Yield and yield components in bread wheat (Triticum aestivum L.) under non-stress and drought stress conditions

The experiment was conducted at the Agricultural Research Center of East Azarbaijan province during the cropping seasons of 2012 -2013 in order to evaluate effect of water stress on morphological traits, yield and yield components. In this research, five genotypes of winter wheat cultivars were used which were certified for Azerbaijan (cold and arid climate). Cultivars were included: Alvand, Azar 2, MV17, Sardari and Omid. The experimental design was implemented in form of factorial based on completely randomized design with three replications and two irrigation combination (normal irrigation and drought stress after heading). The results demonstrated that in non-stress condition, grain yield had positive and significant correlation with all traits except for flag leaf area, number of fertile tiller and 1000-grains weight. In drought stress condition, grain yield had positive and significant correlation just with straw yield and harvest index and also had negative and significant correlation with number of fertile tiller and plant height. Path analysis in each experimental condition revealed that under non-stress condition, direct effect of biological yield on grain yield was higher than other traits. Number of fertile tiller with low relative intensity had positive direct effect and plant height had negative direct effect on grain yield.