The effect of nozzle type in an unmanned aerial sprayer on the activity of herbicide haloxyfop-R-methyl against volunteer barley

Despite the availability of nozzle types, the role of nozzle on the performance of unmanned aerial sprayer has received less attention. The study was performed in factorial as a completely randomized design to investigate the effect of factors of nozzle type (standard, anti-drift, and air induction) and nozzle orifice number (single, twin, and triplet flat fans) on the deposition of spray droplets at the target site and their drift up to a distance of 5 m from the target site and the efficacy of herbicide haloxyfop-R-methyl against volunteer barley. In all types of nozzles, with increasing the nozzle orifice number, drift increased. Except for the standard nozzle, in other nozzles types, with increasing the nozzle orifice number, the deposition of spray droplets at the target site and herbicide efficacy increased. The lowest (2.7%) and highest (22.5%) drift was observed with the air induction single flat fan nozzle and the standard triplet flat fan nozzle, respectively. The highest (35.2%) and the lowest (8.3%) deposition at the target site was observed with the air induction triplet flat fan nozzle and the standard triplet flat fan nozzle, respectively. The lowest control was observed using the standard triplet flat fan nozzle (38.3%). The highest control of barley with haloxyfop-R-methyl was observed when the air induction twin flat fan (94.3%) and air induction triplet flat fan (91.7%) nozzles have been used; therefore, the selection and installation of these two nozzles on UAV, not only better weed control is achieved, but also an effective step is taken to prevent environmental pollution.