Constraints on water use efficiency of drought tolerant maize grown in a semi-arid environment

•The high stress environment significantly constrained the yield and water use efficiency of the more stress tolerant hybrid as well as those of the less tolerant hybrid.•Crops grown in the sandy loam and fine sand had larger WUE compared with those grown in the clay loam and silt loam, especially under limited irrigation.•One hybrid out yielded the other hybrid while using the same or significantly smaller amounts of water.