How to prevent pumpkin spot disease

Pumpkin spot disease is mainly harmful to leaves and rachis. The bacteria overwintered in the soil with the remains of the disease. In spring, the pathogen was spread by Rain Water sputtering, and the leaf spots were round to nearly round or amorphous at the initial stage of the disease. The leaf margin is dark brown, the junction of the sick part is moist, when the humidity is high, the spot is dense with small black spots, serious leaf spot fusion, causing local death of the leaf. The rachis or flower is black and moist, or black-brown rotten. Prevention and control measures 1. Reasonable crop rotation to avoid planting in low-lying land, timely removal of disease residues of previous crops, deep drying of the soil, spraying disinfectant and 800-fold solution of new high-fat film to disinfect the soil, and disease-resistant varieties were selected. seed dressing with new high-fat film before sowing to ward off underground diseases and insects, isolate virus infection and improve seed germination rate. 2. Strengthening management, timely ploughing and weeding, watering and topdressing, improving inter-plant permeability, and spraying Huawang No. 3 in the growing period to inhibit the growth of main shoots and promote flower bud differentiation; spraying Zhuangguatiling before flowering, young fruit stage and fruit expansion stage can thicken melon stalks, increase nutrient transport, promote rapid development of melon body, beautiful melon type, juicy and delicious. 3. Chemical control: in the initial stage of the disease, 70% methyl topiramate wettable powder 800 times liquid and other targeted agents were sprayed every 10 to 15 days, paying attention to spray enough for 2 times in a row; at the same time, cooperate with spraying 800 times liquid of new high fat film to enhance the efficacy, improve the utilization rate of effective ingredients, and consolidate the prevention and control effect.