Volume 2, Issue 8 (September 2005)
Comparisons of Drift Reducing/Deposition Aid Tank Mixes for Fixed Wing Aerial Applications
A field study was conducted to determine the influence of adding spray drift control/deposition aid products to tank mix solutions for fixed wign aerial applications. Downwind horizontal drift, vertical drift, and droplet spectra characteristics in a canopy top were collected on water sensitive paper (WSP) for measurement and analysis. Spread factors for each spray mix sample were determined and were used as part of the analysis procedure with the canopy measurements. DropletScan™ was used to analyze the WSP. Percent area coverage for the horizontal and vertical drift profiles was used as a means to separate differences in treatments. DropletScan™ with adjusted spread factor coefficients was used to calculate Dv.1, Dv.5, and Dv.9 at the canopy top for each treatment. Differences in products at all horizontal and vertical collector positions were measured. When compared to water, results show that some of the products did not provide any benefits for drift reduction and, in fact, may have increased the drift potential. A few of the products exhibited the potential to reduce the amount of drift. Droplet sizes for Dv.1, Dv.5, and Dv.9 increased with the addition of the drift control/deposition aid products into the tank mix. The increases were variable across products and aircraft.