Evaluation of Wheat Cultivars for Physiological Traits under Different Levels of Nitrogen and Irrigation

In order to evaluate the effect of supplemental irrigation and nitrogen amounts on yield and yield components of two dryland wheat cultivars an experimental was carried out in a split split plot design arranged in a randomized complete block design with three replications at the farm of Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran, during 2008-2009. Experimental treatments including supplemental irrigation as the main plot at 4 levels (no irrigation and irrigation at booting, anthesis and grain filling stages) and net nitrogen as a sub plot at 4 levels (0, 50, 100 and 150 kg ha-1) and two wheat cultivars (Sardari and Cross-Alborz) as sub-sub plots. The result showed that the effect of supplementary irrigation, N rate and cultivar were significant on grain yield. The highest of grain yield obtained in supplemental irrigation at anthesis and booting stages with 362.2 and 352.0 g m-2, respectively. The highest amount of grain protein content obtained at non irrigation treatment. Supplementary irrigation at booting, anthesis and grain filling stages increased relative water content and chlorophyll b. The maximum grain yield (337.0 g m-2) was produced with application of 50 kg ha-1 N. Cross-Alborz relative to Sardari cultivar had highest grain and protein yields. To the results of this experiment, supplemental irrigation at Anthesis or stem elongation stage was important compared to the grain filling stage. Irrigation at these stages and also, use of 50 kg ha-1 N, increased grain yield and physiological charactristics of wheat.