Abstract

The experiment was conducted to assess associations between root yield and yield- related traits of orange-fleshed sweetpotato genotypes to identify traits that have maximum effect on root yield of sweetpotato to make possible selection. Twenty-four Orange Fleshed Sweetpotato genotypes were evaluated in 2017 main cropping season at Hawassa Agricultural Research Center using a Randomized Complete Block Design (RCBD) with three replications. Data were collected from 12 traits, and then subjected to analysis of variance (ANOVA), correlations and path coefficient analysis. The estimation of characters  associated revealed that storage root yield was positively and significantly associated with roots number per plant, root length, root girth, harvest index at both genotypic and phenotypic levels. Some of the traits showed a highly significant (p<0.01) positive genotypic and phenotypic correlations while the other traits showed significant negative correlations. The genotypic correlation coefficients were higher than phenotypic correlation coefficients in magnitude indicating fairly strong inherent association between the characters studied. Path analysis revealed that roots number per plant, root girth and harvest index had positive direct effects on storage root yield at both phenotypic and genotypic levels. Based on the results of current study, traits that showed a positive direct effect on storage root yield could be used as the best predictors of storage root yield in sweetpotato improvement program.

Key words: Character association, correlation coefficients, path coefficient, sweetpotato.