Detailed Explanation of Key Techniques for High-Temperature Cultivation of Pleurotus pulmonarius

The Xiuzhen mushroom (Pleurotus pulmonarius) originated in India, growing on the stumps of Euphorbia royleana, hence it is also known as the Indian abalone mushroom; it is also called the ring-stemmed mushroom, and is also known as the miniature oyster mushroom or small oyster mushroom. It is one of the most consumed rare edible fungi, winning consumer favor for its elegant appearance, good eating quality, and vivid color as a side dish.

Currently there are two main cultivated strains of the Xiuzhen mushroom: one is the "small oyster mushroom" introduced from Japan, with a fruiting temperature of 8-24°C. The cap is gray, turning white when mature, growing in clusters with short stems and concentrated fruiting; the second is the Xiuzhen mushroom introduced from Taiwan, China, with a fruiting temperature of 8-24°C, a light gray cap, solitary growth, short stem, and central or off-center attachment.

1. Determination of Cultivation Season

The cultivation time is determined mainly based on market demand to decide the variety and timing of cultivation, and then comprehensively determined by combining local climatic conditions. Generally, the culture time for Xiuzhen mushroom cultivation bags is 25-35 days, and growers should select or produce spawn at all levels according to specific production conditions. In the Hangzhou area, high-temperature Xiuzhen mushroom bag production is scheduled to begin in April, fruiting begins in May, and harvesting can continue until the end of September to early October.

2. Culture Material Formula

(1) Cottonseed hull 93%, wheat bran 5%, light calcium carbonate 1%, sugar 1%;

(2) Cottonseed hull 45%, mixed wood sawdust 40%, wheat bran 10%, sugar 1%, light calcium carbonate 2%, gypsum powder 2%;

(3) Mixed wood sawdust 75%, wheat bran 10%, corn flour 5%, rice bran 8%, light calcium carbonate 1%, sugar 1%.

All raw materials must be fresh, free of contamination, and free of off-odors.

Mixed wood sawdust needs to undergo fermentation treatment before use: first pass through a 2-4 mesh sieve to remove debris; then build a pile with a base width of 5-8 m, height of 1.8-2 m, unlimited length, in a turtle-back shape; sprinkle a small amount of lime powder on the surface of the sawdust, spray water evenly, and allow natural fermentation. After 5-6 days, when the temperature inside the pile rises to about 60°C, carry out the first turning, striving to swap the inner and outer, upper and lower sawdust positions to achieve uniform fermentation; then turn the pile 3 more times at intervals of 6 days, 5 days, and 4 days. The entire sawdust fermentation treatment takes about 25 days, and the sawdust can be used only when it is dark brown and has a certain fragrance.

3. Bag Making and Culturing

(1) Before loading the raw materials, all raw materials should be mixed evenly with water in advance, covered and piled for 24 hours to promote uniform water absorption and softening of the raw materials, which can avoid puncturing the bags during loading and causing contamination during the spawn-running period.

(2) Since Xiuzhen mushroom is more suitable for wall-style cultivation, polypropylene plastic bags of 17X33X0.05 cm are usually used, with a dry material weight of 400-500 g per bag. Avoid mechanical or manual damage during bag loading, and maintain appropriate tightness.

(3) When mixing the material, the water content should be controlled at 60%-65%. When the material is squeezed tightly in the hand, 3 or 4 water droplets should drip from between the fingers, and after releasing the hand the material should still hold its round shape and scatter loosely rather than clump when thrown to the ground.

(4) Sterilization must be thorough, and inoculation must be strictly carried out under aseptic operation. Each bag of production spawn can inoculate 40-50 bags.

(5) Place the inoculated cultivation bags in the culture room in a "well" pattern stacked 4-6 layers for spawn running, or place them on culture shelves for spawn running. During the culture period, frequently check the pile temperature to prevent high-temperature burning of the spawn; if the pile temperature is below 20°C, take measures to increase the temperature. Note that the pile temperature should be controlled at about 25°C. The culture room must be well ventilated with fresh air, and direct sunlight must be prevented.

(6) During the spawn-running period, the bags must be checked frequently, and bags contaminated by miscellaneous fungi or not absorbing nutrients should be promptly removed.

