植保应用技术,大都可以直接用于生产,转化为经济效益。经济效益的估算法多不能达到令人信服的程度。例如很多是将防治与不防治作比较,将损失率换算为保产率。这样就会高估了保产值。因为发生了病虫草灾以后,即使没有新技术推广,农民和推广部门也会使用老技术进行防治,会有一定程度的保产作用。退一步说,即使被害得颗粒不收,也会改种其他作物来弥补,决不束手等待。因此,许多以不防治作为对照的试验或示范, Plant protection technology, most can be used directly in the production, into economic benefits. Economic estimates can not be more convincing. For example, many of them compare prevention with no prevention, and convert the loss rate into a rate of protection. This will overestimate the yield. Because of the occurrence of pest and disease disaster, even without the promotion of new technologies, farmers and extension agencies will also use the old technology for prevention and treatment, and will have a certain degree of yield-keeping effect. Take a step back and say that even if the victims get the grain, they will also make up for other crops instead of waiting. Therefore, many tests or demonstrations that do not control as a control,