Contact persons Dr. A. Mavridis   Dipl.-Ing. agr. at the University of Göttingen,   Dr. sc. agr. at the University of Göttingen.   Activ since 35 years in the field of phytomedicine,  particularly in bacteriology, at the University of  Göttingen, acting as curator of the largest German  Collection of Phytopathogenic Bacteria (GSPB). Long-  standing advisory activity at various companies  within the ornamental plants, vegetable, fruit and  agricultural industry.   Dr. I. Schröder   Dipl.-Ing. agr. at the TU Hannover,   Master sc. agr. at the University of Göttingen,   Dr. sc. agr. at the University of Göttingen.   For 15 years active in phyto-bacteriology. Long-  standing experience in the management of  horticultural plants, the isolation and identification of  pathogens utilizing the most modern methods.