Cypress canker

Lepteutypa cupressi (syn. Seiridium cupressi) is a fungal pathogen belonging to the Ascomycota phylum. It is the primary causal agent of cypress canker, a devastating disease that affects a wide variety of coniferous trees, particularly those within the Cupressaceae family.

The disease primarily impacts various species of cypress, juniper, and arborvitae. Its presence is marked by the formation of cankers on the bark, leading to dieback of branches and twigs. As the fungus colonizes the vascular tissues, it restricts the flow of water and nutrients, causing the foliage above the canker to turn yellow and eventually die.

The life cycle of the fungus is characterized by the production of both sexual and asexual spores within the infected bark tissues. These spores are disseminated primarily by rain splash and wind, moving from diseased branches to healthy plant tissue, where they enter through wounds, pruning cuts, or even natural openings in the bark.

Environmental conditions such as high humidity, cool to moderate temperatures, and poor air circulation within the canopy significantly favor the development and spread of the pathogen. Once introduced into a plantation or nursery, the disease can spread rapidly if not managed promptly, especially among trees weakened by environmental stressors.

Effective management strategies rely on rigorous sanitation and preventive measures. Pruning out and destroying infected branches is essential to reduce the inoculum load. Maintaining plant vigor through proper fertilization, irrigation, and avoiding physical damage to the trunk is crucial for prevention, alongside the use of copper-based fungicides when necessary.