Q: The incidence of black spot disease in cabbage has been on the rise in recent years. Autumn and winter seasons occur in Chinese cabbage, Chinese cabbage, Shanghai green, black leaf white and other varieties, overcast and rainy days, when wet, they are often outbreaks, which seriously affect the yield and quality. How to prevent and treat? Answer: Cabbage black spot mainly damages leaves, petioles and cotyledons. The early stage of disease in the leaves is a roundish chlorotic small spot. It gradually expands to a brown spot with a diameter of 5 to 10 mm. There is a concentric concentric ring pattern. The edges are light green to dark brown. Some lesions have a yellow halo. Humidity When it is large, it produces dark brown moldy layer, and the diseased part is perforated under high temperature and high humidity conditions. In severe cases, lesions converge into large plaques, causing half-leaf or whole leaves to die, and the entire plant leaves dry from the outside to the inside. The lesions on the petioles and stems are spindle-shaped and dark brown in shape. The bacteria can grow normally at 0～35°C. The optimum temperature is 17～25°C. The rain continues, the weather is warm, the planting is too dense, the watering is too much, the humidity in the field is too high, and the variety disease resistance is poor. Favorable conditions. The effective techniques for controlling black spot of cabbage are as follows: Select disease-resistant varieties suitable for the local area as much as possible, rotate with non-cruciferous crops for 2 to 3 years, deepen the soil for site preparation, apply organic base fertilizer adequately, and apply fertilizer organically combined with trace elements; Liquid to improve the disease resistance of vegetables, as well as appropriate close planting and appropriate watering. In addition, the following specific measures need to be taken: (1) soaking in warm water at 50°C for 25 minutes before sowing, cooling and then reseeding after cooling; (2) timely spraying prevention at seedling stage, and the available pharmaceutical agents are: 80% Green Giant 600 to 800 times liquid or chlorothalonil 600 to 800 times; once every 7 days, even spray 3 to 4 times. Pvc Anti Slip Tape,Anti Slip Grip Tape,Non Slip Adhesive Tape,Waterproof Anti Skid Tape Kunshan Jieyudeng Intelligent Technology Co., Ltd. , https://www.jerrytape.com