Detailed Explanation of Oyster Mushroom Bag Cultivation Techniques and Management Methods

At present, there are many methods for cultivating oyster mushrooms in China, including bed cultivation, furrow cultivation, fungus bricks, bag cultivation, and intercropping or relay intercropping with vegetables or crops.

Bag cultivation is a cultivation method in which the substrate is placed into plastic bags, inoculated with spawn, and cultivated until mushrooms appear. This is currently a widely applied cultivation method in production and has many advantages: first, raw materials are easy to obtain (plant straw, bran, husks and other agricultural by-products), making use of waste and turning waste into treasure. Second, it saves labor and is easy to manage. Third, three-dimensional cultivation can make full use of site space. Fourth, various sites can be used, including indoors, greenhouses, and air-raid shelters, and the bags can also be placed in crop and vegetable fields for intercropping.

The process flow of oyster mushroom bag cultivation: prepare substrate -> prepare plastic bags -> fill bags and inoculate -> stack for mycelial growth -> management during the fruiting period -> harvest. Key technical points of oyster mushroom bag cultivation:

1. Preparing the substrate

Oyster mushroom is a wood-rotting fungus, and plant straw, bran, husks and other agricultural by-products containing lignocellulose can all be used as substrate for cultivating oyster mushrooms. Three types are commonly used:

(1) Cottonseed hulls. 1. Take fresh cottonseed hulls and directly add water and mix evenly, so that the water content of the substrate reaches about 65%. For 500 grams of substrate, add 550-650 milliliters of water. 2. Mix the substrate with 1% limewater, with the same water content as above. 3. Mix the substrate with 1% limewater and 0.1% carbendazim, with the same water content as above. Carbendazim has a sterilizing effect, and limewater can adjust the pH value and inhibit the growth of contaminating microorganisms. Therefore, when the temperature is low, contamination by foreign microorganisms is unlikely to occur, and mixing with clean water can reduce costs; when the temperature is high, mix with limewater to prevent contamination; when the temperature is even higher, mix with limewater plus carbendazim to ensure successful cultivation.

(2) Corncobs. 1. Crush corncobs (fresh and mold-free) into pieces the size of soybean grains, soak them in 1% limewater for 24 hours, remove and drain off excess water slightly, add 20-30% cottonseed hulls, and make the water content of the substrate reach about 65%. 2. Corncobs 78%, wheat bran 20%, sugar 1%, gypsum powder 1%, add an appropriate amount of water. Adding cottonseed hulls or wheat bran is to increase nutritional components; substrates other than cottonseed hulls all need additives.

(3) Peanut shells and straw. 1. Crushed peanut shells and straw 78%, wheat bran 20%, sugar 1%, gypsum powder 1%, add an appropriate amount of water. 2. Crushed peanut shells and straw 79%, cottonseed hulls 20%, gypsum powder 1%, add an appropriate amount of water.

For other agricultural by-products used as substrate, the preparation method is basically the same as for peanut shells.

2. Specifications and requirements for plastic bags

Choose plastic tubes with a thickness of 0.03-0.04 cm, a width of 24-30 cm, and a length of 40-50 cm (open at both ends).

3. Filling bags and inoculating

First tie one end of the plastic tube with a plug made from clean old newspaper rolled with cottonseed hulls (diameter 3.3 cm, length 6.6 cm); alternatively, tie a corncob plug 3.3 cm long dipped in 0.3% carbendazim or potassium permanganate solution, sprinkle in some spawn, then add substrate, compacting while filling. When half-filled, sprinkle in another layer of spawn, then continue filling with substrate. When filled to 6.6 cm from the bag opening, sprinkle in some more spawn, level and compact so that the spawn is in close contact with the substrate. Then take another plug and tie the bag opening tightly.

The function of the plug is ventilation. Plugs may also be omitted, but the mycelial growth rate will be somewhat slower. The inoculation amount is generally 10-15% of the substrate. Pay attention to sprinkling more spawn near the bag opening so that oyster mushroom mycelium grows first and contaminating microorganisms find it difficult to breed.

Note: The mixed substrate must be bagged and inoculated on the same day. The inoculation time generally starts from September and continues to early March of the following year. Spring planting should be early, and autumn planting should be late, with the temperature kept below 20 degrees C. This is both beneficial to the growth and development of oyster mushrooms and unfavorable to the growth of contaminating microorganisms. In air-raid shelters or other places where temperature can be manually regulated, production can be carried out all year round.

