GENETIC VARIABILITY AND ASSOCIATIONS AMONG YIELD AND YIELD RELATED TRAITS OF MAIZE (Zea mays L.) GENOTYPES AT HARAMAYA, ETHIOPIA

Maize (Zea mays L.) is one of the most important cereal crops in Ethiopia. It is first in productivity among cereal crops and second in area of production. The experiment was conducted to determine the magnitude and extent of genetic variability; and the association between traits and their contribution to yield in maize genotypes. The field experiment was laid out in a 10x5 alpha lattice design with two replications. The analysis of variance showed genotypic mean squares were significant for eight traits indicating presence of genetic variability among genotypes studied. The highest coefficient of phenotypic and genotypic variation were observed in number of ears per plant followed by above ground biomass yield per plot while moderate GCV and high PCV were observed in grain yield per hectare. High magnitude of broad sense heritability was estimated in number of ears per plant, ear diameter, thousand kernel weight and grain yield per hectare, ear length and number of kernels per row. Grain yield per hectare showed significant and positive correlation with above ground biomass per hectare and harvest index at phenotypic level. Grain yield per hectare showed significant and positive correlation with above ground biomass yield per plot and harvest index at phenotypic and genotypic level. The path coefficient analysis at phenotypic level revealed that the highest positive direct effect on grain yield was exhibited by number of kernels per row, followed by ear diameter, above ground biomass yield per plot. The path coefficient analysis at genotypic level revealed that the highest direct positive effect on grain yield was exhibited by number of ears per plant, followed by thousand kernels weight and above ground biomass yield per plot.