Genetic Variation in N-Use Efficiency of Malting Barley Genotypes

Abstract

Abs t rac t An experiment was carried out in 2010 at Adet, in Northwest Ethiopia, to differentiate the genetic potential of malting barley genotypes in Nitrogen Use Efficiency (NUE), to assess the effect of nitrogen labels and genotype by nitrogen interaction. Nine malting barley genotypes at two levels of nitrogen were evaluated as a randomized complete block design with four replications. Results showed highly significant variation among the genotypes for NUE and yield traits studied. The genotypes EH1603-F5.B1-4, HB-1533 and EH1609-F5.B3-10 had the highest NUE and were higher yielding. The presence of such variation indicates that efficient and high yielding malting barley genotypes can be directly selected. Highly significant variation was observed between N-levels for most of the NUE traits in which higher value was obtained from the lower level of N. Therefore to be economical as well as to prevent environmental effect of N, it is better to use the lower rate of N. There was no significant interaction between N-levels and genotypes. Generally choosing efficient genotypes and the application of low levels of N seems to be the most efficient way to supply nitrogen when grain yield, NUE, and quality are our goals. High phenotypic coefficient of variation (PCV) was observed for UPE (34.57%) and NUE (31.6%). High genotypic coefficient of variation (GCV) was not observed for the studied traits. Of the traits of malting barley studied in t h is experiment, 50% show low heritability which makes selecting for these traits difficult because environmental effect is more evident that genetic effect. Therefore future breeding efforts in malting barley should aim at exploiting the genetic variability available in the test genotypes.