Leptosphaeria maculans (black leg of crucifers, stem canker )
Leptosphaeria maculans
black leg of crucifers, stem canker
Phoma brassicae, Phoma lingam, Phoma oleracea, Phoma napobrassicae, Phyllosticta brassicae, Phyllosticta napi Sacc., Plenodomus lingam, Pleospora maculans, Sphaeria lingam, Sphaeria maculans
Worldwide
CA, GA, HI, ID, IL, KY, NY, ND, OK, OR, WA, WI
2025-10-14
fungus
China, Korea
Restricted to Brassicaceae
LEPTMA
Leptosphaeria maculans is a fungus that causes black leg disease in canola and other cruciferous crops. It spreads mainly through windborne ascospores from infected plant residues, which can travel several kilometers to infect young plants. Rain and humidity trigger spore release and infection. The fungus is also seedborne and can cause early infections in seedlings, especially under humid or crowded conditions.