Thelephora

Thelephora is a genus of basidiomycete fungi known for causing significant issues in forestry and plant nurseries, particularly by affecting young seedlings. The most common species associated with plant damage is Thelephora terrestris, which manifests as a crust-like fungal growth surrounding the base of young tree stems.

The disease is classified as a physical and physiological interference with plant growth. The fungus forms a leather-like fruiting body that tightly wraps around the seedling's stem and root collar. This physical constraint prevents the plant from accessing essential nutrients and oxygen, effectively suffocating the young specimen and leading to necrosis of the stem tissue.

Symptoms are easily identifiable by the presence of brown, fan-shaped, or rosette-like fungal mats at the base of the plant. As the infection progresses, the foliage of the affected seedling turns yellowish or reddish-brown, followed by a total loss of turgor and eventual collapse of the plant as the vascular system is compromised.

The development of Thelephora is highly dependent on environmental conditions, specifically high humidity and poor aeration. The fungus thrives in nurseries where seedlings are planted too densely, or where soil drainage is inadequate, leading to persistent moisture accumulation around the plant base, which acts as a trigger for fungal proliferation.

Management and prevention focus on creating unfavorable conditions for fungal growth. This includes thinning out crowded seedlings to improve air circulation, ensuring proper drainage to prevent waterlogging, and maintaining sanitation by removing decaying organic matter from the soil surface. In severe cases, targeted fungicide applications may be necessary to suppress spore production.

• Maintaining proper plant spacing for airflow.
• Improving soil drainage systems.
• Removing debris to minimize fungal habitat.
• Application of specialized fungicides.