Melogramma

Melogramma is a fungal disease caused by various species of the Melogramma genus. These fungi act as pathogens that primarily colonize the bark and wood of deciduous trees, often leading to necrosis and structural decay if the infection remains unchecked over a long period.

The disease frequently attacks various hardwood species, including beech, oak, and other broad-leaved trees. Pathogens of this type are typically opportunistic, targeting specimens that are already under stress from environmental factors such as drought, frost cracks, or previous injuries caused by mechanical impact or pests.

The primary symptom of Melogramma infection is the formation of distinct, dark-colored stroma that rupture through the bark of branches or main stems. These structures are accompanied by localized bark necrosis, cracking, and eventual drying of the underlying cambium layer, which disrupts the tree's nutrient transport system.

The development and spread of the disease are highly dependent on environmental conditions, particularly high humidity and rainfall, which facilitate spore dispersal. Spores can be transported by wind and rain splash, settling on susceptible tree parts and initiating new infections through any minor surface wounds or cracks in the bark.

Effective management requires a combination of cultural and sanitary practices. Key measures include the regular removal and destruction of infected limbs to reduce inoculum pressure, maintenance of tree vigor through appropriate fertilization and irrigation, and the disinfection of pruning tools to prevent the mechanical transmission of the fungus between plants.