The early prevention of diseases is the key to control the disease. In the developing phase of the growth of crops, but also bacteria breeding period, in addition to strengthen field management on crop, such as rational close planting, thinning the ventilation, drainage and other measures to strengthen, with fungicide to control is crucial. The germs are small, meat suit is not to see, when discovered too late. Such as early prevention medication regularly spraying, rain, rain down, will cause the disease control in not ideal effect in crop damage.
Pesticide bactericide has two types: protective agricultural fungicide and systemic agricultural fungicides. Protective fungicide is the only protective effects on crops, and no treatment effect, and systemic insecticides has to germs cause treatment effect, its protective effect is not obvious. Protective fungicide to prevent disease invasion, form a protective film after spraying, to prevent bacteria and blade contact. But when the bacteria have invaded, is in a latent stage, protective agent will not work. Therefore, the best protective fungicide in before the onset of disease or the occurrence of the initial use of the best. Systemic fungicide is killing invading bacteria, in early disease is best. The use of systemic insecticides when the disease occurred seriously,, with several more medicine, the effect also not too good, on the growth and fruit crops will produce certain effect. So the control of diseases, must be in before the onset of initial drug use .