Key Points of Off-Season Oyster Mushroom Cultivation in Midsummer

Cultivating oyster mushrooms in midsummer usually involves indoor spawn running and outdoor casing soil for fruiting. Using the opposite cultivation method - burying bags outdoors for spawn running and removing bags indoors for cooling and fruiting - can control contamination by competitor fungi during high-temperature periods, favor the growth and reproduction of oyster mushroom mycelium, and increase oyster mushroom yields.

1. Spawn and substrate. Select high-quality medium-to-high-temperature strains for spawn. For the cultivation substrate, choose from the following formulas according to specific conditions. Formula 1: 97 kg small cottonseed hulls, 1 kg gypsum powder, 1.5 kg lime powder, 100 g of 50% carbendazim; Formula 2: 70 kg rice straw, 20-30 kg rapeseed pod hulls, 2 kg compound fertilizer, 0.5 kg urea, 1 kg gypsum powder; Formula 3: 45 kg rice straw, 40 kg wheat straw, 13 kg rice bran, 1.5 kg compound fertilizer, 1.5 kg gypsum powder. To prevent contamination by competitor fungi, add 5 kg plant ash separately to each of the above formulas. Pile up for fermentation and set aside.

2. Bagging and spawning. Use 50 cm x 26 cm polyethylene tube bags. Use thin dry rapeseed stalks tied into small bundles 7 cm long and 4 cm in diameter as ventilation plugs. Tie one end of the plastic bag tightly with a rubber band, and fill the bag with fermented substrate. Before filling, take a short wooden block and bore a hole 7 cm in both diameter and depth in the middle, so as to insert the rapeseed stalk bundle at the bottom of the bag. Use 15 kg of spawn per 100 kg of substrate. Of this, 13.5 kg of spawn is evenly mixed into 20 kg of substrate and distributed at the bag mouths at both ends, 80 kg of substrate is placed in the middle of the bag, and the remaining 1.5 kg of spawn is additionally sown on the surface of the bag mouths at both ends. After the substrate is filled, use a thin wooden stick 1.5 cm in diameter to punch a hole vertically through the center of the bag substrate all the way to the bottom; the upper opening is fitted with a rapeseed stalk bundle as a ventilation plug, just like the bottom. The filled substrate bags are 35-40 cm long, and generally 100 kg of substrate can fill 54-56 bags.

3. Burying bags for spawn running. Choose flat, shaded sandy soil and dig a pit 50 cm deep and 70 cm wide; the length of the pit depends on the number of substrate bags. Sprinkle poisoned soil in the pit to prevent underground pests. Use wooden stakes to make holes 4-5 cm in diameter and 10 cm deep at the bottom of the pit 14 cm from the pit wall, place the spawn bags upright, and insert the rapeseed stalk bundle ventilation plugs into the holes at the bottom of the pit. Make holes and arrange bags in sequence, placing two rows of spawn bags in the pit. After the pit is filled, fill the gaps with lime soil (3 parts lime, 7 parts soil), cover with 10 cm of soil, and cover tightly together with the ventilation plugs. The soil covering the pit surface should be higher than the ground, in a turtle-back shape. Finally, cover with wheat bran, rice husks, or rapeseed pod hulls. Dig drainage ditches around the pit to prevent rainwater from flowing in. After burying the bags for 15-20 days, when the bags are full of mycelium, they can be dug out.

4. Removing bags for fruiting. Line the four walls and ceiling of the mushroom house with plastic film. Remove the bags outdoors on a sunny day (spawn bags that have fully run are all white), roll and peel them off one bag at a time (the plastic bags can be washed, dried, and reused), leave them on a drying yard for 2-3 hours, then move them indoors and stand them upright on the ground covered with wet sand. Spray well water (about 20°C) into the air and onto the wet sand twice daily in the morning and evening to keep the ground moist and lower the room temperature. Open the windows at 8 p.m. every night and close them at 7 a.m. the next morning. In this way, even when the outdoor temperature is above 37°C, the indoor temperature remains only about 28°C and the air humidity stays at about 90%, ensuring safe fruiting.

After the 3rd flush, switch to mushroom-wall fruiting or turning the bags around for fruiting, cover with fertile, loose, sterilized garden soil, and spray nutrient solution, and 2-3 more flushes can be harvested.