Erwinia carotovora as a Stalk Rot Pathogen of Sunflower in North Dakota. N. C. Gudmestad, Plant Pathologist, North Dakota State Seed Department, Cargill, Inc., Fargo, ND 58105. G. A. Secor, Associate Professor, and P. Nolte, Technician, Department of Plant Pathology, North Dakota State University; and M. L. Straley, Sunflower Pathologist, Cargill, Inc., Fargo, ND 58105. Plant Dis. 68:189-192. Accepted for publication 24 August 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-189.

The etiologic agent of a late-season field stalk rot of sunflower (Helianthus annuus) was identified as Erwinia carotovora; a pathovar could not be delineated on the basis of biochemical and physiological data. Sunflowers became more susceptible to the disease as they matured, with peak susceptibility occurring at seed set. Resistance to the disease may exist in advanced breeding selections.

Keyword(s): serogroup, soft rot.