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Title: Electrostatically charged aerial application improved spinosad deposition on early season cotton

Author
item Martin, Daniel - Dan
item Lopez, Juan De Dios
item Latheef, Mohamed - Ab

Submitted to: Journal of Electrostatics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/27/2018
Publication Date: 1/28/2019
Citation: Martin, D.E., Lopez, J., Latheef, M.A. 2019. Electrostatically charged aerial application improved spinosad deposition on early season cotton. Journal of Electrostatics. 97:121-125.
DOI: https://doi.org/10.1016/j.elstat.2018.12.005

Interpretive Summary: Thrips are a serious pest on seedling cotton in Texas and other areas of the Cotton Belt. They are known to cause significant leaf area destruction, delayed maturity and retarded plant growth with reported yield losses in excess of 50%. Studies were conducted to evaluate the effectiveness of a new, organically-labeled (naturally-derived) insecticide when aerially-applied with an electrostatically charged spraying system. In the tests, it was found that charging an aerial-applied spray increases deposition of the spray on the intended targets and produced larger, less drift prone droplets. As chemical costs rise and environmental stewardship remains important, aerial applicators will be able to use the results of this study to make the best use of the chemicals they are applying while protecting the environment from off-target drift.

Technical Abstract: Aerial electrostatic charged application of spinosad (Tracer') was evaluated for spray deposit characteristics and efficacy against thrips on commercial cotton in the Brazos River Valley of Texas during 2007. Using an Air Tractor 402B, electrostatic charged application was compared to uncharged application. Spray deposit on Mylar sheets was significantly greater in electrostatic charged (X = 0.1351 'g/cm2) compared to uncharged sprays (X = 0.1004 'g/cm2). Similarly, analyses of whole plant samples using fluorometric determination of dye tracer showed that there was 65% greater spray deposit in electrostatic charged (X = 0.0403 'g/cm2) compared to uncharged application (X = 0.0244 'g/cm2). Spray droplet size as measured by water-sensitive papers was significantly greater for electrostatic charged (Dv0.5 = 155.7 'm) compared to uncharged application (Dv0.5 = 148.7 'm). Cotton canopy received a significantly greater volume of spinosad active ingredient in electrostatic charged (X = 25.4 %) compared to uncharged application (X = 18.2 %) as measured by the percentage of spray volume applied. Percent reduction in thrips numbers was significantly higher in electrostatic charged application than in the control. Data suggest that the application of spinosad for control of thrips on cotton at 4-5 true leaf stage could be improved with electrostatic charged sprays.