Fig.15. Low-drift nozzles can reduce spray drift.
Almost all major agricultural nozzle manufacturers have recently introduced their version of Low-Drift nozzles (Figure 15). These nozzles are designed to create larger droplets at the same flow rate and operating pressure than comparable standard flat-fan nozzles. This has been accomplished by adding a pre-orifice to the nozzle tip assembly just ahead of the conventional discharge orifice. The pre-orifice reduces pressure at the exit orifice creating larger droplets to reduce drift significantly. For example, research conducted in Ohio recently indicated that volume of spray contained in drift prone droplets (smaller than 150 microns) was reduced by 87% when a 0.2 gal/min flow rate capacity Low-drift nozzle was operated at 40 psi compared to a comparable size Standard Flat-fan nozzle operated at the same pressure. Many studies are being conducted to evaluate effectiveness of these nozzles, both to reduce drift and to provide good pest control. Detailed information about the description of low-drift nozzles and their effectiveness in reducing drift can be found in two other OSU Extension publications by Ozkan (1998), and Ozkan and Derksen (1998).