Dark green sunken mottle

Dark green sunken mottle is a serious viral disease caused by the Peach dark green sunken mottle virus (PDGSMV), which belongs to the genus Marafivirus. This pathogen infiltrates the vascular system of the host, disrupting normal physiological processes and severely impacting the tree's health.

The primary host for this virus is the peach tree (Prunus persica). It is classified as a significant threat in stone fruit cultivation, affecting orchard productivity and fruit quality. The virus is capable of persisting in the host for many years, often resulting in long-term decline.

Symptoms are most visible during the active growing season. Affected leaves exhibit characteristic dark green, sunken spots accompanied by tissue chlorosis or necrosis. These deformations are often associated with shortened internodes and a stunted appearance of the infected branches, giving the canopy a sparse look.

The spread of the virus occurs primarily through vegetative propagation, specifically via contaminated budwood or scion material. Mechanical transmission through pruning tools that have not been sterilized between trees is another critical pathway, making orchard hygiene a priority for all fruit growers.

Currently, there are no curative treatments for infected trees. Prevention is the only viable strategy. Management efforts must focus on:

• Sourcing propagation material from certified virus-free nurseries.
• Sterilizing all pruning shears and saws after each individual tree.
• Promptly rogueing and removing any trees that show consistent symptoms.
• Implementing rigorous quarantine measures for new plantings.