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A field experiment was conducted in the rainfed upland rice producing areas of Ethiopia; Gonder, Pawe and Shire-Maitsebrie during 2017 and 2018 cropping seasons. Thirteen upland rice varieties were tested with the objective of examining the agronomic performance and yield stability of the varieties using Additive Main Effect and Multiplicative Interaction (AMMI) and Genotype and Genotype by Environment (GGE) biplot analysis. The AMMI analysis of variance for grain yield detected significant effects for genotypes, environments and genotype by environment interactions. Environment effect was responsible for the greatest part of the variation, followed by genotype by environment interaction and genotype effects. Based on the AMMI stability analysis G1, G2 and G5 were the most stable genotypes, while G13, G3 and G12 were the most responsive ones. The GGE biplot also showed that G13, G3, G12 and G10 have long vectors and located far away from the biplot origin and hence are considered to have larger contribution to GEI. Among the tested genotypes G1 (Fogera-1), G5 (Andassa) and G2 (Adet) gave high yield and good stability across environments and can be recommended for production for the testing sites and similar upland rice producing areas of Ethiopia.

Rice (Oryza sativa L.) is one of the major staple food crops for about 65 % of the world’s population. A rice field experiment was conducted at Tselemti district of North Ethiopia during the main wet cropping season 2015-16 and 2016-17. The current study was proposed to evaluate the adaptability and yield performance and to identify stable, high-yielding, disease-resistant and early maturing upland rice genotype(s) in local environments. Sixteen upland rice genotypes including the standard check were evaluated. The tested genotypes are both released and unreleased genotypes and gained from national rice research programs. The experiment was laid out in a randomized complete block design of three replications. Combined analysis of variance revealed significant variations in genotypes for most traits but there is non-significant for genotype by environment interaction based on the selected analyzed traits and this implied the genotypes were not affected by the environment and the superiority genotypes across environment is constant. The highest grain yield of 3.5 t ha-1 was recorded by G4-Tana (41.8 Qt ha-1), followed by G2-Getachew (39.5 Qt ha-1). So, even if the stability didn’t analyzed the Genotype Tana and Getachew were relatively highest in mean grain yield across environments and hence, both genotypes could be recommended for cultivation by the farmers and this variety should be demonstrated and popularized in larger scale to make use of its merits.

In order to evaluate the performance of improved maize genotypes, an experiment was conducted at Medebay zana and Laelay Adiabo district of North western of Tigray, Ethiopia, during 2014 and 2015 main cropping season. The experiment was laid out in a randomized complete block design with three replications. The data were recorded on plant height, ear height, number of ears/plot, plant and ear height, days to 50% anthesis, silking, maturity, grain yield and 1000 grain weight. All varieties showed significant differences with each other for all the traits studied in most environments but incase of genotype by environment combined data revealed most of the traits gave nonsignificant result and indicated better to focus and recommend on the stable genotypes across the environments. Variety Gibe-2 and Gibe-1 had the top two highest grain yield of 5114.15 kg ha-1 and 4964.96 kg ha-1. Melkasa-6 was the early maturing variety as compared with standard checks of melkasa-2 and the remained varieties. The highest plant height and ear placement of 237.28, 120.80, respectively cm was noted in variety Gibe-1. This variety may be susceptible to lodging. These varieties had a wide genetic background, thus showing grain yield ranges from 1748 to 5114 kg ha-1. So, generally maize variety of Gibe-1 and Gibe-2 were found most promising, which has the potential to increase the average yield of maize in Medebay zana and Laelay Adiabo districts and is therefore recommended to demonstrate for general cultivation in both districts.