Control Methods and Technical Key Points for Physiological Diseases of Oyster Mushrooms

Oyster mushrooms have the characteristics of wide adaptability, strong stress resistance, a wide range of cultivation material sources, simple cultivation techniques, and high economic benefits. In recent years, oyster mushroom production has developed rapidly in our county, but in production, various non-infectious physiological diseases often occur due to poor management, causing yield reductions and directly affecting the economic benefits of oyster mushroom production. Based on many years of production practice experience, we have summarized the symptoms and control techniques of several main physiological diseases that commonly occur in oyster mushroom production.

1. Excessive mycelial growth

In oyster mushroom production, excessive mycelial growth often causes the mycelium to become dense and clump together, forming old mycelial skin that does not produce mushrooms. This is mainly caused by aging spawn or by using aerial mycelium for transfer when subculturing first-level spawn. In production, if the mushroom house is poorly ventilated, the temperature is too high, or the film covering time is too long, it can also cause excessive mycelial growth and no mushroom production. Control methods: strengthen spawn production management; during the fruiting body differentiation stage, increase the ventilation of the mushroom house and lower the mushroom house temperature. When old mycelial skin appears during cultivation, promptly scrape off the old mycelial skin, scratch the mycelial blocks and mycelial film to induce mushroom production.

2. Mycelial degeneration and shrinkage

During the mycelial growth or mushroom production stage, the mycelium turns yellow, turns brown, shrinks, and dies. This is caused by an unsuitable carbon-to-nitrogen ratio in the substrate, or excessively high water content, poor ventilation, and a stuffy and hot mushroom house. Control methods: adjust the carbon-to-nitrogen ratio of the substrate, reduce the water content of the substrate, sow at the appropriate time, and avoid damage during high-temperature periods.

3. Fruiting body shrinkage and death

This is mainly caused by unsuitable environmental conditions during the mushroom production stage. For example, when the temperature exceeds 23°C for low-temperature varieties or exceeds 28°C for medium-temperature varieties, or when air humidity is below 80%, the fruiting bodies shrink and die due to massive and rapid evaporation of water; excessive spraying causes small mushrooms to become waterlogged; when mushrooms are very dense, insufficient nutrients cause the small mushrooms to die from starvation. Control methods: according to the cultivation season, select suitable varieties and avoid mushroom production during high-temperature seasons; after mushroom buds appear, raise the humidity of the mushroom shed to 90%, and strengthen ventilation as the fruiting bodies grow. Try to avoid spraying water directly onto the mushroom bodies.

4. Deformed mushrooms

1. Shriveled mushrooms: the cap is small and shriveled, the stipe is long, and the texture is hard. It is caused by relatively high temperature and relatively low humidity.

2. Big-foot mushrooms: only the stipe grows, and the cap does not grow. It is caused by poor ventilation and excessively high carbon dioxide concentration.

3. Long-stipe type: the stipe is slender and the cap is very small; in the early stage, it appears as loose, densely distributed fruiting body masses with abnormal stipes, resembling coral. It is caused by removing the film too late and insufficient light.

4. Bumps growing on the cap: the upper side of the cap, especially the edge, is covered with bumps of varying sizes. In severe cases, the entire cap is covered with bumps. After bumps form, the fruiting body grows extremely slowly, directly affecting commercial quality and yield. This phenomenon generally occurs in winter, caused by making a fire indoors for heating in the cultivation room, excessively high accumulated carbon dioxide concentration, and cultivation bags being close to draft openings, where cold wind stimulation causes uncontrolled cap growth and bump formation.

Control methods: properly control the mushroom house temperature; during the mushroom production stage, the temperature is best controlled at 15-28°C. When high temperature occurs, cool down by sprinkling water and ventilating. During the mushroom production stage, provide about 200 lux of scattered light, maintain air humidity at about 90%, ventilate appropriately, and control carbon dioxide concentration below 0.1%.

Oyster mushroom production is three parts spawning and seven parts management. As long as suitable varieties are selected according to the cultivation season and careful management is carried out according to variety characteristics, oyster mushroom production will achieve relatively high economic benefits.