Diseases

Apple Scab

Malus Mill.

A fungal disease of apple trees caused by the ascomycete fungus Venturia inaequalis. It affects all aerial organs of the plant, causing necrosis, fruit deformation, and premature defoliation.

In the reference 238 varieties crop Apple, where this is mentioned in the description.

The causative agent is the fungus Venturia inaequalis, which is highly specialized to apple trees. The pathogen infects leaves, fruits, sepals, pedicels, and young shoots. On leaves, the disease manifests as olive-black velvety spots, and on fruits, as suberized areas that lead to cracking and deformation.

The high genetic variability of the pathogen allows it to overcome the monogenic resistance of cultivars. In modern breeding, Rvi resistance genes, including Rvi6 (formerly known as Vf), are used to combat the disease. Pyramiding several resistance genes into a single genotype is recognized as an effective strategy to ensure long-term protection of the crop.

General information about the subject — on the page Scab.

Sources8

Varieties of Apple 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.