Drift evaluation tool to raise awareness and support training on the sustainable use of pesticides by drift mitigation

Abstract

In order to protect water and other sensitive areas from spray drift, and make the best use of mitigation measures, an evaluation of drift risk should be made prior to a spray application. The objective of this work was to develop a practical, interactive tool to evaluate the risk of spray drift for specific weather and field situation, and propose effective measures to mitigate this risk. This should help the pesticide user to make better decisions in order to reduce potential spray drift contamination. The Drift Evaluation Tool (DET) is intended to be used by the pesticide users and advisors, and hence raise their awareness on the effect of factors influencing spray drift and on mitigation measures to reduce drift risk. The aim was to offer a simple and practical application software that would be user-friendly and educative to encourage its wide use. The operator communicates with the software via its simple and intuitive visual interface. He is guided through three pages and asked to select in the proposed lists of options the parameters that best reflect his actual situation. On the first page the user determines the application site: within or beyond the zone of awareness (buffer zone plus boom width), i.e. whether or not risk of drift need to be considered. On the next page he determines actual weather and field conditions: wind direction and velocity, air temperature and humidity, crop height and adjacent structures. Once the items are selected the Drift Risk Value SITUATION (%) (DRVS) is calculated and expressed both in figure and graphically. Thus, the user can see directly how variations in weather and field conditions may affect the spray drift risk. Depending on the risk level appropriate practical recommendation appears on the screen. On the last page the user simulates mitigation measures by selecting different application techniques and application parameters. He may select spray drift reduction class of the simulated technique, boom height and driving velocity. For each selection a Drift Risk Value – APPLICATION (%) (DRVA) is calculated to show the effect of the selected risk mitigation measures. The final recommendation is given to the user based on the determined risk level. The algorithm of calculation of drift risk values for the selected items is based on available results of drift studies, and where information was missing, especially on interactions between factors, an expert judgment was used in the algorithm.