M.A. Thesis:

Effect of folair applicationof alege on yeild and yeild components of barely in salinity stress conditions

In order to investigate the effect of foliar application of seaweed extract on yield and yield components of barley under salinity stress, a factorial experiment in a randomized complete block design with three replications was conducted in Shamakan, Sabzevar. The experimental factors included application rate of seaweed extract at four levels of 0, 2, 4, and 6 l/ha and foliar application time at three levels of foliar application at the tillering, stem elongation and two foliar applications in tillering and stem elongation. The results showed that foliar application of different rates of seaweed extract increased plant height, number of tillers per plant, number of fertile tillers per plant, spike length, 1000 seed weight, biological yield, grain yield and harvest index of barley compared to non-foliar application conditions. The highest plant height of barley was observed in the treatment of 2 l/ha seaweed extract, which did not show significant difference with 4 l/ha treatment. There were no significant differences between 2, 4 and 6 l/ha of seaweed extract application rates in relation to number of tillers per plant, number of fertile tillers per plant, spike length, 1000 seed weight and harvest index. The time of foliar application of seaweed extract had a significant effect on all characteristics except spike length and biological yield. The highest plant height and 1000-seed weight were observed in the treatment of foliar application of seaweed extract at the tillering stage. Two foliar applications of seaweed extract at the tillering and stem elongation stages produced the highest number of tillers and fertile tillers per plant. There were no significant differences between treatments of seaweed extract foliar application in the tillering stage and its two foliar applications in tillering and stem elongation stages with respect to plant height, tiller number per plant, number of fertile tillers per plant and 1000-seed weight. The highest grain yield was obtained in two foliar applications of 2 l/ha of seaweed extract at tillering and stem elongation stages, which did not show significant differences with the treatment of two foliar applications of 4 and 6 l/ha of seaweed extract. According to the results, two foliar applications of seaweed extract at a rate of 2 l/ha during tillering and stem elongation stages are recommended to produce maximum barley yield under severe salinity stress conditions.

Keywords: Barley, tillering, stem elongation, seaweed extract, foliar application