Erfassung der Spraydrift und Verfluechtigung bei der Anwendung von Pflanzenschutzmitteln. T. 3 Entwicklung eines Computermodells zur Berechnung der Spraydrift auf der Basis der Modellversuche. Abschlussbericht

To evaluate the spraydrift of insecticides outside the treatment area, i.e. hop and wall-fruit cultures, the dependence as well of deposits on distance as of the fraction remaining in the air on distance and height were measured. The experiments were evaluated together with the data of other studies of the 'Arbeitskreis Spraydrift' and are now the bases of the estimation of spraydrift within the registration of pesticides in Germany. Apart from all above variations in application of pests experiments with fluorescent dyes along a trial with an area of 115 m"2 modeling an orchard of wall-fruit were carried out in order to quantify exclusively the influence of meteorological factors. As well measured downwind surface deposits as the concentration of the suspended particulate matter pointed to more or less strong dependence on the wind direction and strength, the relative humidity and the stability of the vertical stratification along the first meters of the surface. Based on the elaborated data a computer model 'MOPED' was developed. It predicts spraydrift depending and meteorological parameters, nozzle type and the culture. A wind tunnel system to determine the volatilisation rates of pesticides according to a BBA-guideline was build up. Volatilisation was determined by trapping vapours out of parital stream on polyurethan foam. Pesticides were sprayed on soil or plant stands using a moving nozzle. Problems occured by keeping the soil moisture constant. For a renewed guideline more preciseness regarding the application procedure and the size of the volatilisation area is suggested. (orig.)SIGLEAvailable from TIB Hannover: RN 8908(94-150,3) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman