Dermea canker

Dermea canker is a fungal disease caused by species of the genus Dermea, which leads to bark necrosis and limb dieback in various woody plants. The disease is characterized by the colonization of the vascular system and bark tissues, resulting in progressive decay of the branches.

The primary hosts of this pathogen are stone fruit trees, including cherries, plums, apricots, and peaches. The fungus typically gains entry into the tree through natural openings, such as lenticels, or through anthropogenic damage like pruning wounds, frost cracks, or insect-damaged areas.

Symptoms initially appear as depressed areas on the bark surface. As the infection progresses, these areas become discolored, necrotic, and cracked. In moist conditions, small, dark, cushion-like fruiting bodies emerge from the affected bark, releasing spores that serve as primary inoculum for further spreading the disease within the orchard.

The development of Dermea is highly dependent on environmental factors, particularly excessive moisture and cool to moderate temperatures. Spores are dispersed through rain splashes and wind, making wet springs particularly hazardous for orchard health. Trees that are stressed due to poor soil fertility or drought are significantly more susceptible to infection.

The impact of this disease is severe, often leading to the death of major scaffold branches and, in advanced cases, the entire tree. Effective management requires a combination of cultural practices, such as removing infected limbs, and chemical control through the application of fungicides during dormancy or active growth stages to protect vulnerable tissues.

• Sanitary pruning of all infected and necrotic branch sections.
• Application of pruning wound sealants to prevent fungal entry.
• Copper-based fungicidal sprays to reduce spore populations.
• Maintaining tree vigor through proper fertilization and irrigation.
• Regular monitoring for early signs of bark discoloration and cracking.