Mung bean yellow mosaic

Mung bean yellow mosaic is a devastating viral disease caused by members of the Begomovirus genus within the Geminiviridae family. These viruses contain a circular single-stranded DNA genome. The pathogen infiltrates the plant's vascular system, causing systemic infection that disrupts the normal development and physiological health of susceptible leguminous crops.

The host range includes major grain legumes such as mung bean, cowpea, soybean, and black gram. The virus is capable of persisting in various weed species during the off-season, which serves as a reservoir for the primary inoculum in subsequent planting cycles. This persistence makes management particularly challenging in tropical and subtropical agricultural regions.

Symptoms of the disease are quite distinct and can be easily identified in the field. Key diagnostic features include:

• Bright yellow or golden mottling patterns on the leaf surfaces.
• Stunted growth and reduced leaf size compared to healthy plants.
• Deformed foliage with crinkling or puckering effects.
• Drastic reduction in pod production and poor seed set.

The transmission of the virus occurs exclusively through the whitefly Bemisia tabaci. The insect acquires the virus while feeding on infected plant sap and transmits it to healthy plants. Environmental conditions such as elevated temperatures and low humidity are highly favorable for the proliferation of whitefly populations, leading to rapid and widespread dispersal of the viral disease throughout a field.

Management strategies must focus on both vector control and cultural practices. Effective methods include the use of resistant or tolerant crop cultivars, which is the most sustainable approach. Furthermore, farmers should implement integrated pest management (IPM) to control whitefly populations using targeted insecticides, ensure weed-free borders around fields, and follow strict field sanitation protocols to remove symptomatic plants early in the season.