Begomovirus macroptilaurei

Causative agent and disease type. Begomovirus macroptilaurei is a plant virus belonging to the Geminiviridae family. It is a viral pathogen characterized by circular single-stranded DNA. As a systemic disease, it disrupts the physiological processes of host plants, leading to severe metabolic imbalances that inhibit healthy growth and development.

Affected crops. The virus primarily affects legume species (Fabaceae family). It has been identified as a significant threat to common beans (Phaseolus vulgaris) and certain wild species within the Macroptilium genus. Due to its host range, it poses a recurring threat to both commercial agricultural fields and wild biodiversity in tropical and subtropical regions.

Symptoms and signs. Symptoms caused by this virus include characteristic mosaic patterning, chlorosis, and crinkling of the leaves. Infected plants typically exhibit significant stunting and reduced internode length. Reproductive development is often severely hampered, leading to deformed pods or total flower abortion, which significantly impacts overall crop yields.

Conditions for development and spread. The primary vector for this virus is the sweet potato whitefly (Bemisia tabaci). The transmission is persistent, meaning the insect acquires the virus while feeding on infected sap and remains infectious throughout its lifespan. Warm and humid conditions favor both the vector's population growth and the rapid spread of the viral infection throughout the field.

Control and prevention measures. Effective management requires an integrated pest management (IPM) strategy. Since there is no cure for viral plant infections, preventative actions are paramount:

• Application of systemic insecticides to manage whitefly populations.
• Sanitation practices, including the removal of infected host plants and weeds.
• Deployment of virus-resistant plant varieties when available.
• Use of physical barriers like fine-mesh screens in protected cropping systems.