Agricultural measures for the prevention and control of pests and diseases in edible mushroom cultivation

1. Brown rot, also known as bubble disease, wet bubble disease, etc. It mainly affects button mushrooms, straw mushrooms, oyster mushrooms, etc. The disease is caused by a fungus called Mycogone perniciosa. The main symptoms are: the conidia and chlamydospores of Mycogone perniciosa infect only the fruiting body, not the mycelium. When the fruiting body is lightly 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. If the fruiting body is infected before differentiation, it forms an irregular mass of tissue resembling a hard-skinned puffball, covered with a layer of white fuzzy mycelium that gradually turns dark brown, and dark black droplets often exude from the diseased tissue. If infection occurs after the cap and stipe have differentiated, the stipe turns brown, and infection on the gills produces a white mycelial growth. Route of transmission: Mycogone perniciosa is a common soil fungus, and the soil and waste around the mushroom house are its sources of infection. Therefore, the pathogen is mainly carried to the mushroom beds and mushroom blocks through casing soil, air, operators, tools, insects, mice, and so on. Control measures: If the casing soil is contaminated by Mycogone perniciosa, it can be treated by pasteurization (60°C) for one hour, or the casing soil can be disinfected with 4% formaldehyde. A 1:500 solution of carbendazim or thiophanate-methyl can also be sprayed on the casing soil for sterilization. When the disease first appears, watering should be stopped immediately, the ventilation of the mushroom house increased, and a 1%-2% formaldehyde solution or 1:500 carbendazim solution sprayed on the growing racks, walls, and floor for sterilization. In severe cases, the original casing soil must be removed and replaced with new soil. The diseased mushrooms should also be destroyed, and all tools disinfected in a 4% formaldehyde solution.

2. Wilt disease, also known as dead wilt disease, is a physiological disease. It mainly affects button mushrooms, oyster mushrooms, Phoenix mushrooms, Ling mushrooms, nameko mushrooms, etc. The main symptoms are: after the mushroom buds form, fruiting bodies of various sizes can develop this disease. After onset, growth stops, they 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 physiological obstruction. The main causes are that after primordium formation the substrate is too dry, causing the mushroom buds to wither; or that fruiting is too dense and nutrients cannot be supplied, causing some small mushrooms to die; or that the temperature in the mushroom house is too high, the humidity too great, and ventilation poor, with a lack of oxygen, causing the carbon dioxide content in the air to be too high; it can also be caused by accidentally bruising the mushroom buds when harvesting, or by excessive fruiting producing phytotoxicity. Control measures: When the fruiting bodies begin to wither, the cause must first be identified and corresponding measures taken. Under no circumstances should pesticides be sprayed in the mushroom house after fruiting, otherwise phytotoxicity easily occurs. Especially for oyster mushrooms and Phoenix mushrooms, dichlorvos must absolutely not be sprayed during the fruiting period.

3. Malformed mushroom disease is also a physiological disease. During the formation of fruiting bodies, if edible mushrooms encounter unfavorable environments and conditions that prevent the fruiting bodies from developing normally, various kinds of deformities will appear. The main symptoms are: small and thin caps, slender stipes, and early veil opening. 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, where the fruiting body is coral-like or has a very small cap while the base of the stipe is thick. The main causes are insufficient light, poor ventilation, too high a carbon dioxide content, and too little oxygen. The tilting of fruiting bodies generally occurs toward the side with light; the cause is the phototropism of the fruiting body during growth, mainly resulting from uneven light in the mushroom house. The phenomenon of mycelial shrinkage, and sometimes even death, that frequently occurs during different growth stages is mainly due to the spawn not being vigorous and failing to colonize the new substrate; or to unsuitable water content of the substrate, either too dry or too wet; or to excessively high temperature inside the substrate causing mycelial burning; or to poor ventilation within the substrate; and it may also be due to unsuitable pH in the substrate. There is only one control measure, which is that throughout the production process, every procedure and every process must be carried out strictly and scientifically according to requirements, so as to avoid various adverse consequences that lead to production failure.

4. Damping-off, also known as wilt disease, 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 small and stops growing. In the early stage of the disease, it is not easy to distinguish from healthy mushrooms in appearance; only the cap darkens, the mushroom body stops growing, and finally it becomes a mushroom.