Canker

Canker, caused by the fungus Ceratocystis fimbriata, is a devastating vascular disease affecting a wide variety of crops worldwide. As a highly destructive pathogen, it primarily attacks the internal tissues of the plant, disrupting the transport of water and nutrients, eventually leading to the death of the host.

The host range of Ceratocystis fimbriata is diverse, impacting vital agricultural industries. It is particularly notorious for damaging crops such as Citrus species, Coffea arabica and Coffea canephora, Theobroma cacao, and Humulus lupulus. Different strains of the fungus exhibit high host specificity, meaning specific biotypes are adapted to thrive on specific plant hosts.

Typical symptoms manifest as deep, sunken necrotic lesions on stems and trunks, often accompanied by gum exudation. As the disease progresses, the foliage wilts, yellows, and drops prematurely. Internally, the woody tissue shows distinct staining and necrosis, which confirms the vascular nature of the infection and the systemic spread of the fungal mycelium.

The development and spread of the disease are heavily influenced by environmental factors such as high humidity and soil moisture. The fungus primarily enters the host through fresh wounds caused by pruning, storms, or insect activity. Beetles are known to act as primary vectors, carrying spores from infected to healthy trees, thus facilitating rapid field-wide dissemination.

Effective management requires a multi-faceted approach. Preventive measures include strict quarantine protocols for imported plant material and the thorough sanitation of pruning tools. Once an infection is detected, the affected plants should be removed immediately and destroyed. Chemical control is often limited, so focus remains on cultural practices that minimize tree stress and injury.

• Strict sanitation of all pruning tools
• Immediate removal and burning of infected trees
• Pest management to reduce vector attraction
• Planting of certified, disease-free nursery stock