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二、发生量的预测1959年以来,我们对玉米螟生活史及数量消长进行了研究,以此为根据,设计出予测发生数量的方法.1、玉米螟数量消长的主导因素及在测报上的应用影响玉米螟发生量的因素很多,有虫口基数、寄主作物面积、天敌数量及气象条件等。但在实践中,不分主次地采用多因素进
Second, the amount of forecasting Since 1959, we have corn stalk life history and the number of growth and decline, as a basis, to design a measure of the number of occurrences.1, the main reasons for the decline in the number of corn borer and in the report The application of corn borer affect the occurrence of many factors, the number of insect population, the host crop area, the number of natural enemies and weather conditions. However, in practice, regardless of primary and secondary use of multi-factor into