Rhynchosia golden mosaic

Rhynchosia golden mosaic is a devastating viral disease caused by viruses belonging to the genus Begomovirus (family Geminiviridae). This systemic disease poses a significant threat to global agricultural stability, particularly affecting legume crops in warm climatic zones.

The primary crop of economic concern for this pathogen is soybean. The virus also infects a wide range of wild legumes, particularly species within the Rhynchosia genus, which serve as crucial reservoirs that maintain the viral inoculum in the environment throughout the year.

Symptoms typically manifest as bright yellow or golden mosaic patterns on the foliage, accompanied by leaf curling, stunted plant growth, and reduced internode length. In severe cases of early-season infection, soybean plants may show complete lack of pod development, leading to total yield loss.

The transmission of the virus is strictly mediated by the whitefly Bemisia tabaci in a circulative, non-propagative manner. The insect acquires the virus while feeding on infected plant tissues and subsequently transmits it to healthy soybean plants, making the management of insect populations a critical factor.

Integrated management practices for prevention and control include:

• Deployment of resistant or tolerant soybean cultivars developed through breeding programs.
• Strict monitoring and control of whitefly populations using targeted insecticide applications.
• Elimination of alternative host weeds in and around the fields to reduce the primary infection source.
• Implementing cultural practices such as crop rotation and adjusted sowing dates.
• Application of physical barriers or reflective mulches where economically feasible to deter insect vectors.