Brick cap mushroom

Hypholoma sublateritium, commonly known as the brick cap, is a species of wood-decay fungus that acts as a pathogen in agricultural and forestry settings. While it primarily functions as a saprotroph breaking down dead wood, it can colonize weakened living trees, contributing to white rot and long-term structural deterioration of the host plant.

The disease mechanism involves the penetration of fungal hyphae through wounds in the bark or exposed roots. Once established, the fungus secretes enzymes that degrade lignin and cellulose within the wood, which is a classic symptom of white rot. This biochemical activity compromises the tree’s structural integrity, eventually leading to internal cavitation.

The fungus affects a variety of broad-leaved trees, including orchard species such as apple and pear trees. It thrives in environments where organic debris, such as stumps or fallen branches, is left to decay, providing a continuous source of inoculum that can bridge the gap to healthy, albeit stressed, vegetation.

Symptomatology typically involves the emergence of clustered, brick-colored fruiting bodies at the base of the trunk or on exposed roots during late summer and autumn. Inside the tree, the wood becomes bleached, soft, and fibrous. In advanced stages, the tree exhibits a significantly reduced capacity to transport nutrients, leading to progressive dieback.

Prevention is centered on rigorous orchard hygiene:

• Removal of old stumps and decaying wood debris.
• Proper pruning techniques to minimize large wounds.
• Application of protective wound dressings on significant cuts.
• Monitoring soil health to prevent root rot conditions.