Genetic variation in durum wheat in N-use efficiency and heritability of traits at different N fertilizer application levels

Twelve durum wheat (Triticum durum L.) genotypes were evaluated for Nitrogen Use Efficiency (NUE) and related traits using two rates of nitrogen fertilizer application (69 kg N ha-1 and 115 kg N ha-1) in a randomized complete block design with three replications. The experiment was done on a Vertisol at Adet Agricultural Research Center in the 2009 main cropping season. The highest Nitrogen Utilization efficiency (73.1 %), Nitrogen Use Efficiency for protein (55.0 %) and NUE (38 %) were recorded for genotype Asassa. Yerer was the poorest in NUE (22 %), Nitrogen Uptake Efficiency (57.7 %), and NUTE (37.9 %). All nitrogen use efficiency traits responded negatively to nitrogen fertilizer. All the traits, except Nitrogen Utilization efficiency, did not respond to the genotype by nitrogen interaction effect. NUE was positively correlated with NUPE (r = 0.81), Nitrogen Use Efficiency for Protein (r = 0.76), and NUTE (r = 0.56). Heritability value of NUE traits was low.