Effect of moisture regimes on yield and water use efficiency in three wheat cultivars in karaj

The present study was conducted at the research farm of Agriculture College and Natural Resources at the University of Tehran as a randomized complete block design (RCBD) with three replications in 2014-2015. The aim of this study was the determination of optimum moisture regimes to maximum yield and water use efficiency in wheat plant. Three varieties of wheat included (Pishtaz, Sivand and Parsi), and 12 moisture regimes (70, 90, 110 & 130 mm cumulative evaporation at vegetative growth stage and 90, 110 & 130 at reproductive growth stage). in the following, the moisture levels were applied based on the evaporation rate from class A evaporation pan . The main effects of cultivar and moisture regimes had significant effects on all studied traits. Among the surveyed cultivars in the current study, the highest yield was recorded in Pishtaz cultivar, this superiority had been shown with the highest grain yield as well as the highest number of grains, 1000-grain weight and harvest index. The highest yield was observed in control moisture regime (T79), and increasing the time of irrigation intervals from 70 to 90, 110 or 130 mm cumulative evaporation from pan evaporation class A, grain yield decreased approximately 15, 19 and 27%, respectively. However, per irrigation treatment group of vegetative growth stage (70, 90, 110 & 130), increasing intervals irrigation from 90 to 110 and 130 mm cumulative evaporation at reproductive growth stage did not cause a significant reduction in grain yield.