1. Reasons:
A. Improper management and excessive water-spraying in low-temperature season.
B. Too low temperature in greenhouse, sporocarps live in poor environmental condition for a long term.
C. For some mushroom varieties, the fruiting period situates in the three or four flushes, fungus sacks are ill-nourished, sporocarps fail to get sufficient nutrients after mushroom buds appear, which results in yellow and dead mushrooms.
2. Control methods:
A. Frequently spray pesticides in greenhouse and do it once a week.
B. When the temperature of greenhouse is relatively low, be sure to avoid excessive water-spraying.
C. Try to raise the temperature of greenhouse and conduct proper management, it is preferred to keep the daytime temperature of greenhouse in above 15 degrees.
D. Spray all kinds of disease-resistant agents and production booster on mushroom bodies.