Abstract
The prevalence of potato leafroll luteovirus (PLRV), potato S carlavirus (PVS), potato X potexvirus (PVX), and potato Y potyvirus (PVY) was determined in fields planted with tubers of the imported certified cultivar Alpha, tubers saved from the previous year's crop of imported certified Alpha, and tubers of the local cultivar, Zalinge, in the potato-growing regions of Elgaily, Elsororab, and Wad Ramly in the Sudan. Increased levels of infection across viruses were consistently found in fields planted with tubers saved from the previous year's crop produced from imported certified Alpha over those obtained with the original imported certified Alpha. The local Zalinge was heavily infected with potato viruses. Significantly high infection levels of PVS (89.6%), PLRV (23.6%), and PVX (18.7%), but not PVY (1.9%) were detected in Zalinge. In Alpha types, however, the most prevalent virus was PVX (8.2%), followed by PVS (3.9%), PVY (3.2%), and PLRV (1.9%). Significant regional variation in the incidence of these viruses and virus by cultivar interaction were also detected. Higher infection levels were found in potato fields in the Wad Ramly region. Implications of these findings with respect to potato production and management of potato viruses in the Sudan are discussed.