Yellow leaf curl of solanaceous crops

The causative agent of this disease is a virus belonging to the genus Begomovirus. It is a persistent circulative virus that colonizes the phloem of host plants. Due to its systemic nature, the virus causes profound physiological changes, preventing the plant from developing normally and significantly impairing photosynthetic efficiency.

Primary hosts for this virus include members of the Solanaceae family, specifically tomatoes, peppers, and eggplants. The host range can also extend to various weeds, which act as reservoirs, allowing the virus to survive between cropping cycles and maintain a steady source of infection in the agro-ecosystem.

Symptoms are characterized by upward leaf curling, yellowing of leaf margins, and stunted growth. Infected plants show reduced fruit set and poor fruit development. In severe cases, the entire plant may collapse, leading to total yield loss, as the virus interferes with the transport of nutrients from leaves to fruits.

The development and spread of the virus are strictly dependent on the whitefly Bemisia tabaci. The insect acquires the virus while feeding on infected sap and transmits it to healthy plants. Transmission efficiency increases with temperature, making warm, humid climates ideal for rapid disease outbreaks.

Managing the disease requires a multi-faceted approach centered on vector suppression. Effective prevention strategies focus on using resistant varieties, rigorous weeding of host weeds, and applying chemical or biological insecticides to manage whitefly populations before they reach threshold levels in the field.

• Deployment of resistant crop varieties.
• Implementation of greenhouse exclusion screens.
• Sanitation practices including rogueing of infected plants.
• Monitoring whitefly population dynamics using yellow sticky traps.