Xylobolus

Xylobolus is a genus of fungi recognized for causing white rot in woody plants. These fungi play a significant role in the forest ecosystem by decomposing dead wood, but when they attack ornamental or orchard trees, they become serious pathogens that compromise the structural integrity of the affected plants.

The host range of Xylobolus includes various deciduous trees such as oak, beech, and birch, as well as several species of fruit trees. The infection typically begins when fungal spores enter the plant through wounds, pruning cuts, or bark fissures caused by frost or mechanical damage, where they establish a colony within the xylem tissue.

Key symptoms include the formation of crust-like or shelf-like fruiting bodies on the surface of the trunk or branches. Inside the wood, the fungus secretes enzymes that break down lignin, resulting in a bleached, fibrous, and fragile appearance. This advanced decay often makes trees unstable, increasing the risk of structural failure during severe weather.

Environmental conditions conducive to the development of Xylobolus include high humidity, stagnant air, and moderate temperatures, which facilitate the production and dispersal of spores. The pathogen is primarily spread by wind, rain splashes, and sometimes by insects that inhabit the wounded areas of the bark.

Managing the disease relies on integrated arboricultural practices, such as removing infected wood and preventing mechanical injury to healthy trees. Regular monitoring is essential to detect the fruiting bodies early. If the infection is detected, affected limbs should be pruned cleanly, and the wood should be removed from the site to prevent further spore dispersal.