Pycnoporus cinnabarinus

Pycnoporus cinnabarinus, commonly known as the cinnabar-red polypore, is a wood-decay fungus that acts as a pathogen causing white rot in trees. It plays a significant role in the natural decomposition of dead wood but can be detrimental to ornamental and fruit trees.

This fungus primarily infects broad-leaved tree species, such as birch, cherry, and rowan. It functions as a weak parasite or saprotroph, invading the host through wounds, broken branches, or frost cracks in the bark, ultimately colonizing the heartwood of the tree.

The primary symptom of infection is the presence of distinctive, vibrant cinnabar-red fruiting bodies on the trunk or branches. Internally, the fungus decomposes both cellulose and lignin, leading to a bleached, fibrous, and soft texture of the wood, which significantly compromises the structural stability of the host tree.

The development of this pathogen is highly dependent on humidity levels and the availability of compromised wood. Spores are dispersed through the air, and upon landing on a suitable substrate—specifically wounded surfaces—they germinate and develop mycelium that penetrates deep into the wood tissue.

Effective management and prevention strategies include:

• Prompt removal and proper disposal of infected branches or dead trees to eliminate the source of spores.
• Treating mechanical injuries and pruning cuts with protective horticultural sealants.
• Enhancing tree vigor through proper fertilization, watering, and soil management.
• Ensuring good air circulation within the orchard by thinning crowns and removing unnecessary vegetative debris.