Abstract The analysis of variance showed that there were substantial differences between all of the maize and sweet corn genotypes for all of the characteristics across all three settings. All maize characters showed a small difference between phenotypic and genotypic variance, with the exception of grain yield per plant and ear girth in E1, and the number of kernel rows per ear and test weight in E2, E3, where environmental variations had less of an impact. High genotypic and phenotypic variation for ears per plant was found in sweet corn, suggesting a moderate environmental effect on expression of this characteristic in generations E1, E2, and E3. Except for ear girth, number of kernel rows per ear, and grain yield per plant in E1, maize phenotypes were highly heritable and advanced genetically by a large percentage in all three environments.