Evaluation of adaptability and stability of tef (Eragrostis tef (Zucc.) Trotter) varieties using GGE bi-plot analysis in South and Southwestern Ethiopia

Abstract

This study was carried out to evaluate released tef varieties for yield stability using GGE biplot method and to identify high yielding and well adapted varieties for the South and Southwestern Ethiopia. The experiment was conducted using twenty-one tef varieties obtained from a tef breeding program based at Debre zeit Agricultural Research Center. The trial was laid out using randomized complete block design with three replications in six locations during the 2018 of main cropping season. Data was collected on days to heading, days to maturity, grain filling period, plant height, fertile tillers, panicle length,culm length, lodging index, thousand seed weight, above ground biomass, straw yield, harvest index and grain yield. The result of combined analysis for grain yield of twenty-one tef varieties tested across six environments showed that there is a highly significant difference among the environment, genotypes and genotype by environment interaction. Yield data were analyzed using the GGE (that is, G, genotype + GEI) biplot method. Environment explained 69.4% of the total sum of squares, and genotype and genotype x environment interaction explained 17.5 and 7.9%, correspondingly. The first 2 principal components (PC1 and PC2) were used to create a 2-dimensional GGE biplot and explained 48.07 and 18.6% of GGE sum of squares, respectively. The GGE biplot identified three tef growing mega-environments. The first mega environment consisted of environments Ambo,Bedele,Arjo and Areka with variety G11 and G15 as the winning variety and the second sector represents Melko with G2 as winning variety while the third section represents Omonada with G8 as the winner variety. The varieties Kena (G3),Felagot (G9) and Wellekomi (G12) were low yielding and unstable during the experimental year.The varieties Dukem (G15),Heber-1 (G11),Quncho (G1) and Abola (G7) were found to be the most stable varieties and with mean grain yield exceeding the grand mean. The varieties Dukem,Heber-1 and Quncho were found to be benchmark or ideal varieties and can be recommended for wider cultivation in the South and Southwestern Ethiopia.