• Kana, H. A.
  Department of Plant Science and Biotechnology, Faculty of Life Sciences, Federal University of Lafia, Nasarawa State, Nigeria
  




• Ugbedeojo, A. M.
  Department of Plant Science and Biotechnology, Faculty of Life Sciences, Federal University of Lafia, Nasarawa State, Nigeria
  




• Ogah, G. O.
  Department of Plant Science and Biotechnology, Faculty of Life Sciences, Federal University of Lafia, Nasarawa State, Nigeria
  




• Lawal, J. I.
  Department of Plant Science and Biotechnology, Faculty of Life Sciences, Federal University of Lafia, Nasarawa State, Nigeria
  




• Abu, F. N.
  Department of Soil Science, College of Agriculture, Science and Technology, Lafia, Nasarawa State, Nigeria
  

This study evaluated the efficacy of foliar-applied green-synthesized iron oxide nanoparticles (FeNPs) on the growth, yield performance, and genetic stability of eleven improved soybean genotypes across two savanna agroecological locations in Nasarawa State, Nigeria (Akwanga and Lafia). Combined analysis of variance revealed that genotype significantly influenced pod number per plant (P < .001) and 1000-seed weight (P < .05), while location significantly affected germination count, branch number, plant height, days to 50% podding, and pod count (P < .001). Foliar FeNP treatment exerted a statistically significant main effect on mean seed count per pod (P < .05). Genotype × environment interactions were non-significant for pod count and 1000-seed weight but significant for seed count per pod (P < .05). Phenotypic coefficients of variation (PCV: 14.09%–34.27%) consistently exceeded genotypic coefficients of variation (GCV: 0.00%–21.10%) across all evaluated traits, resulting in low-tomoderate broad-sense heritability estimates (0.00%–37.90%). Broadsense heritability was highest for pod count per plant (37.90%) and plant height (36.69%), whereas seed count per pod exhibited zero genotypic variance (0.00%). Akwanga supported significantly higher vegetative growth and structural pod yield (53.45 pods per plant) than Lafia (44.14 pods per plant). Under FeNP-treated conditions, genotype V5 (TGx2020- 4e) achieved the maximum plant height (61.33 cm) and maximum branch count (12.00), alongside V2 (12.00), whereas untreated control plots displayed uniform performance across varieties. Foliar FeNP supplementation did not induce significant shifts in overall phenological maturity schedules or total 1000-seed weight across genotypes. These findings indicate that while foliar FeNP supplementation enhances mean seed count per pod and vegetative growth in specific responsive accessions, overall agro-morphological traits and yield components in soybean are predominantly governed by genetic architecture and environmental factors.