Evaluation of stress tolerance indices in some new maize hybrids

In order to study drought tolerance indices and to introduce tolerant maize hybrids in drought conditions, an experiment was conducted at the experimental field of Seed and Plant Improvement Institute, in 2009. The experiment was carried out using split-plot in a randomized complete block design (CRBD) with three replications. The main plots consisted of three levels of irrigation regimes (irrigation after 70, 100 and 130 mm cumulative evaporation from evaporation pan class A) and sub-plots included 14 new corn hybrids. Based on kernel yield of hybrids in normal and stress conditions, mean productivity (MP), geometric mean productivity (GMP), stress tolerance index (STI), tolerance (TOL), yield index (YI), yield stability index (YSI), stress susceptibility index (SSI) trait and change (%) attributes were calculated. The results showed that, in addition to significant correlation under normal and mild drought stress conditions MP, GMP, STI were determined as the best indices. Under normal and water deficit stress TOL and SSI were the best indices for introduce drought tolerant maize hybrids. The KSC700, KLM76004/3-2-1-1-1-1-1-1×K3545/6 and K47/2-2-1-2-2-1-1-1×K3544/1hybrids also identified as tolerant hybrids under drought stress conditions.