俗话说:凡事预则立,不预则废。病虫害防治也是一样。20世纪80年代末,中国北方发生小麦赤霉病。由于该病以往只发生在长江中下游,北方小麦种植区没有开展对该病的预测工作,也没有进行防治,1989年仅河南省就损失了8.85亿公斤小 As the saying goes: everything preconditions, not premeditated. The same is true for pest and disease control. In the late 1980s, wheat head blight occurred in northern China. As the disease occurred in the middle and lower reaches of the Yangtze River in the past, the northern wheat growing areas did not carry out the prediction of the disease and did not prevent it. In 1989 alone, Henan province lost 8.85 billion kg