Stability analysis of seed yield and agronomic performance of black cumin (Nigella Sativa L.) genotypes in Amhara Region, Ethiopia
Black cumin is an annual spice crop valued for its nutritional, medicinal and economical importance. Although the Amhara Region of Ethiopia possesses suitable agroecological conditions for black cumin production, seed yield remains below the national average, largely due to the limited availability of improved varieties. This study was conducted to evaluate the agronomic performance, genotype x environment interaction (GEI) and seed yield stability of promising black cumin genotypes. Multi-environment trials were carried out at three locations during the 2021 and 2022 main cropping using a randomized complete block design with three replications. Eighteen advanced genotypes and two standard check varieties were evaluated. Combined analysis of variance revealed significant differences among genotypes, environments, and genotype x environment interactions for all measured traits. Genotypes Moyale-230777 (G12), Achefer-9068 (G2), and Gofazuria-90517 (G7) exhibited the highest mean seed yields of 647.6 kg ha-1, 647.1 kg ha-1, and 623.9 kg ha-1, respectively. However, Achefer-9068 had lower oleoresin content. Moyale-230777(G12) and Gofazuria-90517 (G7) showed yield advantages of 17.8% and 26.8%, respectively, over the standard check varieties Dershaye and Aden. The genotype with environment interaction in the seed yield data of six environments (location and year combinations) was analyzed using AMMI and GGE biplot models. The result showed that environment had the greatest effect (53.0%) followed by GEI (32.2%) and genotype (14.9%). Based on AMMI, AMMI stability value (ASV), yield stability index, oleoresin content, and GGE biplot analysis G12 and G7 ranked the 1st and 2nd the genotypes for their yield performance, quality, identifying top performing genotypes with wide adaptability across the testing environments. Consequently, these genotypes were selected for on-farm verification, and accession number Moyale-230777 (G 12) has been released for commercial production in 2024 under the name “Tena”. Therefore, variety Tena is recommended for demonstration, scaling-up and commercial cultivation in the spice growing of Amhara Region and other similar agroecological zones.