Journal of Agricultural Science and Food Research
Open Access

Abstract

A Mathematical Investigation on Active Release in Soil and its Validation in Greenhouse Studies

Min Zhao, Mary Rushton, Ray Boucher, Matt Kalinowski, Keith Harris, Lei Liu, Jon Babcock and Monica Olson

Encapsulation can be used to mitigate the degradation of pesticides in a hostile environment. The design of the right release profile, however, is critical to tune the balance between the degradation and uptake into plants for pest control. In this paper, we use Compound A, an insecticide that undergoes rapid degradation in soil, as an example to demonstrate how mathematical modeling combined with a greenhouse study, can be utilized to suggest an optimal release profile and help the design of controlled-release formulation for an active ingredient (AI). First, a mathematical model was constructed to understand the minimum dosage requirement to meet the 1-month insect control target. Then a spiking greenhouse test with the defined use rate was designed to validate the model. Combination of these data led to the determination that the minimum dosage in microbiologically active soil for 1-month insect control was 0.03-0.045 μg AI/g soil. The spiking test demonstrated that controlled-release of Compound A achieved through appropriate encapsulation technology would deliver sufficient insect control for 1 month, with at least 9 times reduction on its use rate if applied without encapsulation. This information can serve as a guide in selecting the composition of the polymeric encapsulant as well as improving the translation from lab screening to greenhouse test, and eventually helping to improve the translation to field performance.