Improving physiological performance and grain yield of maize by salicylic acid treatment under drought stress

A field experiment was conducted as a split-plot based on a randomized complete block design with three replications in ۲۰۲۰ to investigate the effect of different salicylic acid (SA) levels on physiological traits and grain, oil, and protein yields of maize (MV ۵۲۴). The irrigation treatments were normal irrigation (irrigation after ۶۰ mm evaporation), and irrigation disruptions from tassel emergence up to seed formation and from tassel emergence up to harvest maturity. The plants were sprayed with three levels of SA (۱, ۲, and ۳ mM) and water at the tassel emergence stage. The irrigation and SA treatments were assigned to the main and subplots, respectively. Irrigation disruption at reproductive stages caused a decline in mean leaf water content (LWC), membrane stability index (MSI), chlorophyll content, leaf area index (LAI), grain yield, oil percentage, oil and protein yields, and an increment in leaf temperature and protein percentage, compared to normal irrigation. Application of SA, especially with ۳ mM concentration, increased mean LWC, MSI, chlorophyll content, LAI, and grain, oil, and protein yields of maize. The highest positive correlation with grain, oil, and protein yields was recorded for LAI, followed by LWC and chlorophyll content index. These results suggest that water supply at reproductive stages is essential for successful maize production. Nevertheless, a foliar spray of ۳ mM SA can improve the field performance and productivity of maize under normal and limited water availability.

Keywords:

Chlorophyll , Drought Stress , grain oil , growth regulator , Maize