Atropellis canker

Atropellis canker (caused by the fungus Atropellis apiculata) is a significant fungal disease that affects the bark and sapwood of various pine species. This pathogen induces localized tissue death, leading to the formation of characteristic cankers that can girdle the stem and branches of the tree.

The disease primarily targets species within the Pinus genus. It is particularly problematic in natural forest stands and plantations where environmental conditions promote the long-term survival of the fungus. The pathogen acts as a slow-moving parasite, gradually debilitating the host tree over several growing seasons.

Symptoms of an infection include sunken areas on the bark accompanied by persistent resin flow, known as resinosis. As the fungus matures, small, black apothecia emerge from the affected bark tissue, serving as the primary source of spore production. Internally, the wood under the canker displays a distinctive blue-black staining, which significantly degrades the timber quality.

The development of Atropellis canker is closely linked to cool, moist climates and high stand density. Spores are primarily dispersed through splashing rain and wind currents, gaining entry into the tree through small wounds or bark fissures. Trees that are already stressed due to poor soil, drought, or overstocking are significantly more susceptible to infection.

The impact of this disease ranges from reduced radial growth to the eventual death of the tree if girdling is complete. Protective and preventative measures include:

• Systematic removal of infected trees through sanitary thinning.
• Reducing forest density to improve air circulation and reduce humidity.
• Avoiding unnecessary mechanical injuries to trees during harvesting operations.
• Regular monitoring of high-risk pine stands to identify early signs of necrosis.