Main Diseases and Control techniques of Pleurotus ostreatus in North China

1 soft rot

1.1 symptoms of the disease the surface of the culture material or mushroom body is covered with a layer of white woolly bacteria, slender and soft but growing fast, and the gradually infected mushroom body spreads light brown morbid from the base of the fungus, and the mushroom body gradually soft rot; about a week after infection, the mushroom body loses automatically or falls down with a gentle touch, just like Chinese cabbage with soft rot, but the soft rot mushroom body has no smell. The growth rate of the mushroom body that has not yet soft rot is very slow, and the cap is gradually yellowish, lifeless and not bright, which is obviously different from the normal mushroom body; the infected materials no longer produce mushrooms, even if barely budding, they will soon be soft rot, without commercial value.

1.2 the pathogen of soft rot generally lives in the surface tillage layer (20cm), especially in the land with high content of organic matter and fertile soil, and the base of the pathogen is very high, such as vegetable garden soil, seedling bed soil and 100m soil around the village. Generally speaking, the land for the production of Pleurotus ostreatus is mostly at the end of the village, in front of the house and behind the house, and the cultivation soil is also used locally, so it is easy for bacteria to pollute the cultivation materials. when the temperature in the cultivation shed is 15-30 ℃ and the relative air temperature is about 90%, the spores germinate rapidly, and the hyphae first infect the culture medium, and then with the expansion of the number, the harm gradually deepens, or the culture materials no longer produce mushrooms. Or make the mushroom body that has occurred gradually soft rot.

1.3Preventive measures ① cultivation greenhouse is built far away from the disease area, which is the fundamental means of prevention. When ② continues to produce in the disease area, the cultivation greenhouse should be treated as follows: a. Incineration: remove all the upper shelf poles and coverings of the original greenhouse, scrape off the wall, remove 1~3cm, after the ground is loosened about 10cm, lay about 20cm waste crop straw or firewood and grass in the shed, pile as high as possible around the root of the wall, light up and burn. The incinerated ash is turned into the soil and leveled the ground, re-coated and sealed as far as possible, and can be put into use in about 10 days. b. Drug sterilization: scrape off the 1cm from the greenhouse wall, loosen the 5cm on the ground, prepare 6% formaldehyde aqueous solution, control the usage in 200~600g/ square meters according to the degree of the disease, and carry out blanket spray sterilization. Attention points: first, spray evenly, do not leave any dead corner, no medicine area; second, spray fast, it is best to use high-pressure sprayer 2 to 3 people to operate; third, seal the greenhouse entrance and vent immediately after spraying, which can be used in a week. According to the degree of the disease, carbendazim 0.3~0.6kg and formaldehyde 0.2~0.4kg can be dissolved in 100kg water, and the greenhouse can be treated and sprayed uniformly according to the above method, which also has a good effect. Carbendazim of 0.3% dry weight was added to the ③ cultivation material or active starter was used for high temperature fermentation (65-70 ℃). ④ cultivation soil treatment: far away from the cultivation area is the old cultivation area, the primary bacteria area to take the soil, sifted so that the soil particle diameter below 3mm, the fine soil after screening, it is best to make it fully dry, each ton of soil with 50% carbendazim 250g, 36% formaldehyde 400g mixed with water 500kg, mixed twice and sprayed liquid, and then covered with plastic film, about a week later. ⑤ bag into the shed for a period of time, especially after the emergence of mushrooms, if white woolly (villi)-like hyphae appear on the surface of the culture material, you should immediately use knife and shovel tools to scrape off the 2cm base material in the disease area, and apply 400x carbendazim solution in this area to clean the scraped material and incinerate it, not to use burial, nor to discard it casually. Once infected mushrooms occur in ⑥, we should immediately strengthen ventilation and stop spraying water to minimize the air humidity in the shed, and immediately remove the diseased mushrooms, refer to the above measures to clean up the sick areas and deal with diseased mushrooms, and use tools to soak and sterilize in 400 times carbendazim solution. After 1 week and 2 weeks, if there is no fungal mycelium growing, the normal management can be resumed. In the early stage of ⑦ or when there is no mushroom growing in the tide, the surface of the culture material can be scraped once, and the method is the same as above. The disease of ⑧ is serious or found later, and the cultivation greenhouse which has formed serious harm does not need to carry out the above treatment, but only remove the base material and re-carry on the greenhouse sterilization treatment before cultivation and production.

2 rot disease

2.1 at the initial stage of the onset of disease symptoms, light yellow water-stained spots and patches appeared on the cover, and then the mushroom body became light yellow or khaki water-stained quickly. Rotten and give off a foul smell, the seriously affected mushroom shed smells as bad as a chicken coop, and the infected mushroom body is as rotten as cooked, losing its edible value.

2.2 the pathogenic bacteria are very small and widely exist in culture materials, water and soil. Air transmission and human body introduction and insect pests are all important causes of the disease. Especially when the fermentation of the culture material is not thorough or uneven, and the fungus or mushroom place is not clean, bacterial diseases are easy to occur. Because bacteria spread quickly when the conditions are suitable, such as 10: 30 ℃, relative air humidity is 90%, it is very harmful. When the temperature is too high or too low and the humidity is too low, bacteria can form dormant spores, which can exist for a long time under adverse environmental conditions, germinate and continue to form harm when the conditions are suitable. In addition, the high temperature environment, especially under the heat preservation condition of mushroom shed in winter and spring, is generally accompanied by poor ventilation, which is also an important reason for the regional harm of bacterial diseases.

