Disease Pathology and Control techniques of Pleurotus ostreatus

Pleurotus ostreatus, also known as Pleurotus ostreatus, is a fashionable and rare mushroom product welcomed by domestic and foreign markets in recent years, and has become the highlight of cultivated varieties. However, the mycelium and fruiting body of the mushroom contain a smell of almond, so there are many diseases and insect pests, most of which are caused by the infection of pathogens and pests, which are called infectious diseases. Growers often fail to identify pathogens and pathogens, resulting in the blind use of chemical pesticides, which not only can not effectively control, but also lead to mushroom body damage, excessive agricultural residues and poor cultivation efficiency. Here, the characteristics, pathogens and control measures of common infectious diseases are introduced as follows.

1. The fruiting body affected by brown rot stopped growing, and the tissue and folds of the cap and stalk turned brown, and finally rotted and smelly. The pathogen was Alternaria verrucosa, which mostly occurred on the bag with high water content, and the incidence increased when the temperature was 20 ℃. Mainly through the transmission of contaminated water or hands and tools in contact with diseased mushrooms, invading the intercellular space of the fruiting body tissue to propagate, causing the disease.

Prevention and control measures ① to do a good job of mushroom shed disinfection, the culture medium must be thoroughly sterilized; during the emergence of ②, moisturizing and replenishing water should be cleaned, and ventilation should be strengthened to avoid being in an environment of high temperature and humidity for a long time; the injured mushrooms of ③ should be removed and destroyed in time, and then stop spraying water, increase ventilation and reduce space humidity. ④ sprayed the bacterial bag with 50 times solution of streptomycin 1 ∶ to kill the bacteria contained in the bag and avoid the recurrence of the disease during the second stubble of mushrooms; ⑤ mushrooms were harvested in time and before the cover was fully expanded. Fresh mushrooms harvested should be processed or processed in time, and should not be stored for too long in summer.

two。 The cap of the soft rot was shrunk, the fold and stalk were empty, bent and soft, and finally withered and shrunk. The pathogen is Fusarium solanum which erodes the fruiting body tissue to form a layer of gray-white mildew, which is part of the sporophore and conidia. This pathogen is widely distributed in all kinds of organic matter at ordinary times. the conidia floating in the air have a high incidence under the condition of high temperature and humidity, and serious infection leads to poor harvest.

Control measures ① raw material exposure, the water content of the culture medium should not exceed 60%, after bagging, sterilization should be thorough; ② inoculation should be carried out when the temperature is low at midnight, strictly aseptic operation; before the opening of the ③ bag, spray 1000 times with 50% dichlorvos EC to sterilize, control the appropriate temperature of 23: 25 ℃, and the space relative humidity is 80%. During the onset of ④ young mushroom, the lime supernatant of pH8 can be sprayed, or 1500 times of low toxic 20% triazole copper EC can be sprayed and killed. When the disease occurs in the mature period, it is harvested in advance and soaked in 5% lime water. The product is washed with clean water and dried.

3. The stipe of susceptible mushroom shrank and withered, rudimentary and withered, but did not rot, which reduced the yield and quality. The pathogen is Fusarium oxysporum. Most of the reasons are poor quality of culture materials, such as cottonseed hull, sawdust, wheat bran and other raw materials, such as caking and mildew mixing, long loading sterilization time, resulting in base material rancidity, incomplete material bag sterilization, pathogens hidden in the culture base, occurring when the temperature exceeds 28 ℃.

Control measures ① optimized base materials, cottonseed shell, wheat bran and other raw materials require no caking, no mildew; ② bagging to the upper stove sterilization time not more than 6 hours, sterilization on 100 ℃ to maintain 16-20 hours; ③ sterilization culture to prevent high temperature burning, indoor drying, moisture-proof, anti-direct sunlight; ④ bag timely opening to increase oxygen to promote the smooth formation of primordium fruiting body. The temperature of mushroom is 23-28 ℃, and the relative humidity is 85%-90%. Once the disease occurs during the development of ⑤ fruiting body, the base material of the affected part should be harvested in advance, and the base material of the affected part should be scratched off in time, and the 1500-fold solution of 75% chlorothalonil should be sprayed to promote the continued growth of mushroom after 2 days of rest and culture.

4. Black spots appeared in the fruiting bodies of the injured fruit bodies, which were distributed on the cap and stalk, and the color of the mushroom body was obviously contrasted. The light ones affect the appearance of the products, and the heavy ones cause mildew. The pathogen is cephalosporium, which is mainly transmitted by air, wind, rain and fog; it is often infected by operators' skills and tools; the disease is easy to occur when the temperature of the mushroom room is 25: 30 ℃, poor ventilation, too much water spraying and too much liquid water deposition.

