稻瘟病是我区一种严重威胁水稻生产的常见病害,在大流行年份,其穗瘟危害所带来的损失是相当严重的,加强对此病的流行预测,做好防治工作是一件十分重要的事情。许多研究证明,稻瘟病的发生除涉及栽种水稻的抗病性强弱外,在很大程度上还和年度间气候条件的变化有关。为了解该病的流行规律,近几年来,我们通过电子计算机,对地处杭嘉湖平原桐乡县的有关稻瘟病发生的历史资料进行了系统的研究分析,发现当年连作晚稻稻瘟病的大流行都是出现在上一年秋冬季光照强,湿度小的年份,见表1。从表1可知, Rice blast is a serious disease in our region which is a common threat to rice production. In the year of pandemic, the damage caused by its panicle blast is quite serious. It is very important to strengthen the epidemic prediction of this disease and make prevention and treatment work well important things. Many studies have shown that the occurrence of blast is related to the resistance of cultivated rice to a large extent and to the change of climatic conditions in the year. In order to understand the epidemic law of the disease, in recent years, we conducted a systematic research and analysis on the historical records of rice blast in Tongxiang County, Hangjiahu Plain through electronic computers. We found that the pandemic associated with the late rice blast was Appear in the autumn and winter of the previous year, strong light, low humidity years, shown in Table 1. As can be seen from Table 1,