in height. Nursery stock transplants well.
Growth is initially slow, but increase rapidly after the first year. Following the first year of establishment, average annual growth rates of 2.3-2.6 cm in diameter and 2.0-2.3 m height have been recorded in American Samoa (Adkins 1994). Trees planted 1 x 2 m apart for windbreaks, and at a spacing of 2 x 2 m in plantations can be thinned in three to five years to provide fuelwood and construction materials. As a shade tree, spacing varies from 5-10 m depending on the companion crop and site. The trees resprout easily allowing for coppice management with good survival.
Despite an inability to suppress weeds, the seedlings are rather hardy and can survive with minimal maintenance. Adenanthera pavonina is compatible with most tropical field and tree crops, allowing for their usage in integrated production systems.
Although Allen and Allen (1981) indicate the inability of A. pavonina to nodulate, this legume is generally considered to be nitrogen-fixing. Sparse, fast growing, brown nodules with isolates confirmed to be Rhizobium have been observed by Lim and Ng (1977). The author observed root nodules, both in old nursery stock and in the field, during research conducted in American Samoa. Norani (1983) confirmed the presence of VA mycorrhiza on the roots of nursery stock.
Despite its susceptibility to crown damage in high winds, the ability to recover is remarkable. No insect or disease problems have been reported.
Additional investigation concerning the nitrogen-fixing ability on native and naturalized populations is required. Continued research on fuelwood production and fodder usage is necessary.
Adkins, R v-C. 1994. The role of agroforestry in the sustainability of South Pacific Islands Species Trials in American Samoa. MS. Thesis, Utah State University. Logan, Utah 133 p.
Allen, O.N. and E.K Allen 1981. The Leguminosae: a source book of characteristics, uses, and nodulation. University of WisconsinPress. Madison, Wisconsin. 812 p.
Balogun, A M. and B.L. Fetuga. 1985. Fatty acid composition of seed oils of some members of the Leguminosae Family. Food Chemistry, 17(3): 175-82.
Basu, D. and R.K. Chakraverty. 1986. Dormancy, viability and germination of Adenanthera pavonina seeds. Acta Botanica Indica, 14 (1): 68-72.
Benthall, A P. 1946. Trees of Calcutta and its neighborhood. Thacker Spink and Co. Calcutta. 513 p.
Burkill, I.H. 1966. A dictionary of the economic products of the Malay peninsula, 2 ea., Volume 1, A-H Government of Malaysia and Singapore. Kuala Lumpur, Malaysia. 1240 p.
Clark, W.C. and R.R.Thaman (eds). 1993. Agroforestry in the Pacific Islands: Systems for sustainability. United Nations University Press. Tokyo, Japan. 279 p.
Lim, G. and H.L.. Ng. 1977. Root nodules of some tropical legumes in Singapore. Plant and Soil, 46: 317-27.
Little, E.L. Jr. and F.H. Wadsworth. 1964. Common trees of Puerto Rico and the Virgin Islands. Agriculture Handbook No. 249. USDA Forest Service. Washington, D.C. 14446 p.
Norani, A. 1983. A preliminary survey on modulation and VA mycorrhiza in legume roots. Malaysian Forester, 46: 171-74.
Rajaguru, A S.B. 1990. Availability and use of shrubs and tree fodders in Sri Lanka In: Devendra, C. (ed). Shrubs and tree fodders for farm animals. International Development Research Centre. Ottawa, Ontario, Canada pp: 237-43.
Watt, J.M. and M.G. Breyer-Brandwijk. 1962. The medicinal and poisonous plants of southern and eastern Africa, 2 ed. E &; S
FACT 96-03 June 1996
Acacia mangium Willd. is one of the major fast growing species used in plantation forestry programs throughout Asia and the Pacific. Due to its rapid growth and tolerance of very poor soils, A. mangium is playing an increasingly important role in efforts to sustain commercial supply of tree products while reducing pressure on natural forest ecosystems.
Acacia mangium is in the family Leguminosae, sub-family Mimosoideae. It has rapid early growth, and can attain a height of 30 meters and a diameter of over 60 centimeters (MacDicken and Brewbaker 1984). Inflorescences are on loose spikes up to 10 cm long with white or cream colored Bowers. When in full blossom, the inflarescences resemble bottle brushes. The flower has a mild, sweet fragrance. The dark green, glabrous phyllodes can be up to 25 cm long and 10 cm broad. The seed pods are broad, linear, irregularly coiled, and up to 3-5 mm wide and 7-8 cm long. The seeds are dark brown to black, shiny, vary in shape, and range from 3-5 mm long and 2-3 mm wide. Seeds mature 6-7 months after flowering (Pinyopusarerk et al. 1993).
Acacia mangium has a chromosome number of 2n=26. Hybrids with A. auiculiformis have the potential to become an important source of planting material for plantation forestry. The hybrid seems to be more resistant to heart rot than A. mangium but tends to be more shrub-like. Moreover, the hybrid has the straight bole and stem of Acacia mangium and the self-pruning ability of A. auicullformis (Tbrahim 1993).
Distribution and Ecology
Acacia mangium is native to Australia Indonesia and Papua New Guinea, but now has a latitudinal range from 19° S to 24° N and a longitudinal range from 88° to 146° E. Acacia mangium is a low-elevation species associated with rain forest margins and disturbed, well-drained acid soils (pH 4.56.5). Altitudinal range is from sea level to about 100 meters, with an upper limit of 780 meters. It is typically found in the humid, tropical lowland climatic zone characterized by a short dry season and a mean annual rainfall between 1446 and 2970 mm. Acacia mangium can tolerate a minimum annual rainfall of 1000 mm. Mean monthly temperatures range from a low of 13-21C and a high of 25-32° C. Though considered an evergreen species, A. mangium does not grow continuously throughout the year. Growth seems to slow or cease in response to the combination of low rainfall and cool temperatures. Dieback occurs during prolonged frost (5-6° C).
When monthly rainfall is below 100 mm, trees exhibit signs of moisture stress (Pinyopusarerk 1993).
Acacia mangium tolerates a soil pH as low as 3.8, and has performed well on lateritic soils with high amounts of iron and aluminum oxides. Acacia mangium has survived on soils with as much as 73% aluminum saturation (Duguma 1995). It is intolerant of saline conditions, shade, and low temperatures. Due to dense foliage, broad phyllodes, and shallow mot system, A. mangium is more susceptible to wind damage than other Acacia species.
Propagation and Silviculture
Although natural regeneration is excellent in clear-felled a' burned fields, nursery propagation is the most common regeneration practice. Hot water treatment for 30 seconds promotes quick seed germination. There are 80,000-100,000 seeds per kilogram. Seed can be sown directly into nurse pots or sown in trays and transplanted to pots aft germination.
Seedlings are retained in the nursery for 12 weeks or until they have attained a height of 25-40 cm. Srivastava (1993) recommends two mot prunings and hardening off of the seedlings before out-planting. In low phosphorus soils in the Philippines, Acacia mangium seedlings fertilized with 30 g/tree of phosphorus showed significant increase in growth compared to seedlings that were not fertilized (Manubag et al. 1995).
Spacing of the seedlings in the plantation depends on the intended uses and soil fertility. Since natural pruning is poor, trees should be planted at close spacing. Plantations cultivated for pulpwood usually have a 4 x 4 m spacing with 830 trees per hectare. For timber production, seedlings planted at 3 x 3 m spacing provide strong lateral competition and fast diameter growth. Seedlings should be planted at wider spacing to produce heavier branches for chipwood and fuelwood (Srivastava 1993). On infertile sites, final stocking should be around 600 700 stems per hectare.
The first weeding should be two months after out-planting. Weeding of noxious plants such as climbers, creepers, and vines is recommended, but less harmful weeds can be left in the field to maintain lateral competition. The number of follow-up weedings will depend upon each site. In areas where Imperata has a stronghold, weedings should be frequent.
Pruning schedules also depend on intended use. In agroforestry systems branches are pruned regularly to prevent competition with agricultural crops. To produce quality sawlogs, all branches below the height of 6 meters should be pruned regularly. These branches must be pruned before becoming 2 cm in diameter to avoid fungal infections (Srivastava 1993).
On degraded Imperata grasslands, Otsamo et al. (1995) observed that A. mangium had a mean annual volume increment of 10 m³/ha/year. In a 15-year rotation, precommercial thinning should occur at 24 months, followed by a thinning at 36 months Per this schedule, volumes are between 290 and 439 m³/ha after ten years' growth.
Acacia mangium has a wood density ranging from 420 to 600 kg/m³ and a specific gravity of 0.65 (MacDicken and Browbaker 1984). Due to ease of drilling and turning, it is a popular wood for furniture, agricultural implements, crates, particle board, and wood chips. Acacia mangium is also suitable for manufacturing charcoal briquettes and activated carbon. It has a calorific value of 4,8004,900 Kcal/kg. Acacia mangium's susceptibility to heart rot limits its use for sawn timber, but it is a common pulp and paper crop in Sumatra, Sabah and Vietnam. Nontimber uses include honey production, adhesives, and as an ornamental and shade tree for roadsides or other urban forestry uses. Acacia mangium sawdust provides good-quality substrate for shiitake mushrooms.
Since A. mangium can grow on marginal soils, many farmers choose to plant this species to improve soil fertility of fallowed fields or pastures. Since trees with diameters of 7 cm are fire resistant, Acacia mangium plantations can be used as fire breaks.
Highly effective Rhizobium strains have been identified for Acacia mangium (de Faria 1995). Acacia mangium teas a relationship with some VAM fungi including Thelephora ramariods, Gigaspora margarita, Glomus etunicaturm, and Scutellispora calospora.
Pests and Diseases
The major pests associated with A. mangium cause damage to seedlings, branches and stems, or wilting caused by root damage. Damage does not result in death, but may deform or suppress tree growth (Hutacharem 1993).
Most disease agents of A. mangium are associated with or caused by fungi. Common disease symptoms are damping off, heart rot, powdery mildew, stem galls, dieback, leaf spots, and root rot (See 1993).
Duguma, B. 1995. Growth of nitrogen fixing trees on moderate to very acid soils of the humid lowlands of southern Cameroon. In Evans D. 0. and LT. Szott eds. Nitrogen Fixing Trees For Acid Soils. Proceedings of Workshop m Turrialba, Costa Rica, July 3-8 1994: Winrock International and CATIE. pp. 195-206.
Faria S. M. de. 1995. Occurrence and rhizabial selection far legume trees adapted to acid soils. In Nitrogen Fixing Trees For Acid Soils. pp. 295-301. See Duguma 1995.
Hutascharem, C. 1993. Chapter 9: Insect pests. In Awang K and D. Taylor eds. Acacia mangium Growing and Utilization. MPTS Monograph Series No. 3. Bangkok. Thailand Winrock International and FAO. pp. 163-203.
Ibrahim, Z. 1993. Chapter 2: Reproductive biology. In Acacia mangium Growing and Utilization pp. 21-34. See Hutacharem 1993.
MacDicken, K and J. L. Brewbaker. 1984. Descriptive summaries of economically important nitrogen fixing trees. NFT Res. Rpts. 2:46-54.
Manubag J. B. Laureto J. Nicholls. and P. Canon. 1995. Acacia mangium response to nitrogen and phosporus in the Philippines. In Acacia mangium Growing and Utilization. pp. 32-35. See Duguma 1995.
Pinyopusarerk K. S.B.Liang, and B.V.Gum. 1993. Chapter 1: Taxonomy distibution, biology and uses as an exotic. In Acacia mangium Growing and Utilization pp. 1-20. See Hutacharem 1993.
Otsamo, A. G. Adjer, T. S. Hadi J. Kuusipado K Tuomela, and R. Vuokkko. 1995. Effect of site preparation and initial fertilization on establishment and growth of four plantation trees species used in reforestation of Imperata cylindrica (L.) Beauv. dominated grasslands. For. Ecol. and Mgmt. 73:271-m.
See L S. 1993. Chapter 10: Diseases. In Acacia mangium Growing and Utilization pp. 203-238. See Hutacharem 1993.
Srivastava P.B.L 1993. Chapter 7: Silvicultural practices. In Acacia mangium Growing and Utilizatzon.pp. 113- 147. See Hutacharem 1993.
