PESTDEC: A simulation approach to insecticide application decision-making for soybeans

A method for using crop growth and pest population dynamics simulation models for real-time insecticide application decision-making is presented. The example discussed makes use of a soybean growth model and a velvetbean caterpillar model. The simulation models are used in conjunction with field scouting data to determine the status of the field on the date when an insecticide decision is to be made. Multiple simulations are made of possible future conditions to obtain an expected value for profit for the treat/do not treat decision. A technique for comparing different decision algorithms is also presented. In simulations of numerous hypothetical situations, PESTDEC recommendations resulted in higher average profit than three other decision-making methods. PESTDEC erred more toward recommending an insecticide application when one was not needed than vice versa.