Pesticide application as affected by spray modifiers

Abstract Spray modifiers are materials which affect the physicochemical characteristics of pesticides and hence can enhance or detract from the eventual biological effect. The purpose of this paper is to discuss the effect that spray modifiers (especially adjuvants) have on the interactions and complexities of the pesticide application process. Foliar application of Crop Protection Agents (CPAs) includes a complex of inter‐linked events: atomization, transport, impaction, retention, deposit formation, movement on or in the plant, and the final biological result. New regulatory constraints question the benefits of many adjuvants and thus use of spray modifiers will be brought to increasingly higher research interest. At the Laboratory for Pest Control Application Technology (LPCAT), studies on spray modifiers have addressed the problem of identifying (and understanding) these interactions, many of which can be mathematically modelled. The overall aim of the research discussed is to identify the benefits and costs of using spray modifiers and to better understand the role that they may have in the pest control process.