Heritability of some quantitative characters in five varieties of maize (Zea mays l.,) under the influence of various levels of nitrogen
field experiment was conducted at the Kano University of Science and Technology Wudil teaching and research farm during the 2010 and 2011 rainy seasons. Five varieties of maize were studied to estimate components of genetic variance and heritability of some quantitative characters that might exist among them, under the influence of different levels of Nitrogen fertilizer. The experiment was laid out in a randomized complete block design, and replicated three times. The genotype × different levels of nitrogen fertilizer (G × N) influenced the expression of the ear height and yield component. Analysis of variance for plant height revealed highly significant differences among varieties with genotypic coefficient of variation (1.67%) which is smaller than the phenotypic coefficient of variation (1.72%). The estimate of broad-sense heritability was high (0.79), thus showing the presence of considerable amount of genetic variation in total phenotypic variation. While the analysis of variance for ear height showed highly significant differences among genotypic coefficient of variation (0.93%) which is smaller than the phenotypic coefficient of variation (1.05%). The estimate of broad-sense heritability was high (0.49) indicating the presence of considerable amount of genetic variation in total phenotypic variation. The results confirmed the
findings of other researchers on high heritability for plant height. Analysis of variance for grain yield per plot showed greater Genotypic variance than the environmental variance with genotypic coefficient of variation (5.33%) which is smaller than the phenotypic Coefficient of variation (6.24%)and the estimate of broad sense heritability (0.78) was moderately high.
Keywords: Heritability, variation, ear height, genes.