2.3 Control measures ① base material should be fermented fully and evenly, 0.2% formaldehyde should be added before sowing, mix well and then sow seeds in bags. ② culture and mushroom sheds were sprayed with carbendazim formaldehyde solution before opening. ③ sprayed 600x DDV around the mushroom shed to prevent the entry of insects. ④ found that the mushroom body has water stains, that is, quickly check the incidence of the disease in the shed. If the infected mushroom exceeds 20%, the diseased mushroom should be removed completely, and the surface layer of 1~2cm in the infected area should be scraped. 5% formaldehyde can also be sprayed and buried evenly. In the mushroom shed with serious ⑤, immediately strengthen ventilation, stop spraying water, remove diseased mushrooms and healthy mushrooms, form a mushroom-free period, spray 6% formaldehyde solution and 200 units of streptomycin or 1% bleach respectively.

3 truffles

3.1 the symptoms of the disease are similar to the hyphae of Pleurotus ostreatus and can not be distinguished by the naked eye. It can go deep into the substrate to compete with the hyphae of Pleurotus ostreatus for nutrition, water and living space, inhibit the growth of Pleurotus ostreatus and make it lose its ability to produce mushrooms. After the mycelium is physiologically mature, ascomycetes are formed on the mushroom surface of the culture material, especially in the area around the bacteria column in contact with the soil during border planting; the ascomycetes are brain-shaped wrinkles in shape, very similar to walnut kernels without astringent skin, wrinkled and uncomfortable. When it first appeared, most mushroom farmers mistakenly thought it was the budding of Pleurotus ostreatus, but there was still no differentiation after a few days, but the milky white in the initial stage of the ascomycete changed to light milky yellow, and then gradually to light yellowish brown to brownish red, and its volume was also constantly expanding. At this time, it is too late to take various measures to prevent and cure. When the disease is serious, the whole batch of cultivation materials can not produce mushrooms. The smell of high concentration of bleach in the shed is one of the important signs of truffle occurrence.

3.2 the cause of the disease is that Cysticercus diellii is a malignant miscellaneous bacteria in the cultivation and production of edible fungi. A large number of spores exist in soil or base materials, and their vitality is extremely strong. When the air humidity is more than 70% at a temperature of 16-35 ℃, they can germinate quickly and cause harm. The pathogen is particularly harmful to Pleurotus ostreatus cultivated with soil mulching.

Control measures ① culture materials must be fully and evenly fermented, and the water content is not more than 63%. The treatment of ② cultivated soil refers to the foregoing. Before the ③ bacteria bag enters the greenhouse, in addition to treating the greenhouse according to the above requirements, the bleach solution with a concentration of more than 1.2% is re-sprayed twice at intervals of 5 days. There is a record of disease in the area, but also spray carbendazim, formaldehyde solution. Once the occurrence of truffles is found in ④, ventilation should be strengthened immediately in the greenhouse, temperature and humidity should be reduced, and the affected area and its outer edge 3cm (depth depends on the time and degree of the disease) should be dug out, the treated fine soil should be backfilled, and 1% bleach solution should be sprayed once in the whole shed, and 400x carbendazim solution should be smeared on the diseased part.

4 downy mildew

4.1 at the initial stage of the onset of disease symptoms, white, cotton-like hyphae were formed on the surface of the culture material, and the coverage was slowly expanded, and the mycelia did not produce mushrooms wherever they went, and then infected the normal buds and the base of the mushroom body, so that the mushroom body became yellowish yellow to yellowish brown, soft and rotten, and the rotten mushroom body smelled slightly in the later stage, but it was much less than that of rotting mushrooms infected by bacterial diseases. The infected mushroom area and the mold mycelium cover area no longer produce mushrooms.

4.2 the cause of the disease is that the mold can occur and harm in the temperature range of mushroom growth, and it mostly occurs in the cultivation season from late autumn to early spring, that is, there is a trend of low temperature. In particular, this season is the prime time for mass production, so I feel more and more serious about the disease. A large number of spores of the mold are parasitic in soil, base materials and water, and can also be transmitted by humans and insects through the air. The spores ejected by infected mushroom bodies is one of the important ways to aggravate the damage.

4.3 Control measures ① cultivation shed, treatment of cultivation soil, refer to "Prevention and Control of soft Rot". After ② discovers the diseased mushroom, increase the ventilation in the mushroom shed, stop spraying water to dry the surface of the base material, remove the diseased mushroom and incinerate it in time, and avoid forming new pollution sources after discarding. ③ treats used tools and diseased mushroom occurrence areas with 5% formaldehyde or 80 times bleach. In the mushroom shed with severe incidence of ④, the surface layer of the base material was treated after daylighting, the surface layer was scraped off, and then the carbendazim and formaldehyde solution was re-sprayed and sealed for 48 hours, then the ventilation was strengthened, no water was sprayed, and the mushroom management was repeated after about 10 days. Once the disease is found in the specialized village (area) of ⑤ edible fungus production, it should be forbidden to visit and visit each other in order to avoid cross-contamination.

5 Mushroom disease

The diameter of the cap is about 1cm, the whole mushroom body (mushroom cluster) is dry, white, ossified, not soft, not rotten, not smelly, some cover epidermis is tight and shiny, some cover seems to have a layer of powder. There is no change in the culture material, but there will be no more mushrooms after that.

5.2 the cause of the disease is that a large number of molds are parasitized in the cracks and raw materials in the soil mushroom shed, and air, human body and insects are also important ways of transmission.

5.3 there is no specific medicine for prevention and control measures, the key point is "prevention", properly reducing the temperature in the shed and increasing ventilation, and drug control refers to "soft rot".