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农作物病虫害的发生程度,是制订防治策略的重要依据。长期以来没有统一标准。大多靠经验臆断,或各行其是,实难准确评价病虫害的发生程度。植物保护13卷第5期“农作物病虫害发生程度评价方法探讨”一文,用密度与防治指标比值(即密度系数)评价农作物病虫害发生程度,目的是对各种病虫害发生程度进行科学地评价,正确指导农业生产,经济有效地控制病虫危害。笔者认为这一问题的提出是很有意义的、但对该文作者所提内容与方法尚有若干问题值得商榷。 一、病虫害发生程度的内容。病虫害发生程度主要包括发生量(害虫单位面积的发
The occurrence of crop pests and diseases is an important basis for formulating prevention and control strategies. There has been no uniform standard for a long time. Most rely on the assumption of experience, or go its own way, it is difficult to accurately assess the extent of pests and diseases. Plant Protection 13 Volume 5 “Crop Pest and Disease Evaluation Method” article, the ratio of density and control indicators (ie, density coefficient) to evaluate the extent of crop pests and diseases, the purpose is to evaluate the extent of various pests and diseases, the correct guidance Agricultural production, economic and effective control of pests and diseases. The author thinks it is very meaningful to put forward this question, but there are still some questions on the content and method of the author. First, the extent of the content of pests and diseases. Incidence of pests and diseases mainly include the occurrence of pests per unit area of hair