Leaf-disease monitoring and warning of growers in the South-German sugarbeet crop

Leaf diseases represent a considerable risk in terms of yield and quality f or beet production in many areas. Starting in 1993, a team headed by Profes sor Dr. J.A. Verreet (University of Kiel) commenced field trials extending over several years to collect basic decision data on combating Cercospora b eticola and Erysiphe betae (IPS model sugar beet). The scientific knowledge collected in this way could be put into practice between 1996 and 1999 in collaboration with the Sugar Beet Growers' Association and state consultati on agencies in the South of Germany. A monitoring net consisting of approxi mately 200 locations (with 1 to 2 monitoring stocks) has been set up in the Sudzucker AG area for this purpose. A warning message is sent over the med ia (internet, fax, post, phone, agents, etc.) to the affected growers, reco mmending monitoring of their stocks if the threshold value for control is e xceeded in a region.