FACT 96-05 September 1996
Acacia auriculiformis A. Cunn. ex Benth. is a multipurpose, leguminous tree in the subfamily Mimosoideae. It has been planted for fuelwood production, erosion control, ornament and shade in many tropical areas in the world. Its rapid early growth: ability to fix nitrogen; tolerance of infertile, acid. alkaline, saline or seasonally waterlogged soils; and tolerance of moderate dry seasons make it a very useful species for rehabilitation of degraded lands. The scientific name comes from the Latin 'auricula'-external ear of animals and 'forma' form, figure or shape', in allusion to the shape of the pod.
It is commonly a tree, 8-20 m in height, heavily branched with a short bole. On favorable sites it can grow to 30 40 m tall and 80100 cm diameter with a straight, single stem. The bark is gray or brown, more or less smooth in young trees. becoming rough and longitudinal fissured with age. Mature foliage consists of phyllodes, which may be straight or falcate, acute or sub-falcate, 10-20 cm long and 1.5-3.0 cm wide. Phyllodes of sapling may attain 30 cm in length and up to 5.0 cm in width. There are 3 prominent longitudinal nerves running together towards the lower margin or in the middle near the base, with many fine crowded secondary nerves, and a distinct gland at the base of the phyllode (Pedley 1978).
Inflorescences are in spikes up to 8 cm long in pairs (seldom three) in the upper axils. Each inflorescence is comprised of about 100 tiny (3.8x4.1 mm) bright yellow flowers (Ibrahim and Awang 1991). Flowers are 5-merous; the calyx 0.7-1.0 mm long, with short lobes; the corolla is 2-2.5 times as long as the calyx. Stamens are approximately 3 mm long. The pods are slightly woody, glaucous and transversely veined, about 6.5 cm long and 1.5 cm wide. They are initially straight or curved but become very twisted and irregularly coil on maturity. The seeds are broadly ovate to elliptical, about 4-6 mm long and 3 4 mm wide. Each seed is encircled by a long red, yellow or orange funicle. There are 60,000 seeds per kg.
Acacia auriculiformis occurs from near sea level to 400 m, but is most common at elevation less than 80 m. It is predominntly found in the seasonally dry tropical lowlands in the humid and subhumid zones. The mean annual rainfall in its natural range varies from 700-2000 mm, and the dry season (i.e. monthly rainfall less than 40 mm) may be 7 months. The mean maximum temperature of the hottest month is 32-34°C and the mean minimum of the coolest month is 17-22°C.
The species is commonly riparian, i.e. ringing perennial rivers and semi-perennial creeks, and tends to form discontinuous populations along drainage systems. It is found most commonly on clay soil types, found most commonly on clay soil types however it exhibits the ability to grow in a variety of soils including calcareous sands and black cracking clays. It can also tolerate highly alkaline and saline soils. Seedlings have the ability to compete with Imperata cylindrica during early growth phases and once mature may reduce the grass to a sparse ground cover.
Acacia auriculiformis is endemic to Australia, Papua New Guinea and Indonesia. having a disjunct distribution in three main areas: the lowlands of southern half of the island of New Guinea (Papua New Guinea and Irian Jaya, Indonesia); the lowlands of tropical Northern Territory, Australia; and the Cape York Peninsula of northern Queensland, Australia It has been widely introduced to many tropical countries in South and Southeast Asia Africa and Latin America.
Heartwood varies from light brown to dark red. The wood makes attractive furniture and is suitable for construction work, turnery and carving. Plantation-grown trees have shown promise for the production of unbleached kraft pulp-for bags and wrapping paper; and high quality neutral sulphite semichemical pulp-for corrugating, medium and higher-grade packaging products (Logan 1987). The wood has a high basic density (500650 kg/m³) and a calorific value of 4700-4900 kcal/kg, which make it ideal for firewood and charcoal.
Land Rehabilitation & Landscaping.
The spreading, denselymatted root system stabilizes eroding land. Its rapid early growth even on infertile sites, and tolerance of both highly acidic and alkaline soils make it popular for stabilizing and revegetating mine spoils. It is used for shade and ornamental purposes in cities where its hardiness, dense foliage and bright yellow flowers are positive attributes.
The bark has sufficient tannins for possible commercial exploitation (Abdul Razak et al. 1981). A natural dye, used in the batik textile industry in Indonesia, is also extracted from the bark. Its flowers are a source of bee forage for honey production (Moncur et al. 1991).
Propagation is generally by seed. Pregermination treatment is essential to promote seed germination. Immersion of seed in ample boiling water for 1-2 minutes is suitable to break dormancy. Germination is rapid after pretreatment and typically exceeds 70%. In general, 3-4 months are needed to raise seedlings to a plantable size, 25 cm in height. Inoculation with appropriate rhizobia may be beneficial, especially when seedlings are raised in sterilized soil.
Establishment is successful by containerized seedlings or by direct seeding. Containerized seedlings generally give higher survival, especially in areas of heavy weed competition. In the field, weed control is essential during the first 1-2 years. A small dose of NPK fertilizer in the first year helps improve initial growth - fertilization rates depend on quality. Recommended spacing is 2x2 or 2x4 m. Acacia auriculiformis has the ability to coppice, but it is not a vigorous sprouter. It responds well to pollarding.
An increment in height of 2-4 m per year in the first few years is common even on soils of low fertility (Boland 1989). On relatively fertile Javanese soils receiving 2000 mm annual rainfall, a mean annual increment of 15-20 m³/ha is obtainable but on less fertile or highly eroded sites the increment is reduced to 8-12 m³/ha (Wiersum and Ramlan 1982). Recommended rotation is 4-5 years for fuelwood, 8-10 years for pulp and 12-15 years for timber. One or two thinnings are required with longer rotations, depending on initial spacing, site quality and tree growth.
Acacia auriculiformis can fix nitrogen after nodulating with a range of Rhizobium and Bradyrhizabium strains. It also has associations with both ecto- and endo-mycotthizal fungi.
The propensity to produce multiple and crooked stems reduce its utility. It is susceptible to fire; even trees 10-15 years old can be killed. Stressed trees are found to be highly susceptible to attack by leaf insects.
Genetics & Provenances
Isozyme studies revealed marked genetic variation in A. auriculiformis. Three distinct groups of populations corresponding to the geographic distribution in Papua New Guinea, Queensland and Northern Territory (Wickneswari and Norwati 1991). These regional groupings are also apparent in seedlling morphology (Pinyopusarerk et al. 1991). Additionally, field trials have shown marked differences in growth and form. Provenances from Papua New Guinea have the highest production while those from Queensland have a high proportion of single stems. Those from the Northern Territory are inferior in both growth and form (Harwood et al. 1991).
Selection and breeding for superior growth and stem form are now underway in many countries, including Thailand and Vietnam Natural hybrids of A. auriculiformis x A. mangium have shown desirable characteristics; e.g. vigor, fine branching and tendency for a strong apical dominance. These characteristics lead to healthy trees with single stems and a good clear bole. Production and vegetative propagation of these hybrids warrant detailed study.
Abdul Razak, MA, Low, C.K and Abu Said, A. 1981 Determination of relative tannin contents of the barks of some Malaysian plants. Malaysian Forester 44:87-92.
Boland, D.J. (ed.). 1989. Trees for the tropics: growing Australia, multipurpose trees and shrubs in developing countries. ACIAR Monograph No. 10,247 pp.
Harwood C.E., Matheson, A.C. Gororo, N. and Haines, M.W. 1991 Seed orchards of Acacia auriculiformis in Melville Island, Northern Territory, Australia. In: J.W. Turnbull (ed), Advances in topical acacia research. ACIAR Proceedings No. 35. pp 8791.
Ibrahim, Z. and Awang, K 1991. Comparison of floral morphology flower production and pollen yield of Acacia mangium and A auriculiformis. In: Advances in tropical acacia research. pp 26-29 See Harwood at al. 1991.
Logan, A.F. 1987. Australian acacias for pulpwood In: J.W Turnbull (ed), Australian acacias in developing countries. ACIAR Proceedings No. 16. pp 89-94.
Moncur, M W., Kleinschmidt, G. and Somerville, D. 1991. The role of acacia and eucalypt plantations for honey production. Advances in tropical acacia research. pp 123-27. See Harwood e al. 1991.
Pedley, L. 1978. A revision of Acacia Mill. in Queensland Austrobaileya 1(2):75-234.
Pinyopusarerk. K Williams, E.R, Boland, D.J. 1991. Geographic variation in seedling morphology of Acacia auriculiformis. Australian Journal of Botany 39:247-260.
Wickneswari, R. and Norwati, M. 1991. Genetic structure of natural populations of auriculiformis in Australia and Papua New Guinea In: Advances in tropical acacia research. pp 94-95. Se Harwood e' al. 1991.
Wiersum. K.F. and Ramlan, A. 1982. Cultivation of Acacia, auriculiformis in Java, Indonesia Commonwealth Forestry Review 61:135-144.
NFTA 95-05 September 1995
Pentaclethra macrophylla Benth., the oil bean tree. is the sole member of the genus occurring naturally in the humid lowlands of West Africa. It is a leguminous tree (family Leguminosae, sub-family Mimosoideae), and recognized by peasant farmers in the southeast of Nigeria for its soil improvement properties. A related species viz. Pentaclethra macroloba (Wild) is native to South America (Norris 1969). Pentaclethra macrophylla has been cultivated in Nigeria since 1937 (Ladipo 1984) and for many years in other West African countries where its seed is relished as a food. Pentaclethra macrophylla was not known to nodulate until recently (Ladipo et al. 1993). With the diverse native uses of this species, and the present research effort on it, its utility could be further enhanced for agroforestry development in the humid tropics. The species is relatively fast-growing and seedlings will achieve a height of 1.5 m in the first year on good sites.
Trees grow to about 21 meters in height and to about 6 m in girth (Keay 1989). The tree has a characteristic low branching habit and an open crown which allows substantial light under its canopy. This characteristic accounts for the trees use in combination with food crops on farms and particularly in home gardens in south east Nigeria.
The bole produces a reddishorange coloration after a slash is made. Stem form is usually crooked and buttressed. Some straightstemmed and less buttressed trees, which can pass for good timber, are occasionally seen in the forests. Bark is grayish to dark reddish brown (Keay 1989), thin and patchy with irregular pieces flaking off.
Leaves possess a stout angular petiole. The compound leaves are usually about 20-45 cm long and covered with rusty hairs giving a scurfy effect particularly along the upper surface but this eventually falls off. There are 1012 pairs of stout opposite pinnae. The middle pairs are 713 cm long and also have rusty hairs along the central grove. There are usually 12-15 pairs of opposite stalkless pinnules (leaflets), each 12-15 cm long 5-10 mm broad, with the middle pairs longest. Leaflets often have a rounded tip but are sometimes notched; the base is unequal. Flowers are creamy-yellow or pinkish-white and sweet smelling. Flowering commences at variable periods within West Africa. The main flowering seasons is between March-April with smaller flushes in June and November. Fruits are available at most periods of the year because the large woody pods are persistent.
The pods are 40-50 cm long and 5-10 cm wide. Fruit splits open explosively with the valves curling up. This is the form in which they appear on most trees. Usually, pods contain between 6-10 flat glossy brown seeds which may vary in site. The seed are up to 7 cm long. This is the edible product and source of the oil; hence the name 'the oil bean tree.
Table 1: Common uses of Pentaclethra macrophylla in West Africa
Part of Plant
Fences end parings
Carving bowls, etc.
Seed craft (beadings)
Bark & seed
Smoke of burnt leaf
Bark as liniment
Bark as lotion
Distribution and Ecology
Pentaclethra macrophylla occurs from Senegal to Angola and also to the Islands of Principe and Sao Tome. This multipurpose tree is endemic to the humid and some parts of the sub-humid zones of West Africa. It does not occur in the highlands although, growth can be good where rainfall is adequate and temperatures are never cooler than 18°C. The annual mean temperature requirement is about 25°C and rainfall between 1000-2000 mm. After about 2-years growth in the forest, trees become relatively fire resistant and resprout readily when lopped.
