Response of maize hybrids under limited irrigation capacities: yield and yield components

Authors: Schwartz, Robert; BELL, JOURDAN - Texas A&M Agrilife; Baumhardt, Roland - Louis; Colaizzi, Paul; Hiltbrunner, Bridgette; Witt, Travis; Brauer, David

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2022
Publication Date: 1/31/2022
Citation: Schwartz, R.C., Bell, J., Baumhardt, R.L., Colaizzi, P.D., Hiltbrunner, B.A., Witt, T.W., Brauer, D.K. 2022. Response of maize hybrids under limited irrigation capacities: yield and yield components. Agronomy Journal. 114:1338-1352. https://doi.org/10.1002/agj2.21013.
DOI: https://doi.org/10.1002/agj2.21013

Interpretive Summary: Producers often experience sizable yield losses in corn because irrigation cannot meet demand. This has become a common occurrence in the semiarid Texas High Plains where irrigation supply from the Ogallala Aquifer is in decline. Drought tolerant corn hybrids may reduce yield losses during periods of water stress. Scientists from ARS (Bushland, Texas, and El Reno, Oklahoma) and Texas A&M AgriLife studied the effect of irrigation level and planting rate on yield three maize hybrids, two of which were considered drought tolerant. Hybrid did not influence yield, aboveground biomass and water use efficiency in all three study years. Although kernel number and kernel weight differed among hybrids, this did not influence yield because kernel weight compensated for reduced kernel number. At high plant densities, grain yield was reduced at the low irrigation rate in years with below average precipitation. Mitigation of yield reductions under limited irrigation capacities in the Texas High Plains can be achieved by concentrating irrigation on less land area and optimizing planting rates.

Technical Abstract: Grain yield of maize (Zea mays L.) in the semiarid Texas High Plains (THP) is greatly reduced when irrigation cannot meet peak water requirements. Drought tolerant hybrids may mitigate yield losses resulting from water deficits. Scientists from ARS (Bushland, Texas, and El Reno, Oklahoma) and Texas A&M AgriLife examined the effect of irrigation capacity (8.47 and 4.23 mm d-1) and planting rates (74,000 and 95,000 seeds ha-1) during three growing seasons (2016–2018) on grain yield and yield components of three maize hybrids, two of which were considered drought tolerant. Crop water deficits at the low irrigation level usually extended from seventh leaf collar to dough stage. Mean grain yields varied from 5.2 Mg ha-1 under the low irrigation level to 19.9 Mg ha-1 at the high irrigation level. Hybrid did not influence grain yield and aboveground biomass in all three years. Although kernel number and kernel weight were significantly influenced by hybrid across all years, this did not result in grain yield differences because greater kernel weight compensated for reduced kernel number. Harvest index did not significantly differ between conventional and drought tolerant hybrids. In 2016, grain yield was significantly influenced by plant density only at the low irrigation level, with 44% greater yields at the low stand density. For the patterns and level of water stress observed during these three growing seasons, the three hybrids performed similarly. Besides using hybrids well adapted to the region, mitigation of yield reductions under limited irrigation capacities in the THP can be achieved by concentrating irrigation on less land area and optimizing planting rates.