Detailed Explanation of Four Key Points for Winter Cultivation and Management of Oyster Mushrooms

1) Light should be strong rather than weak. Light is not only an important way to raise the shed temperature in winter, but also an important means to increase yield and improve mushroom quality. Light intensity and duration should be determined according to the insulation performance of the mushroom shed and weather conditions. If the insulation performance of the mushroom shed is good and the nighttime temperature can be maintained above 5°C, then the straw mats on the shed roof can be uncovered early and covered late, extending the daytime light duration as much as possible; otherwise, the daytime light duration in the mushroom shed should be correspondingly shortened. As for weather conditions, when the temperature is below 5°C, on sunny and cloudy days, under the condition of ensuring a shed temperature of 5°C, the light duration should be increased as much as possible; on rainy days, light can be added to the shed between 11:00 and 15:00 when the daytime temperature is relatively high; on snowy days, adding scattered light to the shed is sufficient. Light intensity also directly affects the yield and quality of oyster mushrooms. In mushroom sheds with stronger light, the fruiting bodies of oyster mushrooms are darker in color, the caps are thicker, the mushroom slices have good toughness, and the yield can also increase by about 20%. In practice, it has been found that even for the same white oyster mushroom variety, under conditions of stronger light, its fruiting body color will also turn light gray, or even reddish-brown; while for the same black oyster mushroom variety, when cultivated under high temperature and dim light, its mushroom slices will still grow light white, or even white. Therefore, in cultivation management, one should first weigh the relationship among mushroom quality, yield and selling price, and then determine the light intensity and duration in the mushroom shed. Comparatively speaking, appropriately increasing light will significantly improve the benefits.

2) Water should be less rather than more. Winter temperatures are low, evaporation from the shed floor and the surface of the substrate is low, the respiration of mycelium under low-temperature conditions is greatly reduced, and the water consumed is correspondingly reduced. In addition, management of the mushroom shed focuses on heat preservation and the shed is often kept closed, so most of the water vapor in the shed is difficult to release outside the shed. The above three factors lead to a relatively low water requirement inside the shed, and watering in the mushroom shed should be controlled and must not be excessive. For mushroom sheds that are relatively large in space, have fewer mushroom logs placed in them, or have good ventilation and are relatively easy to warm up, it is appropriate to spray water once every 1-2 d (days); otherwise, once every 2-4 d (days). In winter, it is appropriate to spray hot water at about 50°C inside the shed, maintaining the relative humidity in the shed at 85%-95% and keeping the surface of the substrate relatively moist. When spraying water, remember that "closed-shed water" must not be sprayed, that is, water must not be sprayed under closed-shed conditions without ventilation. This is because when water is sprayed under sealed conditions, the relative humidity in the shed will remain at 100% for a long time, water is in a saturated state, the normal physiological activities of the fruiting bodies are hindered, and normal growth is difficult, causing the mushroom slices to curl upward, or even wither and die, resulting in physiological diseases.

3) Ventilation should be frequent rather than strong. Ventilation and air exchange can increase the oxygen content in the mushroom shed, but the cold air outside the shed will then invade the shed, thereby lowering the temperature of the mushroom shed. Therefore, in winter, under the premise of ensuring that the oxygen in the shed is sufficient, the ventilation time should be reduced as much as possible. For mushroom sheds that are relatively large in space and have good ventilation conditions, it is appropriate to use short-duration light ventilation for air exchange, 3-4 times per 1 d (day), 30 min (minutes) each time; otherwise, it is appropriate to ventilate 8-10 times, 20 min (minutes) each time, while also supplemented by human walking around so that the corners with poor ventilation can also exchange air normally.

4) Heating should be economical rather than luxurious. Temperature is an important factor affecting the emergence of young oyster mushroom buds and normal growth in winter, and is also one of the important factors affecting production costs. In management, under the premise of meeting the lower temperature limit required for normal growth of oyster mushrooms, fuel input should be reduced as much as possible. If the shed temperature is too low or the temperature difference is too small before budding, mushroom buds are very difficult to form; if the shed temperature is too low after budding, the fruiting bodies basically stop growing and remain in a cauliflower-like state without differentiating for a long time, or even if they differentiate, the mushroom slices will be covered with small white spines or mushrooms will grow on mushrooms, forming deformed mushrooms and reducing commercial value. Therefore, in management, before and after mushroom bud formation, solar energy should be the main heating method, and when necessary, a stove can be used to maintain the shed temperature above 5°C, so as to facilitate heat preservation and widen the temperature difference, promoting mushroom bud formation; after most mushroom bags have shown buds, it is appropriate to control the shed temperature at about 8°C to ensure normal growth of the fruiting bodies.