INFLUENCE OF NITROGEN FERTILIZATION LEVELS ON GRAIN YIELD AND ITS COMPONENTS IN BARLEY (Hordeum vulgare L.)

Grain yield and its components are very important and complicated in barley and highly have been influenced by agronomic applications and environmental factors. On the other hand; this is depend on combination varied plant traits (agronomic and quality). For this season, the study was designed to evaluate the effects of different nitrogen fertilization levels (0, 10, 20, 30 and 40 kg ha^-1 of N) on the agronomic performance of five barley cultivars in two growing seasons. Split plot layout within randomized complete block design with 3 replications was used in both years. The response to fertilization levels were evaluated through GGE (Genotype main effects and Genotype x Environment interaction) biplot graphic methodologies and regression. Combined analysis of variance of nitrogen applications of five cultivars showed highly significant (p 0.01) difference between the cultivars, nitrogen applications and interaction. There were genetic variability among cultivars on grain yield and yield components in response to nitrogen fertilization. The results showed that biggest increases on yield and yield components were observed under 40 kg/ha^-1 nitrogen fertilization level, while thousand grain weight was the biggest under without nitrogen application. The higher performance of yield and yield components was associated with higher nitrogen fertilization in regression analysis. The results of the this study has been recommended that it should be use and study higher nitrogen application levels than 40 kg ha^-1 of N in the next barley studied.