Alternanthera curly top virus

The disease is caused by a virus belonging to the Begomovirus genus within the Geminiviridae family. This pathogen is characterized by a circular single-stranded DNA genome. As a systemic plant pathogen, it invades the vascular tissues, causing significant physiological disruption that leads to visible growth abnormalities and stunted development in the host.

The primary host for this virus is Alternanthera species, though it may also impact other plants within the Amaranthaceae family. The virus acts as a persistent threat in regions where wild host plants are prevalent, allowing it to survive through non-growing seasons and serve as a reservoir for infection in newly planted agricultural crops.

Symptoms typically manifest as severe curling, twisting, and crumpling of the leaves, accompanied by reduced leaf size. Infected plants exhibit stunted growth, shortened internodes, and often show signs of interveinal chlorosis. The impact on plant development is progressive, significantly reducing the vigor and overall yield of the cultivated crop.

The transmission of the virus is primarily facilitated by the whitefly Bemisia tabaci. The insect acquires the virus while feeding on infected plant sap and transmits it during subsequent feeding bouts on healthy plants. Favorable conditions for widespread outbreaks include warm temperatures and high humidity, which support the rapid population growth of the whitefly vector.

Management and prevention practices include:

• implementing strict weed control to remove host reservoirs;
• using systemic insecticides to control vector populations;
• deploying sticky traps for monitoring and early detection of vectors;
• ensuring spatial isolation between susceptible crop stages;
• practicing integrated pest management (IPM) to minimize chemical reliance.