Crotalaria begomovirus

Crotalaria begomovirus (Begomovirus crotalariae) is a plant pathogen belonging to the Geminiviridae family. It is a viral agent with a circular single-stranded DNA genome, responsible for significant systemic infections in various legume crops, leading to severe physiological disruptions in affected host plants.

The virus primarily affects Crotalaria species but can also infect a variety of leguminous weeds and cultivated plants. It acts as an obligate parasite, relying entirely on biological vectors for transmission between hosts, which distinguishes it from viruses that spread through seed or mechanical contact in the field.

The clinical symptoms of the disease include pronounced mosaic patterns on the foliage, leaf curling, crinkling, and stunted growth. Infected plants exhibit a marked reduction in vigor, often failing to reach their developmental potential. The loss of leaf surface area due to deformation significantly impacts the plant's photosynthetic capacity, resulting in lower yield outcomes.

The transmission mechanism is mediated exclusively by the silverleaf whitefly (Bemisia tabaci) in a persistent, circulative manner. Once the insect acquires the virus during feeding, it can transmit the pathogen throughout its lifespan. Warm and humid environmental conditions are highly favorable for both the survival of the vector and the rapid multiplication of the viral particles within the host.

Management of Crotalaria begomovirus centers on strict integrated pest management (IPM) practices. Key strategies include the deployment of systemic insecticides to manage whitefly populations, the use of physical barriers like fine-mesh netting in nurseries, and the removal of alternative host weeds from the field borders. Crop rotation and selection of tolerant cultivars remain the most effective long-term strategies for prevention.