Control measures: ① keep the mushroom clean and hygienic, well ventilated, prevent high temperature and humidity; keep bacteria at the right temperature after ② inoculation, strengthen ventilation, and let the hyphae develop normally; ③ should grasp the principle of light, diligent and fine water spraying at the stage of mushroom emergence, and should be ventilated in time after each spraying; when ④ young mushroom is damaged, it can be sprayed 1500 times with 20% triazole copper EC. Remove the adult mushroom in time, dig up the surrounding contaminated parts, and spray 4000 times of new phytotoxin, or 1000 times of 5% isobarbazide wettable powder.

5. The fruiting bodies of the victims of mildew rot appeared mildew and blackened, rotted down, and smelled of ammonia, which spread quickly and, in serious cases, caused the whole batch of mildew to fail. The pathogen is Trichoderma viride, which erodes the surface of the fruiting body, turns pink and white at the initial stage, and gradually turns green and black until it is eroded and smelly. Due to the incomplete sterilization of the material bag, the pathogen lurks in the substrate, which leads to the occurrence of mushroom, which is transferred from the mycelium to the fruiting body. At the same time, due to the high humidity of the mushroom room and poor ventilation, the injured mushroom lost its commercial value.

Prevention and control measures ① thoroughly clean the environment around the inoculation room, culture room and mushroom shed. Spray 400-fold carbendazim and 200-fold phenol solution within a distance of about 30 meters around the mushroom shed. When the base number of bacteria is on the high side, 100-fold phenol solution is sprayed in the mushroom shed and sealed for 2 days before it can be used. The water content of the ② bag should not exceed 60%, and it should be thoroughly disinfected to prevent the bacteria from hiding. The aseptic operation of ③ inoculation was strictly carried out, and the culture room was sterilized every 5 days. Drugs should be used alternately with 150-fold sterilization and 200-fold phenol. After the occurrence of disease in ④, the disease bag can be removed from incineration or buried deeply, and 50-fold 100-disease-free medicine solution can also be used as organic fertilizer after soaking and breaking, composting and fermentation.

6. Withering disease often occurs shortly after the appearance of primordia and can not differentiate into fruiting bodies, affecting the harvest of a crop of mushrooms. The pathogen is caused by nematode worms. Often due to plum rain, dampness and lack of ventilation, nematodes pierce into the hyphae with needles and suck cell fluid, resulting in mycelial decline, unable to provide nutrients and water for primordium growth and differentiation, resulting in death. Sometimes they will directly chant about the primordia and young mushrooms, so that the fruiting body loses the ability to grow and die.

Control measures ① mushroom house and all appliances are disinfected in advance, and nematodes are not given living conditions. ② culture materials were collected and fermented at first, and then bagged and sterilized. The temperature of ③ germ culture should be controlled, and it should be no more than 28 ℃. When the air temperature is high, it should be carried out in time to release heat from bags, open all doors and windows at night, and ventilate all night, so that the stack temperature and bag temperature can be reduced, and the matrix should be nurtured to increase stress resistance. ④ opened its mouth to increase oxygen at the right time to promote the normal metabolism of mycelium and turn from vegetative growth to reproductive growth as scheduled to produce good mushrooms. ⑤ young mushroom stage spraying water should be less should be frequent, not excessive, to prevent stagnant water. At the same time, pay attention to ventilation and create suitable environmental conditions. Remove the injured ones in time, and scratch the surface layer, stop spraying water for 2 days, rejuvenate the mycelium, and then spray the right amount of water to promote the growth of mushrooms.

7. Empty sore disease fruit body formation period often occurs by, insect bite disability empty sore, loss of commercial value. The main pests of pathogens are small bacteria mosquitoes, flea flies and purple jumping insects. Most of these pests are caused by litter and weeds around the mushroom shed, which provide parasitic and multiplying conditions for the pests. In addition, the pest control facilities in the mushroom room are not complete, and the pests fly in without hindrance.

Prevention and control measures ① do a good job in the environmental hygiene of the mushroom house and its surroundings, and disinfect it with lime to block the source of insects. The doors, windows and ventilation holes of ② mushroom house are equipped with 60-mesh screen to prevent adults from flying in, and regularly spray 2000-fold solution of plant preparation of insecticide or Yitaibao on the Internet. Install black light trap in ③ room, or put 0.1% 7051 insecticidal EC in half washbasin under room light. You can also apply viscose on the board and hang it near the light to kill invading pests. ④ control medication, in case of necessity, it can be killed by spraying 3000 times of Regent solution with low toxicity and low residue or 2000 times of Nongmengte solution.