Sweet potato mosaic virus

The causal agent of this disease is Potyvirus duobatatae, a member of the Potyviridae family. It is a systemic plant pathogen that specifically targets plants within the Convolvulaceae family, most notably sweet potatoes (Ipomoea batatas). Once established, the virus spreads through the vascular system of the host, severely compromising plant physiological functions.

The primary host for this pathogen is the sweet potato crop. The virus infects all vegetative parts of the plant and resides within the storage roots, which poses a significant risk for the spread of the disease through infected vegetative propagation materials. Because the virus is systemic, every piece of an infected plant contains the pathogen.

Typical symptoms include mosaic patterns, chlorosis, leaf distortion, and stunted development. In severe cases, the foliage becomes puckered and reduced in size, leading to a visible decline in the plant's overall vigor. The manifestation of these symptoms can vary depending on the host variety, plant age, and environmental conditions such as temperature and light exposure.

Transmission occurs primarily through aphid vectors in a non-persistent manner, meaning the virus is acquired and transmitted rapidly during short feeding probes. Furthermore, mechanical transmission is a common pathway in fields where tools are shared between plants or where handling of healthy and infected crops occurs simultaneously without proper sanitation protocols.

The impact of this disease on crop productivity is significant, often resulting in reduced tuber yields and lower-quality harvests. Effective management relies on proactive strategies:

• utilizing virus-indexed, tissue-cultured plantlets;
• implementing strict vector control programs to manage aphid populations;
• practicing rigorous field sanitation and rogueing of symptomatic plants;
• ensuring proper quarantine of incoming plant materials.