Factors Affecting the Severity of Seed-piece Decay, Incidence of Blackleg, and Yield of Norgold Russet Potato in North Dakota. N. C. Gudmestad, Assistant Professor, Department of Plant Pathology, North Dakota State University, Fargo 58105. P. Nolte, and G. A. Secor. Research Specialist, and Associate Professor, Department of Plant Pathology, North Dakota State, University, Fargo 58105. Plant Dis. 72:418-421. Accepted for publication 7 January 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0418.

The influence of cultural practices under rain-fed production conditions on the development of seed-piece decay, nonemergence, and blackleg of Norgold Russet potato was studied in North Dakota in the field in 1984 and 1985. The bruising of seed before preparation of seed pieces significantly increased seed-piece decay and nonemergence in 1984. Pulp temperature of tubers at cutting did not affect any disease of potato caused by Erwinia carotovora. Levels of contamination by E. carotovora significantly increased the incidence of seed-piece decay, nonemergence, and blackleg in both years.

Keyword(s): Erwinia carotovora subsp. atroseptica, E. c. subsp. carotovora, seed tuber contamination, soft rot potential, Solanum tuberosum.