The current study was carried out at Shandaweel Agric. Res., Station, Sohag, Governorate, A.R.C., Egypt to assess the performance, combining ability and heterosis of 28 F₁ crosses, their 11 parents and the check hybrid Shandaweel-1 under two irrigations levels in 2022 and 2023 summer seasons for days to 50% blooming, plant height, 1000-grain weight and grain yield/plant. Years, irrigations, genotypes, their partitions (Parents, crosses and parent vs. crosses) and all interaction with the genotypes effects were significant (p<0.01) for all traits under study except between years and the second order effects for 1000-grain weight overall environments. Some crosses were significantly earlier, taller, heavier grain weight and higher grain yield compared to their parents and the check hybrid. The female parent BSH-32 appeared to be the best general combiners for earliness and grain yield at different environments. The cross ASH-32 × MR-812 recorded significant or non-significant SCA effects in desirable direction for earliness, plant height and grain yield under different environments. This cross was considered the best combination for these traits. Most of the crosses were significantly negative heterosis in days to blooming and positive in plant height and grain yield at different conditions. The crosses ASH-32 × MR-812 and ASH-32 × NM-36565 exhibited significant heterosis in desirable direction for earliness, taller plants and higher grain yield, coupled with significant specific combining ability and per se performance under different environments. Hence, these crosses could be utilized to develop the crosses with these traits.