The natural distribution of P. macrophylla suggests that it is endemic to relatively acid soils. The species will also tolerate water logging as in the low altitudinal riverine areas of southeast Nigeria, Togo and Cameroon.
The unusual feature of leaf loss during the wet seasons has been observed in the field on some individual trees of Pentaclethra macrophylla and this could be an important trait for selection for farmers. Although no provenance trials of this species have been conducted. tree phenotype in natural populations shows considerable variation in crown shape, fruit morphology and seed size.
Pentaclethra macrophylla is planted on the fringes of compound farms mainly for its edible seed. Its empty dry fruit pods are used as fuelwood for cooking. Leaves are shed during the dry season and farmers believe this contributes to soil fertility within the home garden. Pentaclethra macrophyilla wood is highly suitable for fuelwood and charcoal making (other uses are listed on Table 1). Farmers protect this species on farms because of its open crown form which does not inhibit crop plants grown under its canopy. Litter drop is appreciable. The species is believed to enhance soil nutrient and organic matter content.
The seed is large with approximately 50-80 seeds per kg. Because seeds are edible, they are not usually available for seedling production. When available in the open market, they are usually non-viable because of their short longevity (recalcitrant). Consequently seed should be planted immediately. Storage at 15°C can extend longevity for about three months.
Seed pre-treatment is required. Mechanical scarification and soaking in water for 24 hours will enhance germination.
Adult trees are easily marcotted (air layered), but only juvenile stem cuttings will root if treated with IBA (20 ppm). Seedlings produced in nurseries and hardened-off before out-planting make the best planting material.
Pests & Diseases
No serious pest and disease problems are known but stem borers have been recorded on some old trees and mild defoliation of juvenile seedlings is not uncommon. The species is reported to be termite resistant.
• Forestry Research Institute of Nigeria, PMB 5054, Ibadan, Nigeria
• ICRAF/IRA Project P.B. 2067 (Messa), Yaounde, Cameroon
Abbiw, D. 1990. Useful plants of Ghana. Kew Botanic Garden. Kew, UK. 337 pp.
Isawumi. M. A. 1993. The common edible fruits of Nigeria part II. The Nigerian field 58. Parts 3-4, 64 pp.
Keay, R. W. J. 1989. Nigerian Trees. Claredon Press, UK. 281 pp.
Ladipo, D.O. 1984. Seed problems in fuelwood plantations in Nigeria. Paper prepared for the International Symposium on Seed Quality of Tropical and Subtropical Species. Bangkok. 12 pp.
Ladipo, D. O., Kang, B. T. and Swift, M. J. 1993. Nodulation in Pentaclethra macrophylla Benth; a
multipurpose tree with potential for agroforestry in the humid lowlands of West Africa. Nitrogen Fixing Tree Research Reports 11: 104-105.
Norris, D. O. 1969. Observation on the nodulation status of rainforest leguminous species in Amazon and Guayana. Tropical Agriculture 46(1) 145 pp.
Okafor, J. C. and Fernandez, E. C. M. 1987. Compound farms of southeast Nigeria. A predominant agroforestry homegarden system with crops and small livestock. Agroforestry systems 5(2) 153 pp.
NFTA 95-03 June 1995
Native to Central and South America, representatives of Myroxylon are used in folk as shade trees for cultivated crops, ornamentals, and for fine timber. Balsam and its essential oil are used to flavor baked goods, candy, chewing gum, gelatin, ice cream, pudding, soft drinks and syrups, and as incense in churches. Balsam oil is also used in perfume, cosmetic and soap industries. Seeds are used to flavor aguardiente, a popular alcoholic beverage in Latin America (Duke 1981). Common names include: bÃ¡lsamo, palo de bÃ¡lsam (Spanish America in general), cedro chino, nabal (Mexico), chirraca, sÃ¡ndalo (Costa Rica), tache, tofu (Colombia), estoraque (Peru), cabreÃºva vermelha (Brazil), incienso, and quina (Argentina)(Chudnoff 1984).
Myroxylon balsamum (L.) Harms (family Legununosae, subfamily Papilionoideae) grows to 34 m in height and 1 m in diameter. The bark is generally gray and spotted with yellow rough areas. The 3-11 leaves are alternate, evergreen and oddly pinnate, 6-9 cm long and 3-4 cm wide (Duke 1981), and have scattered, translucent, glandular oil dots or lines (Allen and Allen 1981). Flowers are whitish, and the corolla contains 5 petals (Fuentes, 1993). The winged pod is 8-13 cm long and 2.5 cm broad and contains one seed at the tip (Duke 1981).
There is confusion about the number of species and varieties in the genus Myroxylon. Wiersema et al. (1990) reports two species: M. balsamum (L.) Harms native to southern Mexico, Central America, Colombia and Venezuela and; M. peruiferum L.f. native to northwest Argentina, Bolivia, Brazil, Colombia and Peru. Duke (1981) reports one species in South America M. balsamum (L.) Harms. In Brazil Lorenzi (1992) reports M. balsamum (L.) Harms end M peruiferum L.f. as synonymous.
Wiersema et al. (1990) also reports two varieties: M. balsamum var. balsamum in Panama, Colombia and Venezuela; and M. balsamum var. pereirae (Royle) Harms from southern Mexico through Central America. Duke (1981) reports only one variety-M. balsamum var. pereirae (Royle) Harms-distributed along the Pacific Coast jungles of Central America.
Myroxylon balsamum grows in areas with annual precipitation ranging from 1350-4030 mm (average 2640 mm), annual mean temperature of 23-27°C, and soils with pH 5-8 (Duke 1981). In northwestern El Salvador it grows from 450-700 m altitude in an area known as the ''balsam zone" (Fuentes 1993).
Myroxylon balsamum var. pereirae is reported to grow on poor but well-drained soils, at altitudes up to 600 m (Duke 1981).
Representatives of the genus are found in southern Mexico Central America, Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina and Brazil. Myroxylon balsamum var. pereirae has been introduced to southern Florida, Ceylon, India and West Africa (Duke 1981).
Myroxylon balsamum var. balsamum and M. balsamum var. pereirae yield gums called tofu and Peru balsam, respectively. These gums are used mainly as a flavoring in cough syrups, soft drinks, confectioneries, ice cream and chewing gums (Duke 1981).
Trees are wounded to collect gum by three methods. 1) V-shaped cuts are made in the bark taking care not to girdle the tree and cups are placed under cuts to collect gum. 2) Trees are burned at the base. Strips of bark are pulled off, crushed and placed in hot water to soften the balsam and facilitate its flow. The cooled balsam sinks to the bottom and can be separated (Duke 1981). 3) Sections of the tree trunk are beaten with a wooden club and then vertical incisions 8 cm wide are made in the bark. A few days later the incisions are heated with fire to stimulate gum flow incisions are not burned. Rags are placed over the incisions and removed when they are saturated. Crude presses are used to extract gum from the rags (Fuentes 1993).
Gum harvesting begins on 20 to 30-year-old trees with minimum diameters of 12-15 cm (Fuentes 1993). Twentyyear-old trees yield about 3 kg of gum per year (Allen and Allen 1981). With proper management trees yield gum for 30 to 40 years. Prices per half kilogram of unrefined and refined gum in El Salvador in 1993 were approximately 17 and 24 colonel, respectively (Fuentes 1993). This is US$2.003.00 at current exchange rates.
El Salvador, a major producer of Peru balsam, exported about 48 MT annually in the late 1970's and early 1980's. Tolu balsam is produced in Colombia, the main source, Venezuela and the West Indies (Duke 1981).
Balsam gum contains about 60% cinnamein, a volatile oil extracted by steam distillation. The oil is used in highgrade perfume, cosmetic and soap industries (Duke 1981).
Balsam wood is used for flooring, furniture, interior trim, turnery and railroad ties. It is moderately difficult to work but can be finished smoothly with a high natural polish. Heartwood is reddish brown, turning deep red or purplish upon exposure, and very resistant to attack by decay fungi. Specific gravity is 0.74-.0.81. Shrinkage values from green to ovendry are very low for a wood of this density (Chudnoff 1984).
Tolu balsam is used as a feeble expectorant in cough mixtures, and as an inhalant for catarrh and bronchitis. Peru balsam is used extensively as a local protectant, rubefacient, parasiticide in certain skin diseases, antiseptic, and applied externally as an ointment, or in alcoholic solutions. It is rarely used internally as an expectorant. Alcoholic extracts of tofu and Peru balsam inhibit Mycobacterium tuberculosis (Duke 1981).
Myroxylon balsamum (L.) Harms is used in El Salvador as a shade tree in coffee plantations. There are no government initiatives to promote formal planting of the species-it is propagated mainly through natural regeneration (Fuentes 1993).
Seeds are wind dispersed and may be collected from the tree as they begin to mature. Balsam tree' in Brazil flower from July to September and set seed in October and November. There are approximately 1,700 seer per kilogram (Lorenzi 1992).
Seed should be planted in a mixture of clay and organic matter to a depth of .5 cm, covered with fine soil and watered daily. Germination beds or container' should be partially shaded. Seeds germinate (greater than 50%) in 1530 days. Seedlings are ready for outplanting in 5 months. Seedlings grow to 2.5 m in 2 years (Lorenzi 1992).
Allen and Allen (1981) report nodulation of Myroxylon balsamum. Nodulation of M. balsamum has not been reported in Brasil (S.M. de Faria, personal communication).
Myroxylon balsamum (L.) Harms var. balsamum and M. balsamum (L.) Harms var. pereirae are attacked by a number of fingi: Meliola xylosmae, Myiocopron pereirae, Pecksia pereirae, Phylosticta myroxyli, Phomopsis sp. and Tabutia xylosmae (Duke 1981).
Allen, O.N. and Allen, E.K. 1981. The Leguminosae: a source book of characteristics, uses and nodulation. Madison, WI (USA): The University of Wisconsin Press, p. 453.
Chudnoff, M. 1984. Tropical timbers of the world. Agricultural handbook number 607. Washington, DC: U.S. Department of Agriculture, Forest Service, p. 113.
Duke, J. 1981. Handbook of legumes of world economic importance. New York, NY: Plenum Press, pp. 173-77.
Fuentes, R.E. 1993. El bÃ¡lsamo en El Salvador: una especie con potencial econÃ³mico. Revista Forestal Centroamericana. No. 6, AÃ±o 2. Turrialba, Costa Rica: CATIE, pp. 38-41.
Lorenzi, H. 1992. Ãrvores Brasileiras: manual de identificaÃ§Ã£o e cultivo de plantas arbÃ³reas natives do Brasil. Nova Odessa, SP: Editora Plantarium, p. 220.
Wiersema, J.H., Kirkbride, J.H., Jr. and Gunn, C.R. 1990. Legume (Fabaceae) nomenclature in the USDA germplasm system. Technical Bulletin No. 1757: U.S. Department of Agriculture, pp. 371-72.
NFTA 95-04 June 1995
Ougeinia dalbergioides Benth. (Leguminosae, Subfamily Papilionoideae) is a monotypic genus formerly classified as Ougeinia oojeinensis and Dalbergia ougeinesis. It is a valuable timber and fodder species restricted to India. The natural forests containing this tree have been severely degraded by timber exploitation. Ougeinia dalbergioides is most commonly called sandan.
Ougeinia dalbergioides is a medium-sized semi-deciduous tree, commonly attaining 40-50 cm in diameter breast height (DBH) and 7-14 meters in height (Troup 1921). The stem is often crooked, but in some areas the tree is straight. The bark, varying from pale pinkish-brown to dark bluish gray, is somewhat rough and exfoliates in irregular thin soft scales. Leaves are pinnately trifoliate, smooth above and lightly pubescent below. The obovate leaflets are generally 6-12 cm long and 2-15 cm wide, but size varies greatly. Leaf margins are entire.
The light-pink to white flowers emerge in clusters from February to May. The previous years branches generally do not bear flowers. Branches bearing flowers are leafless, while others retain leaves. Flowering trees are conspicuous and afford a beautiful sight. Pods have a distinct seam, are 5-10 cm long and 1 cm wide. They mature and ripen in May to June and fall chiefly in June. Normally, pods remain closed until seeds germinate. Mature pods yield 2-5 viable seeds. The smooth brown seeds are 10-12 mm long and 5 mm wide. Trees do not seed heavily each year (Troup 1921).
