Spectrum, Velocity and Drift of Droplets Sprayed by Nozzles With and Without Air Induction and Mineral Oil

Abstract

ABSTRACT:The aim of this study was to evaluate the spectrum, the velocity and the potential drift risk of droplets sprayed by nozzles with and without air induction, with the addition of mineral oil to the spray solution. The experiment was conducted in a completely randomized design with five replications; in a factorial model 2 x 2 (two spray nozzles and spray solution with and without mineral oil Assist ® ). Spray nozzles with and without air induction were evaluated, with nominal flow rate of 1.14 L min -1 and pressure of 300 kPa. The spectrum and the velocity of droplets were evaluated directly, using a droplet analyzer (VisiSize D30) in real time based on the analysis of high-resolution images. The drift potential was evaluated in an open circuit wind tunnel. The data were submitted to analysis of variance and comparison test. In general, the addition of mineral oil (1.5% V V -1 ) resulted in an increase in the velocity of droplets, reduced drift and more homogeneous droplet spectrum. Air induction nozzles promoted larger and less homogeneous droplets, but they little affected the velocity of the droplets. There is an inverse correlation between drift potential and volume median diameter (VMD), which indicates that VMD can be used to predict the behavior of drift risk.

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

“…This result is in accordance with those found by Cunha et al (2004), who obtained similar results when analyzing flat fan spray tips, in which the variation of V<100 values followed VMD variations inversely. França et al (2017) also observed a correlation between V<100 and VMD, demonstrating that these values strongly change inversely, in which the addition of one results in a decrease of the other.…”

“…This parameter allows for estimating the drift risk potential (DRP) of an application. Because these droplets have a tiny mass, they can easily be carried by the wind away from the target area of treatment (França et al, 2017).…”

“…Besides representing a loss to the growers, it can cause impacts on human health, food security, and environmental contamination (França et al, 2017;Palardy & Centner, 2017). Drift can still be cumulative, increasing the selectivity of resistance to commercial molecules, directly affecting the sustainability of applications (Carvalho et al, 2018).…”

Spray nozzles, working pressures and use of adjuvant in reduction of 2,4-D herbicide spray drift

“…between DRP and VMD should be used with caution, in which the higher the VMD, the lower the risk of drift (França et al, 2017). For a more rigorous comparison of the quality of the application between hydraulic nozzles models, one must also observe the SPAN produced by each equipment (Cunha et al, 2004).…”

Effect of Adjuvants and pH Adjuster on the Efficacy of Sulcotrione Herbicide

“…Adjuvants can modify the viscosity of the spray liquid [20]. This parameter affects drop atomization as well as deposit formation [21].…”