1. Symptoms: the disease usually occurs from April to October. At the beginning of the disease, small yellow spots appeared on the leaves and gradually expanded into round or irregular spots. The diseased spot is yellowish brown or grayish brown, and there is a yellow halo around the leaf blade.
2. Prevention and control methods: in the early stage of the disease, the whole tree body needs to be protected by spraying medicine. 70% of the solution can be killed to 300-500 times, amoxicillin to 1000-1500 times or carbendazim to 50% to 500-600 times.
1. Symptoms: the disease occurs from July to November. In the early stage of the disease, there will be light brown spots on the leaves. With the increase of the disease, the small spots gradually expanded into round like spots with dark brown edge.
2. Prevention and control method: in the early stage of the disease, propiconazole emulsion can be used for spraying, and spraying again every 30 days or so. Or spray it with benzene special wettable powder once every 7-10 days, 2-3 times continuously.
1. Symptom: red spider is also called mite. It damages the leaves of Sweet osmanthus with adults, nymphs and larvae, destroys the chloroplasts and makes them lose their green spots.
2. Prevention and treatment: once the disease is found, spray the leaves immediately. We can use acarid, aphid, Triadimefon and other drugs. Make sure that both sides of the blade can be sprayed evenly. Once a week, 2-3 times in a row can be cured.
