Bacterial stem and peduncle canker of greenhouse pepper

Disease losses to Erwinia carotovora subsp. carotovora were 12 and 20% in 1996 and 1998, respectively, in greenhouse peppers (Capsicum annuum) at St. David's, Ontario. The disease was also observed on field peppers near Harrow in 1996-1997. Symptoms consisted of dark brown to black cankers on the stem nodes and fruit peduncles, dark discolouration of the internal stem tissue, and internal breakdown of the pith with stem hollowness in some cases. Extensive physiological and biochemical tests were conducted on all isolates recovered to verify identity. Reactions of greenhouse and field strains were generally similar with a few exceptions. Spraying, spraying + wounding or rubbing, and stem inoculation were conducted with selected isolates. 'Early California Wonder' pepper plants that were wounded and then sprayed with a bacterial suspension consistently showed extensive collapse of stems and death of plants 4 days later regardless of isolate used. 'Trust' tomato plants (Lycopersicon esculentum) showed a similar response or, in some cases, developed an internal brown stem discolouration and hollowness. Spraying or spraying + rubbing of leaves with isolates also caused extensive disease development but fewer plants were affected. Greenhouse and field isolates caused similar symptoms on both tomatoes and peppers. This is the first report of bacterial stem canker on greenhouse peppers in Canada.