去年我市种植大白菜面积2.5万亩,普遍混合发生病毒病、黑腐病、软腐病和霜霉病,发病面积达2.3万亩,占播种面积的92%,其中绝产面积1.1万亩,另有1.2万亩减产60～80%,经济损失高达9312万元,其为害程度历年罕见。现将病害大流行因素浅析如下:一、发芽期遇干旱我市大白菜播种期为8月上旬。去年8月上旬,我市 Last year, the city planted an area of ​​25,000 acres of Chinese cabbage, the prevalence of mixed virus disease, black rot, soft rot and downy mildew, the incidence of 2.3 million mu, accounting for 92% of sown area, of which 11,000 mu of abusive area , And another 12,000 mu cut 60% -80%, economic losses as high as 93.12 million yuan, the degree of damage over the years rare. Now the disease pandemic factors are as follows: First, the drought in the germination period City Chinese cabbage sowing period in early August. In early August last year, our city