论文部分内容阅读
使用农药不仅要看防治适期,还要看病、虫害的发生数量和为害程度。那么,当一种害虫发生后,怎样衡量是否达到了防治标准呢?这是个较为复杂的问题,应从多种因素全面考虑,如植物的品种及其对病虫害的耐受能力、药剂种类、防治方法、防治效果及经济收益等。所以,正确制定防治标准,应掌握几个基本原则。(1)经济上要合算。也就是使用较小的防治费用能大大地挽回害虫所造成的经济损失。
The use of pesticides should not only look at the appropriate period of control, but also see the disease, the number of pests and the degree of harm. So, when a pest occurs, how to measure whether it has reached the standard of prevention and control? This is a more complicated issue, which should be considered comprehensively from a variety of factors, such as plant variety and its tolerance to pests and diseases, the type of agent and the method of prevention and treatment , Prevention and control and economic benefits. Therefore, the correct formulation of prevention and control standards, should grasp a few basic principles. (1) economically cost-effective. That is, the use of smaller control costs can greatly save the pests caused by the economic losses.