High-yield technique for bag cultivation of oyster mushroom on fermented coarse sawdust substrate

At present, with the development of the edible mushroom industry, the demand for raw materials is also growing. In recent years, the price of fine sawdust in the three northeastern provinces has soared, while coarse sawdust has become waste (such as the coarse sawdust sifted out through the electric sieve on the chipper and the coarse sawdust produced by the branch and twig crusher). The author used the locally abundant coarse sawdust as the main fermentation ingredient to cultivate oyster mushrooms, and the summary is as follows:

1 Test strain Oyster mushroom 2026, whose mother culture was provided by the Shijiazhuang High-tech Edible Mushroom Station in Hebei. The stock culture was a corn kernel medium, with corn kernels 99% and gypsum 1%. Soak or boil the corn kernels, add gypsum and mix well, fill into glucose bottles, sterilize under high pressure or normal pressure, and after inoculation culture at 25°C for 14 d to fully colonize the bottles.

2 Substrate formula Cultivated spawn formula: a. sawdust 75%, rice bran 13%, wheat bran 10%, gypsum 1%, soybean powder 1%; b. hardwood sawdust 78%, cornmeal 20%, gypsum and lime 1% each. Water 60%. Use 17 cm x 33 cm x 0.04 cm polyethylene bags, fill 1.1 kg of spawn per bag, seal the caps and place into iron baskets, after normal-pressure sterilization take them out and cool to 25°C, then inoculate under sterile conditions, and when the mycelium has grown to half the height, begin fermenting the coarse sawdust.

3 Mixing materials and building the pile Fermented substrate formula: a. coarse sawdust 70%, rice bran 14%, wheat bran 10%, soybean powder 3%, gypsum 1%, quicklime 2%; b. coarse sawdust 68%, rice bran 10%, cornmeal 15%, soybean powder 4%, gypsum 1%, quicklime 2%; c. coarse sawdust 65%, rice bran 20%, cornmeal 10%, soybean powder 2%, gypsum 1%, quicklime 2%. First mix the coarse materials and the fine materials evenly, dissolve the soybean powder in water and sprinkle it evenly over the material and stir well; the water added is best at 60%-65%, pH 6-8. Shape the mixed raw materials into a pile with a bottom width of 150-250 cm and a height of 80 cm, with unlimited length; the slope of the pile sides should not be too great. Use a 5 cm diameter wooden stick to make ventilation holes on the pile, with a hole spacing of 20 cm and hole depth reaching the bottom of the pile. If the pile is built indoors in an empty room, close the doors and windows immediately; if the pile is built outdoors, cover it with straw curtains to maintain the humidity of the pile. In high-temperature seasons, after building the pile, first spray dichlorvos or 500-800 times dilution of beta-cypermethrin on the surface of the material; spray the material surface. In winter, mix the material with hot water, so the temperature rises quickly and the fermentation time is shorter. After building the pile, check the temperature frequently; generally after 48 h, when the temperature at a depth of 25 cm in the pile reaches 60°C, maintain it for about 24 h, then begin the first turning of the pile, opening the doors and windows when turning. After rebuilding the pile, spray 0.5% dichlorvos or phoxim on the material surface to kill insects, then make ventilation holes, close the doors and windows, and when the material temperature again reaches 60°C, maintain it for 24-48 h before the second turning. After rebuilding again, keep the material temperature at about 60°C for 3-4 d, and fermentation is complete. Opening the pile, the material can be seen to have turned brown with a floury white powder, with a fresh fragrance, soft to the touch, and not sticky to the hand, and it is then ready for cultivation.

4 Bagging, inoculation and mycelial growth If the fermented material has little water, add clean water; the best water content is 58%-63%. Use 50 cm x 25 cm x 0.02 cm polyethylene tube material punched with three rows of micropores by sewing machine needle holes; first tie off one end, put in spawn and tie tightly with string. Then add one layer of spawn and one layer of material, for a total of 4 layers of material and 5 layers of spawn; after filling, tie the bag tightly, with a spawn rate of 12%-15%. Move into the mycelial growth room and stack in a crisscross pattern 5 layers high; in low-temperature seasons, stack flat 4-5 layers high. During mycelial growth, the temperature is 20-25°C, the relative air humidity is 50%-65%, and the light should be dimmer; during mycelial growth, pay attention to turning the bags and strengthening ventilation management. After 15-20 d, the mycelium fully colonizes the bags and enters fruiting management.

5 Fruiting management Arrange the fully colonized bags 6-7 layers high; in high-temperature seasons, 3-4 layers is best. At this time, increase the temperature difference, and after about 1 week, mushroom buds appear. Then the bags can be opened for fruiting management; the timing of opening the bags must be well controlled, because too early makes the material surface dry easily and causes the mushroom buds to die, while too late affects the quality of the mushrooms. After opening the bags, strengthen ventilation and control the temperature at 15-22°C and the humidity at 85%-95%. Be careful not to spray water onto the mushroom buds. After 4-6 d, the first flush of mushrooms can be picked for market. After harvesting, dry for 3 d, then carry out normal management again; 3-4 flushes of mushrooms can be produced, and afterward a supplementary nutrient solution should be added in time. Water supplementation formula: urea 50 g, monopotassium phosphate 100 g, magnesium sulfate 10 g, add water 50 kg. Dissolve the fertilizer water in a large bucket, install an outlet pipe at the bottom of the bucket and connect it to a water pump. Connect the outlet pipe of the water pump to a water distributor, and connect the 3-4 small pipes coming out of the water distributor to plastic pipes and then to the sprayer valve. Then use a 25 cm long hollow sprayer rod, punch 25-28 holes in the rod, insert it into the middle of the bag and begin water supplementation; supplementing 700-900 g of nutrient solution per bag is best. With conventional management, the biological efficiency can reach 180%-200%, thus achieving high and abundant yield.