PT  - JOURNAL ARTICLE
AU  - Larbi, Peter A.
AU  - Zhuang, George
AU  - Thistle, Harold W.
AU  - Willett, Michael J.
TI  - Downwind Drift from Grape Airblast Spray Applications: Field Evaluation to Support Mechanistic Model Development
AID  - 10.5344/ajev.2025.25005
DP  - 2025 Oct 01
TA  - American Journal of Enology and Viticulture
PG  - 0760025
VI  - 76
IP  - 2
4099  - http://www.ajevonline.org/content/76/2/0760025.short
4100  - http://www.ajevonline.org/content/76/2/0760025.full
SO  - Am J Enol Vitic.2025 Oct 01; 76
AB  - Background and goals Pesticide drift and its potential for human and environmental exposure are of significant concern during vineyard airblast spray applications. This study aimed to quantify drift from grape vineyard pesticide applications for the purpose of validating an ongoing drift mechanistic model development.Methods and key findings A field study was conducted in a commercial Vintage Red table grape vineyard in Del Rey, California. The spray application of a fluorescent tracer dye solution was completed in 20 test runs, with the sprayer making four passes along the third drive lane upwind from the edge of the vineyard. Using a flat plastic card, artificial foliage, and horizontal and vertical polyester string samplers, airborne dye drift and drift deposition were captured, analyzed by fluorometry, and expressed as percentage of the applied rate. Meteorological data during the experiment were recorded inside and outside the vineyard using two meteorological stations with sensors installed at various heights. Airborne drift value significantly reduced (p < 0.05) from a downwind distance of ~8 to ~23 m, where it was measured. For all samplers, drift deposit also generally declined progressively, with downwind distance up to ~165 m under the different meteorological conditions that prevailed.Conclusions and significance The results and data provide a more complete understanding of potential downwind pesticide exposure caused by drift, which will be utilized in confirming and/or developing new best practices for spray application to promote efficiency, effectiveness, and environmental sustainability.