Taphrinomycetes

Taphrinomycetes is a class of ascomycetous fungi that act as obligate parasites on various plant species. These fungi are globally recognized for causing significant physiological disruptions in their hosts, leading to distinct morphological changes and crop yield losses.

The most economically important hosts for these pathogens are stone fruits, specifically peaches, nectarines, plums, and cherries. The infection usually targets emerging vegetative tissues, such as young leaves and succulent shoots, as well as developing fruits.

Symptoms often manifest as severe leaf distortion, curling, and abnormal thickening of the leaf blades. The tissues may turn yellow, pink, or red. A characteristic white, velvety coating appears on the surface, representing the fungal fruiting bodies (asci) releasing spores into the environment.

The disease cycle is heavily influenced by environmental conditions, particularly cool and wet weather during the bud-break stage. The fungi overwinter as blastospores on the bark surface and within bud scales, becoming active as soon as conditions allow for infection of the newly emerged leaves.

Control measures are predominantly preventative, as curative treatment is often ineffective once symptoms are visible. Key strategies include:

• applying copper-based fungicides before bud swelling;
• maintaining orchard hygiene by pruning infected shoots;
• selecting resistant or tolerant cultivars;
• ensuring proper air circulation within the tree canopy.