Phaeomarasmius

Phaeomarasmius is a genus of fungi belonging to the order Agaricales, which can act as a pathogen or wood-decay agent on various woody plants. In an agronomic context, these fungi are recognized for their ability to colonize weakened tree tissue, potentially causing significant damage to bark structure and the overall health of fruit and ornamental trees.

The disease is primarily identified as a form of wood and bark decay. The causative agent infiltrates the tree through wounds, such as pruning cuts, frost cracks, or sites damaged by insects. Once established, the mycelium spreads within the bark and cambium layers, interfering with the plant's vascular integrity and causing localized necrosis.

Visible symptoms include the emergence of small fruiting bodies (mushrooms) on the affected bark, accompanied by dark, sunken, or cracked lesions. As the disease progresses, the impacted sections of the tree or individual branches may show signs of wilting, premature browning, and eventually dieback as the nutrient flow is severely restricted.

Favorable conditions for the development of Phaeomarasmius include high ambient humidity, moderate temperatures, and lack of air circulation within the tree canopy. Such environmental factors promote spore germination and fungal growth, making neglected orchards or dense, poorly pruned plantations particularly susceptible to infection.

Protecting plants from this fungus requires a combination of good sanitation and cultural practices. Regular inspection of the trees is essential to detect early infections. Any diseased branches should be removed and destroyed immediately to prevent the spread of spores. Protective painting of tree wounds with specialized coatings is also a recommended preventive measure.

• Sanitary pruning of infected wood.
• Sterilization of pruning tools between uses.
• Application of fungicidal pastes to fresh wounds.
• Improvement of canopy aeration to reduce humidity.