Yellow fairy cup

Yellow fairy cup (Latin Calycina citrina) is a saprotrophic fungus belonging to the Helotiaceae family. While primarily a decomposer of dead wood, its presence on living trees often indicates areas of decay and reduced vitality, making it a subject of interest for arborists and foresters.

The fungus is characterized by its bright yellow, disc-shaped apothecia that emerge from decaying wood surfaces. These fruiting bodies produce spores that facilitate the spread of the fungus throughout the forest or orchard ecosystem under favorable environmental conditions.

It typically colonizes hardwoods such as beech, oak, and birch. It acts as a secondary invader, targeting damaged bark, pruning cuts, or dead branches. By secreting enzymes, the mycelium breaks down lignin and cellulose, which progressively weakens the wood structure of the host tree.

Development is heavily dependent on moisture. High humidity and cool temperatures are ideal for the growth of Calycina citrina. Spore dissemination occurs primarily through rain splashes and air currents, allowing the fungus to colonize new susceptible wooden substrates in moist environments.

To prevent the negative impact of this fungus on tree health, it is essential to maintain proper sanitation. Pruning damaged or dead branches, cleaning tree wounds, and applying protective antifungal agents are critical measures. Ensuring adequate light penetration and ventilation within the canopy helps create an environment unsuitable for fungal establishment.

• Sanitary pruning of dead or decaying wood.
• Application of wound dressings to prevent colonization.
• Improved air circulation in high-density plantings.
• Removal of infected woody debris from the site.