|
|
AVRDC
International Cooperators'
Fact Sheet |
|
Crucifer
Diseases Bacterial
Soft Rot |
|
|
Damage Symptoms Soft rot occurs on all crucifer crops, but it is particularly damaging to Chinese cabbage and common cabbage. Infected plant tissues first develop a water-soaked lesion that enlarges rapidly in diameter and depth. The affected area becomes soft and mushy and generally turns a dark color in advanced stages of disease development. Soft rot-infected cruciferous plants almost always give off an offensive odor, perhaps in part due to invasion by secondary organisms. Disease losses from soft rot may occur in the field, transit, or storage. Conditions for Development Soft rot bacteria persist in infected plant debris, in association with plant roots, in low numbers in the soil, and in association with several insects. Wounds such as leaf scars, insect injury, mechanical injury, lesions caused by other pathogens, etc. are the primary avenues of soft rot bacterial invasion. Rainfall and high temperatures enhance infection in the field. Transit and storage infection may develop from bacterial contamination that occurred in the field or during postharvest from handling equipment and storage containers. Soft rot bacteria can grow over a temperature range of 5-37°C with an optimum temperature of about 22°C. |
|
|
Control Disease management is based primarily on sanitation and cultural practices. Sufficient time should be allowed for crop residues to decompose before planting a second crop. Vegetable crops should be rotated with cereals or other non-susceptible crops. Fields should be well drained to reduce soil surface moisture and plants should be spaced sufficiently to allow ventilation for rapid drying of foliage. Rain shelters to prevent soil splash and foliage wetting should also reduce soft rot incidence. |
|
Last updated: 2001. Information from: Vegetable Diseases: A Practical Guide. Lowell L. Black, AVRDC. |
|
|