Irpex rosettiformis

Irpex rosettiformis is a wood-decaying fungal pathogen belonging to the Polyporaceae family. This fungus is primarily known for causing white rot in woody plants, leading to the gradual degradation of structural timber and the compromise of the tree's overall vitality.

The fungus typically targets weakened trees, including fruit-bearing and ornamental species. Infection sites are usually mechanical wounds such as pruning cuts, frost cracks, or damaged bark, which provide the pathogen with an entry point into the internal xylem and phloem tissues.

The most prominent symptom of Irpex rosettiformis is the appearance of its distinctive rosette-shaped fruit bodies on the trunk or branches. The internal wood becomes soft and brittle, losing its load-bearing capacity, which eventually leads to structural instability and potential death of the affected plant parts.

Environmental factors such as high humidity, poor aeration within the canopy, and stagnant air significantly favor the spread of the fungus. Spores are disseminated by wind, rainwater, and vectors like insects or contaminated pruning tools used across infected and healthy trees.

• Regular sanitation pruning to remove infected wood.
• Sterilizing cutting tools with alcohol or bleach after each use.
• Applying wound sealants or fungicidal pastes to large pruning wounds.
• Removing and destroying all infected wood scraps from the orchard.
• Maintaining tree vigor through balanced fertilization and hydration.

The pathogenicity of this fungus lies in its slow, internal progression, which often goes unnoticed until the host is significantly damaged. Consequently, preventing colonization through good arboricultural practices remains the most successful strategy in minimizing the impact of Irpex rosettiformis on susceptible tree stands.