Pepper Thai begomovirus

Begomovirus capsicumthailandense is a viral plant pathogen belonging to the Geminiviridae family. As a systemic disease, it impacts the internal transport of nutrients and causes severe physiological stress in host plants. This virus is characterized by its ability to spread rapidly within agro-ecosystems through specific insect vectors, causing significant economic damage.

The primary host for this pathogen is pepper (Capsicum annuum). While other solanaceous crops may be susceptible under experimental conditions, pepper remains the most commercially important target. Infection typically occurs when plants are young, though adult plants can also be affected, leading to reduced overall vigor and diminished agricultural productivity.

Symptoms of the infection typically manifest as foliar chlorosis, interveinal yellowing, and severe leaf curling or distortion. The stunted growth of the plant, combined with shortened internodes, gives affected peppers a bushy, unhealthy appearance. Fruit development is negatively impacted, resulting in smaller, malformed, and often unmarketable produce.

The virus is transmitted by the whitefly Bemisia tabaci in a circulative, non-propagative manner. The insect acquires the virus while feeding on infected plant sap and transmits it during subsequent feeding sessions on healthy plants. High temperatures and drought conditions often lead to larger whitefly populations, thereby increasing the prevalence of the virus in the field.

Effective management and prevention of the disease are focused on breaking the cycle of transmission:

• management of whitefly populations using targeted insecticides;
• implementation of physical barriers such as insect-proof netting;
• rigorous rogueing of symptomatic plants to reduce inoculum sources;
• controlling alternative weed hosts that harbor the virus;
• utilizing resistant or tolerant pepper cultivars in endemic areas.