Detailed explanation of the key technical points for courtyard greenhouse cultivation of oyster mushrooms

Using idle space in farm courtyards to build plastic film mushroom greenhouses for cultivating oyster mushrooms has the advantages of low investment, easy control of temperature and humidity, convenient management, and good returns. The main technical points are as follows:

1. Construction of the mushroom greenhouse: build the mushroom greenhouse facing south, against the west wall or east wall. The site should be slightly elevated to prevent water accumulation. Before building the greenhouse, the ground must be thoroughly cleaned to avoid garbage, weeds, and filth on the ground contaminating the environment inside the greenhouse. Use wooden posts or cement posts for support, and a bamboo pole structure is best for the roof, covered with plastic film and then with straw curtains for shade. The mushroom greenhouse is required to have a certain slope. Generally, because sanitary conditions in farm courtyards are somewhat poor, in order to prevent contamination by competing fungi and pests, the mushroom house should be disinfected and treated for insects 3 days to 4 days before sowing. For insect control, 1% dichlorvos is generally used to spray around the inside of the greenhouse, then it is sealed for 24 hours and fully ventilated. For disinfection inside the greenhouse, sulfur (10 g/cubic meter) fumigation can be used, or formaldehyde and potassium permanganate fumigation, sealed for 24 hours and then fully ventilated, and 1% limewater should be sprayed on the walls and posts inside the greenhouse, with a small amount of lime powder scattered on the ground.

2. Selection of spawn: for spring cultivation, medium-to-high temperature varieties can be selected. When selecting spawn, eliminate spawn contaminated by competing fungi and old spawn that has separated from the bag wall, and select spawn with white, dense, and sturdy mycelium for sowing.

3. Preparation of the substrate and sowing: using cottonseed hulls as the substrate has the advantages of convenient cultivation, a low rate of contamination by competing fungi, and high mushroom yield, and is the first choice for first-time mushroom growers. Choose fresh cottonseed hulls without mold, and it is best to sun-dry them for 1 day to 2 days before mixing. The general mixing ratio is: cottonseed hulls 100 kg, superphosphate 2 kg, quicklime 1 kg, carbendazim 0.1 kg. When the substrate is squeezed by hand, it is appropriate for water droplets to appear between the fingers without dripping down. The tools used for mixing should be disinfected with 1% limewater.

Oyster mushrooms cultivated in courtyard greenhouses generally use plastic bag cultivation. The sowing method for bag-cultivated oyster mushrooms is mostly layer sowing, with one layer of spawn at each end of the bag and two layers of spawn in the middle. The sowing amount is suitably 20% of the dry material weight. The compactness of the substrate when filled into the bag is very important. If filled too tightly, oxygen is insufficient; if filled too loosely, moisture evaporates easily, the mycelium does not contact the substrate closely, and the mycelium colonizes the substrate slowly. The appropriate compactness should be such that when pressed by hand, the substrate feels elastic, no pit can be pressed into it, and no creases appear when the spawn bag is moved. After sowing, use a machine needle to make several small ventilation holes at both ends of the spawn bag and at the inoculation sites in the middle, so as to improve ventilation conditions inside the spawn bag and speed up mycelial growth. Sow in seasons with lower temperatures. The spawn bags can also be perforated before bagging.

4. Management during the mycelial growth period: after bagging is completed, place the spawn bags in the mushroom house or mushroom greenhouse for mycelial growth, generally arranged in a wall style. Light is not needed during the mycelial growth period, and the mushroom house should be shaded.

The optimum temperature for oyster mushroom mycelial growth is 18°C to 22°C. The substrate temperature should be controlled at 24°C to 27°C. Ventilate 2 times to 3 times a day, about 30 minutes each time. As the temperature rises, gradually increase ventilation. During high-temperature periods, ventilate day and night. During low-temperature periods, cover with straw curtains or paper quilts at night for insulation, roll them up during the day to let in light, raise the greenhouse temperature, and ventilate at noon. From the early stage of mycelial growth, frequently check the moisture of the spawn bags. If the temperature is found to be too high, promptly turn the bags, swapping the positions of the upper and lower layers of spawn bags so that the temperature is uniform and growth is consistent, and at the same time inspect and eliminate spawn bags with competing fungi. Be careful not to break the mycelium when turning the bags, so as not to affect normal mycelial growth.

At a suitable temperature, generally 25 days to 30 days after sowing, the mycelium can "run through" the substrate. The mycelium changes from snow white to grayish white, and yellow water exudes, marking that the mycelium has reached physiological maturity and begins to fruit. At this time, a day-night temperature difference of 8°C to 10°C and scattered light stimulation should be provided to promote fruiting. The manager should remove part of the straw curtains to increase the amount of scattered light in the greenhouse, and moderately increase ventilation to raise the day-night temperature difference.

5. Management during the fruiting period: when the mycelial growth period ends and the fruiting period begins, inspect the spawn bags every day. If mushroom primordia are found, untie the string at the mouth of the spawn bag, roll up the bag mouth, and spray an appropriate amount of water inside the greenhouse so that the relative air humidity in the greenhouse remains at 80% to 95%. Continue to provide scattered light in the greenhouse; the light intensity should be such that small characters in a newspaper can be read clearly inside the greenhouse. Insufficient light easily produces deformed mushrooms. Keep the temperature at 10°C to 25°C. The oxygen demand increases during the fruiting period, so ventilation should be increased. Poor ventilation and excessively high carbon dioxide concentration will form large-stipe mushrooms, affecting yield and quality. In order to maintain relative air humidity, spray water on the ground, walls, and airspace 2 times to 3 times a day, using light spraying, fine spraying, and frequent spraying. Spray frequently in dry weather and strong wind, and spray less or not at all on cloudy and rainy days. In the early fruiting stage, be sure not to spray water on the spawn bags or young mushrooms, otherwise the primordia and young mushrooms are prone to rot and death. Only when the caps have grown to more than 2 cm can water be sprayed on the spawn bags and mushroom bodies.

After the first flush of mushrooms is finished, the plastic film in the middle of the spawn bags can be removed, and a mushroom wall can be rebuilt by the method of one layer of spawn bags and one layer of nutrient soil (mud). This can increase the water and nutrient supply to the spawn bags and significantly increase mushroom yield. For the nutrient soil (mud), generally choose high-quality vegetable garden soil or clay loam rich in organic matter, remove crop residues, gravel, and the like, add 10% plant ash, 2% superphosphate, 0.5% urea, and 3% lime powder, mix well, spray with 500-fold chlorothalonil solution and 1500-fold dichlorvos solution, seal with plastic film for 2 days, and then use.