Mungbean yellow mosaic India virus

Mungbean yellow mosaic is a severe viral disease caused by Begomovirus vignaradiataindiaense, a member of the Geminiviridae family. The virus is characterized by its circular, single-stranded DNA genome. It establishes a systemic infection within the host plant, profoundly altering the physiology, pigment composition, and growth patterns of the affected crops.

The primary host for this virus is the mungbean (Vigna radiata). However, the pathogen has a broader host range and can infect various other legumes, including common beans, black gram, and pigeon pea. The wide range of host plants allows the virus to survive and persist in the environment, moving between crops as soon as the vector population increases.

Symptoms typically manifest as yellow patches or spots on the leaf surface, which eventually coalesce to form a mosaic pattern. In advanced stages, the entire leaf may become yellow or white, severely limiting photosynthesis. The plants exhibit stunted growth, reduced leaf size, and significant floral abortion, which leads to a dramatic drop in yield and poor seed quality.

Transmission occurs exclusively via the whitefly (Bemisia tabaci), which picks up the virus during feeding and transmits it to healthy plants. High ambient temperatures and optimal humidity are key environmental triggers that promote the rapid build-up of whitefly populations. Consequently, the disease often spreads in waves, particularly during the warm seasons when insect vectors are most active.

• Cultivation of resistant or tolerant mungbean varieties.
• Stringent vector control using appropriate insecticides.
• Removal of infected plants to reduce the inoculum load.
• Elimination of weeds that serve as alternative virus hosts.
• Adjusting planting dates to avoid high whitefly activity periods.

The impact of this virus on agriculture is profound, as it can cause complete crop failure in susceptible fields. Since there is no chemical cure for systemic plant viral diseases, management must be proactive. Integrating agronomic practices with pest control is the only viable strategy to protect yields and maintain the economic viability of legume farming in affected areas.