Abstract

Sweetpotato is considered as a lowland crop and the potential of the crop has not been fully exploited in the highland areas. The objective of the current study was to screen released and elite sweetpotato genotypes in highland areas in order to identify best genotypes for release. The screening work was conducted at Gedeb district at an altitude of 2350 meters above sea level during the main rainy season in 2019. The experiment consisted of 110 new sweetpotato genotypes from diverse origins and three recently released check varieties. An augmented block design was used in order to accommodate the large number of genotypes. The analysis of variance indicated the presence of significant differences (p<0.01) among the new entries for root yield, number of roots per plant and reaction to Sweetpotato Virus Disease (SPVD). The root yield of the new entries ranged from 1.43 to 56.20 t ha-1 while that of the checks varied from 20.51 to 28.71 t ha^-1. High root yield that ranged from 31-56 t ha^-1 was recorded from 14 genotypes. SPVD severity scores varied from mild symptoms to severe with severity scores ranging from 1 to 4. Most of the evaluated genotypes showed low SPVD severity scores implying the resistance/tolerance of the genotypes. Based on the traits concerned, more than 50 genotypes are identified and selected for further multistage evaluations and variety development for the highland environments in Ethiopia and other East African countries with similar agro-ecologies.

Keywords: Augmented design; Highland; Root yield; Screening; Sweetpotatos