1、 Cause of disease

It is infected with macular disease mostly because of three factors. One is the variety problem. Some varieties have poor disease resistance and are easy to be infected with various diseases. For example, the disease of Jufeng variety will be very serious when it comes to disease. Second, the rainy season is easy to cause mildew, white rot and other diseases, and the nutritional consumption of infectious diseases is too much. In this way, when it comes to winter, there are few nutrients and the physiological balance is unbalanced. When the new shoots grow young leaves, it is easy to yellow leaves. Third, the soil is too alkaline, so the iron element will become insoluble iron, which can not be absorbed, and the leaves will turn yellow over time

2、 How

This disease should be prevented in advance, fertilized regularly at ordinary times, and supplemented with various nutrient elements required by the plant in time to promote its vigorous growth. We should also pay attention to the pH of the soil and adjust the acid in time, so that the soil is suitable, the viscosity will not be too heavy, and it is also beneficial to growth. In addition, the garden should be cleared in winter to remove the dead branches and leaves, so as to reduce the incidence of diseases

3、 With what medicine

Now that we know the cause of the disease, the medication is also very simple. In the early stage of the disease, it is necessary to spray ferrous sulfate or mix it with citric acid solution. The drug is used once every 7-10 days, and the effect can be effective two or three times. Just do a good job of prevention in the later stage