Pepper leaf curl virus

The causative agent of the disease is Begomovirus warburgi, a member of the Begomovirus genus within the Geminiviridae family. This virus contains a single-stranded circular DNA genome. It acts as an obligate plant parasite, causing severe physiological disturbances that disrupt the host plant's metabolic functions, specifically interfering with chlorophyll synthesis and carbon fixation.

The primary hosts of this virus are members of the Solanaceae family, with peppers (Capsicum species) being the most economically affected. The virus is not transmitted mechanically through sap or seeds, but relies entirely on biological vectors for successful transmission, making it a persistent challenge for both greenhouse and field-grown vegetable production.

Symptoms of infection include upward leaf curling, severe yellowing or mosaic patterns, and significant stunting of the plant height. The leaves often become leathery and thickened, while the internodes are significantly shortened. The overall fruit yield is drastically reduced because the infection interferes with normal flowering and fruit setting processes, leading to smaller, distorted, and unmarketable produce.

The spread of the virus is strictly linked to the population density of the whitefly (Bemisia tabaci). Environmental conditions such as warm, humid climates provide ideal breeding grounds for the whitefly, facilitating the rapid transmission of the virus across fields. The virus remains within the vector's body, allowing a single insect to transmit the pathogen to multiple healthy plants throughout its lifespan.

Effective management strategies require a multi-faceted approach:

• Rigorous control of whitefly populations using integrated pest management (IPM) practices.
• Implementation of physical barriers like fine-mesh insect-proof netting in greenhouses.
• Strategic removal and destruction of infected plants to serve as primary inoculum sources.
• Weed management to eliminate alternative host plants that harbor both the virus and the vector.
• Selection of resistant or tolerant pepper varieties that suppress viral replication.