Sweet potato leaf curl virus

Pathogen and Disease Type
Sweet potato leaf curl virus (Begomovirus ipomoeacanaryense) is a viral pathogen classified within the genus Begomovirus and the family Geminiviridae. This disease is characterized by systemic infection, which severely disrupts the metabolic processes and physiological development of host plants. The virus is primarily transmitted by insect vectors in a persistent circulative manner, making management challenging.

Host Range
The primary host for this virus is the sweet potato (Ipomoea batatas). However, various wild species within the Convolvulaceae family also serve as alternative hosts. These wild relatives can act as asymptomatic reservoirs for the virus, allowing it to persist in the environment and spread to agricultural fields during the growing season.

Symptoms and Signs
Affected plants exhibit distinct visual symptoms including severe curling, twisting, and deformation of the leaves. Chlorotic spots or mosaic patterns are frequently observed on the foliage. Infected plants often display stunting, reduced internode length, and a general decline in vigor. As the infection progresses, the capacity of the plant to produce high-quality, market-ready storage roots is significantly impaired.

Development and Economic Impact
The spread of the disease is inextricably linked to the population dynamics of the whitefly (Bemisia tabaci), which acts as the main vector. Warmer temperatures accelerate the life cycle of the vector, leading to rapid disease dissemination across fields. The economic impact is substantial, as infected crops suffer from both reduced yields and poor tuber quality, leading to significant financial losses for farmers.

Management and Prevention
Effective management of this viral disease relies on a multi-pronged approach:

• Planting only healthy, virus-indexed sweet potato cuttings.
• Implementing rigorous whitefly control programs using integrated pest management (IPM) practices.
• Removing and destroying symptomatic plants to eliminate the source of the virus.
• Maintaining field hygiene by controlling invasive weed hosts in the Convolvulaceae family.