Description and testing of the model PERO for grapevine downy mildew predictions

The agrometeorological model PERO (developed by D. Hoppmann, Geisenheim, DWD) adresses to one of the most important plant disease of grape-vine, the downy mildew (Plasmopora viticola). PERO calculates the infection start of grapevine disease Peronospora and its further development as numbers of visible and invisible oilspots. Leaf wetness is needed and can be calculated by the physical model DROPBEN. The time step is one hour, the output are daily results for PERO and hourly for DROPBEN. The model serves for practical recommendations to plant protection services and vine growers. For some sites of European vine growing areas the model behaviour has been tested compared with asessed data of plant disease.