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三代棉铃虫发生期正值棉花蕾铃生长盛期,若防治不适时,则引起蕾铃脱落,直接影响棉花产量。而三代棉铃虫卵峰日年度间差异较大(我区1971年—1976年早晚最多相差16天),经验预报准确率不高。本文根据本区16年的历史资料,应用“列联表简化综合相关法”对三代棉铃虫卵峰日进行预测,符合率为100%。现简介如下。一、资料处理通过对16年资料综合分析,从诸多因子中选取三个相关性较好的因子(Xj)来预测三代棉铃虫卵峰日 y(月/口)。其中 X_1为7日上旬和中旬平均温度之和(℃);X_2为6月上旬温湿系数(平均相对湿度/平均温度);X_3为4月上旬和中旬平均温度之和(℃)(见表1)。
The occurrence of three generations of cotton bollworm is positive when the peak of cotton bud growth, if the prevention and treatment of discomfort, then lead to fall off, directly affect the cotton yield. The three generations of cotton bollworm egg peak day difference between the larger (my area from 1971 to 1976, up to a difference of 16 days, morning and evening), the empirical prediction accuracy is not high. Based on the 16 years of historical data in this area, the application of “contingency table simplified comprehensive correlation method” to predict the third generation cotton bollworm egg peak day, with a coincidence rate of 100%. Now the introduction is as follows. First, the data processing Through a comprehensive analysis of 16 years of data, from a number of factors to select three good correlation factor (Xj) to predict third generation cotton bollworm egg peak y (month / mouth). Where X_1 is the sum of the average temperature in the early and mid-July 7 (℃); X 2 is the temperature and humidity coefficient (average relative humidity / average temperature) in early June; X_3 is the sum of the average temperatures in early and mid- 1).