获取复配农药最佳增效配方的一种简易方法

借鉴共毒因子法评价农药复配联合作用的思想，将参与复配的单剂引起25％死亡率的剂量定为零水平，利用二次回归通用旋转组合设计安排实验研究氯氰菊酯和喹硫磷复配对斜纹夜蛾（Spodoptera litura）2龄幼虫的增效作用，得出杀虫剂使用量与斜纹夜蛾幼虫死亡率机率值之间的关系，从共毒系数（CTC）的计算公式推导出共毒系数与杀虫混剂中两单剂使用浓度N1、N2之间的数学关系，CTC＝100／N1／α N2/b（α、b分别为氯氰菊酯和喹硫磷的LC50），进而确定最优化问题的目标函数j=N1/α＋N2／b，利用国际统计分析软件SAS的NLP过程求最大共毒系数和最优配方，所得结论与共毒系数法一致。

A Simple Method to Obtain the Optimal Synergistic Mixture Ratio of Combined Pesticides

The dosage resulted in a mortality of 25% was considered as zero level, from the base of co-toxicity factor evaluating joint action of two insecticides. Bioassay was arranged with quadratic regression rotation composite design method to study the combined synergism of cypermethrin and quinalphos on the 2nd-instar larvae of common cutworm, Spodoptera litura. The relationship between the death probability of target insect and the dosages of the insecticides was described by a quadratic polynomial. The mathematical relationship between co-toxicity coefficient (CTC) and the dosages of the insecticides (N1,.N2) was deduced from the calculating formula of CTC. i.e. CTC a,b represent the medium lethal concentrations of cypermethrin and quinalphos, respectively. So the formula, was taken as the goal function of optimization problem. Finally, the maximum CTC and optimal mixture ratio of cypermethrin and quinalphos were obtained with the program. NLP of SAS. These results were very consistent with the ones of Sun's (1960) method.