Bacterial Pathogens: Reducing Seed and In Vitro Survival by Physical Treatments

Abstract

Cotyledon lesions on cucumber [Cucumis sativus] 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.degree. C and 75% relative humidity. The treatment reduced seed germination. P. lachrymans did not survive dry in vitro at 50.degree. C and 75% relative humidity for 1 day. This pathogen and 8 other plant-pathogenic bacteria [Agrobacterium tumefaciens, Corynebacterium nebraskense, Erwinia stewartii, P. phaseolicola, P. solanacearum, P. syringae, Xanthomonas campestris, X. nigromaculans f. sp. zinniae] survived poorly in vitro at 75% vs. 0 or 34% relative humidity.