Hollyhock yellow-vein

Hollyhock yellow-vein is a viral disease caused by the Hollyhock yellow-vein virus (HJYVV), a member of the Begomovirus genus. This plant pathogen is characterized by its reliance on insect vectors for transmission and its ability to cause systemic infection within host plants.

The primary hosts of this virus are plants belonging to the Malvaceae family, most notably the hollyhock (Alcea rosea). While primarily affecting ornamental plants, the virus can pose a significant challenge to gardeners due to its ability to weaken the host, making it susceptible to secondary pathogens.

The hallmark of the disease is the yellowing of leaf veins, which manifests as a net-like pattern. As the infection progresses, leaves may become crinkled or distorted. Infected plants often show stunted growth, reduced floral production, and overall vigor loss, which negatively impacts their ornamental value.

The virus is transmitted by whiteflies (Bemisia tabaci), which act as efficient vectors. These insects ingest the virus while feeding on infected sap and transmit it to healthy plants during subsequent feeding sessions. High temperatures and the presence of whiteflies in the environment create ideal conditions for the disease to spread rapidly.

Management of the virus centers on prevention, as there is no cure for systemic viral infections in plants. Key strategies include:

• Regular monitoring and control of whitefly populations using biological or chemical insecticides.
• Immediate removal and destruction of symptomatic plants.
• Using certified, virus-free seeds or planting stock.
• Weeding areas near the garden to eliminate potential secondary hosts.