External loading of an orchard sprayer with agrochemicals during application

External contamination of sprayers during the application of Plant Protection Products (PPP) can lead to a serious threat for operators and the environment. The residue of PPP stays often on the sprayer surfaces until the end of the spray season when the sprayer is cleaned for winter storage. The external loading of the sprayer with PPP can be a source for point source pollution and a risk for the operator when in contact with uncovered body parts. To quantify the external loading of PPP on a tractor and a sprayer when spraying an orchard samples were taken after 10, 20, 40, 80 and 160 minutes of spraying. These times coincide with treated areas of 0.25, 0.50, 1, 2 and 4 ha of an apple orchard. Four repetitions were done in time spraying the fluorescent tracer Brilliant Sulpho Flavine. The amount of tracer on the tractor (back cabin screen, left/right cabin screen, front side top hood) and the sprayer (left/top/right side of tank at the front and middle of the sprayer, left/top/right side of fan house, centre back side fan inlet) parts were quantified. Spray deposit was measured using collectors attached to the sprayer and tractor surface, by wiping of 100 cm2 surface area and by high pressure cleaning of the whole tractor and sprayer following ISO 22368-2. Results show a decrease in additional loading of the sprayer in time elapsed, suggesting saturation of the collectors and surface area. Total external loading of the sprayer was around 10 L, being 1.3% of total sprayed volume with more than 90% in and around the sprayer fan