Detailed Explanation of the Shade-Shed Layer-Rack Bag Cultivation Technique for Black Wood Ear Mushroom

    Although the bag cultivation technique for black wood ear mushroom was successfully developed in China long ago, due to climate constraints, the related technology had not been widely promoted and applied in our province for a long time. Based on the climate characteristics of our province, we developed a shade-shed layer-rack bag cultivation technique for black wood ear mushroom suitable for promotion in our province.

Cultivation season: Based on the growth temperature of black wood ear mushroom and the climate characteristics of our province, it is advisable to prepare the spawn bags from the end of November each year to the end of January of the following year, and to move them into the shed for fruiting in early March.

Substrate formula: broadleaf tree sawdust 49%, corn cob (cottonseed hull) 29.5%, rice bran (wheat bran) 20%, gypsum powder 1%, lime 0.5%. The moisture content of the substrate should be 60%-65%. Raw materials must be fresh and free of mold. Broadleaf tree sawdust and corn cob should be crushed to the size of soybean grains, not too fine, otherwise the air permeability of the substrate will be affected.

Spawn bag preparation: Use 17 cm x 45 cm x 0.004 cm low-pressure high-density polyethylene plastic bags, which must be uniform in thickness and free of micropores. Mix the substrate thoroughly according to the formula so that all raw materials and water are fully combined. When the prepared substrate is squeezed tightly, water should seep out between the fingers but not drip. After the substrate is prepared, it should be bagged immediately. Before bagging, fold and tie one end of the plastic bag into a slip knot. After filling, fold and tie the other end into a slip knot as well. The bags should be filled with moderate tightness, uniform from top to bottom, with a level surface and no gaps. After bagging, sterilize promptly. Generally, a normal-pressure sterilization stove is used. Place the prepared spawn bags into the normal-pressure sterilization stove and heat with a strong fire, raising the temperature inside the stove to 100°C within 5 hours and maintaining it for 20 hours to thoroughly sterilize the spawn bags. When the temperature of the spawn bags drops to 60°C, move them into the inoculation room while hot. During transport, handle the spawn bags gently. If small holes are found in the bags, seal them with adhesive tape. After the spawn bags cool to room temperature, perform aseptic inoculation in the inoculation room or inoculation box. The cultivation spawn should have robust mycelial growth, appropriate mycelial age, and no contamination. Strictly follow aseptic operating procedures to inoculate both ends. After inoculation, tie the bag openings tightly and move them into a disinfected culture room for mycelial incubation.

During the spawn bag culture and mycelial incubation period, the temperature in the early stage should be controlled at 28°C to allow the mycelium to germinate and colonize as quickly as possible. After the mycelium has covered the substrate surface, lower the temperature to 25°C, and do not exceed 30°C, otherwise the mycelium will be damaged by heat. Ventilate twice a day for 30 minutes each time to keep the indoor air fresh. The room should be kept dry, and the indoor relative air humidity should be controlled below 70%. Culture in the dark; hang black cloth over doors and windows to block light and provide a dark environment. If the light is too strong, the mycelial growth rate will slow down, and in the later stage of incubation the spawn bags are prone to forming fruiting bodies prematurely, affecting yield. During the incubation period, turn the stacks. The first turning should be carried out 5 days after inoculation, and thereafter once every 10 days. When turning, swap the positions of the spawn bags from top to bottom and from inside to outside so that the mycelium grows evenly. While turning, check for contamination by foreign microorganisms. If spawn bags with yellow, red, green, blue-green, or other colors are found, remove them promptly for treatment. For lightly contaminated bags, inject a medicinal solution mixed from 75% alcohol and 36% formaldehyde at a ratio of 2:1. For severely contaminated spawn bags, carry out sterilization treatment to prevent the spread of contaminating microorganisms. Generally, the mycelium can fully colonize the spawn bags in 35-50 days.