Tinder fungus

Fomes fomentarius, commonly known as the tinder fungus, is a destructive wood-decaying fungus that primarily attacks deciduous trees. As a parasitic organism, it infiltrates the host tree through wounds, exposed heartwood, or broken branches, establishing a pervasive mycelium network within the trunk.

The host range is extensive, significantly affecting species such as birch, beech, oak, and various other hardwoods. Its presence in orchards and woodlands is of major concern because it compromises the structural integrity of the tree, leading to decay, reduced timber quality, and an increased hazard of windthrow.

Symptoms of infection are initially internal, but the emergence of perennial, hoof-shaped, grey-to-brownish conks on the bark serves as a clear indication of advanced colonization. The affected wood undergoes white rot, becoming soft and spongy, often displaying distinct black zone lines that delineate the fungal colonization areas.

The spread of this fungus is facilitated by the release of spores that are easily transported by wind and rain. Favorable conditions for colonization include high humidity, stagnant airflow, and temperatures that support the mycelial growth inside the wood. Once established, the fungus can persist for many years until the host tree succumbs.

Effective management focuses on prevention through silvicultural and horticultural practices. It is crucial to maintain tree vigor to increase natural resistance and to minimize mechanical damage to the bark. Whenever wounds occur, they should be treated promptly with fungicides or wound sealants to prevent fungal entry. Infected trees should be removed and destroyed to limit the inoculum source in the vicinity.