Integrated control of cereal mildews : monitoring the pathogen : proceedings of a seminar in the Community Programme of Coordinated Research on Energy in Agriculture held in Freising-Weihenstephan, Federal Republic of Germany, 4-6 November 1986 / sponsored by the Commission of the European Communities, Directorate-General for Agriculture, Coordination of Agricultural Research ; edited by M.S. Wolfe and E. Limpert ; organized by G. Fischbeck and E. Limpert