• It is caused by Phoma lingam and occurs in most regions, specially in areas with rainfall during the growing period.
• The fungus is carried by the seed and hence it may occur from the early stage.
• Stem of the affected plant when split vertically, shows severe black discoloration of sap stream. Whole root system decays from bottom upwards.
• Frequently, the affected plants fall over in the field.

Management

• Seed infection can be prevented by spraying the seed plants with copper oxychloride or with an organo mercuric compound.
• Seed treatment with Captan or Thiram 4g/kg of seed, followed by seed treatment with Trichoderma viride 4g/kg.
• Pusa Drumhead, a cabbage cultivar has been reported to be tolerant under field condition.