Economic water use efficiency of corn (Zea maysL.) hybrids as affected by irrigation regimes: a case study in West Iran

Water deficit stress is the main limiting factor in corn production in different regions of Iran. Choosing appropriate corn hybrids and well-managed irrigation practices will result in significant water savings (WS) and good outcomes. Therefore, a randomized complete block design arranged in split plots with four replications was used to evaluate the effect of irrigation regimes on some agronomic traits of corn hybrids. Three different irrigation regimes (irrigation after depleting 60%, 70%, and 80% of field capacity (FC) as water deficit stress, mild water deficit stress and well-irrigated treatment, respectively) were allocated to main plots and four grain corn hybrids (KSC 500, KSC 647, KSC 700, and KSC 704) were randomized in subplots. The results indicated that grain yield (GY), harvest index (HI), and relative water content (RWC) decreased, whereas water use efficiency (WUE), WS, and irrigation efficiency (IE) increased, with increasing water deficit stress intensity. Irrigation after depleting 70% of FC caused the highest economic WUE (1.01 kg grain m−3). In addition, late maturing hybrids (KSC 700 and KSC 704) showed higher values of all measured traits, except for HI, compared to mid-maturing hybrids (KSC 647 and KSC 500).