Short‐season corn hybrids to avoid heat and drought stress in the Mid‐South USA

Abstract

AbstractCorn grain yield is extremely responsive to the weather conditions during the growing season. Drought stress, as a result of high temperatures and limited naturally occurring precipitation, often limits grain yield in the Mid‐South. Drought stresses often occur during the transition from the vegetative to the reproductive growth stage, which is most impactful to yield because of the high water demand. Our hypothesis was that short‐season corn hybrids of <110 d (∼2700 growing degree units) could avoid heat and drought by flowering earlier when these heat and drought stresses are less likely. Our objective was to evaluate short‐season hybrids in Mid‐South environments along with standard full‐season hybrids for grain yield. The study was conducted in Brooksville and Starkville, MS, in 2015 and Starkville and Verona, MS, in 2016. Earlier maturing hybrids tasseled 3–7 d before standard full‐season hybrids, providing very little benefit from a drought avoidance perspective. Choosing full‐season hybrids increases yield potential in high‐yielding environments in Mississippi in which growing degree units are not limiting as in northern geographies. Short‐season hybrids did not aid in the avoidance of heat and drought and limited overall grain yield. Across all locations, there was a 0.8 bu ac−1 increase in corn grain yield for every day increase in relative maturity from 92 to 120 d.