Symptoms: The victim's blade initially became a water-stained spot, and gradually developed into a brown edge, a middle gray, and a near-circular lesion. The lesions were born with small black spots. The diseased leaves were easy to fall off, and water-stained yellow-brown spots appeared at the beginning of the disease, and then gradually expanded into near-circular or irregular brown depressed spots. There are concentric rings and dense black spots on the lesions. When the humidity is high, light red viscous substances can be seen on the lesions, and the lesions shrink and break when dried. Prevention and control measures: 1 Implement crop rotation and use resistant varieties. 2 Seed disinfection, seed soaking in warm water at 52Â°C for 12 minutes before sowing, and seed dressing with 0.3% seed weight of Formamide or 50% Ketodane wettable powder. 3 Increase the application of phosphorus and potassium fertilizer, reasonable irrigation, timely removal of old, diseased leaves and diseased fruit. 4 In the early stage of disease, 75% chlorothalonil 600 times solution or 50% methadone WP 500 times solution can be sprayed, sprayed every 7-10 days, and sprayed 3 times.