Plums and Custard

Tricholomopsis rutilans, commonly known as Plums and Custard, is a wood-decay fungus that belongs to the family Tricholomataceae. While it is often studied as an edible species in mycology, in the context of arboriculture and forest pathology, it acts as a significant pathogen that contributes to the degradation of coniferous wood through the formation of brown rot.

The primary hosts for this fungus include various coniferous species, most notably pine and spruce. The fungus acts as a facultative parasite, often colonizing stressed or wounded living trees, although it is more commonly found on stumps, deadwood, and fallen logs. It gains entry into the host tissue through existing wounds in the bark, such as frost cracks or insect damage.

Symptoms of the infection become evident when the fruiting bodies of the fungus emerge from the bark of the trunk or the stump. These vibrant yellow and red mushrooms are clear indicators of internal decay. Within the tree, the fungal mycelium breaks down structural components of the wood, leading to increased brittleness and loss of structural integrity, which significantly weakens the host.

Environmental conditions that favor the spread and development of Tricholomopsis rutilans include high humidity and the presence of abundant woody debris. Spores are easily dispersed by wind currents, allowing the fungus to rapidly colonize new areas, especially in forest stands that are not adequately maintained or that have suffered from recent environmental stress.

Mitigation and forest protection strategies are essential to minimize the impact of this pathogen:

• Conducting systematic sanitary logging to remove infected timber.
• Clearing stumps and deadwood to eliminate reservoirs for the fungus.
• Promoting overall tree vigor through proper site management.
• Protecting tree trunks from mechanical injury to prevent fungal entry.