农作物病虫发生级别与自然危害损失率关系辨析

摘要

The natural loss rate of crop diseases and pests collected nationwide with occurrence level 5 was mostly between 1 5%-45%,which objectively confirmed that different diseases and pests at the same occurrence level existed differences between natural loss rates.On one hand,the relationship between the amount of pests and dis-eases and natural loss rate showed logistic curve theoretically,on the other hand,there is a comparison of human perceptual experience in the determination of diseases and pests occurrence level.What is more,the natural loss rate of pests with occurrence level 5 is generally lower than 50%.For a unified and simplified relationship and easy calculation,we approximately identified the natural loss rate of the pests at adjacent level from 1 to 5 as double rate exponential curve relationship.%在全国范围内征集的农作物病虫5级自然损失率大多在15%~45%之间，客观证实了不同病虫发生级别相同时自然危害损失率之间存在差异。一方面病虫发生量与其自然危害损失率之间理论上为逻辑斯蒂曲线关系，另一方面病虫发生级别的判定存在着人为的经验感知比较，加之病虫5级自然损失率一般低于50%，为统一简化关系且便于计算，我们将病虫1~5级相邻发生级别间自然危害损失率近似确定为倍率指数曲线关系。