A study was conducted to determine the effect of sweet potato growing methods on the yield of three sweet potato varieties. The field experiment was conducted at Africa University farm in Mutare Zimbabwe. The trial had five treatments and was designed as a 5x3 factorial experiment with treatments arranged in a Completely Randomized Block Design (CRBD) with three replicates blocked against irrigation lines. The five different sweet potato growing methods used were: Treatment 1 (use of mounds), Treatment 2 (use of ridges), Treatment 3 (flat method/minimum tillage method), Treatment 4 (use of sacks) and Treatment 5 (use of plastic buckets). The three sweet potato varieties grown were: Beauregard (Orange fleshed), Okinawa purple (Purple fleshed) and German II (White fleshed). Data was collected on the growth and yield parameters. The growth parameters measured were: Sweet potato vine length, number of leaves and number of branches. The yield parameters measured were: sweet potato tuber length, diameter, yield in tons per hectare and harvesting index. From the yield parameters, the study showed that sweet potato varieties performed differently under different growing methods. Beauregard variety produced the highest overall yield of 15.5 tons per hectare p<0.05 under treatment 4 (use of sacks). Okinawa purple variety produced its highest yield of 9.83 tons per hectare p<0.05 under treatment 4 (use of sacks) and German II produced its highest yield of 13.7 tons per hectare p<0.05 under treatment 1 (mounds). All varieties recorded their lowest yield in treatment 5 (plastic buckets) which was significantly different from the highest yields in all the other growing methods. The highest overall Harvesting Index of 44.6% was obtained by Okinawa purple variety grown in treatment 1 (mounds). German II and Beauregard varieties recorded their highest Harvesting index of 40.5% and 38.7% respectively from plants grown in treatment 4 (use of sacks). All the varieties recorded their lowest harvesting index from plants grown in treatment 5(plastic buckets). The study demonstrated how different growing methods impact yield and growth of three sweet potato varieties. The research showed that Beauregard and Okinawa purple varieties yield best with the use of sacks while the German II variety performs optimally with mounds. The findings provide valuable insights for optimizing sweet potato cultivation, offering practical guidance for farmers and researchers aiming to enhance sweet potato production.
Keywords: Agronomy, Harvesting index, Sweet potato, Variety, Yield