Splanchonema platan

Splanchonema platan is a specific fungal pathogen belonging to the Ascomycota division, known to cause bark necrosis in various species of plane trees (Platanus). As a specialized pathogen, it primarily colonizes the bark tissues, disrupting the tree's vital functions and leading to the progressive decline of affected branches or the tree itself over several seasons.

The host range is essentially limited to Platanus species. The infection is characterized by distinct necrotic lesions on the bark, which become discolored and cracked as the fungus consumes the underlying tissues. This damage provides entry points for secondary infections and wood-boring insects, further compromising the structural integrity and aesthetic value of the tree.

The life cycle of the pathogen is driven by environmental moisture and the availability of vulnerable host tissues. The fungus overwinters in infected bark and produces ascospores during warm, wet weather. These spores are disseminated by rain splash, wind, or insect vectors, effectively infecting adjacent healthy bark tissues and facilitating the spread of the disease within a stand of trees.

Environmental conditions play a critical role in the outbreak of this disease. Factors such as high humidity, heavy rainfall, and prolonged periods of canopy wetness favor the growth and reproduction of the fungus.

• High relative humidity;
• Presence of open wounds on the bark;
• Stress caused by drought or improper maintenance;
• High planting density hindering air circulation.

Control and prevention strategies center on strict sanitation and the maintenance of tree vigor. All infected branches must be pruned promptly, and tools should be disinfected between trees to prevent the spread of spores. Application of protective wound dressings on larger pruning cuts and providing adequate irrigation can significantly boost the tree's natural defense mechanisms against the progression of the pathogen.