Water Use and Grain Yield in Drought‐Tolerant Corn in the Texas High Plains

Drought is an important factor limiting corn (Zea maysL.) yields in the Texas High Plains, and adoption of drought‐tolerant (DT) hybrids could be a management tool under water shortage. We conducted a 3‐yr field study to investigate yield, evapotranspiration (ET), and water use efficiency (WUE) in DT hybrids. One conventional (33D49) and 4 DT hybrids (P1151HR, P1324HR, P1498HR, and P1564HR) were grown at three water regimes (I100, I75, and I50, referring to 100, 75, and 50% ET requirement) and three planting densities (PD) (5.9, 7.4, and 8.4 plants m−2). Yield (13.56 Mg ha−1) and ET (719 mm) were the greatest at I100but WUE (2.1 kg m−3) was the greatest at I75. Although DT hybrids did not always have greater yield and WUE than 33D49 at I100, hybrids P1151HR and P1564HR consistently had greater yield and WUE than 33D49 at I75and I50. Compared to 33D49, P1151HR and P1564HR had 8.6 to 12.1% and 19.1% greater yield at I75and I50, respectively. Correspondingly, WUE was 9.8 to 11.7% and 20.0% greater at I75and I50, respectively. Greater PD resulted in greater yield and WUE at I100and I75but PD did not affect yield and WUE at I50. Yield and WUE in greater PD (8.4 plants m−2) were 6.3 to 8.3% greater than those in smaller PD (5.9 plants m−2). The results of this study demonstrated that proper selection of DT hybrids can increase corn yield and WUE under water‐limited conditions.