Pepper (Capsicum annuum) Soft Rot Caused by Erwinia carotovora subsp, atroseptica . John R. Stommel, Research Geneticist, USDA-ARS, Vegetable Laboratory, Plant Sciences Institute, Beltsville, MD 20705. Robert W. Goth, Research Plant Pathologist, Kathleen G. Haynes, Research Geneticist, USDA-ARS, Vegetable Laboratory, Plant Sciences Institute, Beltsville, MD 20705; and Seong Hwan Kim, Plant Pathologist, Pennsylvania Department of Agriculture, Bureau of Plant Industry, Harrisburg 17120. Plant Dis. 80:1109-1112. Accepted for publication 18 June 1996. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1996. DOI: 10.1094/PD-80-1109.

Erwinia carotovora subsp, atroseptica caused soft rot of pepper (Capsicum annuum) fruit in field plots at Beltsville, MD, in 1994. The pathogen was identified as E. carotovora subsp. atroseptica based on carbohydrate utilization and fatty acid profiles. This is the first report of a bacterial fruit rot of pepper caused by E. carotovora subsp, atroseptica. Inoculation techniques were evaluated for reliable induction of pepper soft rot. Inoculation of puncture wounds provided more consistent lesion development than inoculation of Carborundum-induced abrasion wounds or nonwounded tissue. Significant differences in susceptibility of puncture-inoculated pepper genotypes to E. carotovora subsp, atroseptica-induced soft rots were noted. Virulence of E. carotovora subsp, atroseptica, E. carotovora subsp, carotovora, and E. chrysanthemi were compared at warm (23°C) and cool (10°C) temperatures. E. carotovora subsp, carotovora and E. chrysanlhemi caused the greatest soft rot decay of pepper fruit at 23°C. At 10°C, fruits inoculated with E. carotovora subsp, atroseptica were the most severely affected, suggesting that E. carotovora subsp, atroseptica has the potential to cause significant postharvesl decay losses during cool storage conditions.

Keyword(s): fruit decay, inoculation technique