Pigeonpea sterility mosaic virus

The causative agent of the disease is Emaravirus toordali, which primarily infects pigeonpea (Cajanus cajan) crops. This viral pathogen causes a severe systemic infection that effectively halts reproductive growth, rendering the affected plants completely sterile.

The primary vector responsible for the transmission of the virus is the eriophyid mite Aceria cajani. As these mites feed on the sap of infected plants, they acquire the virus and transmit it to healthy plants, facilitating rapid spread within the field and surrounding areas.

The hallmark symptom is the complete absence of flowers and pods, known as sterility. Before this stage, plants exhibit distinct signs such as leaf chlorosis, mosaic patterns, and severe leaf stunting, resulting in a bushy, broom-like appearance of the infected shoots.

Environmental conditions play a crucial role in disease dissemination, specifically the prevalence of the mite vector. Warm and humid conditions favor the population growth of Aceria cajani, while continuous cropping of pigeonpea without fallow periods ensures the pathogen's survival.

Economic damage is substantial, as infected plants yield no grain. Management strategies include:

• Planting resistant or tolerant pigeonpea cultivars.
• Effective control of the mite vector using acaricides.
• Adhering to strict crop rotation to break the pathogen's cycle.
• Removing volunteer plants that act as viral reservoirs.