油菜病毒病是我国长江流域冬油菜区的主要病害。在重病区病害流行年份,一般损失率达20—30％,重者在70％以上,造成油菜籽产量的严重损失。病毒病的流行程度与苗期气象条件有十分密切的关系,尤其是和10月份降水量相关极为显著。该病发病率资料年代较短,用以预测尚有一定困难。为了做好该病发生趋势展望,本文选用上海、南京、杭州、武汉、合肥等站10月份降水资料,应用灰色系统理论,建立一套 Rape virus disease is the main disease in the winter rapeseed area of ​​the Yangtze River valley in China. Disease prevalence in the ward years, the general rate of loss of 20-30%, severe cases in more than 70%, resulting in serious rapeseed production losses. The prevalence of virus disease is closely related to the seedling weather conditions, especially the correlation with precipitation in October. The incidence of the disease information age is shorter, there are still some difficulties to predict. In order to do a good job in forecasting the trend of the disease, this paper selects precipitation data of October from Shanghai, Nanjing, Hangzhou, Wuhan and Hefei, and applies gray system theory to establish a set of