Year of Publication

2020

Degree Name

Master of Science (MS)

Document Type

Master's Thesis

College

Agriculture, Food and Environment

Department

Plant and Soil Sciences

First Advisor

Dr. Travis Legleiter

Abstract

Dicamba injury to sensitive soybean and other broadleaf crops due to drift is a major issue and label restrictions have been created to mitigate dicamba drift. One restriction is the mandated use of low drift nozzles to spray dicamba; these nozzles produce larger droplets and minimize the production of driftable fines. Experiments were conducted to evaluate herbicide coverage, deposition, and efficacy. Three spray nozzle designs and different weed densities were the main factors in the analysis. Dicamba plus glyphosate was applied to 5 to 10 cm tall weeds with a Turbo TeeJet (TT11005) nozzle and two drift reduction nozzles approved for dicamba applications: Turbo TeeJet Induction (TTI11005) and Pentair Ultra Lo-Drift (ULD12005). Weed densities were categorized into different levels and established in a 0.25 m2 quadrant prior to post application. Deposition of spray solution on targeted weeds was not different despite coverage differences observed on Kromekote spray cards. The results from this research has shown that drift reduction nozzles do not reduce herbicide efficacy onto targeted weed species because spray solution deposition was equivalent across nozzle. High weed densities may reduce overall herbicide performance, and in some cases may interact with nozzle design.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2020.123

Funding Information

Kentucky Soybean Board

2018-2020

Included in

Weed Science Commons

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