EVALUATION OF MAIZE HYBRIDS TO TERMINAL DROUGHT STRESS TOLERANCE BY DEFINING DROUGHT INDICES

WOS: 000389137600001Terminal drought stress is one of the most important environmental stress factors which can cause a significant reduction in maize productivity. Therefore, to identify the best selection indices for drought tolerance in maize under terminal drought conditions, this research was conducted in two field experiments with some maize hybrids in two cropping seasons (2014 and 2015) under two moisture levels (normal irrigation and water deficit-water stress) at grain filling stage. Results of study revealed that, yield and major yield traits of hybrids adversely affected due to terminal drought stress, it also causing a reduction in productivity with compare normal irrigation conditions. Water stress significantly affected on maize hybrids and there were high variation among hybrids, which could be befits for screening the genotypes. The special attention was paid to hybrids 71May69, Aaccel and Calgary were showed less reduction of grain yield under terminal drought stress. Concerning the genotypes with high stress susceptibility index (SSI) and tolerance index (TOL) were considered as high susceptible to drought and only suitable for irrigated conditions. Accordingly, the positive relationship between stress indices, drought resistance index (DRI), geometric mean productivity (GMP), harmonic mean (HM), mean production (MP), stress tolerance index (STI) and Yield index (YI), and grain yield could be used as the best selection indices for identifying the tolerant hybrids under terminal drought stress