Virus diseases are one of the most important production constraints facing sweetpotato producers. In the US four viruses are common; each is very similar to the most common, sweetpotato feathery mottle virus (SPFMV). Yield, skin color, shape and quality of storage roots can be greatly reduced when sweetpotatoes become infected with these viruses. Yield reductions can exceed 40%, and cracks may develop in the roots making them unmarketable. Often 100% of plants in a field are infected by the end of one growing season. Many sweetpotato viruses are vectored by aphids and whiteflies. These insects can be carried on machinery and the wind, and are responsible for spreading viruses both short and long distances. 

Planting clean, virus-tested plants can help mitigate the issues caused by sweetpotato viruses.