Ougeinia dalbergioides is native to sub-tropical regions of India. It is common at elevations of 300-1500 m. At higher elevations it remains a small tree. The optimum mean annual temperature in its habitat ranges from 20 20-47°C with a relative humidity from 49-90%. The optimum rainfall appears to range from 950-1900 mm. This species is not found in wet regions. Characteristic of limestone soils, sandan grows well on dry exposed sites and eroded hills (Troup 1921). It also occurs on alluvial soil, red clay, black cotton, and rocky soil. Its best growth and greatest size is attained in the lowlands on alluvial soils. Sandan is a component of mixed deciduous and sal (Shorea robusta) forests. It is associated with pines at the higher limits of its elevation range.
Ougeinia dalbergioides is found in the sub-Himalayas foothill and plains of the Punjab eastwards to Bhutan. It is also common in Central and Northern India and in some parts of Southern India It is an important species in Uttar Pradesh and Madhya Pradesh.
Ougeinia dalbergioides yields a valuable timber. The sapwood is grey and narrow, the heartwood is light golden brown, hard, strong, heavy and elastic-specific gravity is 0.84 and average weight is 865 kg/cubic meter. The wood airseasons slowly without much degradation. The wood can be kilnseasoned without difficulty, but requires slow and careful drying. Planks 2-5 cm thick require 16-20 days to season (Pearson and Brown 1932; Trotter 1944). The wood does not require preservative treatment. It is difficult to work, but turns well and takes polish readily. Though originally considered difficult to peel, it is now frequently utilized for plywood. The timber of this species is superior to teak (Tectona grandis) in terms of shock resistance, shear strength and hardness (Pearson and Brown 19321. Sandan timber is used in the manufacture of agricultural implements, construction timbers, furniture and textile mill implements. It is also a specialty timber for marine. It is a good fuel with a calorific value of 4900-5200 Kcal/kg (Krishna and Ramaswami 1932).
The leaves are highly valued as cattle feed. Farmers lop side branches, but often spare the main limbs to assure good growth and future supplies of fodder. In some areas, natural stands of this species are such important fodder resources timber harvesting is forbidden. Leaves contain 12- crude protein (Singh 1982).
Bark fibers are suitable for making rope (Pearson and Brown 1932; Trotter 1944). The bark is used as a fish poison and to reduce fevers. A sap exudate is used to make a medicine to treat dysentery. The tree is a host-plant for lac producing insects. The resulting shellac is of high quality (Purkayastha and Krishnaswamy 1958).
Ougeinia dalbergioides is readily propagated from seed. The seeds do not retain their viability for long and should be used within 12 months of maturity. Once collected seed should be properly dried and stored in sealed containers. A kilogram contains 28,000-33,000 seeds. To maximize germination, pods should be broken into fragments containing one seed and soaked in water for 24 hours before sowing (Uniyal and Nautiyal 1992). Seed should tee sown 1 cm deep. Germination occurs in 3-8 days. Direct sowing is very successful and highly recommended (Troup 1921; Kadambi and Dabral 1955).
Nursery-propagation accelerates seedling growth, however the large taproot of sandan makes transplanting difficult. Establishment by stump sprouts gives good results. One-year old seedlings with root-collar diameters of 5 cm are recommended. For stump production, seedlings should be cut 23 cm above the root-collar and 20-25 cm below. Propagation by root cuttings is successful, but stem cuttings yield poor results.
Young trees and seedlings need a moderate amount of shade. However, once established O. dalbergioides requires full Asunlightlight for its best development. Although young trees are throught and frost sensitive, mature trees are hardy. A tree spacing of 3 x 6 m is recommended for timber production.
Mean annual growth increment averages between 3-20 mm in DBH. Trials in Srinagar indicate keeping seedlings free of heavy weed competition for 3-4 years will improve growth and survival. Under this management scheme, trees attained heights of 4-5 m and DBH of 10.5 cm in 6 years. Conversely, heavy weed competition can kill seedlings. Sandan coppices well and produces abundant root-suckers. This characteristic is particularly useful for controlling erosion along steep banks and eroded hillsides. Fast-growing coppice and root-suckers attain 7-10 m in height and 12-17 cm in DBH after 20 years. Coppice and root-suckers can be managed for timber production. In Madhya Pradesh forests are commonly managed simultaneously for sandan and teak production. The exploitable diameter for O. dalbergioides timber is generally 30 cm.
Sandan is very susceptible to heart rot (Fomes caryopnhylla), buff brown pocket rot (Polystictus nilgheriensis) and white spongy rot (Asterostromella rhodospora). The tree is also susceptible to a number of defoliators and borers. The latter also attack dead wood (Kadambi and Dabral 1954). Timber exploitation has degraded the natural stands of this species. To reverse this condition, improved natural forest management and the establishment of large-scale tree plantations are necessary.
As with many other leguminous plants, Ougeinia dalbergioides forms nitrogen fixing symbiosis with Rhizabium bacteria. Reliable estimates of its nitrogen fixing capacity are not available.
A variant of this species has been reported to occur at a frequency of 4% in Srinagar. Variants differ morphologically from the normal plants by producing narrower leaves with 46 leaflets instead of three. The morphological difference has been retained by trees established in an arboretum in 1985 (Purohit et. al 1987). These plants grow 30% slower than the normal plants. Detailed investigations on the physiology of variant plants are in progress.
Kadambi, K. and S. N. Dabral. 1955. Studies in the suit ability of different methods of artificially regenerating forest trees. Indian Forester 81(2):129.
Krishna S. and S. Ramaswami. 1932. Calorific values of some Indian woods. Forest Bulletin No. 79, (New Series). Chemistry, Government of India, Central Publication Branch Calcutta Pearson, R. S. and H P. Brown. 1932. Commercial timbers of India. Volume 1. Government Press, Publication branch Calcutta p 352-356.
Purkayastha, B. K and S. Krishnaswamy. 1958. Trials of Albizia lucida and Ougeinia dalbergioides as new lac hosts for the baisakhi crop in Chota Nagpur. Indian Forester 84(3):137.
Purohit A. N., A. R Nautiyal, P. Thapliyal, and S. K Bhadula 1987. Physiology of Ougeinia dalbergioides Benth. and its mor phological variant I. Germination, growth behavior and carbon dioxide exchange rate. The International Tree Crops Journal 4 165-175.
Singh, R.V.1982. Fodder trees of India. Oxford & IBH Publishing Co., New Delhi. 259 p.
Trotter, H. 1944. The commercial timbers of India and their uses. Government Press, Delhi. 22? p.
Troup, R. S. 1921. The Silviculture of Indian Trees. Volume 1. Oxford University Press, Oxford. p 228-296.
Uniyal, R. C. and A. R. Nautiyal. 1992. Effect of presoaking in water in germination of Ougeinia dalbergioides seeds. Nitrogen Fixing Tree Research Reports 10:176-177.
NFTA 91-06 November 1991
Prosopis alba and Prosopis chilensis are native to the semi-arid regions of northwestern Argentina and northern Chile. Locally they are called el arbor or, the tree, because of their widespread occurrence and importance. Since these species have often been confused in the literature, it is useful to treat them together. Once leaf patterns have been observed, differences between species become obvious.
Prosopis alba (Grisebach) and P. chilensis (Molina Stuntz) (subfamily Mimosoideae, family Leguminosae) are small to medium-sized trees up to 12 m in height and 1 m in diameter. Both species have thorny and thornless variants. The most distinguishing feature between the two are the number and spacings of leaflets.
The trees have compound leaves each with numerous leaflets along several pairs of pinnae. P. alba usually has 2-3 pairs of pinnae (but up to 4 or 5) with 30-50 sets of 10 mm long leaflets per pinnae (Burkart 1976). P. chilensis generally has fewer leaflets per pinnae (about 10-29) and usually no more than two pair of pinnae per leaf. In P. alba, the 1-2 mm wide leaflets nearly touch the pinnae, while in P. chilensis, leaflets are about 1 cm apart.
Abundant, greenish-white to yellow flowers occur on spike-like racemes. Pods of both species are beige to offwhite, from which the species name alba, or white, originates. In contrast, other Argentine species have redtinged to dark purple pods (P. flexuosa and P. nigra).
The pods of P. alba are typically 20 an long, 4-5 mm thick, and 20-25 mm wide. They are sickle-shaped with the entire pod occurring in the same plane. Although P. chilensis pods are the same color, they are shorter (about 15 cm) and not as wide (about 15 mm). The pods of P. chilensis are seldom flat and have a tendency to be rolled up along the long axis. P. alba pods also usually have a thicker mesocarp indicating a greater pod sugar content. The name P. chilensis has been incorrectly applied to the North American species P. glandulosa and P. velutina, and to the naturalized P. juliflora that occurs in the Sudan.
Over 20 species of Prosopis occur in the semiarid and arid regions of northwestern Argentina, making Argentina the center of genetic diversity for Prosopis, although probably not the center of origin (Burkart 1976). P. alba is native to the plains and low sierra of subtropical Argentina, extending into Uruguay, Paraguay, southern Brazil, and Peru (Burkart 1976) up to 1,500 m elevation.
In Argentina, P. chilensis grows in regions that experience lower winter temperatures and lower rainfall than P. alba (E. Marmillon, pers. comm.). In areas with groundwater between 3 and 10 m below the surface, such as in drainage channels and along groundwater sinks, P. chilensis may occur in areas with less than 250 mm rainfall. If no groundwater is available, annual rainfall must exceed 350400 mm for large trees (25-100 cm diameter) to occur. Trees of both species have been identified that grew in seawater salinity (Rhodes and Felker 1987).
Over most of the trees' range the climate is subtropical with annual temperatures averaging about 20°C. In northern Argentina along the border with Paraguay, the frosts are light (-3 or -4°C), but further south near Cordoba occasional frosts of -12°C occur. When grown in Texas, nearly all spineless trees of P. alba froze to ground level with frosts of -12° C. Both species occur in areas that experience 45°C, so high temperature stress is not a problem.
The wood of these trees is relatively dense (about 700-800 kg/m³) and makes an excellent fuel whether burned directly or first converted to charcoal (Tortorelli 1956). The timber is valued for furniture, doors, cobblestones, and parquet floors. The reddish/brown wood has a volumetric shrinkage much lower (ca. 5%) than that of other quality furniture woods (ca. 15%). As a result, joints in furniture have much less tendency to open during conditions of changing humidity.
The pods but not the leaves of the trees are readily eaten by domestic livestock. Pods are high in sugar (about 35%) (Oduol et al. 1986) and contain 10-12% crude protein. Seeds are sometimes ground into a concentrate for animal feed. Large trees, 40 cm in basal diameter and 7 m in canopy diameter, may produce 40 kg of pods under optimal conditions. Because of water constraints, tree spacings must be considerably greater than canopy diameters.
The pods of both trees are eaten by native peoples, especially as a ground flour. Contemporary milling techniques and product formulations with Prosopis flour has been described (Sounders et al. 1986). Bees produce honey from the flowers.
The large size of the trees and more rapid growth than other Prosopis (e.g., P. glandulosa) have led to widespread use of P. alba and P. chilensis for shade, windbreaks, and as ornamentals in Argentina and in Arizona and California, USA. They also contribute nitrogen and organic matter to soils (Johnson and Mayeux 1990). These trees are candidates for erosion control and soil stabilization in arid lands.
Seeds are difficult to extract from the gummy pulp. Prosopis pods can be ground in a meat grinder after drying pods in an oven at 52°C overnight, which will also serve to scarify the seeds. For good germination seeds require scarification of the seed coat with a file or knife. There are about 36,000 seed/kg.
Outstanding trees have been cloned using roofings or cutting techniques that require control over light intensity and air temperatures (Klass et al. 1984). To obtain the highest survival under semi-arid controls, seedlings are grown in long (38 cm) narrow (3.8 x 3.8 cm) cardboard plant bands and planted with the container still on (Felker et al. 1988). Machanical and chemical weed controls to maximize growth are available (Felker et al. 1986).
