Effect of irrigation regimes on growth analysis of different wheat(Triticum aestivum L.) cultivars

This study was carried out in order to evaluate drought stress effects on yield, yield components and growth analysis of winter wheat (Triticum aestivum L.) at the Karaj Azad University in year 2006-2007. A split- plot arrangement of treatment in a randomized complete block design with four replication. The experiment had two crossed factors as water treatment and variety. Water stress factor in main plot had 8 treatments as T1(irrigation in 40% soil moisture depletion ), T2 (irrigation in 60% soil moisture depletion), T3(irrigation in 80% soil moisture depletion),T4(no irrigation at stem elongation stage ), T5(no irrigation from stem elongation to ripening stage) , T6(no irrigation at flowering stage), T7(no irrigation from start of flowering to ripening stage )and T8(no irrigation at grain filling stage). Two experimental winter wheat varieties (Chamran and Marvdasht) were grown in sub plot. During the study, grain yield and related characteristics, growth indices and correlation among all treats were evaluated. in order to calculating of growth indices such as leaf area index(LAI), total dry matter (TDW), crop growth rate (CGR), relative growth rate (RGR), leaf weight (LW), leaf area ratio(LAR.From the purpose of studying the dry matter accumulation several equations were tested. Changes trend of dry matter during the growing season indicated that dry matter accumulation of all treatments from primary stage to 155 days after sowing was gradual, from 180 days after sowing was linerand finally was declined due to he falling of leaves.