Submitted to: Pest Management Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/12/2008
Publication Date: 6/1/2009
Citation: Latheef, M.A., Carlton, J.B., Kirk, I.W., Hoffmann, W.C. 2009. Aerial electrostatic-charged spray for deposition and efficacy against sweetpotato whitefly on cotton. Pest Management Science. 65:744-752. Interpretive Summary: Sweetpotato whiteflies (SWF) are a serious pest in cotton causing significant control costs to cotton farmers. This study compared the effectiveness of an electrostatic aerial spray system and a conventional aerial spray system for controlling SWF in cotton. While the electrostatic spray system generated significantly smaller drops than the conventional system, the level of control of SWF eggs and large nymphs was not significantly different between the two spray systems. The study showed that the electrostatic system used in this study will provide the same level of SWF control as the conventional spray system and increase efficiency of the spray applications.
Technical Abstract: Efficacy of aerial electrostatic-charged sprays was evaluated for spray deposit characteristics and season-long control of sweet potato whitefly (SWF), Bemisia tabaci biotype B (a.k.a. B. argentifolii), in an irrigated 24-ha cotton field. Treatments included electrostatic-charged sprays at full and one-half active ingredient (a. i.) label rate, uncharged sprays and conventional sprays applied with CP nozzles at full label rate with several different insecticides. Spray droplet size was significantly smaller for electrostatic-charged sprays compared with that for conventional sprays in the top- and mid- canopy. Seasonal mean numbers of viable eggs and live large nymphs in plots treated with electrostatic-charged sprays were comparable to those treated with conventional applications. Lethal concentration (LC50) for electrostatic-charged sprays for adults was comparable to that for conventional sprays. The amenability of electrostatic-charged sprays to a wide array of pesticides with different chemistries should be a useful tool in combating insect resistance. Results reported here suggest that the potential for obtaining increased efficacy against whiteflies using electrostatic spray charging system exists and that additional research will be required to improve charge-to-mass Q/M ratio to increase deposition of pest control materials to the lower surfaces of cotton leaves where the whiteflies reside.