Biomass yields of trees grown under short rotation systems (3 yrs) on dose spacings (1.5-3.0 m) have been high. Field trials in Texas, USA, using a high productivity P. alba clone, produced 39 dry metric tons/ha in three years at a site with 650 mm annual rainfall (Felker et al. 1989). Trees grew about 2.2 m in height per year. However, excellent weed control coupled with mechanical cultivation was required to achieve these high yields.
A single rhizobia strain that effectively nodulated 13 Prosopis species (Felker and Clark 1980) is available from LiphaTech (3101 West Custer Ave., Milwaukee, Wisconsin 53209). Rhizobium for Prosopis species is also available from NifTAL through NFTA.
PROBLEMS AND PESTS.
Twig girdling insects (Oncideres spp.) cause minor damage to these trees. An undescribed "disease" causes the terminal shoots to die. Over a period of years this necrosis gradually spreads downward and eventually may kill the entire tree. These Prosopis can become weeds in heavily grazed areas.
Burkart, A. 1976. A monograph of the genus Prosopis (Leguminosae subfam. Mimosoideae). J. Arnold Arb. 3:217 249; 4:45-525.
Felker, P. and P.R Clark. 1980. Nitrogen fixation (acetylene reduction) and cross inoculation in 12 Prosopis (mesquite) species. Plant and Soil 57:177-186.
Felker, P., D. Smith, and C. Wiesman. 1986. Influence of chemical and mechanical weed control on growth and survival of tree plantings in semi-arid regions. Forest Ecology and Management 16:259-267.
Felker, P., C. Wiesman, and D. Smith. 1988. Comparison of seedling containers on growth and survival of Prosopis alba and Leucaena leucocephala in semi-arid conditions. For. Ecol. Manage. 24:177-182.
Felker, P., D. Smith, C. Wiesman, and R.L. gingham. 1989. Biomass production of Prosopis alba clones at two non irrigated field sites in semi-arid south Texas. For. Ecol. Manage. 29:135-150.
Johnson, H.B. and H.S. Mayeux. 1990. Prosopis glandulosa and the nitrogen balance of rangelands: extent and occurrence of nodulation. Oecologia 84:176-185.
Klass, S., R.L. gingham, L. Finkner-Templemen, and P. Felker. 1984. Optimizing the environment for rooting cuttings of highly productive clones of Prosopis alba (mesquite/algaroba). J. Hort. Science 60:275-284.
Oduol, P. A., P. Felker, C.R. McKinley, and C.R. Meier. 1986. Variation among selected Prosopis families for pod sugar and pod protein contents. For. Ecol. Manage. 16:42-433.
Rhodes, D. and P. Felker, 1987. Mass screening Prosopis (mesquite) seedlings for growth at seawater salinity. For. Ecol. Manage. 24:169-176.
Saunders, R.M., R. Becker, D. Meyer, F.R. del Valle, E. Marco, and M.E. Torres. 1986. Identification of commercial milling techniques to produce high sugar, high fiber, high protein and high galacto mannan gum fractions from Prosopis pods. For. Ecol. Manage. 16:169-180.
Tortorelli, L. 1956. Maderas y Bosques Argentinos. Acme Agency Press, Buenos Aires, Argentina 646 p.
NFTA 94-06 June 1994
Sesbania sesban is a many-branched, soft-wooded tree that grows rapidly and is useful for fodder and green manure. This species has long been used for browse and soil improvement in India and Africa. Recent interest in multipurpose, nitrogen fixing trees has caused it to be collected, studied, and recommended for fodder ''banks" and alley cropping.
Sesbania sesban (L.) Merrill is a tree that grows to 8 m height. This papilionaceous (pea-like flowered) legume bears racemes of 4-20 yellow flowers that may be lightly to heavily streaked with purple. Sesbans have pinnate leaves with 20-50 opposite pinnules on a rachis 3-12 cm long. The leaf rachis and the underside of the leaflets are often pubescent. The pods are usually 10-20 cm long and contain up to 40 seeds that are brown, or dark green mottled with black. The trees usually have one main stem, but they may develop many side branches if they have space. Sesban's many branches often give the tree a shrubby appearance. It tends to have a spreading habit due to its wide branching angle (as wide as 4560°).
Within its genus, sesban is classified in the subgenus Sesbania, and thus is more closely related to the annual sesbanias grown far green manure (such as S. cannabina, others?) than to the - other well known perennial species of the genus, S. grandiflora, which is in the subgenus Agati (Evans 1990). Several varieties of sesban are recognized. The botanical distinctions among sesbanias are often difficult far non-botanists to see, and sometimes sesban is confused with the annual types of sesbania.
Sesban occurs naturally in semiarid to subhumid areas with 5002000 mm of rainfall. It seems to do well under bimodal rainfall distributions, where heavy rains and even flooded conditions are followed by a pmgressively drier season. It grows from sea level to 2000 m elevation, but the upper limit is uncertain. It does not tolerate frost. It is uniquely well adapted periodic waterlogging and flooding. Soil alkalinity and salinity is tolerated to a considerable degree. Some research suggests that certain sesban types may grow well on acidic soils. Sesbans are relatively short-lived, and under intensive browsing or cutting management will not last more than 3-5 years. Their rapid seedling growth is conducive to short-term fallows and to replanting if management should reduce growth vigor.
Sesban is found throughout the tropical and subtropical parts of Africa, Asia, and Australia It is not widely distributed in the Americas. Africa is its center of diversity, and sesban probably originated there; its former name is S. aegyptiaca. From northeastern Africa, S. sesban var. sesban and its variants were spread across southern Asia, possibly by man. Within Africa, S. sesban var. nubica is the type most commonly found, and there arc several sesbanias closely related to sesban, such as S. goetzei and S. cinerascens (Gillett 1963).
Sesban is mostly used as fodder and for soil improvement. its wood is used only to a lesser extent (Evans and Macklin 1990).
The leaves and tender branches of sesban are high in protein (20-25% crude protein) and have high digestibility when consumed by ruminants, such as cattle and goats. Antinutritional factors are suspected to be present in sesban fodder. Feeding sesbania fodders to monogastric animals (such as chickens, rabbits, and pigs) is not recommended.
Reports of feeding sesban to ruminants conflict. Trials in Australia feeding sesban to heifers showed live weight gains, but trials with young goats in Samoa found a lack of weight gain. Until further research provides clear guidelines, caution should be used in feeding ruminants with sesban fodder at more than 10-20 percent of diet.
Sesban establishes quickly and grows rapidly. In Africa it is often allowed to grow scattered throughout annual crop fields for the nitrogen it provides. It has been used in experimental alley cropping systems to provide mulch and greenleaf manure to intercrops. Sesbans can be somewhat shallow rooted, and may compete with adjacent crops.
Sesban's wood is light in weight compared to the woods of Calliandra and Leucaena, but it is often harvested for firewood in Africa and India It has been used in India to make charcoal. The wood is not durable and should not be considered for timber use. The branches have been used as poles in temporary structures such as sheds and mud daub huts.
Because sesban grows so rapidly, it has potential for pulpwood production. Plantings at about 10,000 tree/ha have produced 15-20 tons of woody biomass (dry weight) in one year.
Flowers of sesban are known to be added to stews and omelets in some regions, perhaps mainly as a decorative element.
Various medicinal uses for sesban have been recorded in Africa and Asia (Evans and Rotar 1987, Evans and Macklin 1990). The leaves and flowers are used in medicinal poultices and teas. which are said to have the effect of astringence, or contraction of body tissues. Bark exudates from sesban produce a gum of medium commercial quality.
Culture and Management
Sesban is generally propagated from seed, although it has been rooted from cuttings, and research has revealed that it can be established by tissue culture. Seed scarification usually improves germination. Recommended hot water scarification is a 30second dip in water heated to just below boiling. Seed weights range from 55-80 per gram for S. sesban var. sesban to 80-130 per gram for var. nubica.
Plants grown for fodder production can be placed as close as 30-50 cm apart in rows 1 m apart. Appropriate distances between rows in alley cropping will depend on the variety grown, the ecology of the site, and intensity of management.
Experimental fodder cutting trials have yielded 20 tons/ha dry matter in the first year. However, sesban cannot be managed with the severity that Leucaena tolerates in fodder and wood biomass production systems. If sesban is cut too low (below 50-100 cm) or too frequent (more than 4-6 cuttings per year) death of the plants can result. When cutting sesban it is recommended to leave 10-25% of the foliage on the plants.
In some climates, such as the highlands of Kenya, sesban may have a sparse canopy and weed competition can be a problem. This characteristic makes sesban a good intercrop. Sesban has been grown with the fodder grass Brachiaria mutica in India, and to provide shade to young coffee plants in Kenya In climates where sesban grows more vigorously, weeds are shaded out and companion plants may be adversely affected; this type of growth has been observed in Hawaii and Jamaica (Roshetko et aL 1991).
The rhizobia strains that nodulate sesbanias are somewhat specialized and may not be present where sesbanias have not been grown previously. Test plantings should be done to see if effective rhizobia are present in the soil. If not, use of a rhizobia inoculant at planting will be necessary.
Sesban is not a tree for timber or reforestation in the ordinary sense of forestry or silviculture. Because the range of its ecological adaptability is not yet well known, test plantings should be done before large-scale plantings are planned. Sesban has been observed occasionally to die back under cutting management; fungal infection may be the cause. Leaf-feeding insects sometimes limit production. Seed chalcids can reduce seed recovery.
Evans, Dale O. 1990. What is Sesbania? Botany, taxonomy, plant geography, and natural history of the perennial members of the genus. In: B. Macklin and D. O. Evans (eds), Perennial Sesbania species in agroforestry systems. Nitrogen Fixing Tree Association. p. 5-19.
Evans, D. O., and Macklin, B. (eds). 1990. Perennial sesbania production and use. Nitrogen Fixing Tree Association 41 p.
Evans, D. O., and Rotar, P. P. 1987. Sesbania in agriculture. Westview Press, Boulder, Colorado, U.S.A.
Gillett, J. B. 1963. Sesbania in Africa (excluding Madagescar) end southern Arabia Kew Bulletin 17:91-159.
Roshetko, J. M., Lantagne, D.O., and Gold, M. A. 1991. Direct seeding of fodder tree legumes in Jamaican pastures. Nitrogen Fixing Tree Res. Reports 9:68-70.
Financial support for this NFT Highlight was provided by the Rockefeller Brothers Fund through the Southeast Asia NGO Support Program.
A Publication of the Nitrogen Fixing Tree Association Winrock International 38 Winrock Drive Morrilton AR 72110-9537
NFTA 91-04 July 1991
Prosopis cineraria is a versatile species, providing fodder, fuel food, timber, and shade, as well as affecting soil improvement and sand dune stabilization. It is commonly used in dryland agroforestry in India and Pakistan. The tree is known locally as jandi or khejri (India), jand (Pakistan), and ghaf (Arabic). Its synonym is P. spicigera.
Prosopis cineraria (L.) Druce (family Leguminosae, subfamily Mimosoideae) is one of 44 species of leguminous trees and shrubs in the genus. It is a small, thorny, irregularly branched tree, 5-10 m high. Evergreen or nearly so, it forms an open crown and has thick, rough gray bark with deep fissures.
Leaves are alternate, bipinnately compound with 1-3 pairs of pinnae. Each pinna has 7-14 pairs of leaflets, 15 mm long and 2-4 mm broad. The thorns are straight with a conical base and distributed sparsely along the length of the stem. They first become visible when the seedlings are 6-8 weeks old. In this respect, P. cineraria differs from the thorny New World species of Prosopis (e.g., P. juliflora) which have thorns in pairs at the nodes but thornless internodes.
The 0.6 cm yellow-green flowers are borne on 5-23 cm spike-like racemes. Up to 25 dull brown seeds, 03-0.8 cm long, are contained in each of the light yellow pods, which are long (8-19 cm), narrow (0.4-0.7 cm), and cylindrical. As with other Prosopis, rooting can be very deep; the tap root of P. cineraria may penetrate vertically up to 20 m or more (Mahoney 1990).
