Rust of stone fruits

The causal agent of this disease is the fungal pathogen Leucotelium pruni-persicae, which is a specialized rust fungus. It predominantly affects stone fruit trees, causing significant agricultural losses if the infection is not properly managed during the growing season.

The disease targets various species of the Prunus genus, including peach, nectarine, plum, apricot, almond, and cherry trees. These cultures are particularly vulnerable during periods of high humidity and moderate temperatures that favor fungal sporulation.

Visual symptoms usually appear on the leaves as small, yellow-green spots that gradually develop into dusty, rust-colored pustules on the underside of the foliage. In severe cases, the infected leaves turn yellow, curl up, and drop prematurely, leading to a defoliation of the tree canopy.

The pathogen thrives in conditions of high environmental moisture, such as frequent rainfall, heavy dew, or irrigation water hitting the leaves. The rust fungus survives the winter primarily as teliospores on fallen leaves, which serve as the primary source of infection for the upcoming spring season.

The economic impact of this disease is substantial due to the reduction of the leaf area, which limits the tree's ability to perform photosynthesis. This results in weaker tree development, reduced fruit quality and size, and decreased winter hardiness, making the orchard more susceptible to other environmental stresses.

• Rigorous sanitation by removing and burning fallen leaves in autumn.
• Pruning techniques to promote airflow and light penetration in the canopy.
• Strategic application of systemic and contact fungicides as recommended by agronomists.
• Monitoring the orchard for early symptoms to prevent the spread of the pathogen.