A fungal disease of leeks caused by the pathogen Alternaria porri, characterized by the formation of elliptical lesions with a purplish hue and concentric rings on the leaves.
In the reference
13
varieties
crop Leek,
where this is mentioned in the description.
The causative agent of the disease is the fungus Alternaria porri, with the potential involvement of the associated species Alternaria alternata. The infection manifests on leaves as primary water-soaked spots with a white center, which expand into an elliptical shape under temperatures of 20–30°C and high humidity.
Affected areas develop a purple or violet coloration, surrounded by a yellow halo. A characteristic symptom is the formation of concentric zones at the site of sporulation, which, in cases of severe infection, leads to the necrosis of the leaf blade or its breakage at the site of infection.
General information about the subject — on the page
Alternaria blight.
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.