Causes and treatment of fruit drop of golden pomelo in cloudy and rainy days

The reason for fruit drop is mainly due to the lack of flower thinning and insufficient application of Xiehua fertilizer in the early stage, and at present, pomelo is still in the physiological fruit drop stage, proper spraying of foliar fertilizer can alleviate fruit drop. However, fruit drop is only one aspect, and a series of diseases caused by overcast and rainy weather are also a problem that can not be ignored. At this stage, anthracnose, brown rot and canker of pomelo will break out at the same time. In view of the main diseases at present, 70% methyl topiramate wettable powder can be used alternately to control anthracnose, such as 70% methyl thiophanate wettable powder, 80% Dasheng Mmur45 wettable powder, 50% carbendazim wettable powder and 50% carbendazim wettable powder to control anthracnose. The control of brown rot blight can be controlled by spraying 1000 times of Ke Phytophthora or 1500 times of Phytophthora, with emphasis on the middle and lower parts and fruits, and pay attention to pruning withered branches, picking diseased fruits and concentrated treatment of fallen fruits. For peptic ulcer, 77% can be killed with wettable powder or 600 times copper oxychloride solution. The diseased branches should be pruned properly before spraying, which can avoid infection and enhance the efficacy. Sunny weather should be chosen when spraying. However, Lu Youli, a grower in Songkou Town, Meixian County, believes that as long as it does not rain all day, you can choose the right time to spray pesticides. Although the effect is not as good as the sunny day, the effect is quite obvious as long as you choose the right node. "when the disease has spread on a sunny day, it's too late to repent."