In an attempt to determine the genetic behavior governing inheritance of yield and its component traits, this investigation was conducted throughout the four growing seasons 2018/2019 to 2021/2022 under normal and nitrogen stress conditions. The parents and their five populations (P1, P2, F1, F2 and F3) of two crosses were layout in a randomized complete block design with three replications. Scaling test illustrated the existence of non-allelic interactions (epistasis) for most studied characters in the two crosses. Results demonstrated that additive and non-additive gene effects were significant and govern the inheritance of yield and its component traits while, dominance gene effects were higher in magnitude than additive effect under normal and nitrogen stress conditions. Significant positive heterotic estimates relative to mid and better parent were obtained for most studied characters under normal and nitrogen stress conditions. Regarding potence ratio, over and partial dominance was observed for all studied characters in both crosses at normal and nitrogen stress conditions. broad sense heritability estimates ranged from 73 % to 98 % under normal condition and from 65 % to 97 % under nitrogen stress condition. Moreover, Narrow sense heritability estimates ranged from 29 % to 96 % under normal condition and from 17 % to 89 % under nitrogen stress condition. The most accurate predictions of expected genetic advance (GA%) and narrow sense heritability (hn2) revealed selection efficiency for the no. of spikes per plant, no. of kernels spike, and grain yield in these studied populations under normal and nitrogen stress conditions.