Leaf spot disease leaf spot disease trichloroethyl cyanuric acid + phenyl ether metronidazole, or pyraclostrobin, or tebuconazole, or aliconazole, or pyrimethanil, or ethermethrin, or thiessence copper, or thiobacillus copper, or quinolone copper for prevention and control of the effect is very good, every 7 ~ 10 days foliar spraying, continuous spraying for 2 ~ 3 times, can control the onset of the disease, and so that the sick plant to return to normal growth. Add potassium dihydrogen phosphate and natural brassinosteroid with spraying, the control effect is better.