Opportunities to mitigate particle drift from ground-based preemergent herbicide applications

Authors: Kannan, Narayanan; Huggins, Christina

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2022
Publication Date: 3/6/2023
Citation: Kannan, N., Huggins, C.L. 2023. Opportunities to mitigate particle drift from ground-based preemergent herbicide applications. Applied Engineering in Agriculture. https://doi.org/10.13031/aea.15307.
DOI: https://doi.org/10.13031/aea.15307

Interpretive Summary: Although several best practices are available, there are still opportunities to mitigate off-target pesticide drift, protect nearby sensitive crops and address health concerns for humans/animals. The purpose of thestudy is to identify opportunities to mitigate drift from ground-based preemergent herbicide applications. Drift data were collected from seven herbicide applications for corn, soybean and cotton crops, including datafrom three commercial producers using chemically coated water-sensitive cards (appearing yellow) that turned blue after receiving herbicide drift. ImageJ software was used to analyze the water-sensitive cards toestimate the size and number of droplets that drifted. How much of the applied herbicide drifted away from the target (drift volume) and how far the drift went (drift distance) were estimated. Data collected on wind speed, width of the spray, spray height, tractor speed, and spray droplet size were used as parameters to explain the differences in drift volume and drift distance in different experiments using a statistical regression analysis framework. Sprayer boom length and spray height appear to be the dominant parameters affecting drift volume and drift distance, respectively. Study results show a three- to fourfold reduction in drift using a hooded sprayer or spraying at low wind speed.

Technical Abstract: Although several best practices are available, there are still opportunities to mitigate off-target pesticide drift, protect nearby sensitive crops and health concerns to humans/animals. The purpose of the study is to identify opportunities to mitigate drift from ground-based preemergent herbicide applications. Seven herbicide applications were tested for corn, soybean and cotton, including three regional commercial producers.Drift data were collected using water sensitive cards. ImageJ was used to analyze the droplet spectrum. Drift volumes and drift distances were estimated for each experiment. Data collected on wind speed, boomlength, spray height, tractor speed, droplet size (DV50) and chemical application rate were used as explanatory variables of drift volume and drift distance. Individual and multiple linear regressions (MLRs) werecarried out between drift volume, drift distance and the explanatory variables. Our results show a three- to fourfold reduction in drift using a hooded sprayer or spraying in calm weather. Boom length and spray height appear to be the dominant parameters affecting drift volume and drift distance, respectively. The MLR results suggest that we can estimate drift (a) volume reasonably using a combination of boom length,DV50, and tractor speed and (b) distance reliably using a combination of spray height, boom length, and DV50.