Grain yield, evapotranspiration, and water-use efficiency of maize hybrids differing in drought tolerance

Adoption of drought-tolerant (DT) hybrids is a viable strategy for maize production in drought-prone environments. We conducted four-year field studies (2011–2014) to investigate yield, crop evapotranspiration (ETc), and water-use efficiency (WUE) in one conventional (N58L) and one DT hybrid (N59B-DT) under three water regimes (I 100 , I 75 , and I 50 , where the subscripts were the percentage of irrigation applied relative to meeting full ETc) and three plant densities. At I 100 and I 75 , N59B-DT did not show advantage in yield and WUE relative to N58L, however, at I 50 it showed an advantage of 8.5% and 10.5%, respectively. At I 100 and I 75 , high plant density treatment had greater grain yield (9.1%) and WUE (9.4%) than low plant density. Comparing hybrids, N59B-DT had greater yield (5.9%) and WUE (7.3%) than N58L at high plant density. N59B-DT had large advantage over N58L in yield (18.0%) and WUE (26.2%) when the hybrids were grown under severe water deficit (I 50 ) and high plant density (9.9 plants m −2 ). At I 50 , increasing plant density reduced yield (14.1%) for N58L but did not affect yield for N59B-DT. On average, plant density had no effect on seasonal ETc but N59B-DT had more seasonal ETc than N58L at I 100 and I 75 . The results of this study indicate that DT hybrid was tolerant to high panting density. Planting a DT hybrid with a higher plant density may provide greater yield stability under water-limited conditions while also maintaining maximum yield potential when moisture is sufficient.