Gloeoporus dichrous

Gloeoporus dichrous is a species of wood-decay fungus that primarily causes white rot in a wide range of hardwood trees. In the context of arboriculture and horticulture, it acts as a secondary pathogen, taking advantage of structural weaknesses in trees to colonize and eventually break down the woody tissue, impacting the longevity and health of the plantation.

The fungus affects various deciduous species, with fruit trees like apple, pear, and plum being particularly vulnerable if they have existing wounds or are stressed by environmental factors. The pathogen targets the sapwood and heartwood, gradually turning them into a soft, fibrous mass that compromises the structural integrity of the affected tree.

Symptoms of the disease are most evident during the fruiting phase, where characteristic pilei (fruiting bodies) emerge from the bark. These are often resupinate or have reflexed edges, featuring a white to cream-colored pore surface on the underside and a darker, smoky or brownish cap. Inside the tree, the wood loses its density and turns pale, often showing signs of advanced decay.

The development of Gloeoporus dichrous is heavily influenced by high humidity levels and a continuous supply of necrotic wood tissue. Spores are dispersed by wind and can travel over significant distances, successfully infecting new hosts through exposed cuts, broken branches, or bark lesions. The fungus remains active across a broad temperature range, making it a persistent threat in many regions.

The impact of this disease can be devastating, leading to the collapse of affected branches or the total loss of the tree due to structural failure. To effectively prevent and manage the presence of this fungus, practitioners should focus on:

• Executing proper pruning practices to avoid large, jagged wounds.
• Applying wound sealants to any exposed wood immediately after pruning.
• Sanitizing pruning tools with alcohol or bleach solutions between trees.
• Removing and destroying infected wood debris and stumps from the orchard vicinity.