Andrographis leaf curl virus

The causal agent of this disease is Begomovirus andrographis, a member of the Geminiviridae family. It is a DNA virus that relies on specific insect vectors to enter the host plant tissue, causing systemic infection and significant physiological disruption within the vascular system.

The primary host for this viral pathogen is Andrographis paniculata, widely cultivated for its therapeutic properties. The virus can also persist in various weed species that grow near agricultural fields, which serve as reservoirs for the pathogen, ensuring its presence throughout the growing season.

Symptoms are distinct and include severe leaf curling, distortion of the leaf lamina, and mosaic patterns of yellowing. Infected plants typically exhibit stunted development, reduced internode length, and overall dwarfing, which significantly diminishes the quantity and quality of the biomass harvested.

Transmission occurs exclusively through the whitefly, Bemisia tabaci. The virus is acquired by the insect during feeding and is transmitted in a persistent manner to healthy plants. Warm, humid climates facilitate the population explosion of the vector, leading to rapid disease spread.

Management strategies focus on vector control and field hygiene. Key steps include:

• Applying systemic insecticides to reduce whitefly populations.
• Rogueing and destroying symptomatic plants immediately upon detection.
• Maintaining strict weed control around the perimeter to eliminate secondary hosts.
• Implementing crop rotation to disrupt the virus-vector cycle.