1. Symptoms: the disease often occurs in the late autumn when the weather turns cold. The initial symptoms were yellowish and reddish yellow spots on the leaves, and the enlarged spots were round or oval. Under humid conditions, black granular matter appeared on the lesion, and the leaves dried up and fell off later.
2. Prevention and control methods: the key to prevent and control the disease is to do a good job of cold prevention. When cooling down, we should take protective measures for Fusang. When the disease occurs, the sick leaves shall be cleaned up and destroyed in time. At the same time, spray 800 times of 70% methyltobuzin wettable powder, 700 times of 50% carbendazim wettable powder or 500 times of 40% chlorothalonil suspension for treatment.
1. Symptoms: This is a fungal disease, which is serious under high temperature and rainy conditions. At the beginning of the disease, the leaves began to wilt, with yellow brown blotches on the edge, then gradually expanded inward, and later the leaves would dry and fall off.
2. Prevention and control methods: in rainy season, it is necessary to prevent the plants from being washed by rainstorm for a long time, and dry them with 200-500 times methyltobuzin every 10 days before and after the rainy season.
1. Symptoms: in the early stage of the disease, the growth of leaves is weak, and there are red brown dry spots on the edge. At the later stage, the leaves dried and fell off. In the early stage, there was smooth flesh color, and in the later stage, there were rough brown, needle tip size female nematodes.
2. Prevention and control method: if the number of trees is small, you can choose to change the soil, and the new soil must be exposed to the sun for a period of time and disinfected. If the number of plants is large, it can also be treated with aldicarb granules, which can be buried about 0.1g per inch.
