稻粒黑粉病是一种危险性真菌病害,是我国对外检疫对象之一,云南省列为植物检疫对象。湖南、湖北、广东、广西、四川等省(区)有发生,1955年,四川万县山区农业试验场病穗率高达55％,病粒率21％。近年来,此病在湖南省杂交秈稻上发生比较严 Rice powdery mildew is a dangerous fungal disease is one of the external quarantine objects of our country, Yunnan Province, as a phytosanitary target. Hunan, Hubei, Guangdong, Guangxi and Sichuan provinces (regions) have occurred. In 1955, the rate of disease-causing spikes in agricultural experiment stations in Wan County, Sichuan Province was as high as 55% and the rate of disease and grain was 21%. In recent years, the disease occurred in hybrid indica rice in Hunan Province more stringent