The role of Erwinia carotovora in the epidemiology of potato blackleg. II. The effect of soil temperature on disease severity

摘要: Relative disease severity (seedpiece decay or post emergence blackleg) incited byErwinia carotovora var.carotovora (Ecc) andErwinia var.atroseptica (Eca) was studied in the field and greenhouse. When inoculated tubers were planted cool soils greenhouse (7.0–18.5°C average minimum 16–26°C maximum temperature during first 30 days after planting)Eca caused significantly more thanEcc. Under these experimental conditionsEcc did not cause than that found non-inoculated controls. soil temperatures high at planting time (21.4–24.0°C 29.6–35.0°C for planting), inoculation withEcc resulted severe whileEca produced no infection uninoculated At intermediate both infective. Seedpiece by organisms correlated with planting. As increased, withEca. lower opposite result obtained. Field studies showed bothEca andEcc able to typical blackleg infection, former low latter conditions. The data suggest bothEcc andEca are components of potato soft rot complex. Environmental conditions, especially temperature, determine which organism is causative under a particular set