What are the control methods for the 4 types of edible mushroom diseases?

1. Brown rot. Also known as bubble disease and wet bubble disease. It mainly harms button mushrooms, straw mushrooms, oyster mushrooms, etc. The disease is caused by the pathogen Mycogone perniciosa.

Main characteristics: the conidia and chlamydospores of Mycogone perniciosa only infect the fruiting body, not the mycelium. When the fruiting body is lightly infected, the stipe swells into a bubble-like deformity, hence the name wet bubble disease. However, at different stages of fruiting body development, the symptoms also differ. If infection occurs before the fruiting body differentiates, there is an irregular mass of tissue resembling a hard-skinned puffball, covered with white cottony mycelium, which gradually turns dark brown and often exudes dark black droplets. If infection occurs after the cap and stipe have differentiated, the stipe turns brown, and infection on the gills produces 2 kinds of white mycelial growths.

Transmission route: Mycogone perniciosa is a common soil fungus, and the soil and waste around the mushroom house are its sources of infection. The pathogen of Mycogone perniciosa is mainly transmitted to the mushroom beds and mushroom blocks by casing soil, air, operators, tools, insects, mice, and other carriers.

Control measures: if the casing soil is contaminated by Mycogone perniciosa, it can be treated with pasteurization (60°C) for 1 hour, or the casing soil can be disinfected with 4% formaldehyde, and a 1:500 carbendazim solution or thiophanate solution can also be sprayed into the casing soil for sterilization. When the disease first appears, immediately stop watering, increase the ventilation of the mushroom house, and spray a 1% to 2% formaldehyde solution or a 1:500 carbendazim solution on the cultivation racks, walls, and floor for sterilization. In severe cases, remove the casing soil, replace it with new soil, destroy the diseased mushrooms, and all tools should be soaked in a 4% formaldehyde solution for disinfection.

2. Wilt disease. Also known as dieback disease, it is a physiological disease. It mainly harms button mushrooms, oyster mushrooms, Phoenix mushrooms, Ling mushroom, and nameko mushrooms, etc.

Main characteristics: after the mushroom buds form, fruiting bodies of various sizes can develop this disease. After the disease occurs, growth stops, and they turn yellow, shrink, soften, dry out, and finally die or rot.

Cause: the occurrence of this disease is the result of physiological obstruction. The main reasons are that after primordium formation the substrate is too dry, causing the mushroom buds to wither; or the mushrooms emerge too densely and nutrients cannot be supplied sufficiently, causing some small mushrooms to die; or the mushroom house temperature is too high, the humidity is too high, ventilation is poor, and the carbon dioxide content in the air is too high; and careless bumping of small mushroom buds during harvesting can also cause this disease.

Control measures: when the fruiting bodies begin to wither, first determine the cause of the disease and take corresponding measures. Never spray chemicals in the mushroom house after mushrooms have emerged, otherwise pesticide damage is likely to occur. In particular, for oyster mushrooms and Phoenix mushrooms, dichlorvos must absolutely not be sprayed during the fruiting period.

3. Malformed mushroom disease. A physiological disease. During the formation of fruiting bodies, edible mushrooms encounter adverse environments and the fruiting bodies develop various deformities.

Main characteristics: the cap is small and thin, the stipe is slender, and the veil opens early. This phenomenon occurs mostly after the first flush in oyster mushrooms and Phoenix mushrooms, while in shiitake mushrooms it occurs in the first flush. The main causes are high temperature, insufficient light, and nutrient deficiency, etc.

Long-stipe mushrooms mainly occur during the formation of fruiting bodies in the genus Pleurotus, where the fruiting body is coral-like or the cap is extremely small while the base of the stipe is thick and enlarged. The main causes are insufficient light, poor ventilation, and excessively high carbon dioxide content. The tilting of fruiting bodies generally occurs toward the side with light, and the cause is the phototropism of the fruiting body during growth; when the light in the mushroom house is uneven, this disease occurs. The frequent shrinkage of mycelium during different growth processes, and sometimes even death, is mainly due to the spawn not being robust and failing to colonize the new substrate; or the substrate moisture content being too dry or too wet; or the temperature inside the substrate being too high, causing spawn burning; or poor ventilation within the substrate and unsuitable pH, etc.

Control measures: every procedure and every process must be carried out scientifically and strictly according to requirements.

4. Damping-off. It belongs to fungal diseases. It is mainly caused by Fusarium and bean Fusarium. The main symptom is that after the fruiting body is infected, the pith of the stipe shrinks and turns brown, and the mushroom body becomes short and small. When this disease occurs in the early stage, it resembles healthy mushrooms in appearance and is not easy to detect, except that the cap becomes darker, the mushroom body stops growing, and finally becomes a stiff mushroom.

Transmission route: because Fusarium can survive in soil for a long time, transmission through soil is the main route of infection. It can also be transmitted through air and some tools.

Control method: sterilizing the casing soil is the main method for controlling this disease. Generally, a 1:500 carbendazim or thiophanate solution is sprayed for disinfection.