Virus indexing combines knowledge of viruses with methodologies for their detection to assure the effective safe movement of sweetpotato germplasm. Due to low virus titers and the absence of symptoms from single infections in sweetpotato by most viruses, grafting onto indicator plants is often required to boost titers and detect viruses reliably. The commonly used indicator plant is Ipomoea setosa, which is susceptible to most viruses infecting sweetpotato. This standard procedure has been established based on current information for virus testing of sweetpotato germplasm, with the recognition that it will need to be revised as new information becomes available.