Which is more important: spray volume, pressure, or droplet size?
Spray volume is most important. At least 15 gallons, and preferably 20 gallons, per acre of spray volume are needed for ground applications. At least 5 gallons per acre are needed for aerial applications. This volume will be needed to penetrate and thoroughly cover all leaf surfaces in the soybean canopy. Next in order of importance is the droplet size. A medium droplet size (200 to 300 microns) is required to penetrate the canopy and adequately cover the leaf surfaces. Fine to very fine droplets, like those produced from hollow cone nozzles, will not penetrate the canopy and are prone to drift. Large droplets will not give adequate coverage, may bounce off leaves, and because the total number of droplets is less, are more likely to miss the target and land on the ground.