P. cineraria occurs naturally in the dry and arid regions of India, Pakistan, Afghanistan, Iran, and Arabia. It is one of the principal species on higher and older alluvium in the Indus river valley. It is extremely drought tolerant, growing in areas with as little as 75 mm annual rainfall generally 150400 mm (FFN 1991), with dry seasons of eight months or more (NAS 1980).
Slightly frost hardy and tolerant of temperatures up to 50°C, it grows at altitudes from sea level to 600 m. The tree is found in alluvial and coarse, sandy, often alkaline soils where the pH may reach 9.8. In vitro studies have confirmed the nodulation of P. cineraria with Rhizobium.
In areas such as the Wahiba Sands in Oman there exist isolated, ancient P. cineraria trees. It also grows gregariously on sand. Under less extreme conditions, P. cineraria, often in association with Acacia tortilis, may form open dry, woodlands, which are important communities within the desert ecosystem. There is considerable phenotypic variation between individuals in crown shape, growth rate, and branching. Ecotypes growing in highly saline coastal areas have also been identified.
P. cineraria provides excellent firewood (calorific value, cat 5,000 kcal/kg) and charcoal Its wood is favored for cooking and domestic heating (Mahoney 1990). Hard and reasonably durable, the wood has a variety of uses for house building, posts, tool handles, and boat frames, although poor tree form limits its usefulness as timber.
The leaves are an available, excellent, and nutritious fodder, readily eaten by many animals including camels, goats, and donkeys. The tree produces leaves during the extremely dry summer months when most other trees are leafless. Leaves contain 13.8% crude protein, 20% crude fiber, and 18% calcium (FFN 1991). The pods also provide a good fodder, containing a dry, sweet pulp.
Pods are eaten as a vegetable in the human diet in some areas. In Rajasthan, green pods called sangri are boiled and dried (FFN 1991). The flowers are valuable for honey production. The bark can be used in leather tanning and yields an edible gum. Bark and flowers are used medicinally (NAS 1980). In times of famine, the powdered bark has been mixed with flour and made into cakes (Bhandari 1978).
P. cineraria effectively stabilizes sand dunes and can withstand periodic burial (Gates and Brown 1988). Because of a deep taproot, trees are not believed to compete for moisture or nutrients with crops grown dose to the trunk. During the growing season it casts only light shade and is therefore suitable as an agroforestry species. Farmers in arid and semi-arid regions of India and Pakistan have long believed it to increase soil fertility in crop fields. Yields of sorghum or millet increased when grown under P. cineraria, as a result of higher organic matter content, total nitrogen, available phosphorus, soluble calcium, and lower pH (Mann and Shankarnarayan 1980). Other crops traditionally grown amid scattered khejri are maize, wheat, and mustard.
Seeds (25,000/kg) remain viable for decades in dry storage and establish well with 80-90% germination (Mahoney 1990). Soaking seeds in tepid water for 24 h is recommended as a pre-germination treatment. The round end of the seed may also be scarified by scratching or nicking with a file or knife.
P. cineraria is difficult to propagate by cuttings, although treatment with rooting hormones has proved successful in India. Propagation by root suckers and by air layering has been reported. Recent attention has also been given to micropropagation of this species, but it appears that in vitro propagation is more difficult with P. cineraria than with many other Prosopis species. The tree is also considered slower growing than other Prosopis.
Seedlings are raised in a nursery and transplanted when 2-3 months old at the onset of the rainy season. Trees can be planted in close lines as a hedge with 1 m spacing between trees (Mahoney 1990), but tree densities of 50-100/ha are recommended for both agroforestry and silvopastoral systems. One or two weedings are necessary during the first year owing to slow initial growth rate. Early pruning to encourage straight growth is recommended (NAS 1980). The tree responds well to irrigation, tolerating up to 50% sea water.
The tree coppices readily (NAS 1980). Maximum yields of fodder are obtained when the trees are pollarded on a threeyear-rotation. Villagers traditionally lop their trees in winter and store the sun-dried leaves for dry season fodder.
The trees reach 3-5 m high in 5-6 years with an average diameter of 6 cm. Annual firewood yields of up to 2.9 m³/ha have been reported (NAS 1980). A moderate sized tree may yield 45 kg of dry leaf fodder per year.
Although P. cineraria plays a vital role as an agroforestry species in some parts of its natural range, little success has been achieved in planting it elsewhere. Further work is needed to establish the range of conditions under which it might prove useful. P. cineraria displays considerable genetic variation, particularly in populations close to the edge of its natural range, which are often threatened by overgrazing. Genetic conservation of this valuable resource is considered a priority.
Desert locusts (Shistocarica gregaria) and Melolonthidae beetles attack the foliage, and bruchid beetles feed on the mature dried seeds. Termites (Odontoteomen obesus), white grubs (Halorachia spp.), and the gallfly (Goccidomulid gall)) arc also important pests. There is little information on diseases of P. cineraria. This NFT is not suitable for planting in riverine areas or subhumid environments where it can become an aggressive colonizer and spread rapidly.
Bhandari, MM. 1978. Flora of the Indian Desert. Scientific Publishers, Jodhpur, India.
Burkart, A. 1976. A monograph of the genus Prosopis (Leguminosae, subfam. Mimosoideae). J. Am. Arb. 57(3/4): 219-249; 450-525.
FFN. 1991. Spotlight on species: Prosopis cineraria. Farm Forestry News Vol. 4, No. 3.
Gates, P.J. and K Brown. 1988. Acacia tortilis and Prosopis cineraria: Leguminous trees for arid areas. Outlook on Agriculture 17:61 64.
Leakey, R.R.B. and F.T. T. Last. 1980. Biology and potential of Prosopis species in arid environments with particular reference to P. cineraria. 1. Arid Environments 3:9-24.
Mahoney, D. 1990. Trees of Somalia - A field guide for development workers. Oxfam/HDRA, Oxford. p. 133-136.
Mann, H.S. and K.A. Shankarnarayan. 1980. The role of Prosopis cineraria in an agropastoral system in Western Rajasthan. In Browse in Africa, edited by H.N LeHouerou, International Livestock Centre for Africa, Addis Ababa, Ethiopia. p. 437442.
NAS (National Academy of Sciences). 1980. Firewood Crops. Vol. 1. National Academy Press, Washington, D.C. p. 150
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The seeds of certain Acacia species were an important traditional food resource for Australia's desert Aborigines (Crawford, 1982: O'Connell et al., 1983; Latz, 1984; Brand and Cherikoff, 1985; Orr and Hiddens. 1987). According to a recent review (Thomson, 1992), 44 of the 125 Acacia species found in the deserts of subtropical Australia have some potential as sources of human food, including the A. holosericea/cowleana group, A. tumida and A. adsurgens from the large section Juliflorae. These species have a colonizing habit and are characterized by:
• Precociousness, producing seed within 18 to 24 months of planting
• High self fertility
• High fecundity, setting heavy seed crops two to three years after planting
• A short life span of only 5 to 10 years.
They have exhibited very good or outstanding growth and adaptation to other tropical dry zones, notably the Sahelian zone of West Africa (Cossalter, 1987). They have a major, but scarcely tapped, potential to provide a protein-rich food source, particularly as famine reserve food. for the people living in semi-arid regions of sub-Saharan Africa.
Taxonomy and genetic resources
Acacia holosericea/cowleana group.
Recent laboratory and field research has revealed that the widely planted A. holosericea consists of at least four distinct entities of differing ploidy levels (Moran et al., in press: Maslin and Thomson, in preparation). The diploid (2n = 26) species, A. neurocarpa, occurs in moist niches in northwestern Australia and Northern Territory. Key morphological traits are:
• Large, broad phyllodes, especially pronounced in young plants
• Stout, flattened branchlets
• Long (2 mm) linear bracteoles.
The tetraploid (2n = 104) species, A. holosericea, occurs in riverine and woodland habitats in subhumid parts of northern Australia. The pods of both A. neurocarpa and A. holosericea are tightly and irregularly coiled.
The hexaploid species, A. colei ms, is widespread in the semiarid zone of northern Australia. It appears to have evolved as a result of past hybridization between A. neurocarpa and A. cowleana (a tetraploid species). Fruiting plants of A. colei ms are readily distinguished from A. neurocarpa and A. holosericea by their strongly and openly curved pods. A fourth undescribed entity, A. aff. colei, bears a close resemblance to A. colei ms. but is distinguished by its curly pods.
All four species have been subject to field trials in West Africa. They have proven to be fast growing, adapted to most soil types including sands and skeletal soils, and not prone to termite attack or browsing by livestock. Acacia colei ms has shown excellent adaptability to the Sahelian belt of West Africa since its introduction in the early 1970s under the name "A. holosericea" (Mandora provenance) by the Centre technique forestier tropical (Cossalter, 1987).
Acacia colei ms holds great promise for human food production in dry regions of tropical Africa. It tolerates prolonged dry periods and bears heavy seed crops that are easy to collect and clean. The seeds are readily released by fully mature pods, without resorting to pounding that may release an irritating dust. Plants are highly self-fertile, with little apparent within-species variation.
Acacia cowleana is another fast-growing large shrub or small tree with a wide distribution in the semi-arid, subtropical areas of northern Australia. Isozyme studies found only limited intraspecific variation, mainly between populations (Moran et al., 1992). This species performed well in several trials in West Africa. It proved especially promising for sandy soils in southern Niger. However, field trials near Ouagadougou, Burkina Faso, revealed substantial differences in the growth and survival rates of different provenances (IRBET/CTFT, 1989).
Acacia cowleana appears to be directly involved in the evolution of two other species with potential as human foodA. oligophleba and A. aff.cowleana. Acacia oligophleba is a multistemmed large shrub or small tree from warm to hot, subtropical to semi-arid, zones of northwestern Queensland and Northern Territory. Its general appearance suggests a vigorous form of A. cowleana. Pedley (1978) gives a botanical description. One seedlot (CSIRO S13774), under the name "A. cowleana", was included in the FAO/CSIRO series of international provenance trials for A. aneura. At Bandia, Senegal, A. oligophleba grew quickly at first, but plants started to die out after about five years. In ACIAR/QDF trials in southeast Queensland, A. oligophleba an average height of 3.3 to 4.0 m after 3.5 years Bryan and Bell, 1989). Plants flower precociously-at 15 months in southeastern Queensland-and produce heavy seed crops following good summer rains.
Acacia aff. cowleana is a spreading shrub that grows on rocky sites in semi-arid areas of northern Australia. It appears to have arisen through hybridization between A. cowleana and A. gonoclada and closely resembles A. cowleana. Until recently, the two species were confused. New shoots of A. aff. cowleana are covered with reddish-brown resin and this provides a useful distinguishing feature. This species has a unique capacity to produce moderately heavy seed crops from difficult, rocky sites, including those with a lateritic hardpan.
A fast-growing, multistemmed shrub or small tree from the semi-arid to subhumid zones of northwestern Australia. A. tumida has performed well in field trials in Niger, Burkina Faso and Senegal. This species is well adapted to infertile soils, including podzols, laterites and loose. drifting sands. Populations vary considerably in many characters. including plant habit, coppicing ability and seed size. Acacia tumida hybridizes with A. difficilis, A. eriopoda and, less frequently. with A. trachycarpa (Thomson, 1992). Turnbull (1986) provides a full description.
A moderately fast-growing, multistemmed shrub from semi-arid regions of northern and central Australia' A. adsurgens is well adapted to sandy soils. The species is fully described by Thomson and Hall (1989). It has been observed to produce heavy seed crops on infertile sands in southern Niger.
Flowering and seed set in these species depend on the amount and distribution of rainfall in the previous rainy season and on any subsequent, out-of-season rains. In northern Australia, Juliflorae acacias set heavy seed when cumulative rainfall is at least 300 to 400 mm, especially when rain is concentrated towards the end of, or even after, the main rainy season. Clearly, these acacias are capable of producing a useful seed crop in years that are unfavorable to short-duration rainy-season crops such as maize, millet or sorghum.
In native stands. typical yields are 250 to 500 g tree-1, but mature specimens can yield up 1 to 2 kg of clean seed. There is little information on seed production in plantations. Yields are affected by many factors-such as moisture regime, insect predation and management-but seed production in managed plantations at wide spacings (for instance 5 x 5 m) will normally exceed 100 kg ha-1.
