Brown spot of Pleurotus ostreatus

Mushroom brown spot, also known as dry blister disease, verticillium and so on. In some areas, the disease is relatively serious, and the output has suffered a great loss.

Damage symptoms: mushroom buds were killed, poor growth and development, so that the stalk, buds can not be formed, into a dry white clot. When the fruiting body is killed, many needle-sized brown spots are produced on the mushroom lid, and then the spots are enlarged and sunken, and when the middle is gray and white, when it is wet, there are white mildew on the disease spot, that is, conidiophores and conidia, the mushroom stalks are killed, the mushroom stalks become thicker and brown, the outer tissue is peeled off, and the mushroom stalks are skewed into deformities when they grow up.

Pathogen: the disease is caused by the infection of Cladosporium verticillium. The hyphae are gray-white, the conidiophores grow from the hyphae, and the conidia are oval or oval at the top of the peduncles.

Occurrence regularity: bacteria enter the mushroom room mainly through soil, such as soil cover, and can also be brought into the mushroom room through mushroom flies, mites, tools and manual operations. after the disease, conidia are produced and spread by spraying water, airflow and insects. High temperature and high humidity are conducive to the disease, too much water spraying, poor ventilation, high humidity of the overlying soil before mushroom formation, and general disease.

Prevention and control technology

1. Agricultural control

The main results are as follows: (1) the disinfection of culture materials by secondary fermentation is not only beneficial to the growth of mushroom mycelium, but also inhibit the growth of Trichoderma.

(2) the disinfection of covering soil can be treated with high humidity and treated with 60 ℃ for 1 hour.

(3) take measures to prevent mushroom flies and mites from entering the mushroom house.

(4) to control the temperature and humidity under the condition of maintaining the normal temperature of the mushroom room, the window should be opened for ventilation and the humidity should be reduced. Attention should be paid to the soil cover, and the humidity should not be too high. It should be ventilated and humidified in time after watering.

(5) when diseased mushrooms are found in time, the diseased mushrooms with mycelium and culture materials with a depth of 10 cm are immediately dug out, taken out of the mushroom house or burned out of the field, and the diseased holes are filled with aseptic soil. at the same time, all appliances are disinfected with 4% formaldehyde to prevent bacterial infection.

2. Chemical control

(1) before mushrooms grow, 50% benzoate wettable powder 600 times can be sprayed on the cover soil and bed surface. At the initial stage of the disease, 50% carbendazim wettable powder 500 times or 20% methyl thiophanate wettable powder 600 times, 60% Fangmaibao wettable powder 600 times.

(2) if the disease is seriously affected by the replacement of diseased soil and chemicals, all the diseased soil can be shoveled, replaced with disease-free new soil, re-covered, and measures shall be taken to reduce the temperature and humidity in the bed. If necessary, remove all mushrooms, bury or burn the diseased mushrooms deeply, dry the mushroom bed soil for a few days, then spray the surface of the mushroom bed with 2% formalin, and then spray water after formalin volatilized. Note: all utensils are disinfected with% formalin (formaldehyde) solution; spray formalin is easy to cause drug damage, so you should be very careful: first, the concentration should not be high, second, you can not sow immediately (usually after 14 days), the soil should be turned over and ventilated to allow the medicine to volatilize and prevent drug damage.