Abstract
Water stress is the major environmental stresses that affect agricultural production worldwide, especially in arid and semi-arid regions. This research investigated the effect of water deficit on wheat cultivars (Al-gaimi, Sindy-1, Sindy-2, and Hab-Ahmar) grown in the Kingdom of Saudi Arabia. Mild (50%) and severe (30%) water deficit regimes were used with a control of 80% soil field capacity. The effect of water stress on growth parameters was investigated including; plant height, leaf area, dry weights of roots, shoots and whole plant. Relative Water Content (RWC) and Water Use Efficiency (WUE) were also determined. The results indicated that the effect of water deficit on growth depended on the combination of water stress regime and wheat cultivars. Mild water deficit affected Sindy-2 and Hab-Ahmar, while Al-gaimi was less affected with neither decrease in root dry weight nor change in dry weight. Under severe stress, growth was decreased in Hab-Ahmar followed by Sindy-2 then Sindy-1, while Al-gaimi was not affected. Al-gaimi and Hab-Ahmar showed a decrease in RWC under the severe stress. Neither Sindy-1 nor Sindy-2 showed change in RWC due to water stress treatments. WUE decreased under severe water deficit in Hab-Ahmar and Sindy-2, but not affected in Sindy-1 and Algaimi.