Reducing Herbicide Particle Drift: Effect of Hooded Sprayer and Spray Quality

A field study was conducted in 2015 and 2016 to compare particle drift of glyphosate using a fluorescent tracer dye applied with hooded and open sprayers at four spray qualities (Fine [F], Medium [M], Very-Coarse [VC], and Ultra-Coarse [UC]). F and M spray qualities exhibited up to 86% and 56% less drift, respectively, out to 31 m downwind with the hooded sprayer than with the open sprayer. Conversely, VC and UC spray qualities were not affected by sprayer type out to 31m downwind. From 43 to 104m downwind, hooded sprayer applications exhibited approximately 50% less drift than open sprayer applications, regardless of spray quality. From 43 to 89m downwind, F spray qualities, regardless of sprayer type, exhibited higher drift than all other spray qualities. These data indicate that hooded sprayers considerably reduce drift of all spray qualities at short distances downwind. Additionally, at longer distances downwind, both larger spray qualities and sprayer hoods reduced drift independently. Nomenclature: Glyphosate