Alternaria mali

Alternaria mali is a species of fungi in the genus Alternaria, which is known to cause apple blotch, a disease that affects apple trees. This fungus is a significant pathogen in apple cultivation, causing severe damage to the fruit and leaves of the tree.

Taxonomy

The species was first described in 1933 by Japanese mycologist Yoshi Ito, who isolated it from diseased apple trees in Japan. It belongs to the genus Alternaria, a large genus of ascomycete fungi that is a major cause of spoilage in harvested fruit and vegetables, particularly when stored in damp conditions.

Description

Alternaria mali is a dematiaceous (dark-walled) fungus that produces large, dark, multicellular spores. The spores are produced in chains, with the youngest spore at the base of the chain. The fungus is capable of producing a variety of secondary metabolites, including alternariol, alternariol monomethyl ether, and altenuene.

Pathogenicity

Alternaria mali is the causal agent of apple blotch, a disease that causes severe damage to the fruit and leaves of apple trees. The disease is characterized by the appearance of dark, necrotic lesions on the fruit and leaves. The lesions may coalesce, causing extensive damage to the fruit and defoliation of the tree. The disease can result in significant yield losses, particularly in damp, cool conditions which favor the growth and spread of the fungus.

Management

Management of apple blotch involves a combination of cultural practices and chemical control. Cultural practices include pruning to improve air circulation and reduce humidity, and the removal and destruction of infected plant material. Chemical control typically involves the application of fungicides, although the fungus has been reported to develop resistance to some fungicides.

See also

• List of apple diseases
• Alternaria