Tomato leaf curl Gujarat virus

Pathogen and type of disease. Begomovirus solanumgujaratense is a viral pathogen belonging to the Begomovirus genus within the Geminiviridae family. It is a systemic disease that severely disrupts the host plant's metabolic functions. As a geminivirus with a single-stranded DNA genome, it is highly capable of rapid evolution, complicating the development of resistant crop varieties.

Susceptible crops. The virus primarily targets members of the Solanaceae family. Tomato (Solanum lycopersicum) is the most economically significant host, but the virus also infects peppers, eggplants, and various reservoir weed species. These weeds are crucial for the virus's survival during the off-season, acting as a bridge for new infections.

Symptoms and signs. Typical symptoms include severe leaf curling, reduced leaf size, and mosaic-like chlorosis. Infected plants exhibit stunted growth with shortened internodes, resulting in a bushy, compact appearance. Flower drop is common, and fruits that do develop are frequently distorted, small, and lack commercial value, leading to total yield loss in severe cases.

Conditions for development and spread. The virus is transmitted exclusively by the whitefly Bemisia tabaci. The insect acquires the virus by feeding on infected plants and maintains the ability to transmit it for its entire life cycle. Warm, dry weather conditions significantly accelerate whitefly reproduction and migration, creating a high-risk environment for rapid virus transmission across plantations.

Harmfulness and protection measures. The economic impact is devastating, with potential yield losses approaching 100%. Effective management requires an integrated approach:

• Rigorous control of whitefly populations using targeted insecticides and biological agents.
• Use of virus-free, high-quality transplants or certified seeds.
• Removal and destruction of weeds and volunteer plants that serve as virus reservoirs.
• Deployment of physical barriers, such as insect-proof netting, in greenhouse facilities.
• Adoption of crop rotation and planting schedules that avoid peak whitefly activity periods.