一、以往稻瘟病的流行情况及原因分析我国稻谷产区主要集中在长江流域以南的东南部地区,约占全国水稻面积的90%。水稻病害中,稻瘟病是影响高产、稳产的重要病害之一,特别是广大丘陵山区稻瘟病的危害更加突出,常常关系到亿万山区人民的吃饭问题。50—60年代,稻瘟病的危害一般较轻,70年代起流行频率增多,危害损失加重。尤其进入80年代以来,每年都有不少地方稻瘟病大流行。1980年,浙江省仅稻瘟病造成的损失就占该年病虫总损失的一半。同年上海市稻瘟病的损失更多,占病虫总损失的62%.1981年南方早稻稻瘟病大流行,仅福建、广东、江西省约损失稻谷10亿斤。1983年的太湖稻区,1984 First, the prevalence of rice blast and analysis of reasons China’s paddy producing areas are mainly concentrated in the southeast of the Yangtze River south of the region, accounting for about 90% of the country’s rice area. Rice diseases, rice blast is one of the important diseases that affect high yield and stable yield, especially the damage of the rice blast in the vast hilly and mountainous areas is more prominent, and often it is related to the eating problems of the people in mountainous areas. In the 1950s and 1960s, the damage of rice blast was generally mild. Since the 1970s, the epidemic frequency increased and the harm loss increased. In particular, since the 1980s, there have been many local rice blast pandemics every year. In 1980, the loss caused by rice blast alone in Zhejiang Province accounted for half of the total pest losses in that year. In the same year, the losses of rice blast in Shanghai were even more, accounting for 62% of the total losses of pests and diseases. In 1981, the rice blast in the southern part of the country was only caused by a pandemic of rice blast in Fujian Province, with a loss of 1 billion kg only in Fujian, Guangdong and Jiangxi Provinces. 1983 Taihu Lake Rice Region, 1984