Evaluation of root yield performance of newly bred orange-fleshed sweet potato genotypes in Ethiopia

Abstract

Orange-fleshed sweet potato (OFSP) is rich in -carotene and it is the cheapest staple food, easily accessible and year-round source of vitamin A. However, in Ethiopia, the acceptance of the OFSP varieties by farmers was low due to their low root dry matter content (RDMC). Therefore, a crossing block was established in 2013 to cross selected OFSP varieties with white-fleshed varieties in order to improve the RDMC of the OFSP varieties and thereby increase the adoption of the varieties. Nursery and preliminary yield trials were conducted in 2014 and 2015, and finally, national variety trials were conducted at four locations for two years (2016 and 2017) using 12 selected genotypes. The analysis of variance revealed that there was significant difference (p < 0.01) among the varieties for total root yield and RDMC. Two genotypes, Ukr/Eju-10 and Ukr/Eju-13 have been identified as best candidates for release based on their fresh root yield of 28.7 and 26.8 t ha-1, RDMC of 31.9 and 31.4%, resistance to sweet potato virus disease with low score of 1.4 and 1.6, respectively. The flesh colour of the two varieties is deep orange with high -carotene contents of 12.48 and 9.51 mg 100 g -1 , respectively as compared to the standard check (Kulfo), which had 6.91 mg 100 g -1 . The two newly bred candidate varieties were ranked 1st and 2nd based on farmers' preference taste-test. Therefore, the two candidate varieties can be the potential OFSP varieties that can replace Kulfo, which is currently under production in Ethiopia.