Bacterial Pathogens: Reducing Seed and In Vitro Survival by Physical Treatments. Curt Leben, Professor, Department of Plant Pathology, Ohio State University and Ohio Agricultural Research and Development Center, Wooster 44691. John P. Sleesman, Research Farm Manager, Mobay Chemical Corporation, Howe, IN 46746. Plant Dis. 65:876-878. Accepted for publication 19 December 1980. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-876.

Cotyledon lesions on cucumber seedlings were prevented or greatly reduced in laboratory and field tests when seeds, vacuum-infiltrated with Pseudomonas lachrymans, were stored for 3 days at 50 C and 75% relative humidity. The treatment reduced seed germination. P. lachrymans did not survive dry in vitro at 50 C and 75% relative humidity for 1 day. This pathogen and eight other plant-pathogenic bacteria survived poorly in vitro at 75% as compared with 0 or 34% relative humidity.