GENETIC VARIATION OF SOME TRAITS OF MAIZE UNDER POPULATION DENSITIES 2- Yield and yield components

Abstract

To estimate the extent of genetic variability of some maize characters under different plant population, a field experiment was carried out at the experimental field of Dept. of Field Crop, Coll. of Agric. Univ. of Baghdad during fall 2011 and Spring 2012 using three different populations 47.6, 57.1, and 71.4 thousands plants per ha. The cultivars were Buhoth 106 improved and original. The experiments were factorial and laid out in completely randomized block design with four replicates. Several traits were studied in terms of plants’ performance and variations aspects, observations were recorded on ten plants in each treatment. The values of genetic, environmental variance, genetic and phenotypic coefficient variation, stability and heritability of maize were calculated. The highest genetic variationenvironmental variation were 77.11, 57.80, and 32.13 for grains yield, number of grains, and grains’ weight respectively, while the lowest rate was 5.65 for number of ears. The highest heritability was for grains yield 99% then for number of grains 98% and for grains’ weight 97%, while the lowest rate was for number of grains 85%. The highest phenotypic stability was for grains' weight for improved cultivar during fall season. The highest gains' yield was 10.9 Ton/hac. given by the improved cultivar under the population density of 71.4 thousand plants per hac.. The population density has significantly affected the entire studied traits in both seasons, the improved cultivar was superior in the whole traits under study, there was as well a significant interaction cultivars X population in fall season for the traits of grains' weight, number of ears and grains’ yield, while it was non significant for number of grains. We conclude that most of yield components some traits are affecting more by the genetic factors apart from number of ears; therefore we recommend considering number and weight of grains as a criteria in measuring grains' production ability of maize.