Drought Tolerant Corn Yield Response to Water Availability.

Due to decreased availability of irrigation water in central and western Kansas and an increase in water restrictions, producers are looking for more efficient ways to use available irrigation water. Drought-tolerant technologies have become popular in hybrids for low-yielding corn environments across central and western Kansas and are marketed for their ability to produce higher grain yields with less water. The objective of this study was to compare water use, yield, and water use efficiency (WUE) of two types of drought-tolerant (DT) corn hybrids and a high-yielding non-DT hybrid. Water use and yield of two DT and one non-DT, high-yielding hybrid were compared in both rain-fed and irrigated situations. The average yield (normalized to 15.5% moisture) for the irrigated corn was 13,645.8 kg/ha-1, and 7,975.9 kg/ha-1 for the non-irrigated corn, representing an average yield increase of 5,669.9 kg/ha-1. The irrigated corn received a total of 254 mm more water than the non-irrigated corn over the course of the growing season, resulting in an increase of 222 kg/ha-1 for each additional centimeter of water use (including runoff and drainage) averaged across the three hybrids. Throughout the growing season soil moisture content, canopy temperature, ear leaf temperature, and chlorophyll content was measured at various vegetative and reproductive stages. The irrigated corn used a mean of 529.6 mm of water, and the non-irrigated corn used a mean of 296.2 mm of water. The WUE was 253 kg/mm-1 in the irrigated corn, and 257 kg/mm-1 for non-irrigated corn. One DT hybrid exhibited more stable yields across the non-irrigated environment, compared to the other DT hybrid and the non-DT hybrid. This study will provide a better understanding of DT corn hybrids, and their response to water availability for producers who are trying to maximize productivity in water-stressed environments.