Comprehensive control measures of white silk disease of peanut

Peanut white silk disease is a kind of soil-borne fungal disease, which occurs at the stage of peanut pod expansion to maturity. After the damage to the root, pod and stem base of peanut, there was brown soft rot at the beginning, white silk mycelium in the aboveground rhizome (so called white silk disease), and rape seed sclerotia, stems and leaves turned yellow, gradually withered, peanut pods rotted. The effect of prevention and treatment of the disease is poor. Peanut white silk pathogen spreads with soil, running water and seeds, which is very dangerous. Once invaded, the pathogen accumulates year after year, and it is difficult to control and eradicate it later. Under suitable conditions, the hyphae produced by sclerotia germination invade directly from the root or stem base of peanut or from the wound, propagate and cause rhizome disease and rot. Mature sclerotia on new diseased plants can be transmitted by Rain Water, irrigation water, insects, agricultural operations and other factors, causing re-infection. In the whole growing season of peanut, the pathogen can be infected repeatedly for many times, and finally the sclerotia formed by the diseased tissue falls into the soil or remains in the diseased plant to overwinter. Prevention and control measures: 1. Clean pastoral peanuts after harvest will be timely and thoroughly clear the field, leaving no stubble, in order to eliminate the source of overwintering bacteria. two。 Reasonable rotation can be carried out with Gramineae crops for more than 3 years to reduce the accumulation of bacteria. 3. Soil disinfection combined with spring ploughing, deep ploughing, 2 kg / mu with 70% thiophanate methyl, mixed well with fine soil and sprinkled in the soil to eliminate residual bacteria. 4. Strengthen field management to make scientific and rational use of nitrogen, phosphorus and potassium fertilizer, and increase the application of organic fertilizer, zinc fertilizer, calcium fertilizer and boron fertilizer. Check and replenish peanut seedlings in time after emergence to ensure that the whole seedling, moderate density; weeding and famine prevention in the middle growth stage, in order to facilitate ventilation and light transmission, enhance plant disease resistance and control the occurrence of white silk disease. 5. In order to reduce the accumulation and spread of pathogens and control the epidemic speed and degree, the diseased plants were pulled out in time during the growing season of peanuts. 6. Drug control can use 50% isobarbazide, 50% carbendazim 1000 times solution, 40% sclerotia net 600 times solution, 50% carbendazim 800 times solution, or tebuconazole, difenoconazole and other road agents alternately sprayed 2 times 3 times, once every 7 to 15 days, pay attention to spray foot evenly. The root can also be irrigated with 800 times solution of 70% thiophanate during the podding period of peanuts, and the control effect is very obvious.