Two, downy mildew, resistance varies from place to place, it is recommended that allylmorpholine, frost urea manganese zinc, frost fungicide hydrochloride, methyl chloroform manganese zinc, oxamyl manganese zinc, flumorpholine manganese zinc, cyanoformazole, fluoxyfenpyroxam, and so on, the composition of the choice of one or two mixed (in the case of severe), alternating use.
(If it is a protected greenhouse, pay attention to the control of humidity, rainy days with high humidity, it is recommended to use chlorothalonil fumigant to control the disease.)
Prevention-oriented, integrated control (prevention of disease, the dosage is reduced by one). Alternate pesticide components, do not continuously use the same pesticide components. This is the principle of plant protection.