Cavity spot of carrots.

Cavity spot was induced after compacted carrot beds were watered to excess in July or August, but not after treatment in October. Roots grown in pots containingfield soil from the site of a cavity spot outbreak had fewer lesions when supplied witha minimal amount of water than when waterlogged, and when the soil was mixed withpeat instead of sand. Soft rot lesions developed on roots which had been inoculated with the field soiland sealed in pots with wax and stood in water. Anaerobic pectolytic bacteriabelonging to the genus Clostridium were isolated from the lesions and were proven tobe pathogenic to carrot roots. The lesions later resembled cavity spot after the rootswere returned to dry, aerobic conditions.