M.A. Thesis:

Effect of time of application and amount of calcium nitrate on yield and yield components of barley under salt stress

In order to evaluate the effect of time and amount of calcium nitrate on the yield and yield components of barley, a factorial experiment in a randomized complete block design with three replications was conducted in Shamakan, Sabzevar. The experimental factors included calcium nitrate application rate at three levels of 0, 2, 4, and 6 kg/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 calcium nitrate 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. Foliar application time of calcium nitrate had no significant effect on plant height, spike length, biological yield and harvest index of barley. The highest plant height and harvest index were obtained in the treatment of 6 kg/ha and the highest spike length in 4 kg/ha calcium nitrate foliar application. Foliar application of 2 kg/ha calcium nitrate produced the highest biological yield. Application of 4 and 6 kg/ha calcium nitrate reduced biological yield compared to 2 kg/ha calcium nitrate treatment. The highest number of tillers per plant was obtained by foliar application of 2 kg/ha calcium nitrate in the tillering stage, which had no significant differences with foliar application of 2 kg/ha calcium nitrate in the stem elongation and tillering + stem elongation stages. However, the highest number of fertile tillers per plant was observed in two foliar applications of 2 kg/ha calcium nitrogen in tillering and stem elongation stages. The foliar application of 4 kg/ha calcium nitrate at stem elongation stage had the highest 1000-grain weight. The highest grain yield was obtained with two foliar applications of 2 kg/ha calcium nitrate at tillering and stem elongation, which had a significant difference with other levels of calcium nitrate foliar application. According to the results, two foliar applications of 2 kg/ha calcium nitrate in each stage of tillering and stem elongation are recommended for production of maximum yield and yield components of the barley under severe salinity stress conditions.

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