A Complete Guide to New High-Quality Cultivation Techniques for the Oyster Mushroom
The oyster mushroom, also known as the small oyster mushroom, has a crisp, tender texture, a delicious flavor and rich nutrition. It is a type of oyster mushroom harvested when the cap diameter of the fruiting body is less than 3 cm; because the mushroom body is small, fresh and tender, and tasty, it sells extremely well on the market. Over the 2 years since our center introduced it, we have refined and summarized its biological characteristics and cultivation techniques. The new high-quality cultivation techniques for the oyster mushroom are summarized below.
1 Cultivation season
The oyster mushroom is a low-temperature type of fungus; its fruiting temperature range is 5-22°C, with the optimum fruiting temperature range being 13-18°C. In this region it is suitable to fruit in September-October and March-May. According to market patterns, fruiting generally takes place before the Spring Festival, that is, bags are made in September-October and fruiting occurs in October-December.
2 Spawn production
The spawn was selected and isolated by our center from Oyster Mushroom No. 11 (introduced from the Edible Mushroom Cultivation Research Institute of Huazhong Agricultural University). The stock culture medium chosen is enriched PDA medium. The mother spawn medium uses: cottonseed hulls 87%, wheat bran 10%, sucrose 1%, gypsum 1%, lime 1%, with a moisture content of 65% and a pH of 6-7. The cultivation spawn medium is the same as the mother spawn.
3 Selection of substrate
The oyster mushroom is a wood-rotting fungus with a relatively strong ability to decompose cellulose and lignin. Therefore, in production, crop straws such as rice straw and wheat straw are commonly used to produce oyster mushrooms. Straw materials are best used after being crushed into a powder form. In addition, a substrate mixed from multiple materials gives higher yields than a single material; for example, cultivation with pure cottonseed hulls gives a lower yield than cultivation with a mixture of straw and cottonseed hulls. Mixing multiple materials not only supplements the nutrients lacking in a single material and improves the physical conditions, but also lowers raw material costs. Therefore, when cultivating oyster mushrooms, a variety of materials need to be prepared. In addition, nitrogen-rich supplements such as wheat bran, cornmeal and rice bran need to be prepared. Among these, cornmeal has a relatively good effect on increasing oyster mushroom yields. Materials such as lime also need to be prepared to adjust the pH of the substrate. It can be seen that the oyster mushroom is an edible mushroom with very promising prospects. Commonly used medium formulas: (1) cottonseed hulls 20%, wheat straw powder 73%, cornmeal 5% and lime 2%, with a moisture content of 60%-65%; (2) enoki mushroom cottonseed hull spent substrate 50%, cottonseed hulls 20%, rice straw powder 17%, cornmeal 10% and lime 3%, with a moisture content of 60%-65%.
4 Making the spawn bags
Weigh the required raw materials according to the proportions in the substrate formula. First weigh the main materials and spread them flat on the ground, then weigh the supplements. Mix them well and then scatter them over the main materials. Then turn the substrate over with a shovel to mix the main materials and supplements thoroughly and evenly. Add clean water at a material-to-water ratio of 1:1.3 to 1:1.4. After adding the water, mix the substrate thoroughly so that the moisture and nutrients are evenly distributed.
In production, polyethylene plastic bags are commonly used for cultivating oyster mushrooms, with specifications of 22 cm x 42 cm or 23 cm x 45 cm. When using sterilized substrate cultivation, polyethylene plastic bags with specifications of 17 cm x 33 cm can also be used. After filling the bags, sterilize at normal pressure for 12-15 hours. When cooled to below 30°C, inoculate using the two-end inoculation method. When using fermented substrate cultivation, according to the substrate formula, mix the various main materials thoroughly and evenly, build a pile for fermentation, and once the temperature rises above 60°C, turn the pile once a day for 4-5 turns. When the pile material turns brown, when white or grayish-white actinomycetes are present from the upper middle of the pile to 1 cm at the surface, and when the material has a special fermentation aroma with no sour or putrid odor and no ammonia smell, and when the material, after being squeezed hard by hand, releases water only through the fingers, it is ready. Spread out the pile, and when the temperature drops to about 30°C, mix in wheat bran, cornmeal, gypsum powder, lime and compound fertilizer, and at the same time spray in fungicides and insecticides, mix evenly, and then fill the bags. Inoculation uses the 3 layers of substrate and 4 layers of spawn method.
5 Spawn-running management
During the spawn-running period, the main task is to regulate temperature and humidity well, keeping the temperature between the bags at 20-28°C, with the maximum temperature not exceeding 35°C; when the temperature is above 45°C the spawn will be killed by the heat. The minimum should not be below 18°C, otherwise the mycelium grows slowly. When bags are stacked horizontally, the temperature must be checked at all times; when a high temperature above 40°C occurs, ventilation and heat dissipation must be strengthened promptly to lower the temperature. Pay special attention to the fact that 3 days after inoculation the temperature inside the bags begins to rise; at this time the temperature must be checked promptly to prevent high temperatures from killing the spawn. In addition, the cultivation site is required to be dry. During high-temperature periods, ventilation and air exchange must be strengthened to avoid a high-temperature, high-humidity environment that causes contamination by foreign fungi. After 25-30 days, the mycelium will have fully colonized the bags, and fruiting management can begin.
