1. Symptoms: it usually occurs from May to November. High temperature and humidity environment is conducive to the growth and spread of bacteria. The disease can cause the tip and edge of the plant to dry out or curl.
2. Prevention and control method: in the early stage of the disease, spray 300-500 times of 50% captan wettable powder or 400-650 times of 70% mancan wettable powder once a week, and effective prevention and control can be achieved after several times. Usually in the maintenance of sunflower, it is necessary to properly shade to avoid exposure to the sun.
1. Symptoms: caused by fungus invading the plant. It will make the diseased plant dry, and the whole plant may die in serious cases.
2. Prevention and treatment: once found, the diseased leaves should be cut off immediately and treated by spraying with 70% tolbutine 800 solution or 75% chlorothalonil 1000 times solution. Spraying once every 7-10 days, 3-4 times in a row, can effectively control the disease. During the prevention and control period, pay attention to avoid rain and spray.
1. Symptoms: the disease usually starts from the leaf edge and tip of the plant. May cause the leaf of the diseased plant to grow the diseased spot. Most of the lesions are brown, black and brown, slightly raised, with a yellow halo on the edge. It may occur from March to October.
2. Prevention and control methods: remove the diseased leaves in time and burn them intensively and bury them in the soil to eliminate the disease source. In the early stage of the disease, we can spray 800 times of 50% thiophanate methyl WP and 800 times of 75% chlorothalonil WP for treatment.
