Okra yellow mosaic virus

The causative agent of this disease is Begomovirus abelsmoschusretorridi, which belongs to the Geminiviridae family. This virus is a single-stranded DNA plant pathogen that relies entirely on insect vectors for transmission. The primary vector for this virus is the whitefly (Bemisia tabaci), which acquires the pathogen while feeding on infected sap and transmits it to healthy plants.

The disease primarily targets okra (Abelmoschus esculentus) but also affects other members of the Malvaceae family. In many agricultural regions, wild plants act as alternate hosts, allowing the virus to persist in the environment throughout the year and serving as a continuous source of inoculum for subsequent crops.

Symptoms are typically characterized by a vibrant yellow mosaic pattern on the foliage, accompanied by vein clearing and leaf curling. As the infection progresses, affected plants exhibit stunted growth, reduced internode length, and diminished vigor. The physiological stress caused by the virus significantly hinders flowering and fruit development.

The incidence and severity of the disease are heavily influenced by environmental factors that favor whitefly proliferation, such as high temperatures and drought. If left unmanaged, the virus can spread rapidly through a field, causing substantial economic losses. Given that there is no chemical cure for the virus itself, management must focus on vector control and sanitary practices.

Integrated pest management (IPM) strategies for minimizing the impact of this virus include:

• Implementing strict weed control to eliminate reservoir hosts of the virus.
• Using systemic insecticides to keep whitefly populations below the economic threshold.
• Employing physical barriers like fine mesh screens in greenhouses or reflective mulches.
• Rogueing infected plants immediately upon the first appearance of mosaic symptoms to prevent spread.