Watermelon begomovirus

Begomovirus citrulli is a plant pathogenic virus belonging to the genus Begomovirus within the Geminiviridae family. As a single-stranded DNA virus, it causes severe systemic infections in susceptible crops, leading to significant physiological stress and agricultural losses in watermelon production.

The primary host for this virus is watermelon, but it also affects a variety of cucurbitaceous crops, including cucumbers, melons, and squashes. The virus poses a major threat to both field-grown crops and greenhouse production, particularly in tropical and subtropical regions where environmental conditions favor the vector's activity.

Typical symptoms of Begomovirus citrulli include yellow mosaic patterns on leaves, stunted plant growth, shortened internodes, and leaf curling. In advanced stages, the infected plants exhibit severe chlorosis and foliage deformation. The fruit quality is significantly compromised, often appearing deformed, smaller in size, and having poor marketability.

The virus is transmitted by the whitefly Bemisia tabaci in a circulative, non-propagative manner. Once the insect feeds on an infected plant, it carries the virus for the remainder of its life. The spread of the disease is highly correlated with the population density of the whitefly vector, which thrives in warm, humid climates.

Management of the disease relies heavily on integrated pest management (IPM) strategies. This includes the following:

• Rigorous control of whitefly populations using targeted insecticides;
• Use of fine-mesh netting in greenhouses to exclude vectors;
• Effective weed management to eliminate alternative host plants;
• Implementing crop rotation and using resistant cultivars where available.