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.

The aim of this work was to analyze the effect of spray solutions containing new formulations of 2,4-D choline salt (Enlist™ with Colex-D™ and Enlist Duo™ with Colex-D) on the droplet spectra and drift potential generated by flat-fan nozzles. The experimental design included comparisons between solutions with a single herbicide in it: 2,4-D dimethylamine salt (DMA™ 806 BR) and 2,4-D choline salt (Enlist with Colex-D). We also compared the premix of 2,4-D choline salt and glyphosate dimethylamine salt (Enlist Duo Colex-D) with tank mixtures of the 2,4-D dimethylamine salt with three different formulations of glyphosate (Glizmax® Prime, Roundup Transorb R, and Zapp QI). Labeled rates of the herbicides were diluted to 80 L ha−1 and sprayed with flat-fan nozzles at 2.8 bar (Teejet XR11002 and AIXR11002). The volume median diameter and the percentage of droplets smaller than 105 µm (V105) were obtained using an online particle-size analysis system. The drift index was calculated based on data collected in a wind tunnel at a wind speed of 2.5 m s−1. The amount of drift deposited on nylon strings at 2 m downwind from the nozzle was converted to a percentage of the total volume of spray solution sprayed on each replication. The results showed that the new formulation of 2,4-D choline salt engineered for drift reduction (Enlist Colex-D) provided lower drift potential based on both the droplet spectra and the wind tunnel data compared to the standard 2,4-D dimethylamine salt. The same result was found when comparing the premix of 2,4-D choline salt and glyphosate dimethylamine salt with tank mixtures of 2,4-D dimethylamine salt with glyphosate, regardless of whether glyphosate formulation was part of the tank mixture.

The density and distribution of soybean plants can interfere in the plant growth stage and yield, as well as phytosanitary management of this crop. Thus, innovations in production systems must be followed by improvements in pesticide application technology. Therefore, this study aimed to evaluate the influence of soybean sowing arrangements on fungicide application technology, with or without air assistance in the spray boom, using qualitative and quantitative assessments of the spray deposits. In the experiments, a randomized block design with split plots was used. Four soybean sowing arrangements: Conventional (CO), Double row (DR), Narrow row (NR), and Crossed rows (CR) composed the main plots, and fungicide application technologies with air assistance (AA) and without air assistance (WA) in the spray boom composed the subplots, with four replications. For the assessment of spray deposits, Brilliant Blue tracer dye was used in the spray solution, and the spray coverage was evaluated using water-sensitive papers. The effects of different soybean sowing arrangements on deposits and spray coverage were limited. However, an increase in spray deposits on the lower part of the soybean plants was observed with air assistance in the spray boom.