Bean golden mosaic

Bean golden mosaic is a significant plant disease caused by the Bean golden mosaic virus (BGMV), a member of the genus Begomovirus within the Geminiviridae family. The virus is characterized by its geminate particles and a circular single-stranded DNA genome, which is specialized for efficient plant infection.

The virus primarily affects Phaseolus vulgaris (common bean). Infected plants display classic viral symptoms such as golden-yellow mosaic patterns on the foliage, stunted growth, leaf curling, and overall reduction in pod formation, which can lead to near-total yield loss in susceptible varieties.

The biological development of this pathogen is highly dependent on the silverleaf whitefly (Bemisia tabaci), which serves as its exclusive vector. The transmission is circulative and persistent; the virus must enter the insect's hemolymph and reach the salivary glands before it can be inoculated into a healthy plant during the feeding process.

Environmental conditions that favor the proliferation of Bemisia tabaci, such as high temperatures, drought, and lack of natural predators, directly correlate with higher rates of BGMV infection. Once the virus enters a field, it can spread rapidly across a crop, especially in tropical climates where the vector population remains active throughout the year.

Effective management requires a multi-faceted approach. Primary strategies include the deployment of BGMV-resistant cultivars developed through breeding programs, the use of reflective mulches to deter whiteflies, and the strategic application of systemic insecticides. Implementing crop-free periods and eradicating alternative weed hosts are also essential to mitigate the impact of the disease.