Response of three yellow maize hybrids to exogenous salicylic acid under two irrigation intervals

Abstract

Two field experiments were conducted during 2010 and 2011 successive seasons to investigate the response of three yellow maize hybrids (S.C. Giza 166, S.C. Pioneer (N 11) and S.C. Hosary) to exogenous Salicylic Acid (SA) under two irrigation intervals. Treatments included SA concentrations (0, 0.1, 0.5 and 1.0 mM) and two irrigation intervals [12-day (normal irrigation) and 18-day (drought stress)]. Results indicated that, drought stress significantly decreased total chlorophyll, Relative Water Content (RWC), number of grains/row (NGR) and Grain Yield (GY) especially in S.C. Hosary, while percentages of carotenoids and membrane permeability (MP) were significantly increased. Generally, drought stress did not affect flag leaf area (FLA), number of rows/ear (NRE) and 100-Grain Weight (GW). Under both irrigation treatments, total chlorophyll, FLA, RWC and GY significantly increased with increasing SA concentration; whilst MP and carotenoids were significantly decreased. Exogenous SA not only alleviated the inhibitory effect of drought stress but also had a stimulatory effect on physiological traits and grain yield of tested maize hybrids. The highest values of GY and total chlorophyll concentration were recorded in S.C. Pioneer (N 11), while S.C. Hosary attained the highest values of GW and carotenoids and S.C. Giza 166 recorded the highest percentage of MP. Among tested maize hybirds, S.C. Hosary was the most sensitive to drought stress while S.C. Pioner (Nil) was the most tolerent one. In addition, foliar application of SA (0.5 and 1.0 mM) could be used to increase productivity of maize plants and its tolerance to drought stress. © 2013 Asian Network for Scientific Information.