Peach leaf curl

The disease affects peach, nectarine, apricot, and almond, appearing immediately after bud break. Blisters of a pale green, yellow, or scarlet red color form on the leaves, and a whitish waxy coating eventually appears on their undersides. Shoots thicken and become twisted, while affected fruits develop a smooth surface, become covered in cracks, and drop off.

Pathogen development depends on weather conditions: the critical infection period is a cool and humid spring with temperatures between +6 and +15°C. The fungus overwinters on the surface of branches, in bark crevices, and within bud scales. Upon the arrival of dry and hot weather with temperatures above +26°C, infection activity ceases.

The concept of complete resistance to the disease does not exist; however, varietal resistance is often linked to differences in bud break timing: late-maturing varieties are less likely to encounter the peak of pathogen activity. Resistance evaluation in variety testing is conducted visually using a point scale in collection orchards under comparative monitoring in identical conditions.