Caused by: Leptosphaeria maculans
Problem Category: Fungal Disease
Symptoms: Damping-off of seedlings; round or irregularly shaped gray necrotic lesions on leaves with dark margins; lesions may be covered in pink masses in favorable weather conditions.
Comments: Favors warm, wet conditions; higher temperatures result in the development of more visible symptoms.
Management: Cabbage does not have high levels of resistance to blackleg and fungicides use is uneconomical; use disease free seed or treat with hot water to remove fungus prior to planting; remove and destroy crop debris after harvest or plow deeply into soil.