Downy bracket

Trametes pubescens, commonly known as the downy bracket, is a wood-decaying fungus that causes white rot. While it primarily functions as a saprotroph breaking down dead wood, it can act as a facultative parasite, attacking stressed or wounded living trees, which is a significant concern for both arboriculture and forestry.

The fungus typically infests deciduous trees, such as birch, alder, and beech, and can occasionally be found on fruit trees in orchards. It gains entry into the host plant primarily through bark wounds, frost cracks, or improper pruning cuts, subsequently colonizing the sapwood and heartwood of the host.

Symptoms of the infection include the presence of shelf-like, perennial fruiting bodies on the trunk. These are characterized by a velvety, downy texture and a creamy white to pale yellow color. Internally, the infected wood undergoes a white rot process, losing its structural integrity and becoming fibrous and brittle as the fungus decomposes lignin and cellulose.

The development and spread of Trametes pubescens are highly favored by humid conditions and the availability of unprotected wood surfaces. The fungus produces spores that are dispersed via wind currents. Once these spores land on fresh wounds, they germinate and form a mycelium that rapidly permeates the wood tissue, particularly in moist environments.

The economic and ecological impact of this fungus is severe, as it causes crown dieback, reduced vigor, and eventually the structural failure of the tree. As the wood decays, the tree becomes vulnerable to windthrow, and the fungus may continue to produce spores that infect neighboring healthy trees, making it a persistent threat if not managed properly.

• Perform regular pruning to remove infected branches and improve tree health.
• Seal all large pruning cuts and wounds with appropriate wound dressings.
• Remove and destroy severely affected trees to eliminate inoculum sources.
• Maintain optimal tree vitality through proper fertilization and irrigation.