RESPONSE OF BARLEY TO NITROGEN FERTILIZATION, FOLIAR APPLICATION OF MICRONUTRIENTS MIXTURE AND CITRIC ACID UNDER CALCAREOUS SOIL

A field trial was conducted at Nubaria Agricultural Research Station, El-Behira Governorate, Egypt, during two successive growing seasons 2012/2013 and 2013/2014.The aim was to study the effect of nitrogen fertilizer rates i. e. 15, 30, 45 and 60 kg N fed -1 and foliar spray by micronutrient mixture (Fe + Zn + Mn) at concentrations of 0, 133 and 200 ppm for each element and citric acid (0, 1000 and 1500 ppm) on barley cultivar Giza 2000.The rate of 60 kg N fed -1 gave the maximum values of plant height, leaf area/ main stem, number of days to 50% heading, spike length, crop growth rate (CGR) at the first (60-75) DAS and second (75-90 DAS) periods, number of spikes m -2 , number of kernels spike -1 , 1000-kernel weight as well as straw and grain yields, total chlorophyll of leaves at 75 DAS and protein content of grains.Whereas, insignificant differences were observed in grain yield between applying 45 and 60 kg N fed -1 .All growth traits, yield and its components as well as total chlorophyll of leaf and protein content of grains recorded the maximum values when barley plants were sprayed by 200 ppm of micronutrients mixture (Fe + Zn + Mn) for each element plus 1500 ppm citric acid (S 2 ) compared to other foliar spray treatments (S 0 and S 1 ).The interaction between nitrogen fertilizer rates and foliar spray of micronutrients mixture plus citric acid had a significant effect on all traits under study except the number of days to 50% heading.The maximum values of such traits were obtained when barley plants received 60 kg N fed -1 and foliar spray of 200 ppm (Fe + Zn + Mn) for each element plus 1500 ppm citric acid.