Fruit spot development caused by Clavibacter michiganensis subspecies michiganensis on processing tomatoes.
C. M. MEDINA-MORA, J. Bell, M. K. Hausbeck, and D. W.
Phytopathology 89: S100. (suppl.)
1999
บทคัดย่อ
Bacterial canker of tomato, caused by Clavibacter michiganensis subspecies michiganensis (Cmm), occurs worldwide and affects both yield and fruit quality due to spotting. Fruit spotting was studied by spraying flowers once or twice with Cmm at 108 cfu/ml beginning at 5 days pre- to 4 days post-anthesis. In flowers sprayed once, maximum incidence of spotted fruit (15–42%) and maximum severity of spotting (5.1–6.8 spots/diseased fruit) occurred when flowers were sprayed 2 days post-anthesis. In flowers sprayed twice, maximum incidence (78%) and maximum severity (15 spots/diseased fruit) occurred when flowers were sprayed 2 and 5 days post-anthesis. Cmm strains characterized as virulent or avirulent based on a stem inoculation assay were applied to the epidermis of fruits <22 mm in diameter with a paintbrush. Incidence of spotting was 67 to 100% for virulent strains and 75 to 80% for avirulent strains. Severity was 61–110 and 20–36 spots/diseased fruit, respectively. Defining factors affecting fruit spot development may help formulate strategies to control spotting.