Hapalopilus

Hapalopilus is a genus of fungi belonging to the order Polyporales, known for causing white rot in various hardwood species. As an agronomical pathogen, it actively decomposes lignin and cellulose, which leads to the structural degradation of tree trunks and branches, posing a significant risk to the longevity and safety of orchard and forest trees.

The primary host range for this pathogen includes deciduous trees such as oak, birch, beech, and rowan. The infection usually begins when fungal spores penetrate the host tissue through wounds, pruning cuts, or frost cracks, allowing the mycelium to establish itself within the xylem and begin the progressive decay of the inner wood structure.

Symptoms of an infestation are characterized by the emergence of fruit bodies, often appearing as distinct brackets on the surface of the bark. These structures are typically porous and exhibit a specific color range. Internally, the wood becomes bleached, soft, and brittle, significantly reducing its tensile strength and leading to an increased risk of stem failure or branch breakage.

The development and spread of Hapalopilus are highly dependent on environmental factors, specifically high humidity and temperatures that support fungal growth. The disease cycle is promoted when trees are stressed by adverse weather, poor soil conditions, or neglect, providing the fungus with easier access to colonize the interior wood and produce new spores for dispersal.

Management and prevention strategies focus on mitigating the risk of infection and maintaining tree vigor. Key practices include:

• Regular inspection of trees for signs of fungal colonization.
• Pruning of infected branches with tools sterilized between cuts.
• Application of wound dressings to fresh cuts to create a physical barrier against spores.
• Removal and destruction of heavily infected trees to reduce the overall spore load in the vicinity.