Cellar fungus

Cellar fungus (Coniophora puteana) is a common wood-decaying fungus that causes severe brown rot. While historically documented as a structural pest, it is also a significant pathogen in forest pathology and arboriculture, where it attacks weakened trees, reducing their stability and potentially leading to mortality in garden and orchard settings.

The fungus primarily targets both softwood and hardwood species. It colonizes the heartwood and sapwood, degrading cellulose while leaving lignin largely intact. This selective decay process causes the wood to shrink, become brittle, and crack into cubical blocks, a classic diagnostic feature of brown rot.

Visual symptoms include discolored, brownish wood, the presence of thin, olive-brown mycelial mats on the surface, and characteristic cracking. An unmistakable indicator of its presence is a distinct, musty, damp odor, especially in humid conditions where the fungus is actively growing.

Environmental conditions are critical for its development: the fungus thrives in high-humidity environments where wood moisture content is between 30% and 60%. It often enters trees through root injuries or fire scars, and spreads rapidly in shaded, poorly ventilated areas where moisture levels remain consistently high.

Prevention and control strategies focus on maintaining tree vigor and minimizing infection pathways. Key practices include:

• Regular inspection for early signs of decay;
• Proper wound dressing after pruning;
• Improving soil drainage to keep root collars dry;
• Removing and destroying heavily infested wood to reduce spore density in the environment.