Drug-containing droplets from the application of plant protection products (PPP) can be transported and deposited outside of the target area, which is called direct spray drift and affects adjacent waterbodies and other non-target areas. The environmental risk expected through spray drift of PPP is estimated as part of the authorization-process. If necessary, spray free buffer zones of 6 to 100 m must be applied towards surface waters. If drift is reduced by appropriate measures, the width of these buffer zones could be diminished. Four drift reduction measures have been tested under practical conditions of Swiss apple production. Windbreak hedges or injector nozzles reduced drift by approx. 75 % each, a hail net on the top of the orchard by approx. 65 %. A coarse-mesh net as a windbreak at the edge of the field showed an effect of about 20 % drift reduction only.
Spraydrift – mitigation measures in field trials