Symptoms and Control Methods of Brown Spot Disease in Edible Fungi

Damaged crops: Edible fungi

Damage symptoms: Does not infect the mycelium, only infects the fruiting bodies, but can grow along mycelial strands, forming relatively dry grayish-white tissue masses. Infected mushroom buds stop differentiating; after young mushrooms are infected, the caps become smaller, the stems become thicker and brown, forming deformed mushrooms; after the fruiting bodies are infected in the middle to late stages, many pinhead-sized, irregular brown spots appear on the caps and gradually expand into grayish-white depressions. Diseased mushrooms often have their surface layer peeling or cracking, do not rot, and have no foul odor. The disease course is about 14 days.

Classification attribute: Fungal disease caused by Verticillium

Disease characteristics: Contaminated casing soil is the initial infection source; spread in the mushroom house is mainly through watering, splashing water, insects, tools, operations, and airflow, etc.

Control methods: Maintain good hygiene in the mushroom house and prevent mushroom flies and mushroom gnats from entering. Strictly disinfect the mushroom house before and after use; disinfect mushroom-picking tools with 4% formaldehyde solution before use; disinfect or pasteurize the casing soil before use, and strictly prohibit the use of raw soil. Never let the casing soil become too wet. At the early stage of the disease, immediately stop watering and lower the temperature to below 15°C, and strengthen ventilation to remove moisture. Promptly remove diseased mushrooms, and spray 2% formaldehyde or 0.2% carbendazim on the casing soil in the affected area. Spraying 0.2% carbendazim solution on affected mushroom beds can inhibit the spread of the pathogen.

Commonly used chemicals: Carbendazim