Ceratocystis canker

Pathogen and disease type. Ceratocystis canker is caused by the fungus Ceratocystis fimbriata. It is a highly destructive vascular disease that infiltrates the xylem and phloem, leading to systematic necrosis and the eventual collapse of the tree's internal transport system.

Host range and economic impact. The pathogen has a broad host range, posing a significant threat to arboriculture and forestry. Key susceptible species include the plane tree (Platanus), apricot, almond, and peach. The disease is particularly devastating due to its rapid progression and the difficulty of containing it once established in an orchard.

Symptoms and signs of infection. Clinical signs include sunken lesions on the trunk and primary branches. Often, there is visible sap flow (gummosis) from these cankers. Internally, the wood shows dark, necrotic staining. As the vascular tissue fails, leaves typically show signs of yellowing, wilting, and premature abscission.

Development and spread. The fungus thrives in warm, humid conditions. Infection occurs primarily through open wounds caused by pruning, storms, or mechanical damage. Spores can be transported by wind, water splashing, insect vectors like beetles, and contaminated pruning tools, which can quickly spread the pathogen across an entire plantation.

Protection and prevention. Since no chemical cure is fully effective for established systemic infections, management focuses on prevention. Strict sanitation is vital: all pruning tools must be disinfected between trees. Infected wood should be removed and destroyed immediately. Protecting trees from mechanical injury and maintaining overall tree vigor are the best long-term strategies.