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

Abstract

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 (I100, I75, and I50, where the subscripts were the percentage of irrigation applied relative to meeting full ETc) and three plant densities. At I100 and I75, N59B-DT did not show advantage in yield and WUE relative to N58L, however, at I50 it showed an advantage of 8.5% and 10.5%, respectively. At I100 and I75, 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 (I50) and high plant density (9.9 plants m−2). At I50, 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 I100 and I75. 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.