Survival of Xanthomonas campestris pv. phaseoli and Pectolytic Strains of X. campestris in Bean Debris. R. L. Gilbertson, Assistant Scientist, Department of Plant Pathology, University of Wisconsin-Madison 53706. R. E. Rand, and D. J. Hagedorn. Senior Research Specialist, and Emeritus Professor, Department of Plant Pathology, University of Wisconsin-Madison 53706. Plant Dis. 74:322-327. Accepted for publication 16 November 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0322.

Small populations of Xanthomonas campestris pv. phaseoli, causal agent of common bacterial blight of bean (Phaseolus vulgaris), overwintered in bean debris in no-tillage plots. Common blight bacteria were isolated from debris in these plots collected monthly from October to May of 1985–1986 and October to March of 1986–1987 but not from debris in disked or plowed plots after February of 1986 or 1987. Bean plants inoculated with debris collected from no-tillage plots in May of both years developed common bacterial blight, as did beans planted in no-tillage plots the following growing season. Pectolytic strains of X. campestris, which were not pathogenic on bean, were consistently isolated from bean debris collected throughout the winter and spring of both years and colonized beans and weeds in tillage plots the following growing season. Fatty acid analysis of these pectolytic strains of X. campestris was inconclusive for a pathovar designation. We conclude that bean debris can be a source of inoculum for common blight bacteria and that survival of bacteria is influenced by tillage.