Diseases

Blackleg of Rapeseed

Brassica napus L.

In rapeseed, the term "blackleg" refers to two distinct pathological processes: a complex of soil-borne fungi (Pythium, Rhizoctonia, Olpidium) causing seedling damping-off, and phoma stem canker (Leptosphaeria maculans), manifested by necrosis of stem tissues.

In the reference 12 varieties crop Rapeseed, where this is mentioned in the description.

Soil-borne blackleg affects seedlings, causing softening and darkening of tissues in the root collar zone, which leads to lodging and plant death. Disease development is facilitated by poor aeration of heavy soils, high humidity, and crust formation; no specific resistance genes have been identified for this complex of pathogens.

Phoma stem canker, caused by the fungus Leptosphaeria maculans, is characterized by the formation of necrotic spots on stems, leaves, and pods. Resistance in varieties is provided by qualitative R-genes (Rlm1-Rlm11, LepR1-LepR3) and adult plant resistance (APR), with breeding efforts focused on gene pyramiding to counter the variable races of the pathogen.

General information about the subject — on the page Blackleg.

Sources8

Varieties of Rapeseed mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.