Sorghum chlorotic mosaic virus

Sorghum chlorotic mosaic virus (SCMV) is a significant phytopathogen belonging to the genus Potyvirus and the family Potyviridae. It is an obligate virus that causes systemic infections in various cereal crops. The pathogen fundamentally alters plant physiological processes, leading to stunted growth and significant agricultural yield losses worldwide.

The host range of SCMV primarily includes sorghum, maize, millet, and a variety of wild grasses. Infected plants typically display symptoms such as leaf mosaic patterns, yellow chlorotic streaks along the leaf veins, and stunted development. In severe cases, the plant's ability to produce grain is severely compromised, resulting in empty panicles or reduced seed quality.

The transmission of the virus is predominantly mediated by aphid species in a non-persistent manner. The virus is acquired by the aphid during short probing periods on an infected plant and is subsequently transmitted to healthy plants. In the off-season, the virus survives in perennial grass weeds or volunteer crops, which serve as the primary reservoir for new infections.

Environmental conditions favoring the rapid spread of the virus include warm temperatures and high aphid populations. Fields with high plant density can facilitate easier aphid movement, leading to faster transmission rates across the field. Early-season infections are particularly devastating, often resulting in systemic stunting that renders the crop economically non-viable.

Effective management requires an integrated approach to disease control. Key strategies include the deployment of resistant or tolerant cultivars, which is the most sustainable solution. Additionally, farmers should prioritize the eradication of host weeds in and around the field, timely application of insecticides to manage aphid vectors, and the implementation of appropriate crop rotation schedules to break the disease cycle.