Prevention of downy mildew in autumn cabbage
At present, autumn cabbage has entered the rosette period. Rosette stage is the period when the Chinese cabbage roots occur in large quantities and the growth of the leaves is in sudden increase. It is also the basic period for the formation of a large leaf ball, and it is also an epidemic period for downy mildew. Therefore, the control of downy mildew should be strengthened during the rosette stage of Chinese cabbage. First, the cause of the disease Cabbage downy mildew is a fungal disease, commonly known as white mold, frost leaf disease. The main damage cabbage leaves, adult stage was damaged, chlorotic spots on the front surface of the primary leaves, gradually developed into a brown-yellow, white mold layer on the back of leaves, the development of lesions by the veins and was polygonal. The lesions are connected to each other for a long time, so that the diseased leaves will die either locally or entirely. The diseased plants often dry up from the outer layer to the inner layer. In severe cases, there is only a small heart ball. Second, control methods 1. Strengthen field management. Strengthen the management of water and fertilizer, take the rosette stage to promote growth, timely watering, to meet the water required for its growth, before and during the middle of the package, you can spray phytoalexin 6000-9000 times solution or sugar urine (Brown sugar: urea: water =1:4:100), spraying in the morning, spraying on the back of the leaves can increase the resistance of the plants. At the same time, strengthening the top dressing with watering can not only make the cabbage early, but also prevent premature aging. 2. Chemical control. Available in the early onset of 64% antiviral WP 500 times, 72.2% Precike 600-800 times, 72% WP wettable powder 600-800 times, 72% MnZn urea wettable powder 600 times Liquid, 58% metalaxyl MnZn WP 500 times or 70% Prosin Zinc (Aetnax) WP 700 times, sprayed every 7 days, sprayed 2-3 times continuously. Household Cleaner,Grease Cleaner Kitchen,Household Carpet Cleaner,Cleaning Spray Wuxi Keni Daily Cosmetics Co.,Ltd , https://www.wxkenidaily.com