Mushrooms, a fungus in the class Basidiomycetes, have a high nutritional value and are thus very beneficial to humans. Mushrooms contain more essential minerals than red meat, are low in fats and are a good source of protein. Medical research has also shown that mushrooms contain eritadenine, a substance that helps prevent fat build-up in blood vessels.
Many types of mushrooms are grown and collected in Thailand for home consumption and sale in local markets. The mushroom varieties most commonly grown on a commercial scale in Thailand are:
1. Straw mushrooms (Volvariella volvacea)
2. Angel mushrooms (Pleurotus sarjov-coju)
3. Oyster mushrooms (Pleurotus ostreatus)
4. Abalone mushrooms (Pleurotus cystidiosus)
5. Wood ear mushrooms (Auricularia auricula)
In addition to these commercially grown varieties, many types of native mushrooms are also collected for sale and consumption. Unfortunately, many of the naturally occurring varieties of mushroom are poisonous. Hence, people collecting wild mushrooms must be able to distinguish poisonous varieties from those that are edible. To determine if a mushroom is poisonous, boil the mushroom in water, then feed the juice and mushroom to test animals. If the test animals become sick or die, the mushroom is most likely poisonous.
Mushrooms grow naturally in moist, humid environments. Other environmental factors (i.e., temperature, growing medium, light) are also important to varying degrees, depending on the variety of mushrooms cultivated. For example: oyster and angel mushrooms prefer warm, moist climates; wood ear mushrooms like hot, humid weather, and; straw mushrooms require composting organic material as a substrate and relative darkness for proper growth. As one might expect, mushroom varieties native to Thailand grow best in the humid conditions of the rainy season.
The market price of mushrooms fluctuates according to the season. During the rainy season, when the supply of both naturally occurring and commercially grown varieties of mushrooms is plentiful, the price is usually low. Conversely, during the dry season when the weather is not conducive to mushroom growth, the supply of mushrooms drops substantially and the market price climbs.
The market price in Ubon Ratchathani Province for straw, angel and oyster mushrooms ranges from B18-40 per kilogram annually, and from B25-60 per kilogram for wood ear and abalone mushrooms. Many producers of angel, oyster, abalone and wood ear mushrooms sell their produce directly to local restaurants rather than in markets due to the large volume of mushrooms consistently purchased by restaurant owners. This saves time for mushroom growers and simplifies marketing the mushrooms.
Each of the commercially grown varieties of mushrooms mentioned is sold fresh, except for the wood ear variety which can be sold fresh or dried. This offers the cultivator of wood ear mushrooms greater marketing options. During periods of high supply and low market price, growers can dry and store their mushrooms, delaying sales until supply is lower and prices are higher. Additionally, dried wood ear mushrooms are nonperishable and growers can send them to markets that are a great distance from the production site. Approximately 600-700 grams of fresh wood ear mushroom will yield 100 grams of dried mushrooms. The market price for dried wood ear mushrooms in Ubon Ratchathani Province ranges annually from B100-160 per kilogram.
Although angel, oyster and abalone mushroom varieties cannot be sold dried, they can, like wood ear mushrooms, be sent to distant markets if prepared in the following manner: blanch the mushrooms by dipping them in warm water, then immediately place them in a salt water solution (1 kg of salt per 20 liters of water). This solution preserves the mushrooms during shipment to the market for sale.
Thailand also exports mushrooms to several countries, Taiwan being the largest importer. Many of the exported mushrooms are grown in Pon District, Khon Kaen Province, where there is a Taiwanese-owned straw mushroom canning factory in operation. The canning factory personnel give advice to local farmers concerning the cultivation of straw mushrooms and provide the farmers with a market for their produce, buying all mushrooms for B18 per kilogram.