Cherry leaf curl

Cherry leaf curl, caused by the fungal pathogen Taphrina cerasi, is a significant disease affecting stone fruit trees, particularly cherries. This pathogen is a type of leaf-curling fungus that causes abnormal cell growth, resulting in severe deformation of foliage.

The disease primarily targets cherry species (Prunus cerasus and related varieties). While it is not always lethal, the pathogen causes substantial physiological stress. Infected trees exhibit poor growth, reduced fruit quality, and an overall decrease in yield, as the leaves cannot perform photosynthesis efficiently due to severe malformation.

Key symptoms include the development of thick, distorted, and blistered leaves that turn reddish or yellowish in color. As the infection progresses, a white, powdery fungal bloom appears on the leaf surface, indicating the release of spores. Infected leaves eventually become brittle and drop prematurely, often leaving branches bare in mid-summer.

The fungus thrives in cool, damp conditions during early spring. The spores overwinter on bark surfaces or in dormant buds. When the weather becomes favorable, the fungus infects the newly opening leaf buds, spreading rapidly during periods of persistent spring rains or high humidity.

Managing cherry leaf curl requires a preventive approach rather than a curative one. Fungicide treatments, such as copper-based sprays, should be applied in the late winter or early spring before the buds break. Pruning out and destroying infected branches helps reduce the inoculum load in the orchard. Maintaining tree vigor through proper fertilization and adequate spacing further mitigates the impact of the disease.