Control of watermelon anthracnose with benzoconazole

Watermelon anthracnose overwinters on diseased remains in soil by mycelium or sclerotia. In the following year, conidiophores and conidiophores were produced under suitable conditions, which fell on plants or watermelons. After watermelon infection, the disease department produced a large number of conidia, which were spread by wind, rain and irrigation water to carry out repeated infection. The disease can occur at 10 to 30 ℃, with a temperature of 20 to 24 ℃ and a relative humidity of 90.95%. The temperature is higher than 28 ℃, the humidity is less than 54%, and the disease is mild or not. Seeds with bacteria can survive for 2 years, sow seeds with bacteria, and cotyledons are invaded after emergence. Low-lying terrain, poor drainage, or too much nitrogen fertilizer, poor ventilation, serious disease in continuous cropping land. Watermelons harvested in seriously ill fields or after rain also become ill during storage and transportation.

Pesticide control methods of watermelon anthracnose

(1) choose disease-free seeds or disinfect them. Soak the seeds in 55C warm water for 15 minutes before cooling, or soak the seeds in 40% formalin 150 times solution for 30 minutes, then rinse them with clean water, and then soak them in cold water for 5 hours. Watermelon varieties have different degrees of sensitivity to formalin, which should be tested first to avoid drug damage. Or soak the seeds with 150 times streptomycin sulfate for 15 minutes. Melon seeds can also be coated with 20% coating agents.

(2) selecting disease-resistant varieties. At present, there are many varieties of race LBE 3 used in production, so we should pay attention to breeding the varieties of race 2.

(3) rotation with non-melon crops for more than 3 years.

(4) strengthen management and adopt formula fertilization. Apply fully mature organic fertilizer, select sandy soil, pay attention to leveling the land, prevent stagnant water, timely drainage after rain, reasonable close planting, timely removal of field weeds.

(5) for watermelons cultivated in protected areas, smoke method or dust method can be used. See cucumber anthracnose for details.

(6) Pesticide control. At the initial stage of the disease, 50% methyl thiophanate wettable powder 800 times plus 75% chlorothalonil wettable powder 800 times, or 50% carbendazim wettable powder 800 times plus 75% chlorothalonil wettable powder 800 times mixed spray. In addition, 36% thiophanate methyl suspension 500 times solution, 80% anthrax Fumei wettable powder 800 times solution, 2% antimycin (120) water agent 200 times, 2% Wuyisin water agent 150 times, once every 7 to 10 days, continuous prevention and control for 2 times.

(7) spraying benzoconazole, sterilizing for 2-3 hours, controlling the disease for 1-2 days, and lasting for a long time. Benzoconazole shows excellent therapeutic effect in the prevention and treatment of anthracnose, and it is an ideal low-toxic and efficient fungicide, and benzoconazole is more effective in the prevention and treatment of anthracnose.