Yield determination of maize hybrids under limited irrigation

Authors: ZHAO, JIN - Texas Agrilife Research; XUE, QINGWU - Texas Agrilife Research; HAO, BAOZHEN - Xianxiang University; MAREK, THOMAS - Texas Agrilife Research; JESSUP, KIRK - Texas Agrilife Research; XU, WENWEI - Texas Agrilife Research; BEAN, BRENT - United Sorghum Checkoff; Colaizzi, Paul

Submitted to: Journal of Crop Improvement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2019
Publication Date: 4/21/2019
Citation: Zhao, J., Xue, Q., Hao, B., Marek, T.H., Jessup, K.E., Xu, W., Bean, B.W., Colaizzi, P.D. 2019. Yield determination of maize hybrids under limited irrigation. Journal of Crop Improvement. 33(3):410-427. https://doi.org/10.1080/15427528.2019.1606129.
DOI: https://doi.org/10.1080/15427528.2019.1606129

Interpretive Summary: Maize is an important food staple throughout the world. Modern maize varieties can produce high grain yields if water from rain and irrigation are adequate. Development of drought tolerant maize varieties have sought to conserve water. The US Southern Great Plains is a major maize producing region, where most maize is produced under irrigation. However, data are needed to determine how new drought tolerant maize varieties use water under different management strategies in this region. Therefore, scientists at USDA Agricultural Research Service and Texas A&M AgriLife Research tested two drought tolerant maize varieties under three irrigation rates and three planting densities at Etter, Texas. Both varieties showed that a 25 percent irrigation water savings was possible without reductions in grain yield, but reducing irrigation water by 50 percent reduced grain yield by 30 percent. Grain yield increased slightly with higher planting densities, but this may not offset the greater cost in seed. These data will provide maize farmers with management guidelines for maximizing farm profits while conserving water.

Technical Abstract: Hybrids adoption, irrigation management and planting density are important management factors in maize production in the semiarid regions. In this study, a two year field experiment was conducted in the Texas High Plains, where approximately 90 percent of the irrigation water withdrawals were provided by the Ogallala Aquifer with little recharge. The objective was to investigate the maize yield determination, evapotranspiration (ET), soil water extraction and water use efficiency (WUE) under limited irrigation. Two full season hybrids (N74R and N75H) were planted at three water regimes (I100, I75, and I50, referring to 100, 75, and 50 percent of the ET, respectively) and three planting densities (PD 6, PD 8, and PD 10, referring to 6, 8, and 10 seeds per square meter, respectively) in 2013 and 2014. For both hybrids, treatment I50 significantly reduced the grain yield by 4.78 Mg per ha for N74R and 4.22 Mg per ha for N75H averaged cross two years as compare to I100. There were no significant yield differences between I100 and I75. Although ET decreased at water-limited conditions (I75 and I50), the highest WUE were found at I75 (2.36 kg per cubic m and 2.23 kg per cubic m for N74R and N75H). Although the hybrid N75H with drought tolerant trait did not have greater yield than the conventional hybrid N74R, N75H had greater yield stability under water-limited conditions but extracted less soil water than N74R. Among the three water regimes, water deficits decreased biomass, harvest index, and kernel weight, but did not affect kernel mass. Higher planting densities increased biomass and kernel number, but decreased kernel mass, especially in 2013. In addition, yield components of N74R were more sensitive to planting density than N75H.