In northern Australia. predation by various insect pests, such as chalcid wasps, may cause considerable seed destruction. Appropriate quarantine measures are crucial to prevent the accidental entry of Australian insect pests into other regions where these trees are introduced. Fortunately, the Bruchid beetles that cause extensive damage to seed crops in African acacias do not appear to be a serious problem for the Australian Juliflorae species (Doran et al., 1983).
Until recently, knowledge of the use of Australian acacia seeds as human food came exclusively from the desertdwelling Australian Aborigines. Once the pods have turned brown and begun to split, the seed can be harvested quickly by beating the pods onto a large sheet or tarpaulin spread underneath the tree. A particularly efficient technique is to cut the small pod-bearing branches and beat them directly onto a sheet. The seeds of these species, especially A. colei ms and A. tumida, may be cleaned with minimal threshing or winnowing. If rubbed in water, the empty seeds and arils float off.
The dry seeds may be lightly roasted and ground with a little water into a paste: the flavor has been likened to peanut butter (Latz, 1984). The roasted or unroasted seeds may be ground into flour with a stone or wooden mortar and pestle or with a mechanical mill such as used for grinding millet. Acacia seed flour can be mixed with water and cooked as unleavened bread or mixed with wheat flour and baked into bread (20% acacia flour according to Thor burn et al., 1987) or biscuits (50% acacia flour according to Maggiore, 1985).
The large seeds of A. tumida can also be consumed green (Crawford. 1982). Green pods are readily harvested, but nearmature seeds are only available for three to four weeks. The green pods should be lightly roasted to force them open and to dry up any bitter juices. The flavor of green acacia seeds has been likened to peas. but in the case of A. tumida there is a somewhat unpleasant aftertaste.
Recent experience Niger southern that A. that colei is readily integrated into traditional agriculture and enjoys a high level of acceptance as a food source (T. Rinaudo. SIM International. personal communication). No aspect of seed preparation requires new technologies or special skills. The question of acceptability of acacia seed food products is still unanswered in other parts of Africa. Important aspects are texture, taste, appearance and ease of preparation.
With their hard coats, the seeds may be stored at ambient tropical temperatures without deterioration for more than 10 years. If wetted, they neither germinate nor rot easily, making them an ideal food reserve for times of famine.
The seeds of the Juliflorae acacias are rich in nutrients, with high protein, energy and fat contents. The high protein content is noteworthy as the diet in dry sub-Saharan Africa is often lacking in protein, especially for children. Of total dry seed weight, A. adsurgens is 26% protein (Maggiore and Latz, unpublished), A. "holosericea" is 21% (Peterson, 1978), and A. cowleana is 22 to 24% protein (Maggiore and Latz, unpublished). Acacia seed proteins include globulins, and to a lesser extent, albumins that provide a well-balanced source of essential amino acids.
The seeds of most pods contain some potentially toxic proteins, but these are denatured by cooking. Proteinase inhibitors, affecting trypsin and chymotrypsin, have been found in seeds of A. cowleana and other species. but only at levels similar to those found in peas or beans-much lower than levels in soybeans or winged beans (Kortt, 1984). The seeds of these species are reported to be free of the serious neurotoxins present in the seeds of African acacias (Murray, 1984). Further research is required on possible toxic or antinutritional components, but these are unlikely to constitute a hazard in species widely eaten by Australian Aborigines.
The Juliflorae acacias are easily propagated from seed and readily established in the field, either from container-grown seedlings or by direct seeding. Germination is enhanced by immersing the seeds in rapidly boiling water for 60 seconds. The recommendation is to maintain seedlings in a nursery for 10 to 14 weeks. In hot weather, germination usually occurs within seven days and seedlings grow quickly. Inoculation with an effective strain of a Bradyrhizobium root symbiont may promote uniform seedling growth, but is not essential. Turnbull (1986) gives more information on establishment practices for particular species.
Direct seeding is a promising technique for establishing broad-scale plantings. Pretreated seeds should be sown either just before or at the beginning of the rainy season. This approach has proven successful in trials in northern Nigeria and Senegal. However, direct seeding with A. colei ms failed at Tanout, Niger, where annual rainfall was only 170 to 200 mm (P. Beckman, Eden Foundation, personal communication). Successful establishment by direct seeding probably requires rainfall levels of 350 to 400 mm.
In many parts of the Sahel, low bushy windbreaks of Juliflorae acacias could help crop establishment by reducing wind speed and sand blasting. However, competition for soil moisture will probably limit the intercropping potential of these trees in the harsh Sahelian environment. Single or staggered double-row windbreaks. positioned perpendicular to damaging winds at intervals of 40 to 50 m, may provide an effective compromise between conventional windbreaks and alley-cropping systems.
These trees can grow on difficult sites that are unsuitable for traditional crops. Acacia tumida has great potential for stabilizing moving sands, while A. cowleana and A. colei can tolerate hardpan near the soil surface. Low planting densities, of about 400 trees ha~, are suitable for non-arable sites where the objective is to maximize seed production.
Farmers in West Africa are increasingly planting Juliflorae acacias in and around their villages for shade and ornamental purposes. There is considerable opportunity to expand these plantings for combined food and fuelwood production. There is also scope for interplanting fast-maturing Juliflorae acacias with slower-developing, but valuable local trees such as Faidherbia albida (for fodder) or Securidaca longipedunculata (for medicine). When planted in suitable arrangements, the Juliflorae acacias can help protect these trees and provide early yields of food and fuelwood.
Most of the Juliflorae acacias that hold promise for food production have poor coppicing ability. The exception is certain populations of A. tumida that can regrow from basal coppice and root suckers. Most species respond well to light pruning and pollarding, and these practices, when properly applied, may increase plant longevity by several years.
The extent and vigor of regrowth depend on season of cutting, cutting height and retention of phyllode-bearing branches. In Niger, A. colei ms regrew best after cutting in June, while in Senegal the best regrowth was after cutting between May and July. The recommended cutting height is I m, retaining at least one phyllode-holding branch. Plants have been observed to set moderately heavy seed crops within a year of heavy pruning.
Wider use of the Juliflorae acacias as human food requires further investigation in several areas. These include yield potential. management and possible toxic effects associated with long-term high rates of ingestion. The Australian Tree Seed Center (CSIRO Division of Forestry) is currently identifying priority areas for future research and plans to coordinate such activities. Pilot evaluations are urgently needed in different areas of sub-Saharan Africa.
Seed of A. colei. A. cowleana. A. aff. cowleana and A. oligophleba is available from Future Forests. They can be contacted by FAX at (613) 306-6094.
Brand. J.C. and Cherikoff, V. 1985. The nutritional composition of Australian Aboriginal food plants of the desert regions. In G.E. Wickens, J.R. Goodin and J.V. Field, eds. Plants for arid lands. London: Allen and Unwin. pp. 53-68.
Cossalter, C. 1987. Introducing Australian acacias in dry tropical Africa. In J.W. Turnbull, ed. Australian acacias in developing countries. Proceedings 16. Canberra: ACIAR. pp. 118-22.
Crawford, I.M. 1982. Traditional Aboriginal plant resources in the Kalumburu area: aspects in ethno-economics. Records of the Western Australian Museum. Suppl. 15.
Doran, J.C., Turnbull, J.W., Boland, D.J. and Gunn, B.V. 1983. Handbook on seeds of dry-zone Acacias. Rome: FAO.
IRBET/CTFT (Institut de recherche en biologic et ecologic tropicale/Centre technique forestier tropical). 1989. Rapport annuel d'activitÃ©s. Ouagadougou: IRBET/CTFT.
Kortt. A.A. 1985. Characteristics of the proteinase inhibitors of Acacia seeds. In G.P. Jones, ed. The food potential of seeds from Australian native plants. Victoria (Australia): Deakin University Press, pp. 121-45.
Latz. P.K. 1984. Bushfires and bushtucker: Aborigines and plants in central Australia. M.A. thesis. Armidale (Australia): University of New England.
Maggiore, P.M.A. 1985. Utilization of some Australian seeds in edible food products. In G.P. Jones, ed. The food potential of seeds from Australian native plants. Victoria (Australia): Deakin University Press, pp. 59-73.
Maslin, B.R. and Thomson, L.A.J. In preparation. Reappraisal of the taxonomy of Acacia holosericea A. Cunn. ex Don, including the description of a new species, A. colei, and the reinstatement of A. neurocarpa A. Cunn. ex Hook.
Moran, G.F., Thomson, L.A.J., Grant, J.E. and Bell, J.C. In press. Genetic diversity in Acacia holosericea. In A.P.N. House and C.E. Harwood, eds. Australian dry-zone acacias for human food. Canberra: Australian Tree Seed Centre, CSIRO Division of Forestry.
Murray, D.R. 1984. The food value of Acacia seeds. Australian Plants. 13(101):25 - 26. J.F., Latz, P.K. and Barnett. P. 1983. Traditional . modern plant use among the Alyawara of central . Australia. Economic Botany. 37(1):80-109.
Orr, T.M. and Hiddens, L.J. 1987. Contribution of Australian acacias to human nutrition. In J.W. Turnbull, ed. Australian acacias in developing countries. Proceedings 16. Canberra: ACIAR, pp. 112-15.
Pedley. L. 1978. A revision of Acacia Mill. in Queensland. Austrobaileya. 1(2):75-234.
Peterson, N. 1978. Traditional patterns of subsistence in 1975. In B.S. Hetzel and H.J. Frith. eds. The nutrition of Aborigines in relation to the ecosystem of Central Australia Melbourne: CSIRO.
Ryan. P.A. and Bell, R.E. 1989. Growth. coppicing and flowering of Australian tree species in trials in southeastern Queensland. Australia. In D.J. Boland, ed. Trees for the tropics: growing Australian multipurpose trees and shrubs in developing countries. Monograph 10. Canberra: ACIAR. pp. 49-68.
Thomson. L.A.J. 1992. Australia's sub-tropical dry-zone Acacia species with human food potential. In A.P.N. House and C.E. Harwood. eds. Australian dry-zone acacias for human food. Canberra: Australian Tree Seed Center, CSIRO Division of Forestry, pp. 3-36.
Thorburn. A.W.. Brand, J.C., Cherikoff, V. and Truswell, A.S. 1987. Lower postprandial plasma glucose and insulin after addition of Acacia coriacea flour to wheat bread. Australia and New Zealand Journal of Medicine. 17:24-26.
Turnbull. J.W. 1986. Multipurpose Australian trees and shrubs: lesser-known species for fuelwood and agroforestry. Monograph 1. Canberra: ACIAR.
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Sesbania grandiflora is a tree that grows rapidly, provides light shade, and is often grown as an ornamental. This softwooded tree's leaves are used as fodder and its flowers as food. Grandiflora is planted in gardens for its intercropping compatibility and soil-improving properties.
Sesbania grandiflora (L.) Poir. is a tree that grows to 8-10 m in height The pink-red or white flowers of this papilionaceous (pea-like flowered) legume are unusually large (5-10 cm in length and about 3 cm wide before opening); this novelty may be the principal reason for grandiflora having been distributed by man throughout the tropics and subtropics. Within its genus, S. grandiflora is a member of the subgenus Agati, and it is thus more closely related to the unusual littoral sesbanias of Pacific islands than to the more typical sesbanias of subgenus Sesbania, such as the perennial S. sesban and the annual sesbanias grown for green manure (such as S. cannabina).
Grandiflora's pinnate leaves may be 30 cm long, with 12-20 pairs of oblong, rounded leaflets averaging 3-4 cm long and about 1 cm wide. The leaves are borne at the terminals of branches, and the canopy is open, with a thin crown which produces light shade. Its racemes bear 2-3 flowers. The pods are usually 30-50 cm long by about 8 mm wide. The seeds are tan to red-brown, 6-8 x 3-5 mm, 14-20 weighing 1 g. The trunk may reach 25 cm diameter at breast height Grandiflora may live 20 years or more.
grandiflora is very closely related to the endemic Australian species, S. formosa. This relationship supports the supposition that grandiflora may have originated in Indonesia. S. formosa bears white flowers and is often indistinguishable from grandiflora to the casual observer. The two species appear to have similar growth habits and adaptivity, and it is possible that S. formosa also can be used for the purposes described here for grandiflora.
