On and off-target spray deposition from a solid set canopy delivery system and an axial-fan airblast

Parameters: Pyranine

Congratulations to Rajeev Sinha who was awarded a Travel Stipend for his presentation at the 2019 ASABE AIM Conference featuring our 10AU and Trilogy Fluorometers.

Abstract

Off-target drift from airblast sprayers in vineyards and high-density tree-fruit orchards is a key concern among the growers and other stakeholders. A solid set canopy delivery system (SSCDS) is a novel spray application system that can potentially minimize spray drift and associated issues. This study evaluated two different configurations of an SSCDS and an airblast sprayer for within canopy deposition and off-target drift in a vertical shoot position trained vineyard. Canopy deposition and off-target drift were quantified using mylar cards. Associated coverage was quantified using water sensitive papers (WSPs) as samplers. For canopy deposition assessment, the vine canopy was divided into four zones: top-east, top-west, bottom-east and bottom-west. A randomly selected leaf in each zone was fit in with two mylar cards or WSPs on either side to quantify spray deposition and coverage on adaxial and abaxial surfaces of the leaf. A pair of samplers fixed on small wooden blocks were used to quantify ground runoff and drift losses at different downwind sampling distances. Drift poles with samplers at different heights above canopy were used to quantify airborne drift losses. The vines were sprayed with a fluorescent tracer using each of the application systems at 500 ppm in water as a spray mix. The mylar cards and WSPs were analyzed using fluorometry and image processing technique, respectively. Although insignificant, SSCDS configurations had a higher spray deposition compared to the airblast sprayer. However, the airblast sprayer had a significantly higher coverage on the abaxial leaf surface compared to the studied SSCDS configurations. The airblast sprayer also had significantly higher ground and aerial losses compared to the SSCDS configurations. Overall, SSCDS configurations provided canopy deposits equivalent to an airblast sprayer and accounted for significantly reduced off-target drift. Thus, SSCDS based spray application may be a better solution compared to an airblast sprayer for spray application in a VSP trained vineyard. >>View Presentation

Author: Rajeev Sinha

Institution: Washington State University, Washington, USA