More than 270 scientists from 33 countries attended the 6th International Conference on Plant Pathogenic Bacteria in College Park, Maryland, June 2-7, 1985. The Conference was jOintly sponsored by the International Society of Plant Pathology, Bacteria Section and by the United States Department of Agriculture, Agriculture Research Service. The Conference provided an opportunity for the presentation and discussion of recent developments in phytobacteriology. The Conference was organized into five symposia, seven discussion sessions, contributed papers and poster presentations. More than 230 contributions were presented under the following topics: ice nucleating bacteria; detection, identification, nomenclature and taxonomy of phytopathogenic bacteria; applications and impact of new biotechnologies on phytobacteriology; bacterial phytotoxins; diagnostic phytobacteriology; management of bacterial plant diseases; and molecular biology, genetics and ecology, epidemiology of phytopathogenic bacteria. In addition, special sessions focused on Agrobacterium, Erwinia, Psedomonas and fastidious prokaryotes. This reflected the broad spectrum of current research activity in phytobacteriology. Furthermore, interest in this series of conferences clearly continues to increase. Key research scientists who are currently making major advances in phytobacteriology participated in the Symposia and Discussions. One of the most significant recent changes that has occurred in the field of plant pathology generally is the dynamic growth of research in which recombinant DNA technology is being applied in basic studies on bacterial plant pathogens. Results from investigations on the crown gall bacterium have stimulated expansion of research on other bacterial systems.