Phaeothecaceae fungi

The Phaeothecaceae family encompasses a group of ascomycetous fungi that act as significant phytopathogens or epiphytes, affecting a wide variety of woody plants and shrubs. In agricultural practice, members of this family are frequently identified as causative agents of bark and tissue necrosis, which leads to the progressive weakening and physiological decline of the host plant.

The primary manifestation of the disease is localized necrosis of bark and shoots. The pathogen enters plant tissues through mechanical wounds, frost cracks, or natural openings like lenticels. Once inside, the mycelium colonizes the intercellular space, degrading parenchyma cells and disrupting the plant's vascular integrity and nutrient translocation processes.

Commonly affected crops include various fruit trees, such as apples and pears, as well as many ornamental shrub species. Symptoms typically appear as dark, often black or deep brown necrotic spots on the bark. Over time, these areas become cracked and brittle, leading to bark peeling and the exposure of the underlying wood, which further invites secondary infections from other opportunistic pathogens.

The development and dispersal of the fungus are highly dependent on environmental conditions, particularly high humidity and moderate temperatures. Fungal spores are spread by wind, rain splashes, and insect activity. In poorly managed, dense orchards with insufficient canopy aeration, the disease can spread rapidly, creating a sustained infection cycle that is difficult to eradicate.

The economic impact of Phaeothecaceae is characterized by reduced harvest yields and the potential for branch dieback or tree mortality. To protect crops and prevent disease outbreaks, agronomists recommend a comprehensive approach:

• Implementing regular sanitary pruning of infected branches.
• Disinfecting pruning tools after working with affected trees.
• Managing plant density to ensure adequate airflow and lower canopy humidity.
• Applying copper-based fungicides during the dormant season.
• Treating bark wounds immediately with horticultural sealants or protective pastes.