Corn response to later than traditional planting dates in the Texas High Plains

Planting date (PD) can significantly affect corn (Zea mays L.) yield. Our objective was to investigate the effects of hybrid and PD later than traditional time on irrigated corn performance in the Texas High Plains. A 2-yr field study was conducted using four (2013) to six (2014) hybrids and four PDs (mid-May [PD1], late May-early June [PD2], mid-June [PD3], and late June-early July [PD4]). In PD1 and PD2, long-season hybrids had greater yields (12-15 Mg ha(-1)) than short-season hybrids (9-13 Mg ha(-1)). In PD4, short-season hybrids (8-11 Mg ha(-1)) had yield advantage over long-season hybrids (4-10 Mg ha(-1)). Low yield at late planting was related to reduced biomass, harvest index, kernel weight, and kernel number. Seasonal evapotranspiration (ET) was only reported in 2013. The average ET over PDs was 767 mm in a long-season hybrid and 718 mm in a short-season hybrid. Late planting resulted in lower ET (600 mm in PD4 vs. 822 mm in PD1). Hybrid and PD did not affect water use efficiency (WUE) except for 33D53AM, which had low WUE in PD4 due to low yield with late planting of this long-season hybrid. This study demonstrated that high yield (similar to 15 Mg ha(-1)) and WUE (similar to 1.5 kg m(-3)) can be achieved with long-season hybrids when planted before mid-June, but short-season hybrids were a better choice after mid-June. With water limitations, further study is warranted on planting short-season hybrids after mid-June to reduce water use and irrigation.