RT - Journal Article T1 - Effect of drought stress and nitrogen fertilizer on yield and some physiological traits of six barley cultivars JF - jispp YR - 2020 JO - jispp VO - 9 IS - 39 UR - http://jispp.iut.ac.ir/article-1-1360-en.html SP - 1 EP - 14 K1 - Biomass K1 - Grain yield K1 - Malondialdehyde K1 - Proline AB - This experiment was arranged as a split-split plot in a randomized complete block design with three replications at the research farm of Isfahan University of Technology in 2017 to evaluate the effect of drought stress and nitrogen fertilizer on yield and some physiological traits of six barley cultivars. Experimental factors included two irrigation regimes (55 and 85 percent of available soil water), two levels of nitrogen fertilizer (The available amount in the soil (84kg / ha) and 62.5 kg nitrogen from the urea source containing 45% nitrogen) and foreign (Amistar, Campagen, Funky, Mastesca, Shangrila) and Iranian (Yousef) barley cultivars. The results showed that drought stress decreased grain and straw yield by reducing the content of chlorophyll a and b, carotenoid content and the maximum potential quantum efficiency of photosystem II but increased proline and malondialdehyde contents. Nitrogen application increased grain and straw yields under normal irrigation conditions while the opposite effects were observed under drought stress condition. Among studied cultivars, Yousef had the highest grain yield and Funky produced the highest amount of straw under normal irrigation conditions. Normal irrigation and nitrogen application increased the plant height, chlorophyll a but decreased malondialdehyde in all cultivars. The highest grain and straw yield of cultivars were obtained by nitrogen application under normal irrigation. The results from this experiment showed that nitrogen application is not an appropriate strategy to reduce the negative effects of drought stress on the yield of studied barley cultivars. LA eng UL http://jispp.iut.ac.ir/article-1-1360-en.html M3 ER -