Botryosphaeria stevensii

Botryosphaeria stevensii is a fungal pathogen that primarily affects fruit trees, particularly apple trees and pear trees. It is responsible for a disease known as Botryosphaeria canker, which can cause significant damage to affected trees.

Description

Botryosphaeria stevensii is a member of the Botryosphaeriaceae family. It is a necrotrophic fungus, meaning it kills host tissue and then feeds on the dead cells. The fungus produces spores that are spread by wind and rain, and can also be spread by insects and birds. The spores germinate on the surface of the tree and penetrate the bark, causing cankers to form.

Symptoms and Effects

The primary symptom of Botryosphaeria canker is the formation of cankers on the branches and trunk of the tree. These cankers are sunken areas of dead tissue, often surrounded by a raised edge. As the disease progresses, the cankers can girdle branches, causing them to die. In severe cases, the disease can kill the entire tree.

In addition to causing direct damage to the tree, Botryosphaeria canker can also make the tree more susceptible to other diseases and pests. The cankers provide an entry point for other pathogens, and the stress caused by the disease can weaken the tree's immune system.

Management and Control

Management of Botryosphaeria canker involves a combination of cultural practices and chemical treatments. Infected branches should be pruned and destroyed to prevent the spread of the disease. Fungicides can be applied to protect healthy trees, but they are not effective at curing infected trees.

Economic Impact

Botryosphaeria canker can have a significant economic impact on orchards. The disease can reduce the yield of affected trees, and in severe cases, can kill the trees entirely. This can result in significant losses for growers.

See Also

• Botryosphaeria dothidea
• Botryosphaeria obtusa
• Plant pathology