Control of pseudotail brown spot of chrysanthemum

The main results are as follows: 1. the symptom spot is born on both sides of the leaf, nearly round, the initial edge is not obvious, and then it sometimes produces a dark brown thin coil, often growing along the edge of the leaf. The foliar disease spot is light yellow at the beginning, brown to dark brown in the later stage, and grayish brown on the back of the leaf. 2. the disease is caused by fungi, and the pathogen is pseudocercospora chrysanthemum. The pathogen overwintered on the diseased body, carried out primary infection and re-infection with conidia, and spread by airflow and Rain Water sputtering. It is easy to get sick in rainy or foggy weather. 3. Prevention and control methods (1) Horticultural control: combine picking leaves to collect diseased bodies and take them out of the field to burn; clear ditches and drain water, avoid partial application of nitrogen fertilizer, make plants grow healthily and enhance resistance. (2) Chemical control: at the initial stage of the disease, 50% propofol wettable powder was sprayed 1000 to 1500 times, 50% carbendazim wettable powder 500 times per mu, 100 ml root irrigation per plant, once every 7 to 10 days, two or three times; with 75% chlorothalonil wettable powder 147 grams per mu, 75 liters of water, evenly sprayed.