Preventive measures of Black spot of Rose

1. Select disease-resistant varieties. two。 Remove the pathogen. Persist in removing withered and diseased leaves every year to reduce infection of pathogens. 3. Increase resistance. Strengthen field management, rational fertilization, increase the application of phosphorus and potassium fertilizer, clear ditches and drain, no watering, moderate pruning, loosen soil and cultivate soil, improve root activity, improve growth, and enhance plant disease resistance. 4. Chemical control. Spray crystal stone-sulfur mixture 100 times before rose and rose germination at the beginning of the following spring. When the new leaves unfold in summer, they begin to spray until winter. In the early stage of the disease, alternately spraying 1000 times of 75% chlorothalonil wettable powder, or 45% thiabendazole suspension, 40% flusilazole or 25% nitrazole EC, or 40% polysulfide suspension or 50% anthrax Fumei wettable powder or 50% compound thiophanate wettable powder, 70% methyl thiophanate 700-1000 times, 50% carbendazim 80-1000 times The spread of the disease can be controlled by spraying 1000 times of 80% Dysen zinc and 12.5% clear (spot removal) EC, spraying once every 7 days in the rainy season, spraying once in 7 to 10 days in the normal growing season and plum rain season, and spraying 4 to 5 times in a row. When the disease is serious, spray 70% can kill, 30% copper oxychloride suspension 800x, 75% chlorothalonil 500x, 12.5% EC 1000 times, spray 3 to 5 times in a row, once in 7 to 10 days.