Optimization of spray deposition and Tetranychus urticae control with air assisted and electrostatic sprayer

Abstract

Improved spray deposition can be attained by electrostatically charging spray droplets, which increases the attraction of droplets to plants and decreases operator exposure to pesticide and losses to the environment. However, this technique alone is not sufficient to achieve desirable penetration of the spray solution into the crop canopy; thus, air assistance can be added to the electrostatic spraying to further improve spray deposition. This study was conducted to compare different spraying technologies on spray deposition and two-spotted spider mite control in cut chrysanthemum. Treatments included in the study were: conventional TJ 8003 double flat fan nozzles, conventional TXVK-3 hollow cone nozzles, semi-stationary motorized jet launched spray with electrostatic spray system (ESS) and air assistance (AA), and semi-stationary motorized jet launched spray with AA only (no ESS). To evaluate the effect of these spraying technologies on the control of two-spotted spider mite, a control treatment was included that did not receive an acaricide application. The AA spraying technology, with or without ESS, optimized spray deposition and provided satisfactory two-spotted spider mite control up to 4 days after application.

Electrostatic Spraying Effect on Spray Deposition and Powdery Mildew Control in Soybean

“…Application rate was the only factor that influenced spray loss to the soil (Table 9). The electrostatic spraying is an alternative to improve spray solution deposition on targets, promoting, among other benefits, the possibility of reducing the application rate (Cerqueira et al, 2017). However, regarding the reduction of losses to the soil, the highest loss values occurred in the plots that received the highest application rates, with no influence of the technique.…”

“…For this, alternative technologies have been used in the field. Among alternative application technologies used in the field to reduce carrier volumes, electrostatic spraying has been studied by some researchers (Cerqueira et al, 2017;Cunha et al, 2017a). Droplet electrification can increase spray deposition on targets and consequently pesticide efficacy at lower application rates when compared to conventional methods (Patel et al, 2017).…”

Evaluation of Electrostatic Spraying Equipment in a Greenhouse Pepper Crop

“…There are few studies on electrostatic spraying in greenhouses, other than the study carried out by Kabashima et al [27], which used a spray gun equipped with an electrostatic nozzle to control aphids on chrysanthemums, concluding that the level of control was similar to a conventional treatment but using 40-times less water and posing less risk to those applying the treatment. Moreover, in a greenhouse chrysanthemum crop, Cerqueira et al [28] used an electrostatic sprayer to control T. urticae, obtaining good results even though 20-times less volume was used compared to a conventional sprayer.…”

Susceptibility ofTetranychus ogmophallos(Acari: Tetranychidae) toBeauveria bassianaandMetarhizium anisopliae

“…Beauveria bassiana and M. anisopliae caused between 22 and 82% mortality among adult Tetranychus evansi Baker and Pritchard (Prostigmata: Tetranychidae) females under laboratory conditions (Bugeme et al 2008;Wekesa et al 2005). Both entomopathogens cause > 65% mortality among Tetranychus urticae (Koch) (Acari: Tetranychidae), which is a very important agricultural pest in Brazil (Alves et al 2002;Tamai et al 2002;Bugeme et al 2009;Shi & Feng 2009;Moro et al 2011;Cerqueira et al 2017). Six B. bassiana isolates and 7 M. anisopliae isolates were pathogenic to Tetranychus kanzawai (Kishida) (Acari: Tetranychidae), causing > 85% mortality under laboratory conditions, evidencing high potential as a biological control agent (Sanjaya et al 2013).…”