Localized Infections of Siliques and Seed of Cabbage by Phoma lingam. J. M. Bonman, Graduate Research Assistant, Western Washington Research and Extension Center, Puyallup 98371. R. L. Gabrielson, Plant Pathologist, Western Washington Research and Extension Center, Puyallup 98371. Plant Dis. 65:868-869. Accepted for publication 24 March 1981. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-868.

Cabbage siliques and seed, both naturally infected with Phoma lingam, were found in a field in the cabbage seed growing region of the Pacific Northwest. All silique infections were localized, indicating that infection did not progress systemically from basal crown cankers. Infected siliques had internal blackening of the locular walls or the suture, usually confined to the stigmatic end. Few showed visible external signs or symptoms of infection. The difficulty of finding blackleg in Pacific Northwest seed fields suggests that a direct seed test would more reliably predict disease potential of seed lots.