Sida yellow mosaic

Sida yellow mosaic is a significant viral disease caused by viruses belonging to the genus Begomovirus, family Geminiviridae. These viruses are characterized by circular single-stranded DNA genomes and represent a major limiting factor in the cultivation of various Malvaceae species in tropical and subtropical regions.

The host range of the pathogen is primarily centered on members of the family Malvaceae. Key crops affected include cotton, okra, and hibiscus, as well as several wild species of the Sida genus, which serve as crucial reservoirs that maintain the virus in the environment between growing seasons.

The primary clinical symptoms of the disease include severe yellow mosaic patterns, leaf chlorosis, and vein yellowing. As the infection progresses, affected plants display stunted development, shortened internodes, and significant leaf curling. In advanced stages, the plants exhibit reduced flowering and poor fruit or fiber development, which compromises the total economic yield.

Disease epidemiology is fundamentally tied to the population dynamics of its primary vector, the tobacco whitefly (Bemisia tabaci). Environmental factors, such as high temperatures and relative humidity, exacerbate the incidence of the disease by promoting rapid whitefly breeding cycles and enhancing their ability to migrate between plant hosts.

Effective management requires a strategic approach focusing on the following components:

• Integration of insecticide programs to reduce whitefly populations during the critical phases of crop growth.
• Sanitation practices that involve the systematic removal and destruction of host weeds like Sida species.
• Development and use of resistant or tolerant germplasm to limit disease spread.
• Implementation of spatial and temporal isolation techniques to avoid overlap between neighboring susceptible crops.