Bertia

Bertia is a genus of ascomycete fungi, of which Bertia moriformis is the most recognized species. In agricultural and forestry terms, it is recognized as a fungus that colonizes wood and bark, often acting as a decay agent that thrives on weakened, dying, or dead woody plant tissues, participating in the breakdown of structural biomass.

The causal agent is a pyrenomycete fungus that produces distinct perithecia. These fruiting bodies appear as small, dense, black clusters, often resembling the surface of a mulberry fruit, which are typically found on the bark or decaying wood surfaces. Proper identification of these structures is essential for accurate diagnostics in the field.

The fungus primarily impacts various broad-leaved trees, including species such as beech, maple, birch, and hornbeam. While it is often classified as a saprophyte, it can opportunistically invade tissues on trees that are already stressed due to environmental factors, mechanical injury, or poor management, thereby accelerating the necrosis of the wood.

Development and dissemination of the fungus are highly dependent on high humidity and mild temperatures. These conditions favor the germination of spores and the subsequent colonization of wood substrates by the mycelium. The presence of decaying plant debris in the vicinity serves as a primary reservoir for the continued spread of the pathogen.

The economic impact of Bertia is associated with the degradation of wood quality and the increased vulnerability of affected plants to further decline. Integrated management strategies focus on:

• sanitary removal of infected branches;
• maintaining good hygiene in orchards and forests;
• avoiding mechanical damage to tree trunks;
• promoting overall plant vigor to discourage secondary fungal colonization.