6 Fruiting management
Arranging the bags for fruiting: Lay the fully colonized bags horizontally in rows, stacking 6-7 layers of bags per row to form a wall of bags, with 40 cm between rows as an aisle. After arranging the bags, remove the tying string to allow the fruiting bodies to emerge.
Inducing fruiting body formation: After arranging the bags, maintain diffused light in the mushroom house and use the light to induce the formation of fruiting body primordia; the light intensity should be just enough to see to manage the crop. Keep the temperature between 10-20°C, and at night open the doors and windows to widen the temperature difference and stimulate the formation of fruiting body primordia. However, high temperatures must be prevented; when the temperature is above 25°C the primordia will die. Natural humidity is sufficient to meet the needs of primordium formation, so there is no need to spray water to maintain humidity. During this period, keep the temperature at 13-18°C and the humidity at 85%-90%, and prevent the surface mycelium at the bag opening from losing water and drying out, which would affect primordium formation. During primordium formation, the water requirement is low; the fungus mainly uses the water in the substrate to meet its growth needs, but high temperatures above 25°C and high concentrations of carbon dioxide must be prevented, otherwise normal differentiation of the primordia will be affected, resulting in deformed mushrooms or death. In addition, once the primordia have formed, remove the tying string promptly to avoid deformed mushrooms caused by pressure from the sealed opening. Management during the fruiting body growth and development stage: management at this stage is the key to obtaining high quality and high yield, and the main tasks are managing temperature, humidity, light and ventilation.
Temperature management: The fruiting body growth temperature range of the oyster mushroom is 5-22°C, with the optimum growth temperature being 13-18°C. The higher the temperature, the faster the fruiting body grows, with thin caps, pale color, short stipes and reduced quality. When the temperature is above 25°C, deformed mushrooms often grow; when the temperature is below 8°C, nodular growths appear on the cap surface, affecting commercial quality. Therefore, when the temperature is on the low side, reduce ventilation to prevent cold air from entering the mushroom house and lowering the temperature. When the temperature is above 22°C, increase ventilation, reduce light, and at the same time increase water spraying and do a good job of heat insulation and cooling management.
Humidity management: During the growth and development of the oyster mushroom fruiting body, the relative air humidity must be kept at 85%-95% for it to grow and develop. When the humidity is below 70%, the growth rate slows, and in severe cases the young mushrooms wither and die. Humidity is regulated mainly by spraying water to increase humidity. When spraying, adjust flexibly according to climatic conditions: on sunny days and in dry weather, increase the amount of water sprayed, spraying 1-2 times a day; on cloudy and rainy days, spray less or not at all. When spraying, spray little and often, mainly spraying the ground and the surrounding walls; never pour large amounts of water directly onto the fruiting bodies. Once the fruiting bodies absorb too much water, growth stops and they eventually turn yellow and rot.
Ventilation management: During the growth and development of the oyster mushroom fruiting body, the ventilation volume should not be too large, otherwise the stipes will be shorter and the caps will tend to elongate; appropriately reducing the ventilation volume is the key to obtaining high-quality products. Ventilate regularly 1-2 times a day to replenish fresh air and appropriately reduce the carbon dioxide concentration. In short, during the growth and development of the oyster mushroom fruiting body, ventilation should be appropriately reduced and the carbon dioxide concentration increased so that mushrooms with long stipes and small caps can be grown, meeting high-quality product standards.
Light management: During the growth and development of the oyster mushroom fruiting body, diffused light is needed for normal growth and development; the light intensity should be just enough to see to manage the crop.
7 Harvesting and management
Because oyster mushroom fruiting bodies grow in clusters, when most of the caps in a cluster reach a diameter of 1.0-1.5 cm, they should be harvested promptly. When harvesting, support the mushroom body with the palm facing upward, pinch the stipe with the fingers and pick it off. After picking, grade and pack them, and @#@136@#@ immediately.
After harvesting, remove the mushroom bases, dead mushrooms and diseased mushrooms, replenish water and nutrients promptly, and continue fruiting management.
8 Pest and disease control
The main pests and diseases occurring during oyster mushroom cultivation are Trichoderma, Penicillium, Neurospora, mushroom gnats and mushroom flies, among others. Control should be based on prevention, with integrated control. Maintain good environmental hygiene to prevent contamination by foreign fungi such as Trichoderma and Penicillium. Check promptly and detect early; contaminated bags should be placed separately and the contaminated parts injected with 15% prochloraz. Bags contaminated with red Neurospora must be discarded immediately. Pests generally occur in spring and summer and can be trapped and killed with black light lamps, or controlled by spraying biological Chongbaisha (specifically for edible mushrooms). When controlling pests, control them early.