Interaction of nozzles with spray fluids on droplet drift

J.H. Combellack, Spray Smart Enterprises, 7 Michelle Drive, Maiden Gully, Victoria 3551, Australia.


The volume of spray droplets that drift is dictated by droplet size and as well as the physical characteristics of the spray fluid, boom stability and meteorological conditions when spraying. Published data shows that extended range flat-fans generate a more drift prone spectra than either pre-orifice flat fans or turbo TeeJets, while air induction nozzles and twin fluid nozzles are able to generate even less drift. Non-ionic wetters generally increase the volume of drift prone droplets, whereas mineral and vegetable oils as well as lecithin based adjuvants typically have the opposite effect. Field and laboratory drift studies generally confirm the trends shown by droplet size measurements.

Keywords: droplet size measurement, droplet drift, hydraulic and twin fluid nozzles, wetters, adjuvants.


Plant Protection Quarterly (2004) 19 (3) 119-124.