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A study was undertaken during the 2017-18 to 2018-19 cropping seasons at at eleven locations and/or seventeen environments in optimum moisture areas of Ethiopian to identify stable genotypes with high grain yield and release as a variety for optimum-moisture environments. Alpha-lattice design with three replications was used. The combined ANOVA revealed very highly significant differences (p=0.001) among genotypes, environments, and GEI for yield and its components. The environment sum of squares contributed more than the genotype and GEI sum of squares for the total variance of all traits. When we consider the overall mean for grain yield, genotype ETBW8751 (5.12 t ha-1) the highest value followed by ETBW9554 (5.10 t ha-1) whereas the lowest grain yield was obtained from the genotype ETBW8804 (3.67 t ha-1). GGE and AMMI analysis explained almost similar amounts of variation; however, AMMI still show a slightly greater proportion than GGE during our study. According to AMMI and GGE analysis genotype 21 (ETBW9553) was more stable as well as high yielding followed by 22 (ETBW9554) and 2 (ETBW8751. Conversely, 15 (ETBW9547) was unstable, but high yielding. Hidasse had low yields but was unstable. ETBW9554 was validated on farmers' fields and recommended for registration as a commercial variety and finally released in 2020 with its designated local name "Boru" for commercial production for mid to highland agro-ecologies in Ethiopia. [ABSTRACT FROM AUTHOR]

A multi-location Experiment was conducted using 28 genotypes and two checks during the main cropping seasons of 2017 and 2018 at Kulumsa, Dhera, Melkasa, Asasa, Ilala, and Geregera in moisture-stress areas of Ethiopia to evaluate the genotype-Environment interaction effect and grain yield stability of bread wheat genotypes. The experiment was arranged in alpha lattice design replicated three times. The stability analysis was carried out for grain yield using R software. ANOVA showed a highly significant difference among genotypes and genotype×environmental interaction for traits; days to heading, days to maturity, plant height, grain yield, 1000 kernel weight. The average mean yield of the genotypes across the environments was 4.5 with the range of 3.5–5.3 t ha-1. The genotypes ETBW 9578, ETBW 9565, ETBW 9570 and ETBW 9571 were topyielding, ideal, and stable across the ten environments. However ETBW 9589 and Ogolcho were the low-yielding genotypes. The “which-won-where” graph categorizes the genotypes into four groups. The locations within the same group were closely correlated and share the same winning(vertex) genotype. E7 was ideal that has both discriminating abilities of the genotypes and representative of the other test environments. ETBW 9578 gave 37.7% and 39.1% yield advantage over the standard check Kingbird and local check Ogolcho, respectively. As a result the genotype ETBW 9578 was released in 2020 and designated by the variety name “Dursa”. Thus, it was concluded that the Dursa variety could be used as a stable variety for cultivation. [ABSTRACT FROM AUTHOR]

Development of low-nitrogen (N) tolerant and N-responsive durum wheat genotypes is required since nitrogen efficiency has emerged as a highly desirable trait from economic and environmental perspectives. Two hundred durum wheat genotypes were evaluated at three locations under optimum (ON) and low (LN) nitrogen conditions to screen genotypes for low-nitrogen tolerance and responsiveness to an optimum N supply. The results showed significant variations among the durum wheat genotypes for low-N tolerance and responsiveness. The average reduction in grain yield under the LN condition was 48.03% across genotypes. Only 17% of the genotypes tested performed well (grain yield reduction <40%) under LN conditions. Based on the absolute grain yield, biomass yield, and normalized difference vegetative index value, on average, 32, 14, 17, and 37% of the tested genotypes were classified as efficient and responsive, efficient and nonresponsive, inefficient and responsive, and inefficient and nonresponsive, respectively. Considering the absolute and relative grain yield, biomass yield, normalized difference vegetative index values, and stress tolerance indices as selection criteria, 17 genotypes were chosen for subsequent breeding. Among the screening indices, geometric mean productivity, stress tolerance index, yield index, and stress susceptibility index exhibited positive and significant correlations with grain yield under both N conditions; hence, either of these traits can be used to select low-N-tolerant genotypes. The common genotypes identified as LN-tolerant and responsive to N application in this study could be used as parental donors for developing N-efficient and responsive durum wheat varieties. [ABSTRACT FROM AUTHOR]