Effect of end season drought on yield and yield components of wheat cultivars in Karaj region

In order to study the effects of drought stress on yield and yield components of ten winter wheat cultivars, and evaluation of CERES-Wheat model an experiment was conducted in 2010 in Agricultural research station of Islamic Azad university of karaj. The experiment was conducted as a randomized complete block design in split plat arrangement with four replications. First factor was consisted of two different irrigation regimes in cluding a control treatment (T1) and terminate irrigation at flowering stage (T2) in main plots.The second factor was consisted of ten varieties of wheat. In this experiment the grain yield and its components were studied. There were significant statistical differences between irrigations regims in respect to length of spike and peduncle length numbers and spike length, plant height and peduncle length results showed that the interaction of treatments on 1000-grain weight, grain yield, ear number per unit area, yield per spike, spike weight on unit area and harvest index and biomass at P