Inadequate knowledge on appropriate number of nodes of sweet potato vines to be planted and sources of potassium fertilizer to be used are among major factors resulted into low sweet potato productivity in central part areas of Tanzania.  This research aimed at evaluating the effects of four levels of nodes buried and three potash fertilizer sources on growth and yield of three sweet potato varieties. Split-split plot field experiment in complete randomized block design was conducted at Hombolo, Dodoma during 2013/2014 cropping season. Main plot were three sweet potato varieties, Kiegeya, Mataya, and Ukerewe. Sub plot were, four level of buried nodes, (two above ground), five buried nodes (three above ground), seven buried nodes (three above ground) and eight buried nodes (four above ground). The sub - subplot treatments were potash fertilizer sources i.e control no fertilizer used, Potassium chloride (KCl), Potassium nitrogen phosphate (NPK) and Farm yard manure (FYM). Results indicated that there were no significant effects on the yield among varieties used. The number of tubers increased significantly in fertilized plots compared to control. The lowest number of tuber roots (3 tubers) was from control treatment while the highest number of tuber roots (6) was from KCl treatment. The effect of potassium fertilizer sources on root yield were also significant, use of KCl resulted to highest yield (18.84 t ha-1), followed by NPK (17.51 t ha-1), FYM (11.33 t ha-1) and control treatment where no fertilizer applied (8.82 t ha-1). Plating of different number of nodes resulted into significant increase in yield where the highest yield of (15.91 t ha-1) was from eight buried nodes and lowest total yield (11.68 t ha-1) was from four buried nodes. Seven and eight buried nodes with KCl and NPK fertilizers appeared to be appropriate for optimum sweet potato growth, yield and tuberous root quality in the study area and are therefore recommended.