Paul Miller, Waterborne Environmental, Inc
UK scientist Paul Miller will be presenting his work on modelling and thus minimising spray drift.
His work with field trials, wind tunnels and simulations have shown that boom height and the droplet size distribution from the nozzles are the most important variables influencing drift risk with changes in boom height having a greater effect than changes in wind speed.
Abstract
Quantifying the drift risks associated with boom sprayers and options for mitigating these risks
P. C. H. Miller
Silsoe Spray Applications Unit, NIAB TAG, BEDFORD, Bedfordshire, United Kingdom
Risks from spray drift have often been related to horizontal surfaces such as water with contamination from sedimenting droplets but the risks due to the capture of airborne spray drift can be substantially higher in some cases with important implications for risk assessments.
For boom sprayers, results from field trials, wind tunnel studies and mathematical simulation models have shown that boom height and the droplet size distribution from the nozzles are the most important variables influencing drift risk with changes in boom height having a greater effect than changes in wind speed. While increasing forward speed also increases the risk of drift, the effect of this variable is relatively small.
However, there is now evidence that the air disturbance caused by the vehicle and sprayer structure does influence the dispersion of airborne spray particularly in the near field and will influence drift dispersion.