Grandiflora is found in cultivation throughout the tropics and subtropics.
Because wild populations of grandiflora are unknown, its natural habitat is uncertain. grandiflora is grown most successfully in the lowland tropics (below 1000 m elevation) and warm, frost-free subtropics. It can be grown in regions with as little as 800 mm rainfall or as much as 2000-4000 mm. It seems to prefer a birnodal rainfall distribution, growing rapidly during wet seasons but capable of withstanding prolonged dry seasons of up to nine months.
Grandiflora is tolerant of soil salinity and waterlogging, and withstands occasional short periods of flooding. It is well adapted to heavy clay soils.
Fodder, food, and soil improvement are the principal uses for grandiflora
Grandiflora is valued as a fodder in many regions. In south-central Lombok, Indonesia, grandiflora grown around rice paddy bunds provides up to 70 percent of the diets of cattle and goats during the annual eight-month dry season (Mudahan Hazdi, personal communication). The leaves contain as much as 25-30 percent crude protein.
Although ruminants readily consume grandiflora fodder, and its digestibility is high, some feeding studies have indicate that antinutritional factors are present. Until further research provides clear guidelines, caution should be used in feeding S. grandiflora to ruminants and other animals, and restricting feeding to less than 30 percent of dry matter intake is suggested. grandiflora leaf is toxic to chickens and should not be fed to them or other monogastric animals.
Grandiflora is often maintained in gardens and around crop fields for its contribution of nitrogen. The light shade cast by its canopy does not block much light, allowing the growth of companion plants. Falling leaflets and flowers recycle nutrients to the ground. Seedlings grow rapidly enough that they have been used similarly to annual green manure crops. For example, grown around paddy bunds for incorporation before planting the subsequent rice crop.
The wood is rather light and not ideal for firewood or pulping; the bark is thick and corky and is a further detriment to either of these uses. The trunks may be used as poles for temporary shelters and sheds, but they may not last very long due to rots and insect infestation.
Leaves, seed pods, and flowers of grandiflora are sources of food. The young, tender pods are cooked similarly as the green beans. In South Asia the young leaves are chopped and sauteed, perhaps with spices, onion, or coconut milk In the Philippines, unopened white flowers are a common vegetable, steamed or cooked in soups and stews after the stamen and calyx have been removed. Selection of white-flowered varieties that flower profusely has resulted from this use in the Philippines.
grandiflora has been used to shade nurseries and some crops, such as turmeric, as support for climbing crops such as pepper and betel vine, and as an element of windbreaks. The leaves of the tree have various uses in the herbal medical lore of certain regions.
Culture and Management.
Grandiflora is grown from seed, which may be planted without scarification. Stored seeds lose viability within a year or two. Seeds may be direct-sown or transplanted from nurseries; bare-rooted transplants are usually successful.
Seedling growth of grandiflora may be very rapid. Under harsh conditions or neglect, however, seedling survival may be poor. The leaf canopy is open and casts only light shade, hence its popularity in gardens.
Grandiflora cannot be coppiced or pollarded. Harvesting leaves for fodder must be done selectively, to avoid complete defoliation, and cannot be done more than a few times per year. More intensive harvesting, such as managing as a hedgerow, reduces the life of the tree. For example, cutting at 1 m high five times a year can result in tree mortality. Because grandiflora establishes so rapidly, frequent replanting is a management option if heavy harvesting results in tree decline.
Where flowers and pods are harvested for consumption as vegetables, the structure of the tree is shaped by pruning so that the canopy remains low, within reach for convenient harvesting.
The rhizobia strains that nodulate sesbanias are somewhat specialized and may not be present where sesbanias have not been grown previously. Test plantings should be done to see if infective rhizobia are present in the soil, or if use of a rhizobia seed inoculant at planting will be necessary.
Grandiflora's soft wood is susceptible to damage by insects. Fodder cuttings cannot be severe. Seed recovery may be limited by pod pests. Seed viability declines after one year.
Evans, Dale O. 1990. What is Sesbania? Botany, taxonomy, plant geography, and natural history of the perennial members of the genus. In: B. Macklin and D.O. Evans (eds), Perennial Sesbania species in agroforestry systems. Nitrogen Fixing Tree Association. p. 5-19.
Evans, D.O., and Macklin, B. (eds). 1990. Perennial Sesbania production and use. Nitrogen Fixing Tree Association. 41 p.
Evans, D.O., and Rotar, P.P. 1987. Sesbania in agriculture. Westview Press, Boulder, Colorado, U.S.A.
Financial support for this NFT Highlight was provided by the Rockefeller Brothers Fund through the Southeast Asia NGO Support Program.
A Publication of the Nitrogen Fixing Tree Association c/o Winrock International Rt.3,Box 376 Morrilton, Arkansas 72110 USA Tel: 501-727-5435; Fax: 501-727-5417
NFTA 90-03 July 1990
Acacia aneura is known as mulga in its native Australia where it is one of the best known species in the genus. Mulga is the Aboriginal word for a long narrow shield made of acacia wood. It is probably the most important woody forage plant in Australia because it is palatable, abundant and widespread in regions of low rainfall. Its use as an exotic. however, has been restricted by its relatively slow growth rate and its limited capacity to regenerate after fire or severe branch lopping.
Acacia aneura F. Muell. ex Benth. is one of many thornless acacias endemic to Australia. It occurs as a 10-15 m tall, often single stemmed tree in higher rainfall areas but is a 2-3 m high shrub in dry situations or on very shallow soils. Its form and phyllode morphology are exceptionally variable (Midgley and Gunn 1985). The phyllodes range from short and needle-like to long (20 cm), broad (1 cm) and net. Very fine hairs give the foliage an attractive silverygrey appearance.
Small yellow flowers form spikes 1.5-2.0 cm long Thin. flat membranous pods. 2-5 cm long, usually with an obvious narrow wing along their edge, contain dark brown seeds. each with a small pale aril at the base.
Flowering depends on favorable weather conditions and only late summer flowering followed by winter rain leads to seed set (Davies 1976).
Mulga is the one of the dominant species in Australian shrub woodlands. Natural populations extend over an area of 1.5 million km² chiefly in the arid climates where the annual rainfall is 200-250 mm. Mulga ranges in elevation from sea level to 300 m elevation. In many of the drier parts of its distribution mulga occurs as the only species in groves up to 50 m wide and 400 m long with intergrove areas acting as water catchments to provide substantial run-on water.
In the eastern part of its range in northern New South Wales and Queensland mulga is found in semiarid conditions with a mean annual rainfall of 300-500 mm. It experiences hot summers and cool winters with light frosts. Soils supporting mulga are usually acidic sands or sandy loams, which permit easy filtration of water into the upper horizons, but are usually very low in nitrogen and available phosphorus (Turnbull 1986). Acacia aneura can live for more than 50 years, it is drought-tolerant, but very fire sensitive (Kube 1987).
The wide variability in soils and climate together with a high degree of polymorphism suggests that major provenance differences will occur in growth rates and drought and frost tolerance. International provenance trials were initiated in 1984 by FAO and CSIRO Division of Forestry and Forest Products. Canberra (Midgley and Gunn 1985) and trials were established in South Asia the Middle East, Africa and South America.
The heartwood of mulga is dark brown with contrasting markings of golden yellow; the sapwood is white. The wood is very hard, heavy (850-1100 kg/m³) and durable in the ground: it turns well and takes a high polish (Boland et al. 1984). Mulga also makes an excellent firewood and charcoal. In Australia the wood has been used extensively for fence posts but a log size rarely exceeding 2 m x 25 cm usually restricts the use of the wood to small turnery items.
In many parts of Australia mulga forms a significant part of a sheep's diet at all times of the year but without supplementary high quality feed it supplies protein and energy barely sufficient for maintenance of dry-range sheep (Goodchild and McMeniman 1987). Phyllodes have a high crude protein level (11-16%), low phosphorus content (0.05-0.12%) and good palatability (Turnbull et al. 1986, Vercoe in Boland, 1987). Excessive grazing may result in the death of mulga.
Mulga can be used in arid areas to provide shelter and shade, its attractive silvery grey foliage makes it a popular choice for amenity plantings. The Australian Aborigines ground the mulga seed for flour. The seeds have a protein content comparable to dried split peas or peanuts (Caffin et al. 1980). Aborigines also used the resinous phyllodes of desert mulga form as an adhesive resin (Turnbull et al. 1986).
For good germination. seed (50,000110,000/kg) should be scarified by mechanical abrasion or immersed in undiluted sulfuric acid (95% 36N) for 30 minutes and then thoroughly washed in water. Alternatively, immersion in hot water (90°C) for 1 minute will usually break dormancy (Doran and Gunn 1987). Seeds sown in a germination tray are ready for separating into containers within 10 days. The potting mix needs to drain freely but have good moisture holding capacity (Kube 1987).
Nursery growth is slow with seedlings often taking 6-8 months to reach 20 cm tall. When transplanted to the field the seedlings usually require several months without severe moisture stress to survive and in arid areas may need supplementary irrigation. Established seedlings have the ability to survive severe drought. They develop a long tap root and an extensive lateral root system in the top 30 cm of the soil. Acacia aneura needs to be protected from browsing animals while young.
Growth rate is generally slow but is related to moisture conditions. In central Australia planted specimens receiving an average of 370 mm of rainfall a year grew in ten years into multi-stemmed shrubs 3 m tall and 2-4 cm dbh with a crown diameter of 2 m (Kube 1987). Cultivated specimens receiving regular irrigation have reached 10 m tall and 10 cm dbh in 10 years. In trials where rainfall is relatively high, the Charleville, Queensland provenance a broad phyllode form, has grown more rapidly than provenances from central Australia (Ryan and Bell 1989). Trees with different phyllode forms have been observed to have different growth rates (Fox 1980).
A. aneura forms nodules with Rhizobium with which it exhibits a degree of specificity (Roughley 1987). Ectomycorrhizal associations have been observed and there is almost certainly VA mycorrhizal symbiosis (Reddell and Warren 1987).
PESTS AND DISEASES:
In its natural habitat A. aneura is subject to partial defoliation by a range of insects and root damage by termites. Termite damage was light (4% mortality) to moderate (30% mortality) to two provenances aged 18 months in a trial in Zimbabwe (Mitchell 1989).
With its relatively slow growth rate and irregular seeding habits A. aneura is unlikely to become a serious weed.
Boland, D.J., M.H. Brooker, G.M. Chippendale, N. Hall, B.P.M. Hyland, R.D. Johnston, D A. Kleinig and J.D. Turner. 1984. Forest trees of Australia. 4th Ed. Nelson-CSIRO, Melbourne.
Boland, D.J. (ed). 1987. Trees for the tropics: Growing Australian multipurpose trees and shrubs in
developing countries. ACIAR Monograph No. 10. ACIAR. Canberra, Australia.
Caffin. N.,R. Bell. G. Nitchie, S. Weston and N. Ho. 1980. Protein and mineral content of several species of Acacia seeds. Mulga Research Centre Annual Rep. No. 3, 1979. W. Australian Inst. of Tech., Bentley, Australia. p. 43-44.
Davies, S.J.J.F. 1976. Studies of the flowering season and fruit production of some arid zone shrubs and l trees in western Australia. J. of Ecology 64:665-687.
Fox, J.E.D. 1980. Stability in mulga stands in times of drought. in Mulga Research Centre Annual Report No. 3, 1979. W. Australian Inst. of Tech., Bentley, Australia.
Midgley, S.J. and B.V. Gunn. 1985. Acacia uneura seed collections for international provenance trials. Forest Genetic Resources Information 13:21-29.
Simmons. M. 1981. Acacias of Australia. Thomas Nelson. Melbourne.
Turnbull. J.W. (ed). 1986. Multipurpose Australian trees and shrubs. ACIAR Monograph No. 1. ACIAR. Canberra, Australia.
Turnbull. J.W. (ed). 1987. Australian acacias in developing, countries. ACIAR Proceedings No. 16.
ACIAR. Canberra Australia.