A Detailed Guide to the New Bag-Cultivation Method and Growing Techniques for Straw Mushroom
Straw mushroom cultivation originated in South China and was later spread by overseas Chinese to Southeast Asia and parts of Africa; it has a cultivation history of more than 200 years to date. Its flesh is plump, tender and crisp-smooth, its flavor is delicious, and it has high nutritional value, containing abundant protein, essential amino acids for the human body, and vitamin C. Regularly eating straw mushroom can strengthen the body's immunity to disease. It also has certain anti-cancer and therapeutic effects, lowers plasma cholesterol, and has a blood-pressure-lowering effect; it is also a good food for diabetes. It is a food that is both tasty and health-promoting, and it is extremely popular in domestic and international markets, with remarkable economic returns; the input-to-output ratio can reach more than 1:2-3, making it an industry with great development prospects.
Bag-cultivated straw mushroom is a new technique developed on the basis of bag-cultivation technology for oyster mushroom, and it was first created in our county. Bag-cultivated straw mushroom gives stable yields, the method is simple, and mushrooms are produced quickly; generally, harvesting can begin about 10 d after spawning. The production cycle is short and raw materials are abundant; for example, @#@245@#@, corn, sorghum, peanut, soybean, cottonseed hulls, broken cotton, waste cotton, bagasse, paper-mill leftovers, Chinese medicine residue and so on can all be used to grow straw mushroom.
1 Living conditions of straw mushroom
1.1 Nutrition Straw mushroom can utilize a variety of carbon sources, among which monosaccharides are best, disaccharides next, and polysaccharides after that. Monosaccharides and disaccharides can promote rapid mycelial growth, while polysaccharides can promote robust growth of straw mushroom mycelium and enhance stress resistance. Straw mushroom can utilize organic ammonia and ammoniacal nitrogen. Therefore, in actual cultivation, high-quality, thoroughly dried, golden-yellow rice straw must be used.
1.2 Temperature Straw mushroom belongs to the high-temperature type of fungi. The temperature range for mycelial growth is 20-40degC, with the optimum at 32-35degC; below 20degC growth is extremely weak, at 10degC growth stops and the fungus enters a dormant state, and below 5degC or above 45degC the mycelium quickly dies. The temperature range for fruiting body formation is 25degC-35degC, with the optimum at 28-33degC; below 20degC or above 35degC, the growth and development of the fruiting bodies are affected.
Straw mushroom is a constant-temperature fruiting type of fungus, and during the period of fruiting body development and formation it is very sensitive to changes in external temperature. A climate of sudden cold and heat is extremely unfavorable to its fruiting body growth. If the temperature difference reaches more than 5degC, small mushroom buds stop developing or die. Therefore, during cultivation the temperature must be stable above 20degC for production. Otherwise, yield will be affected; although taking heat-preservation measures can still produce mushrooms, the requirements are high, the costs are great, and the technique is extremely demanding, so in actual cultivation it is generally not advisable.
1.3 Moisture Insufficient moisture causes drought, while excessive moisture causes poor aeration, inhibits respiration, and makes metabolic processes impossible to carry out, leading to the death of large numbers of mycelium and mushroom buds. Practice has shown that a moisture content of 60%-65% in the compost is suitable for the growth of straw mushroom mycelium, and it must not exceed 70%. During fruiting body development, the relative humidity of the air is required to be 85%-90%. Above 96%, the mushroom bodies rot easily and are also prone to infection by contaminating microorganisms. Below 80%, straw mushroom grows slowly, and its surface is rough and lacks luster.
1.4 Air Sufficient oxygen is an important condition for the normal growth and development of straw mushroom. Insufficient oxygen and excessive accumulation of carbon dioxide often inhibit respiration and lead to stopped growth or death. Therefore, during cultivation a site with slow air convection should be chosen; however, too much ventilation makes moisture dissipate easily, which is also unfavorable to the growth of straw mushroom, so cultivation in windy spots should be avoided to prevent damage from strong winds.
1.5 pH Among artificially cultivated edible fungi, straw mushroom likes alkaline conditions the most. The optimum pH for straw mushroom spore germination is 7.4-7.5; mycelium can grow within a pH range of 5-8, with the optimum pH at 7.2-7.5, and the optimum pH for fruiting body formation is 5-7. During the development of straw mushroom mycelium, the medium is gradually made acidic; therefore, when soaking the straw, the pH value is required to reach above 12.
1.6 Light The germination of straw mushroom spores and the growth of mycelium can do entirely without sunlight, but the formation of straw mushroom fruiting bodies requires sunlight. Under completely dark conditions no fruiting bodies form; diffused sunlight can promote the formation of fruiting bodies, slightly inhibit the growth of straw mushroom, make it robust, enhance disease resistance, and promote the transformation and deposition of pigments; strong direct light has a severe inhibitory effect on fruiting bodies. Therefore, open-air cultivation must be covered with a straw mulch.