4. Fruiting Management

After 25-35 days of culture, the mycelium grows throughout the entire material bag; continue culturing for 5-7 days. When yellow water appears at the bag mouth mycelium or mushroom buds appear, it indicates that the mycelium has reached physiological maturity and can be immediately transferred to the fruiting room (shed) for fruiting management.

(1) Disinfection of the Fruiting Room (Shed)

About 10 days before the bags are transferred into the fruiting shed, the shed environment should be treated: first use dichlorvos 800-1000 times solution plus beta-cypermethrin 1000 times solution for insect and mite control, then ventilate for one week, and then spread quicklime powder on the ground inside the shed.

(2) Temperature Control

After the physiologically mature bags are placed in the shed and stacked into a wall, remove the sealing ring and plastic, leaving 3 cm in length, and cover with plastic film to preserve heat and moisture. It is believed that increasing the temperature difference inside the shed, preferably 10-12°C, promotes the differentiation of fruiting body primordia. The temperature inside the shed should be controlled at 12-18°C; after most primordia appear, the temperature difference can be appropriately reduced and the shed temperature raised to 14-20°C. When the shed temperature exceeds 25°C, cooling measures should be taken immediately; when the temperature is below 12°C, heating and insulation should be carried out. After each flush of mushrooms is harvested, the material surface should be thoroughly cleaned, removing dead mushrooms, mushroom roots, and debris, and then continue temperature-controlled fruiting management as described above.

(3) Humidity Control

After the bags are placed in the shed and stacked into a wall, control the air humidity inside the shed at 85%-95%. If it exceeds 95%, ventilation must be used to reduce humidity; if it is below 85%, spray water into the air according to the specific situation to maintain air humidity. After harvesting mushrooms each day, fine mist water can be applied to the material surface of the bags and young buds. Specific water management should be based on the actual conditions inside the shed; generally, spray less water on cloudy and rainy days and more on sunny days.

(4) Ventilation

Xiuzhen mushroom is an aerobic fungus, so sufficient oxygen should be provided during the fruiting body growth stage. Poor ventilation often leads to the production of deformed mushrooms. However, ventilation must be coordinated with temperature and humidity control. After each watering, ventilation must be carried out, otherwise it easily leads to high temperature and high humidity. Ventilation time depends on specific conditions. The mushroom wall should not be too high; generally, about 10 layers of bags stacked into a wall is favorable for air circulation.

(5) Light

Xiuzhen mushroom is not a light-loving fungus, but after the differentiation of fruiting body primordia, appropriate light stimulation should be given, with intensity generally controlled at 300-600 LUX, such that book text can be clearly seen inside the fruiting room (shed). Strong light is not conducive to primordium formation, or forms fruiting bodies with thick and short stipes and caps that do not easily open. Long-term placement in a dark fruiting room will seriously affect primordium formation.

(6) Management After Picking

After each flush of mushrooms is harvested, the material surface should be thoroughly cleaned, removing dead mushrooms, mushroom roots, and debris, and sealed for spawn restoration for 3-5 days before entering the management for the next flush. After the second flush, nutrient solution can be injected supplementally (formula: water 50 kg, ammonium sulfate 1%, urea 0.3%, monopotassium phosphate 0.3%, magnesium sulfate 0.15%, glucose 1%, triacontanol and mushroom growth promoter 30 ml each). After water injection, pay attention to heat and moisture preservation so that the mycelium can fully recover.

5. Pest and Disease Control

During the spawn-running period of Xiuzhen mushroom, common contaminating fungi include Trichoderma viride, Penicillium, Mucor, and Neurospora crassa, etc. If found during inspection, they should be promptly removed and treated. The prevention and control of contaminating fungi mainly relies on ensuring aseptic operation during inoculation. The culture room must be well ventilated with fresh air, and the surrounding environment should be clean and tidy. In addition, 5% carbendazim powder at 1000 times can be added to the culture material for protective effect.

During the fruiting body growth stage, insect pests may also occur. The seriously harmful ones include mushroom gnats and mushroom flies. When severe, 50% beta-cypermethrin diluted 1000 times can be used for control. The spraying time should be chosen during the flush transition period to avoid phytotoxicity to the fruiting bodies. During spraying, the front and back of the bags as well as the corners and outer areas of the shed or room must be sprayed at the same time. It is best to carry out spraying from 1-3 PM on a clear day, and do not spray water within 2-3 days after application to prolong the efficacy.