Journal Article: A series of experiments were conducted from 2003 to 2005 to determine the major mechanism through which sweet potato virus disease (SPVD) is spread in farmers’ fields in the Lake Victoria basin of Tanzania. Farmers’ ability to select SPVD-free vines for planting was tested followed by phytosanitary (selection and rouging infected plants) experiments conducted at six different sites in farmer fields in Bukoba and Muleba districts during short rain and long rain seasons in 2003 and 2004. In addition, the effectiveness of using SPVD-free (tissue culture developed and virus-indexed) was tested for three seasons from 2004 to 2005. It was established that farmers have skills to effectively select against SPVD-infected planting vines particularly those with apparent SPVD symptoms. SPFMV and SPCSV vectors largely contributed to new incidences of SPVD compared to the vines-based infections. SPFMV and SPCSV co-existed. The use of virus-free vines in such vector-prevalent environment was found to be fruitless efforts. It was concluded that, the use of cultivars with multiple resistance to sweet potato viruses could be the only feasible management strategies for SPVD in the Lake Victoria Basin