Schizoxylon canker

Schizoxylon canker, caused by the fungus Schizoxylon microsporum, is a pathogenic infection primarily affecting various species of the genus Ulmus (Elm). This fungus is a wood-inhabiting pathogen that compromises the tree's health by disrupting the integrity of the vascular system and the protective bark layer.

The primary host for this pathogen is the Elm tree. The fungus generally targets the trunk and larger branches. It gains entry through wounds, sunscald areas, or damage caused by boring insects. Once established, the mycelium colonizes the bark and cambium layers, leading to localized tissue death and structural weakness in the tree.

Symptoms of the infection typically include depressed lesions or cankers on the bark, accompanied by vertical cracking and oozing. As the disease progresses, the necrotic bark may flake off, exposing the underlying wood. Infected trees often exhibit foliage decline, crown dieback, and reduced vitality as the circulation of water and nutrients is severely impaired.

The development of the canker is heavily influenced by environmental factors such as high humidity and moisture, which facilitate the release and germination of fungal spores. The disease spreads through wind currents, rain splashing, and occasionally via insect vectors. Stressed trees, due to drought, pollution, or poor soil conditions, are particularly susceptible to widespread infection.

Management and prevention focus on reducing the pathogen load and enhancing tree vitality. Key strategies include pruning and destroying infected branches to eliminate sporulation sources. Furthermore, maintaining tree vigor through adequate irrigation and minimizing bark injuries can significantly reduce the risk of successful pathogen colonization. Fungicidal treatments may be applied to wounds to prevent initial infection.

• Sanitary pruning of cankered branches.
• Disinfection of tools used for tree maintenance.
• Protection of the bark from mechanical impacts.
• Monitoring for early signs of bark necrosis.