Cypress canker

Cypress canker is a devastating fungal disease caused by the pathogen Diplodia cupressi. This pathogen belongs to the group of ascomycete fungi that cause necrotic lesions on the bark and cambium of trees, effectively cutting off the tree's vascular transport system and causing branch dieback.

The primary hosts of this pathogen include various species of Cupressaceae, such as Cupressus, Thuja, and Juniperus. The disease is a significant concern for both forest ecosystems and ornamental gardens, as it can cause widespread mortality in susceptible plantations if left unmanaged.

Symptoms typically begin with yellowing or browning of individual twigs or branches, eventually progressing to systemic wilting. Distinctive features include sunken, resinous cankers on the main stems or branches and the development of black, pinhead-sized fruiting bodies known as pycnidia within the infected bark tissues.

The development and spread of Diplodia cupressi are heavily favored by high humidity, mild temperatures, and the presence of bark wounds. Infection often occurs via rain splash or wind dissemination of conidia. Contaminated pruning tools are a primary vector for the transmission of the disease between plants, necessitating rigorous disinfection protocols.

Management and prevention measures include the following:

• Prompt removal and destruction of infected branches to reduce inoculum load.
• Sterilization of pruning equipment using alcohol or bleach solutions between plants.
• Application of copper-based fungicides during the growing season to protect healthy tissue.
• Implementing proper horticultural practices, such as adequate spacing and irrigation, to minimize stress and prevent bark injuries.