GENETIC VARIABILITY AND ASSOCIATION AMONG AGRONOMIC CHARACTERS IN SOME GENOTYPES OF MAIZE ( Zea mays L.) GROWN IN MAYICHOW, NORTHERN ETHIOPIA

A total of sixteen barley (Hordeum vulgare L.) genotypes were evaluated for genetic variability and character associations at two different environments. The genotypes were grown in a simple lattice design. Data were collected on 16 morpho-agronomic characters. The analysis of variance at each location showed significant (P< 0.05) difference for all of the characters, except spikelets per spike gonder This indicated the existence of variability and hence the potential for selection and improvement within characters. The mean performance of the genotypes indicated that local cross Balami which is dominant farmers’ variety at Chencha and genotype Ardu-12-60B at Areka gave high grain yield than the other genotypes. Thousand-kernel weight, tillers per plant, grain protein yield, grain yield, harvest index, spike length and kernels per spike at both locations were found to have high coefficient of variability, intermediate to high heritability and genetic advance as percent of the mean. This means that effective and satisfactory selection for practical improvement of these important traits is possible. Character associations were determined by simple correlation and path coefficient analysis. Grain yield showed positive and significant correlations with thousand-kernel weight, hectoliter weight, biological yield, harvest index and grain protein yield at both locations. Positive associations of grain yield with the principal yield components give an opportunity to simultaneously improve yield and yield contributing characters. Days to heading and maturity exhibited negative correlations with grain yield, indicating that selection for early maturing genotypes will improve grain yield for semiarid environment. Phenotypically, biological yield and harvest index, and genotypically, days to maturity, biological yield, harvest index and spikes per plant exerted favorable direct effect on grain yield at both locations. Selection for biological yield and harvest index would, therefore, be very useful for grain yield improvement. Hence, for future crossing work it could be useful to select individual genotypes from these by considering the special advantages of each cluster and the objectives of the crossing program.