ABSTRACT
Bread wheat (Triticum aestivum L.) is most important cereal crop in
Ethiopia. Lack of genotypes with wide stability across environments has been
one of the most important constraints of wheat production in the country. Field
experiments were conducted in Halaba and Bule, South Ethiopia, in 2016 and
2017, in order to estimate grain yield stability and association among
stability parameters. Fifteen improved bread wheat genotypes were grown under
randomized complete block design with three replications. Mean yield for Halaba
2016, Halaba 2017, Bule 2016 and Bule 2017 was 3.83, 1.89, 2.90 and 3.59
tons/ha, respectively. Genotypes Lemu (3.25 tons/ha) and Mandoyu (3.18 tons/ha)
had high mean yield, and low values of environmental variance (S2i),
coefficient of variation (CVi), stability variance (δ2i), ecovalence
(Wi) and deviation from regression (S2di). Genotypes Biqa (3.69
tons/ha) and Shorima (3.66 tons/ha) had high mean yield, coefficient of
regression (bi) and coefficient of determination (R2i ≥ 0.94) as
well as low values of δ2i, Wi and S2di. Grain yield had
positive rank correlation with bi (r = 0.75, p < 0.01), R2i (r =
0.70, p < 0.01) and rank sum (r = 0.82, p < 0.01). Rank correlation among δ2i, Wi and S2di
was high (r ≥ 0.98, p < 0.01). Present study showed that genotypes Lemu, Mandoyu and
Hidase, and Biqa and Shorima would be recommended for wide adaption, and for
more favorable environments, respectively. It could also be suggested that one
of Wi, δ2i, S2di and rank sum would be used for ranking
of genotypes.