German Regulation – Drift Modelling

The application of plant protection products is associated with the unavoidable occurrence of direct drift. The volume of transported and deposited drops is influenced by prevailing technical, technological, and meteorological conditions. German regulations for handling drift provide two tables including values for drift. They are published by specialists of the BBA. On this basis farmers can handle drift in an easy way. In Germany, first trials to develop a mathematical/physical model “PeDriMo” (Pesticide Drift Model) were made on the basis of step by step calculations for the movement and evaporation of droplet clouds. The multiple regression analysis (by using the SAS procedure1 ) of measured data as part of “PeDriMo” is more feasible than the mathematical/physical calculation and is preferred. The results of a big number of experiments in fields and in orchards with the wide variation of conditions are the basis for the multiple regression analysis. All parameters which could have an influence on the drift sediment as inputs of the model and the sediment itself as output of the model were measured. The model includes the coefficients of the multiple regression analysis and the limits in variation of the relevant influencing parameters. It is the statistic mean for the given meteorological a technological situation. For field sprayers the model has almost been completed. For the more complicated drift from orchard provisional results are shown. The main advantage of the model in comparison to field experiments is that the effect of several influencing parameters can be calculated in their complexity.