Nozzle Type Effect on Soybean Canopy Penetration

Abstract

A spray track was designed and built to conduct replicated laboratory and field studies to compare different nozzle configurations on the ability of each to achieve lower canopy spray coverage. The objective was to determine which nozzle configurations might be more affective in preventing or controlling Asian Soybean Rust. Multiple nozzle types were compared in four laboratory trials and one field trial. Both single and double nozzle configurations were compared. Comparisons were at 187 and 140 L/ha with spraying speeds of 16 km/h. Orifice size and operating spray pressure for each nozzle were adjusted to maintain the desired spray droplet size of 200 to 300 microns VMD (ASABE S-572) at the calibrated flow rate of 2.5 L/m (187 L/ha at 16 km/h) or 1.9 L/m (140 L/ha at 16 km/h). A tank mix solution of water and non-ionic surfactant was used for each comparison to simulate a field spraying scenario. For the field trial, a fungicide was added to the solution to further simulate a field spraying scenario. Water Sensitive Paper was the collection medium and DropletScan was used to measure and compare volume median diameter (VMD), percent area coverage (PAC), and number of droplets per square centimeter (D/SC).