Drought Genetics Have Varying Influence on Corn Water Stress under Differing Water Availability

CORE IDEAS: Limited irrigation of corn is likely to become more prevalent in the future.Drought genetics may make corn yield less subject to detrimental water stress under limited irrigation.Drought genetics had little effect on mitigating water stress in corn.Drought genetics did not consistently improve corn yield under water stress. Irrigated corn (Zea mays L.) in the Great Plains will be increasingly grown under limited irrigation management and greater water stress. Hybrids with drought genetics may decrease the impacts of water stress on yield. The objective of this experiment was to evaluate the effect of drought genetics on corn water stress, water use, grain yield, yield components, and water use efficiency under varying water availability. A 3‐yr (2009–2011) study was conducted at Akron, CO in which corn water use, yield, and yield components were measured for isolines of three corn hybrids with and without drought genetics grown under three water treatments (fully irrigated, no irrigation until just prior to tasseling followed by full irrigation, and limited irrigation throughout the growing season). There was no yield loss from the drought genetics under non‐water‐stressed conditions. There was no effect of drought genetics on water use, yield, or water use efficiency. However, there was a 7% increase in kernels per plant in 2011 and a 5% increase in 1000‐kernel weight in 2010 due to the presence of the drought gene. It does not appear that the non‐commercial, experimental drought genetics tested in this experiment produced any consistent effect on mitigating water stress in corn or on corn water use and yield under varying levels and timings of water stress. Further research is needed in which consistent levels of water stress are imposed during reproductive and grain‐filling growth stages to verify the effects of drought genetics on corn yield.