Penicillium also known as blue mold, is a common contaminant bacteria in the cultivation and cultivation of edible fungi. It can also cause mushroom, oyster mushroom, Pleurotus ostreatus, mushroom, straw mushroom and enoki mushroom etc. under certain conditions. Pathogenicity is a common pathogen that affects the yield and quality of edible fungi. Symptoms When penicillium was detected on the culture surface, the initial mycelium was white, and the colony was nearly round to indeterminate. The appearance was slightly powdery. With the large number of spores, the color of the colonies gradually changes from white to green or blue. The rim of the growing colony is usually 1-2 mm white, and the expansion is slower. The surface of the old colonies is often interwoven to form a layer of membranous material that covers the surface of the culture medium and secretes toxins that cause mycelial necrosis of edible fungi. In the process of seed production, if it occurs seriously, it can cause the corruption of the bacteria species to be scrapped; when the germination period is heavy, it can cause the local material surface to not produce mushrooms. Pathogens and pathogenicity Penicillium that damages edible fungi belong to the fungus Penicillium fungus. Colonies appear bluish-green when grown in large numbers. The pathogens are widely distributed, with more saprophytic or weak parasites, and they are present on many organic substances, producing a large number of conidia, mainly through the air flow into culture materials, and for the initial impregnation. The raw materials used for the feeding of bacteria are also important sources of initial infusion for raw material cultivation. The conidia produced after the impregnation were re-disposed by air flow, insects, artificial water sprays, and management operations. High temperature is conducive to disease, 28 °C -30 °C conditions most likely to occur, conidia 1-2 days that can germinate the formation of white mycelium, and rapid production of conidia. Most penicillins prefer an acidic environment, and culture materials and coverings are more susceptible to acidosis. The growth of faecal fungus is conducive to disease. The growth of thin young mushroom or the removal of mushroom root from mushroom bed without prompt removal is conducive to bacterial infection. Prevention and control methods 1 Do a good job in disinfection and sterilization in inoculation rooms, training rooms and production sites, keep the environment clean and hygienic, strengthen ventilation and prevent the spread of diseases. 2 Adjust the proper pH of the culture material. The cultivation of cultivated mushrooms, oyster mushrooms and shiitake mushrooms can be adjusted to slightly alkaline with 1%-2% lime water. After spraying mushrooms, lime water is used to stimulate the growth of edible mycelium and inhibit the occurrence of Penicillium. 3 bacteria bags can be injected into the local disease 15% formaldehyde solution, Penicillium segmental wood can be used to wash lime, mushroom bed disease can be used 1% clotriaxacin, 0.5% Duofengnong, 0.1% of the protection of power and 0.1% mothraine solution spray Prevention.