小麦病害有赤霉病、锈病、白粉病等。在常熟地区，一般年份赤霉病发生较重，锈病不发生，白粉病发生较轻，对小麦产量的影响一般以赤霉病大主．1999年异常的气候条件，造成小麦白粉病病害严重流行，使小麦产量、品质受到很大影响。为此，对小麦白粉的病害流行原因进行调查分析 Wheat disease scab, rust, powdery mildew and so on. In Changshu area, the general year of severe occurrence of scab, rust does not occur, mildew occurs less on the impact of wheat yield generally big head blight. Abnormal climatic conditions in 1999, causing a serious epidemic of wheat powdery mildew disease, the wheat yield, quality has been greatly affected. To this end, the cause of wheat white powder epidemic investigation and analysis