论文部分内容阅读
为害指数(PAI)是一种反映和评价农业病虫害严重性的新方法。它将常规调查的发生密度(为害率)、发生面积简化成为单一的概念性数值形式,并据此划定发生程度等级,适用于表述县级以上地区短期病虫为害状况和趋势。PAI定义:在某一时段中,害虫(病害)的密度指数与面积指数的乘积,而密度指数为病虫单位面积的发生密度(发病率)占防治指标(或历年密度均值)的倍数,面积指数为病虫发生面积(率)占历年发生面积(率)均值的倍数。
Harm Index (PAI) is a new method to reflect and evaluate the severity of agricultural pests and diseases. It routinely surveyed the occurrence of density (damage rate), the occurrence of the area reduced to a single conceptual numerical form, and accordingly delineated the degree of occurrence level, suitable for the expression above the county level short-term pest damage and trends. PAI Definition: The product of the density index of pests (disease) and the area index in a given period of time, while the density index is the multiplication of the occurrence density (incidence) per unit area of pest and disease control indicators (or the mean annual density) The index is the multiples of the average pest occurrence area (rate) over the annual area (rate) over the years.