1. Organic Agricultural Sciences; University of Kassel; Witzenhausen Germany
2. Department of Crop Production Ecology; Swedish University of Agricultural Sciences; Uppsala Sweden
3. Department of Agricultural and Forestry Sciences; University of Tuscia; Viterbo Italy
4. Research Division Agroecology and Environment; Agroscope; Zürich Switzerland
5. Julius Kühn-Institute, Federal Research Centre for Cultivated Plants; Institute for Epidemiology and Pathogen Diagnostics; Münster Germany