Valsa auerswaldii

Valsa auerswaldii is a species of fungus in the family Valsaceae. It is a plant pathogen that primarily affects apple trees, causing a disease known as canker.

Taxonomy

The species was first described scientifically by mycologist Julius Oscar Brefeld in 1881. The specific epithet auerswaldii honors the German botanist Carl Auerswald, who made significant contributions to the study of plant pathology.

Description

Valsa auerswaldii is characterized by its small, black, and flattened fruit bodies that appear on the bark of infected trees. The spores are elliptical and hyaline, and are produced in asci that are arranged in a layer within the fruit body.

Distribution and habitat

Valsa auerswaldii is widely distributed in temperate regions of the world, particularly in Asia and Europe. It is commonly found on apple trees, but can also infect other rosaceous hosts.

Pathogenicity

Valsa auerswaldii is a significant pathogen of apple trees, causing canker disease. The fungus enters the tree through wounds in the bark and grows in the phloem and xylem, causing the bark to crack and die. This can lead to significant yield losses in apple orchards.

Management

Management of Valsa auerswaldii involves regular inspection of trees for signs of infection, and the removal and destruction of infected branches. Fungicides can also be used to control the disease, but their effectiveness can be limited by the fungus's ability to survive in the wood of the tree.

See also

• List of apple diseases
• Plant pathology