稻粒黑粉病(黑穗病)是由稻粒黑粉病菌侵染引起的一种真菌病害。五十年代初在江西、四川等地曾一度发生较重。近十几年来,由于感病品种的推广,种子的频繁调运和氮肥施用量的增加,病害已在全国各地扩大蔓延。据我们于1980—1984年对98个水稻品种(系)的近200个田块的调查结果,绝大多数品种(系)和田块的病穗率、病粒率,均已明显超过稻曲病,不但影响产量,而且米质变劣。尤其是杂交稻三系制种母本,损失率一般都在二至 Rice powdery mildew (smut) is a fungal disease caused by the infection of powdery mildew. In the early 1950s, heavy losses occurred once in places such as Jiangxi and Sichuan. In recent decades, due to the promotion of susceptible varieties, the frequent transfer of seeds and the increase of nitrogenous fertilizer application, the disease has spread and spread all over the country. According to our survey of nearly 200 plots from 98 rice cultivars (lines) in 1980-1984, the incidence of panicle disease and panicle disease in the vast majority of cultivars (lines) , Not only affect the yield, but also the quality of rice worse. In particular, three lines of hybrid rice seed system, the loss rate is generally two to