Stripped Bed Roughness Effect on Flow Measurement in Trapezoidal Channels with Free Overfalls

Abstract

An experiment was conducted to study the effects of three drought stress levels, mild (70%) and severe (30%) with a control of 100% soil field capacity on six bread wheat cultivars(Sabeer-beg, Aras, Panda, Adena, Rabeaa and Azady) grown in Kurdistan region and their interaction on morphological and growth parameters including; plant height, number of tillers, total dry weight and its partitioning, flag leaf area, relative growth rate at three growth stages tillering, stem elongation and heading. Assuming the decrease percent in yield and its components including; spike length (cm), number of spikes plant-1, number of grains spike-1, 1000-grain weight (g) and grain yield (g plant-1). Analyzing the variance of data shows a great reduction at sever 30% and less reduction at mild 70% field capacity as compared with control 100% in all studied characteristics except spike length, which did not affected due to applying drought stress levels. The cultivars also show significant variation among them in their response to drought through the morphological and growth parameters except in number of tillers at tillering stage, which finally reflected on the final yield, Azady recorded the higher yield and then Rabeaa, Adene, Aras, Panda and finally Sabeer-beg respectively under sever water stress. The combination between bread wheat cultivars and drought stress level also led to a significant variation in all studied characteristics except in plant height at stem elongation, tiller number at the three stages, flag leaf area, stem dry weight at stem elongation, number of spikes per plant and weight of 1000 grains. Finally, an overall sequence water stress tolerance was Adene> Rabeaa> Aras> Sabeer-beg> Azady>Panda.