Plum pox virus

Pathogen and disease type. Plum pox virus (PPV), historically referred to as Prunevirus armeniacae, is the causal agent of sharka disease. It is a highly contagious systemic viral infection belonging to the Potyviridae family. The virus disrupts the plant's metabolic pathways, leading to severe physiological stress and long-term decline in tree health.

Susceptible crops. The virus primarily affects stone fruit species within the Prunus genus. Apricot, plum, and peach are the most susceptible hosts, though nectarine and almond can also serve as reservoirs for the pathogen. Due to its wide host range, it represents a significant economic threat to global stone fruit production.

Symptoms and signs. Symptoms vary depending on the host and climate but typically include chlorotic rings or line patterns on leaves. Fruit symptoms are diagnostic: sunken spots, irregular rings, and deformities appear on the fruit skin. In addition, the flesh of the fruit often develops brown necrotic areas, making it unsuitable for fresh market or processing.

Development and transmission. Transmission occurs primarily through the distribution of infected nursery stock, grafting material, and budding. In the orchard, the virus is spread non-persistently by various aphid species that feed on infected trees and transfer the pathogen to healthy ones. High temperatures and active aphid migration periods significantly increase the rate of spread.

Management and prevention. There is no curative treatment for trees infected with Plum pox virus; therefore, management strategies focus entirely on exclusion and eradication.

• Strict adherence to certification programs for virus-free nursery stock.
• Implementation of rigorous quarantine procedures for imported plant material.
• Regular orchard inspections and the immediate removal of symptomatic trees to limit viral spread.
• Integrated Pest Management (IPM) programs to control aphid populations.
• Maintaining physical distance between new orchards and known infected areas.