Key Points of Off-Season Cultivation Techniques for Oyster Mushrooms During High-Temperature Periods

Off-season cultivated edible mushroom products often sell for 4 to 6 times the price of those in the regular season, yielding quite remarkable returns. To improve off-season edible mushroom cultivation during high temperatures, our institute has explored off-season high-temperature cultivation techniques for oyster mushrooms over the past few years. The results show that off-season oyster mushroom cultivation not only has a high success rate, a short time, fast fruiting and easy management, generally fruiting in 15 to 20 d, with a biological conversion rate of over 90%, but also has a short cycle and significant benefits. It is introduced as follows:

1 Cultivation time arrangement Conventional oyster mushroom cultivation generally stops going to market in mid-May each year; for off-season oyster mushroom cultivation, sowing should be chosen to begin on May 1 each year, from sowing to mid-to-late July. During these three months, sowing can be carried out continuously in stages and batches, and usually mushrooms can be produced and go to market 20 d after sowing.

2 Selection of cultivation varieties The two varieties "Xinxuan No. 1" and "Pinggao No. 1", which are tolerant to high temperature, tolerant to transport, good in quality and high in yield, are used as the main cultivation varieties. These two varieties generally tolerate high temperatures above 33°C during fruiting (each locality may choose varieties suitable for the local area according to conditions). From sowing to fruiting takes only 12 to 15 d, fruiting is not only fast, but the yield is also concentrated, with a biological conversion rate above 90%.

3 Construction of the fruiting shed First, the fruiting shed must be built in a place with good ventilation, shade, relatively high terrain and convenient water sources, with a north-south orientation being best; second, the design of the fruiting shed should provide good ventilation and good shade coverage. If conditions permit, an additional layer of 90% shade netting can be placed 1 to 1.5 m above the fruiting shed.

4 Preparation of oyster mushroom spawn For cultivating oyster mushrooms in the high-temperature season, the stock spawn is required to use cottonseed hull spawn, and the cultivation spawn is required to add 30% corncob to the cottonseed hull material to increase the permeability of the material, accelerate spawn growth, and avoid excessively long spawn age. At the same time, during the mycelial culture period, avoid high temperatures in the spawn bags, which would affect spawn quality.

5 Mixing materials, bagging and inoculation ① Selection of plastic bags: choose low-pressure polyethylene plastic bags of 24 cm x 45 cm x 0.015 cm. ② Culture material formulas: A. 60% cottonseed hulls, 30% corncob, 7% wheat bran (coarse rice bran), 3% lime, 0.1% kemeiling; B. 30% cottonseed hulls, 60% corncob, 5% wheat bran (coarse rice bran), 3% lime, 1.5% phosphate fertilizer, 0.5% Gudazhuang, 0.1% kemeiling. When mixing materials in the high-temperature season, moisture must be controlled to no more than 65%, and the fermented material method should be used for cultivation to ensure a planting success rate above 95%. During fermentation, the temperature of the fermentation pile should be controlled at 60 to 65°C, turning the material once every 1 d (the pile must be turned evenly), and after turning the pile 3 to 4 times continuously, bagging can be carried out. When bagging, the material temperature should drop below 30°C. Spawn is placed at both ends of the bag, with two layers of spawn (the inoculation amount should reach 15% to 20%, changing from multi-layer inoculation to two-layer inoculation), and the opening is tied for mycelial growth. On the 2nd d after inoculation, use a 1-cun iron nail to punch 7 to 8 holes at the tied openings at both ends of the bag to allow air exchange and increase oxygen, accelerating the mycelial growth rate.

6 Management of mycelial growth and fruiting Place the prepared cultivation bags into the cultivation shed and arrange them singly for mycelial growth. Three-dimensional mycelial growth is prohibited. Strictly control the mycelial growth temperature to no more than 35°C, and at most no more than 36°C. If the temperature in the shed is high, strengthen ventilation and spray water to cool it down. Fruiting management: first, place the cultivation bags that have completed mycelial growth in 3 to 4 layers, with two long bamboo strips 5 cm wide placed between each layer to facilitate heat dissipation; second, increase air humidity, ensuring relative air humidity above 85% and ensuring air circulation, so that the oyster mushrooms produced have good commercial characteristics. Note that ventilation should be strengthened even more when it is cloudy or rainy.

7 Timely harvesting Oyster mushrooms grown off-season at high temperatures should be harvested immediately when they reach seven-tenths maturity. Harvesting too early affects yield, and harvesting too late affects commercial characteristics. In principle, it is better to harvest early than late.

8 Precautions ① Staged and batch planting: when cultivating oyster mushrooms in the high-temperature season, materials must be added and sown in stages and batches, with 1500 to 2500 kg of material added each time and one batch of material added each week. Concentrated large-scale one-time material addition is not suitable. This is not only easier to manage, but can also achieve relatively high economic benefits. ② Disease control: in recent years, "yellow mushroom disease" caused by bacterial diseases of oyster mushrooms has had a great impact on oyster mushroom cultivation, reducing yield in mild cases and causing total crop failure in severe cases. Especially in the high-temperature season, high temperature and high humidity can easily cause bacterial diseases, so prevention must be emphasized. The prevention methods are: after fruiting begins, first, spray the site every 5 to 7 d with a 700 to 800 times dilution of "Xijunsha + Junjuesha" to disinfect and prevent disease at the site; second, prohibit spraying large or heavy amounts of water on young mushrooms, so as to avoid forming wounds and increasing infection opportunities; third, once disease occurs, use a 300 to 400 times dilution of Xijunsha + Junjuesha to spray and disinfect key areas, and combine this with ventilation to reduce humidity and alleviate the disease. ③ Insect pest prevention: first, during the material fermentation process, each time the pile is turned, spray the surface of the turned pile once with an 800 to 1000 times dilution of dichlorvos pesticide to prevent adult insects from invading the culture material; second, during the spawn bag culture process, spray the greenhouse and its surroundings once every 7 to 10 d with an 800 to 1000 times dilution of dichlorvos pesticide; third, after fruiting, spray the site and greenhouse once every 5 to 7 d with an 800 to 1000 times dilution of fenvalerate or Diguchong to provide preventive effect. Special note: after fruiting, it is prohibited to use highly toxic organophosphorus pesticides such as dichlorvos and omethoate, and when spraying insecticides, mainly spray the site, and do not spray pesticides on the oyster mushroom fruiting bodies.