Sweet potato leaf curl virus

Sweet potato leaf curl virus (SPLCV) is a plant pathogenic virus belonging to the family Geminiviridae, genus Begomovirus. It is a single-stranded DNA virus that specifically infects the sweet potato (Ipomoea batatas). The pathogen is widespread in tropical and subtropical regions where sweet potato is a staple crop.

The characteristic symptoms of infection include severe leaf curling, stunting of the plant, and significant reduction in leaf size. Infected plants often exhibit a bushy appearance due to shortened internodes. In many cases, the symptoms can be latent, meaning the plant acts as a reservoir for the virus without showing obvious damage, which complicates diagnosis.

The virus is primarily transmitted by the whitefly Bemisia tabaci in a circulative, non-propagative manner. The insect acquires the virus while feeding on infected plant tissues and can transmit it to healthy plants after a short latent period. Furthermore, the use of infected vegetative cuttings for propagation is a major pathway for the long-distance spread of the disease.

The economic impact of SPLCV is substantial, as it leads to reduced root yields and lower market quality. Affected sweet potato plants produce fewer and smaller storage roots. In sensitive cultivars, the disease can cause significant physiological stress, making the plants more susceptible to other abiotic and biotic factors, eventually leading to economic losses for farmers.

Integrated pest management strategies are crucial to minimize the incidence of SPLCV:

• Strict use of virus-free, tissue-culture derived planting material.
• Rigorous control of the whitefly vector population using chemical and biological means.
• Regular inspection and immediate roguing of symptomatic plants within the fields.
• Implementing appropriate sanitation practices and clearing nearby weeds that act as alternative hosts for both the virus and the vector.