Failure reasons: 1. The amount of bran in the formulation of the culture material is too much, resulting in excess nutrients in the mycelia; 2. The hyphae have not reached a physiological maturity when the bag is taken out of the bag, and the mycelium continues to grow after the bag is removed, causing the mycelia to grow in length; After the high temperature was above 25°C, the airborne mycelium on the surface of the bag surface was prolonged. 4. The temperature was below 18°C ​​after bagging, and the surface airborne mycelium grew slowly or stagnated; Insufficient humidity or insufficient shading may cause water loss in the bacteria bar, inhibiting the normal growth of surface airborne mycelium; 6. Occurrence of pests and diseases. The first three conditions often cause the bacteria bar to turn too slowly, the bactopoid is too thick, the color is dark, the mushroom is significantly delayed, the mushroom is small, the individual is large, the tide is not obvious, and the proportion of autumn and winter mushrooms is greatly reduced; The bacteria bar does not turn color or turn color is very shallow, the bacterial skin is too thin, the protective effect is poor, the mushroom is fast, the flower is small, the deformed mushroom is more, and the yield and quality are greatly reduced. Preventive measures: 1. The proportion of bran in the culture material should be controlled at 20% to 22%, and the amount of bran should be less than 20% when using mulberry wood chips; 2. When the hyphae reach physiological maturity, they are taken out of the bag and matured. The sign is: The nodules in the bag change from hard to soft, the inoculated points become brown, and the mushroom primordium is formed. The fungus is flexible. The color of the fungus bar with appropriate maturity is easy to control, and the mushroom is clean and tidy; the cultivation season is good; the temperature during bagging is 20°C～25°C. After the bag is exposed to high temperatures, the sun will be thickened, ventilation will be strengthened, and the humidity of the mushroom bed and the environment will be increased to prevent the dehydration of the mushroom bar. In case of low temperatures, the film is tightly sealed to increase the thickness of the fence on the windward side to prevent cold air from blowing directly into the mushroom bed. Before and after noon to increase light and temperature; 4. After the bag is easy to lose water, bacteria and insect pests, so the mushroom bed should be disinfected before leaving the bag and keep it moist, so that the edge of the bag cover, the film humidity is maintained at 60 % to 95%. Farmers who have cultivated shiitake mushrooms for the first time can use a method of bagging and then gradually unpacking bags after breaking the bag, although it is time-consuming but easy to grasp. China Agricultural Network Editor