Disease Note

Bacterial Stem Rot, a New Disease ot Adzuki Beans in Minnesota. B. W. Kennedy, Department of Plant Pathology. University of Minnesota, St. Paul 55108.. R. Denny, Department of Plant Pathology. University of Minnesota, St. Paul 55108. . Plant Dis. 68:167. Accepted for publication 10 October 1983.. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-167b.

An epiphytotic of bacterial blight severely interfered with establishment in Minnesota of the adzuki bean (Phaseolus angularis L.) industry in 1980. The disease was widespread in commercial and experimental plantings in the state. In 1982, the pathogen was isolated from plants in experimental plots originating from seed in 1980 plantings, and pathogenicity of the bacterium was confirmed in the greenhouse. Some other Phaseolus beans, notably the cultivars Black Turtle and Manitou, were susceptible in greenhouse pathogenicity trials, but navy beans were relatively resistant and pinto bans and soybeans (Glycine max L.) were immune. The bacterium produced weak fluorescence on King's medium 3 but differed from Pseudomonas syringae pv. syringae pv glycinea, and pv. phaseolicola in important biochemical characteristics. In field pathogenicity tests during the 1983 season, the pathogen persisted only in adzuki beans. The bacterium resembles P. adzukicola/ described for the first time in Japan in 1979.