A field experiment was carried out at the center of the guiding and training agricultural Al-Mahnawia – Babel during the autumn season 2103 and autumn 2014 to evaluation the parents and it’s hybrids that production by half diallel crosses under two levels of nitrogen fertilizer (160&320) kg N/ha in order to select the superior hybrids.
During fall season 2014 a field comparison experiment was done according to split plot with R.C.B.D under two levels of nitrogen fertilizer (160 & 320) kg N/ ha as main plot (less important) , however the hybrid and it’s parents as sub plot (more important), with three replications. The mean, heterosis, gene action , combining ability with it’s effects and difference , heritability and the average degree of dominance for all characters was studied.
The biometric analysis variance was significant by (LSD) to comprised among treatments at 5%, the analysis revealed a highly significant difference among the genotypes for all study traits, this means that a large different among the parents. The results showed that the inbred (7) was superior for both nitrogen levels (160 & 320) kg N/ha for grain yield, giving (129.05 , 151.11) kg/ha sequentially , and for total plant uptake of nitrogen giving (475.8 , 613.0) kg/ha sequentially. It reached best introduction for the two characters at the two levels of nitrogen fertilizer. on other hand the hybrid (4×5) gave high range for traits : number of rows / ear (17.79) rows/ear , grain yield reaching (208.18) g/plant , and the best introduction reached (229.25) g/plant at 320 kg N/ha level, leaf area and leaf area index (6004 cm2 , 3.195) sequentially , and the best introduction at 320 kg N/ha level (618.4 cm2 , 3.29) sequentially. Biological plant yield reached (439.20) g /plant , and total uptake of nitrogen (654.40) kg N/ha and the best introduction at 320 kg N/ha level reached (748.50) kg N/ha .
The inbred (ZP607) was excellent by giving high value of general combining ability for number of traits at 160 kg N/ha level therefore, this inbreeds for using possible used at breeding and development program of maize, however the ratio of (gca/sca) larger than one for most studied characters, th