Bean golden mosaic virus

Bean golden mosaic virus (Begomovirus phaseolimexicoense) is a devastating plant pathogen belonging to the Geminiviridae family. It is characterized by its specific transmission mechanism and its ability to cause severe systemic infections, leading to massive yield losses in common bean (Phaseolus vulgaris) production worldwide.

The primary host for this pathogen is the common bean. However, the virus's host range can include other legumes, which serve as alternative hosts, maintaining the viral presence in the environment. The virus hijacks the plant's cellular machinery, primarily affecting the phloem and drastically reducing the plant's overall vigor and capacity to produce fruit.

Typical symptoms include bright yellow mosaic patterns on leaves, which often evolve into leaf curling and severe stunting of the entire plant. Infected plants exhibit shortened internodes and a marked reduction in flower production. Consequently, the pods that do form are often small, malformed, and contain few seeds, leading to total harvest failures in susceptible crop varieties.

Transmission occurs exclusively through the silverleaf whitefly (Bemisia tabaci). Once the whitefly acquires the virus, it remains a vector for the duration of its life, facilitating rapid secondary spread within the field. The severity of the outbreaks is strongly correlated with climate patterns, as warm temperatures and high humidity promote the rapid proliferation of the whitefly vector.

Integrated Pest Management (IPM) is essential for controlling this virus. Strategies include:

• Deploying resistant or tolerant bean cultivars in high-risk areas.
• Implementing strict weed control to eliminate reservoir hosts of the virus.
• Using systemic insecticides to manage whitefly populations effectively.
• Practicing crop rotation and scheduling plantings to avoid peak vector activity periods.