Submitted to: Journal of ASTM International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2017
Publication Date: 10/11/2018
Citation: Fritz, B.K., Hoffmann, W.C., Martin, D.E. 2018. Mass balance and swath displacement evaluations from agricultural application field trials. Journal of ASTM International. 1610:11-23. https://doi.org/10.1520/STP161020170204.
Interpretive Summary: Field verification of spray deposition from any agrochemical application is critical to understanding the deposition of applied sprays. Delineation between the fraction of the applied spray depositing in the intended target zone from that moving off-target can be difficult. A analytical method was developed to account for the total volume of spray material depositing in field conditions as a fraction of the total volume of material applied. Further, a method was developed to calculate the displacement of that applied spray material as a result of wind-driven transport. This analytical approach will ensure proper interpretation of field-collected data and provide applicators with guidance on adjusting application methods to ensure on-target deposition of applied sprays for greater product efficacy while minimizing potential drift.
Technical Abstract: Spray drift is on an ongoing concern for any agricultural application and continues to be the focus for new developments and research efforts dealing with drift reduction technologies, best management application practices and the development of new decision support systems for applicators. Typical field trials aimed to evaluate and compare these new technologies and methods follow several older standard methods or adopt a modified method, most of which lack sufficient in-swath and near downwind data points to allow for an accurate mass balance from the in-swath spray portion and further to determine both the effective swath width of application and the swath displacement resulting from sprayer travel line and/or meteorological conditions present at the time of application. Both are critical to defining the fraction of the applied material that is considered spray drift. This work presents a modified sampling protocol and analysis method designed to allow for a detailed examination and determination of the effective spray swath width as well as the lateral downwind swath displacement to provide a better understanding of data collected during spray application trials ultimately providing applicators with improved guidance.