Effect of late season drought stress and foliar application of nitrogen on yield and some physiological traits of wheat (Triticum turgidum L. subsp. durum)

In order to study the effects of late season drought stress and foliar application of nitrogen on physiological traits and grain yield of wheat an experiment was conducted as strip-plot based on complete randomized blocks design (CRBD) with three replications. The horizontal factor were irrigation treatments (i.e. IR1: full irrigation, IR2: cutting irrigation at grain dough stage and IR3: cutting irrigation at grain milk stage) and the vertical factor were foliar application of nitrogen as urea (N1: control, N2: foliar application of 20 kg. ha-1 urea at flowering stage, N3: foliar application of 20 kg. ha-1 urea at milk stage and N4: foliar application of 20 kg. ha-1 urea at flowering and milk stage). Based on results effects of irrigation and interaction of treatments on relative water content was significant. Effects of experimental treatments and interaction of treatments on leaf chlorophyll were significant. The main effect of irrigation treatment on canopy temperature and hectoliter weight was significant and highest and lowest values of these traits observed in full irrigation and IR3 treatments, respectively. The experimental treatments and interaction of treatments significantly affect grain protein content and decreasing irrigation resulted in increasing grain protein content. Although by cutting the irrigation, protein content in both of treatments (IR2 and IR3) increased but by considering the grain yield it seems that cutting irrigation at grain dough stage is more suitable.