A B S T R A C T Field experiment was conducted to identify the most promising and adaptable sweet potato (Ipomoea batatas L.) variety. Five Orange Fleshed Sweet Potato (OFSP) varieties: variety Beletech (192026 II), Birtukanie (Saluboro), Kulfo (Lo-323), Tulla (CIP 420027) and one local variety were used as experimental treatments and arranged in randomized block design with three replications. Data collected on growth parameters were analyzed using the GLM procedure of SAS Version 9.2. Variety had highly significantly affected the growth parameters; number of branches per plant, number of leaves per plant and vine length and also significantly affected fresh weight and dry matter content of sweet potato roots. For the majority of growth parameters variety, Tulla was preferably the best variety compared to the other three improved OFSP varieties as, well as the local variety and significantly the highest number of branches per plant (41.41), vine length (99 cm), fresh weight (1.56 kg) and dry matter content (54.40%) were recorded from variety Tulla. The result of the correlation analysis also indicated that fresh weight and dry matter content of sweet potato roots were negatively and significantly correlated with number of branches per plant. This indicated that sweet potato producers targeting above ground biomass production should use number of branches and leaves per plant as selection criteria, where as those targeting sweet potato root tubers production, should use the fresh weight and dry matter content of sweep potato roots as selection criteria. Likewise, these growth parameters are important factors for selection of sweet potato and can serve as indicators of adaptability of the crop to the growing conditions of the study area. Therefore, OFSP variety Tulla (CIP 420027) can be used as the most promising and adaptable variety for optimum growth and productivity at the study area, Jimma in the Southwestern part of Ethiopia and combat VAD at community level.

Five orange fleshed sweet potato (Ipomoea batatas L.) varieties: four collected from Adami Tulu Agricultural Research Center and one local variety with orange flesh were evaluated at field condition to identify the highest yielding and adaptable variety. The five varieties: Beletech (192026 II), Birtukanie (Saluboro), Kulfo (Lo-323), Tulla (CIP 420027) and a local variety were used as treatments and arranged in randomized complete block design with three replications. Data collected on yield and yield contributing parameters were analyzed using the GLM procedure of SAS version 9.2. Variety had significantly affected root diameter, marketable tuberous root yield and total tuberous root yield. Significantly the highest root diameter (4.9 cm), marketable tuberous root yield (0.78 t haG 1) and total tuberous root yield (0.88 t haG 1) were obtained from variety Tulla. The result of the correlation analysis also revealed that root diameter and number of tuberous roots per plant were significantly and positively correlated with marketable and total tuberous root yield. Likewise marketable tuberous root yield was also significantly and positively correlated with total tuberous root yield. This indicated sweet potato producers targeting tuberous roots should use root diameter, number of tuberous roots per plant and marketable tuberous root yield as selection criteria. Likewise, these yield and yield contributing parameters are important selection parameters which can serve as indicators of adaptability of the sweet potato to the study area and can also be utilized for making improvement in tuberous root yield of sweet potato. Besides, yield is an important agronomic index that shows the adaptability of a variety to its growing environment and accordingly variety Tulla outperformed the three improved OFSP varieties and the local variety in yield and yield contributing parameters. Therefore, variety Tulla (CIP 420027) was identified as the highest yielding and adaptable OFSP variety under the rain fed condition in the humid tropics of Southwestern Ethiopia at Jimma and potentially combats VAD at community level.