4. Stacking for mycelial growth

Arrange the tied bags layer by layer and stack them together. The number of stacked layers should be determined according to the temperature at the time. When the temperature is about 10 degrees C, they can be stacked 3-4 layers high; at 18-20 degrees C, 2 layers are suitable; above 20 degrees C, the bags can be arranged in a scattered stack or placed flat on the ground to prevent the substrate temperature inside the bags from becoming too high and killing the mycelium. After about 15 days, once the temperature inside the bags is basically stable, stack them 6-7 layers or more.

After inoculation, the substrate temperature begins to rise after 2 days. Be careful to prevent the substrate temperature from exceeding 35 degrees C. When the temperature rises to 32 degrees C, open doors and windows in time and spray water on the ground to cool it down. If the temperature continues to rise, turn the stack or reduce the number of layers. It is best to keep the temperature at about 24 degrees C.

After about 15 days, adjust the stack, putting those with good mycelial growth together and those with poor growth together, and remove contaminated ones. For lightly contaminated bags, untie the bag opening and air them in a cool place for a few days, or smear with 0.3% carbendazim; for heavily contaminated bags, bury them deeply. In this way, fruiting is uniform and management is convenient. Keep the indoor air humidity at about 65%, and the mycelium will grow well in about 30 days.

5. Management during the fruiting period

After the mycelium covers the substrate, after 5-10 days, under suitable environmental conditions, mushroom primordia will appear inside the bag. At this time, untie the bag opening in time, remove the plug (the corncob plug need not be removed), turn the bag opening outward, and expose the cluster of mushroom primordia.

At this point, begin spraying water on the ground, and the indoor relative air humidity should be kept at 85-90%. Spraying frequency: generally 2-3 times a day, more on sunny days, less or none on cloudy days. If the substrate is too dry or the air humidity is too low, the young mushrooms will wither.

Proper ventilation is needed to prevent excessively high temperature and excessively high humidity. Spraying water too early or excessively high temperature and humidity can also cause young mushrooms to die. Poor ventilation and excessively high carbon dioxide concentration will cause abnormal growth of fruiting bodies, forming "big-foot mushrooms."

Also pay attention to light transmission so that the cultivation site has scattered light. Light is a necessary condition for the differentiation of fruiting bodies. In a dark environment, mushroom primordia cannot develop into normal fruiting bodies, but instead grow into a dough-like mass with no commercial value.

In addition, after each batch of mushrooms is harvested, keep warm appropriately during the day and open windows at night to lower the temperature, so that the cultivation site forms an obvious temperature difference, which is beneficial to the transformation of mycelium into fruiting bodies.

6. Harvesting

After mushroom primordia appear, they can be harvested after 5-10 days. The entire growth period of oyster mushrooms, from inoculation to harvest of the first batch of mushrooms, takes about 35-40 days.

When the fruiting bodies stop enlarging, their color changes from dark to light and approaches white, and before spores are discharged is the best harvest time. At this time, the harvested mushrooms are thick and plump, delicious, and high-yielding. Harvesting too early means the fruiting bodies have not yet grown large and the yield is relatively low; harvesting too late means the fruiting bodies have become old and lost their flavor and nutritional value, making them unfit for consumption and sale.

Harvesting method: Press the substrate with the left hand, pinch the mushroom stem tightly with the right hand and twist it off. It can also be cut off with a knife where the mushroom stem is close to the substrate. When harvesting each batch of mushrooms, harvest all of them regardless of size, which makes management convenient.

After each batch of mushrooms is harvested, clean up the dead mushrooms and mushroom stems remaining on the surface of the fungus bag to prevent rotting. Stop spraying water for 4-5 days, then spray water appropriately to keep the substrate surface moist. After about 10 days, mushroom buds will grow again on the substrate surface, and management should still be carried out according to the method for the first batch of mushrooms.

With this method of cultivating oyster mushrooms, after harvesting 4 batches, the plastic bags can also be removed and the fungus blocks buried in vegetable fields, shady woodland, corn fields, or cotton fields (digging furrows along the rows). After watering, 2 more batches of mushrooms can still be produced, which is unmatched by other cultivation methods.