What are the main pest and disease control methods for edible fungi?

1. Brown rot

Also known as bubble disease, wet bubble disease, etc. It mainly damages button mushrooms, straw mushrooms, oyster mushrooms, etc. The disease is caused by a fungus called Mycogone perniciosa. The main feature is that the conidia and chlamydospores of Mycogone perniciosa only infect the fruiting bodies, not the mycelium. When the fruiting body is mildly infected, the stipe swells into a bubbly deformity, hence the name wet bubble disease. However, the symptoms differ at different stages of fruiting body development. When the fruiting body is infected before differentiation, there is an irregular mass of tissue resembling a hard-skinned puffball, covered with a layer of white downy mycelium that gradually turns dark brown, and dark black droplets often seep from the diseased tissue. When infection occurs after the cap and stipe have differentiated, the stipe turns brown, and infection on the gills produces two kinds of white mycelial growth.

Route of transmission: Mycogone perniciosa is a common soil fungus, and the soil and debris around the mushroom house are its sources of infection. Therefore, the Mycogone perniciosa pathogen is mainly carried to the mushroom beds and mushroom blocks through casing soil, air, operators, tools, insects, mice, etc.

Control methods: If the casing soil is contaminated by Mycogone perniciosa, pasteurization (60°C) can be used for one hour, or 4% formaldehyde can be used to disinfect the casing soil. A 1:500 carbendazim solution or thiophanate solution can also be sprayed on the casing soil for sterilization. When the disease first appears, watering should be stopped immediately, ventilation of the mushroom house should be increased, and a 1%-2% formaldehyde solution or 1:500 carbendazim solution should be sprayed on the growing racks, walls, and floor for sterilization. When the disease is severe, the original casing soil needs to be removed and replaced with new soil; the diseased mushrooms should also be destroyed, and all tools should be disinfected in a 4% formaldehyde solution.

2. Withering disease

Also known as dead wilt disease, it is a physiological disease. It mainly damages button mushrooms, oyster mushrooms, Phoenix mushrooms, Lingzhi mushrooms, nameko mushrooms, etc. The main feature is that after the mushroom buds form, fruiting bodies of various sizes can develop this disease. After onset, they stop growing, turn yellow, gradually shrink, soften, and dry out, and finally wither and die or rot.

Cause: The occurrence of this disease is the result of a physiological setback. The main causes are that after primordium formation the substrate is too dry, causing the mushroom buds to wither; or fruiting is too dense and nutrients cannot be supplied adequately, causing some small mushrooms to die; or the temperature in the mushroom house is too high, the humidity is too great, ventilation is poor, oxygen is insufficient, and the carbon dioxide content in the air is too high; or the small mushroom buds are accidentally bruised when harvesting, or excessive fruiting causes phytotoxicity.

Control methods: When fruiting bodies begin to wither, first determine the cause of the disease and take corresponding measures. Never spray pesticides inside the mushroom house after fruiting, otherwise phytotoxicity is likely to occur. In particular, for oyster mushrooms and Phoenix mushrooms, dichlorvos must absolutely not be sprayed during the fruiting period.

3. Deformed mushroom disease

It is also a physiological disease. During the formation of fruiting bodies, if edible fungi encounter adverse environments and conditions that prevent the fruiting bodies from developing normally, various deformities will occur. The main features are: small and thin caps, slender stipes, and early opening of the caps. This phenomenon occurs mostly after the first flush in oyster mushrooms and Phoenix mushrooms, while in shiitake mushrooms it occurs in the first flush. Its main causes are high temperature, insufficient light, and lack of nutrients.

Long-stipe mushrooms mainly occur during the formation of fruiting bodies in the genus Pleurotus, with the fruiting bodies appearing coral-like or with extremely small caps and thick bases of the stipes. The main causes are insufficient light, poor aeration, excessively high carbon dioxide content, and too little oxygen. The occurrence of tilted fruiting bodies usually means they lean toward the side with light; the cause is the phototropism of the fruiting bodies during growth, mainly caused by uneven light in the mushroom house. The mycelial shrinkage that often occurs at different growth stages, and sometimes even death, is mainly due to weak spawn that does not colonize the new substrate; or unsuitable water content of the substrate, too dry or too wet; or excessively high temperature inside the substrate, causing burning of the mycelium; or poor aeration inside the substrate; or possibly unsuitable pH in the substrate.

There is only one control method, which is that in the production process, every procedure and every process must be carried out scientifically and strictly as required, so as to avoid various adverse consequences that lead to production failure.

4. Damping-off

Also known as wilt disease, it is a fungal disease. It is mainly caused by Fusarium and Fusarium solani f. sp. phaseoli. 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 stops growing. In the early stage of this disease, it is not easy to notice in shape compared with healthy mushrooms; only the cap turns dark, the mushroom body stops growing, and finally it becomes a stiff mushroom.

Route of infection: Because Fusarium can survive in soil for a long time, infection through soil is the main route of infection; in addition, it can also be spread through air and some tools.

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