杀虫剂防治三化螟的最佳时间和最适浓度

Optimum time and concentration of insecticide application to control paddy stem borer (Tryporyza incertulas).

杀虫剂使用的最佳时间和最适浓度与很多因子有关,包括害虫种群动态、作物对为害的敏感性、作物单产和产品单价、杀虫剂药效降解速率和杀虫剂效率,以及气候条件等。运用边际分析方法,建立了确定杀虫剂使用的最佳时间和最适浓度的系统模型。此系统模型包括种群动态模型、产量损失预测模型、杀虫剂药效降解模型和杀虫剂效率模型。此外还引入了反映水稻对螟害敏感性程度的加权因子。通过求解一个函数的极大值问题,即可得到使得纯收益最大时的杀虫剂的使用时间和浓度。

Optimum time and concentration of insecticide application depend on many factors including pest population dynamics, crop susceptibility to damage, crop yield in unit area, unit price of production, degradation rate of insectioide and its efficiency, and weather、The marginal analysis method is applied to develop a system model for determining the optimum time and concentration of insecticide application. The system model consists of four submodels: 1) population dynamic model; 2) yield loss forecasting model; 3) insecticide degradation model; and 4) insecticide efficiency model. Moreover, a weighted factor reflecting rice susceptibility to damage of paddy stem borer is introduced. By maximizing a function, the optimum time and concentration of insecticide application can be obtained.