Poplar boeremia

Poplar boeremia is a fungal disease caused by the pathogen Boeremia populi. As a serious threat to various species within the Populus genus, this fungus acts as a necrotrophic parasite, leading to the destruction of host tissue and the formation of characteristic lesions on the bark of stems and branches.

The host range is primarily focused on poplar species and their hybrids, which are widely used in forestry, landscaping, and shelterbelts. The disease is particularly destructive in nurseries, where dense planting and younger trees provide optimal conditions for rapid pathogen transmission and tree mortality.

The diagnostic symptoms of the infection include localized bark necrosis, which manifests as sunken, dark-colored lesions. As the infection progresses, these areas crack and form deep cankers. On the surface of these necrotic lesions, small black pycnidia develop, which serve as the primary reproductive structures for the fungus.

Environmental factors, specifically high relative humidity and moderate temperatures, significantly accelerate the spread and development of the disease. Spores (conidia) are dispersed via rain splashes and wind, entering the tree through natural openings, bud scars, or mechanical wounds caused by insects or frost, thereby initiating new infection sites.

Effective management strategies require a combination of silvicultural practices and chemical control. Key recommendations include:

• Removal and destruction of infected branches and stems to reduce inoculum sources.
• Monitoring for pest damage that creates infection courts.
• Selection of resistant poplar clones suited to local conditions.
• Preventive application of fungicides during high-risk infection periods.

Integrated pest management (IPM) is crucial to mitigate the impact of this disease. By combining rigorous sanitation with chemical applications in high-value nurseries, managers can significantly suppress the disease cycle and ensure the health of poplar plantations in both commercial and urban settings.