A type of symptom in carrot seedlings characterized by blackening and thinning of the root neck, leading to plant lodging. It is an early manifestation of Alternaria blight, caused by fungi of the genera Alternaria and Stemphylium.
In the reference
16
varieties
crop Carrot,
where this is mentioned in the description.
The occurrence of black leg symptoms in carrots is most often due to the development of the fungus Alternaria dauci. The pathogen complex also includes species such as Alternaria radicina, Stemphylium botryosum, and Alternaria tenuissima. The infection manifests as a darkening and constriction of the root neck of young plants, which leads to their death. Under high humidity conditions, the formation of an olive or brown moldy coating is possible on the affected tissues.
Unlike traditional seedling diseases caused by Rhizoctonia or Pythium species, carrot black leg serves as an initial stage of Alternaria blight, which subsequently spreads to the leaves and root crops. At present, data on specific races of the pathogens or genetic markers for resistance to this trait in carrot breeding have not been systematized.
General information about the subject — on the page
Blackleg.
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.