COMBINING ABILITY AND GENE ACTION FOR SOME MAIZE INBRED LINES USING HALF DIALLEL CROSSING AT TWO LOCATIONS DURING TWO SEASONS

This study was aimed to determine combining ability among some maize (Zea mays L.) inbred lines. The crossing was carried out at Kalar Crop Research Center in the spring season (2020). The experiment was conducted at two sites, one of which depends on groundwater and the other on surface water (Kalar\ Sulaimani and Khanaqin\ Diyala) respectively. (Kalar Technical Institute and Khanaqin) in full (2020), and spring seasons (2021). The crosses were conducted using a randomized complete block design with three replications. The results indicated significant differences for all agronomic traits. The genotypic mean squares were highly significant for (3HKW and t.ha-1), and gca was highly significant for (3HKW), but the sca was highly significant for (PH; and t.ha-1) at all environments. The mean performance of minimum days required in fall to reach DTT and DTS; by the cross (1 x 4) in Kalar. But; in the second location by the cross (4 x 5). The highest values for NKPR were recorded by the cross (3 x 5) in the spring season in both locations. Differed the heterosis in all environments for all studied traits.