Evaluation of Droplet Spectra of the Spray Tip Ad 11002 Using Different Techniques

Abstract

Knowledge of droplet spectra generated by spray nozzle tips is important to ensure the quality of applications of plant protection products. However, there are different methods for this evaluation, which can cause difficulty in interpreting the results. This study aimed to evaluate the droplet spectra produced by the flat fan spray tip AD 11002 operated under different pressures and using different techniques and equipment. The volume median diameter (VMD), percentage of spray volume in droplets smaller than 100 µm diameter and relative spam (RS), considering pressures of 200, 300, and 400 kPa were determined using two direct measurement equipment (Spraytec and Shadow Sizer), based on laser diffraction and image analysis, respectively, and a measure based on indirect analysis, through the digitization of water-sensitive paper. Thus, the use of different analysis techniques led to variations of the analyzed parameters. Among the direct measurement equipment, a difference of up to 58% was observed in VMD. The use of water-sensitive paper to characterize droplet spectra must be carried out with great discretion because there is an underestimation of fine droplets. Pressure variations of 200 to 400 kPa did not influence VMD and RS.

Use of different spray volumes and hydraulic nozzles in air-assisted electrostatic insecticide application technologies to control coffee berry borer (Hypothenemus hampei) populations

“…Insecticide application with coarse droplets is an environmentally safe solution, as it reduces drifting effects, and the exposure of both applicators and pollinating insects to insecticides. This corroborates the results found by Cunha, Reis, Assunção, and Landim (2019) and Locatelli et al (2019). However, coarse droplets require extra caution to prevent runoff and loss of insecticide to the soil (Cação, Moreira, Raetano, Carvalho, & Prado, 2019).…”

Impact of a synthetic insecticide and plant extracts on Aphis craccivora (Hemiptera: Aphididae) and coccinellid species in common beans

“…The volumetric median diameter (VMD) stands out, as well as Dv0.1, Dv0.9, percentage of coverage, droplet density, relative amplitude, and others. Studies conducted by Cunha et al (2019) and Sasaki et al (2016) reinforce the importance of these parameters. The application efficiency evaluation variables are obtained by an artificial target, positioned next to the plant leaves, aiming to simulate the deposit of the drops; it is a useful and accessible tool for service providers, producers and researchers (Alvarenga et al 2014).…”

Operational Image Processing Approach for Spray Coverage Measurements in Pesticide Application

“…WSP samples used in spray treatments provide important information regarding spray quality. In research conducted on droplet spectrums, spray penetration, spray -distribution uniformity and droplet transfer to targets, WSPs are positioned on target surfaces (Fox et al, 2003;Cerruto et al, 2013;Salyani et al, 2013;Witton et al, 2018;Cunha et al, 2019) and collected after spray applications for individual analyses with different image -processing software (Cunha et al, 2012). The sampling methodology in the present study structured based on available the literature was constituted sensitively with the aim of obtaining the WSP samples with different spray coating rates.…”