SUSTAINABLE AGRICULTURE FOR FOOD, ENERGY AND INDUSTRY pp669-675 1998 James & James (Science Publishers) Ltd Changes in nitrogen related characters in German spring barley

Abstract

High costs of fertiliser and environmental implications like ground water pollution are causing a concern to the use of nitrogen. Therefore, the efficient use of nitrogen fertiliser is an important goal in plant breeding programs. This study was conducted to assess (1) genetic variability for nitrogen related characters in German spring barley germplasms for enhanced or continued breeding progress,(2) the direction and magnitude of changes in these characters as a result of breeding for high grain yield, and (3) the relationship of some of these traits with dry matter grain yield to make suggestions for future strategies in spring barley breeding programs. Four groups of material, eight old and eight recent two-rowed spring barley cultivars and their F intra-diallel advanced crosses were evaluated in 1995 on a loamy sand soil in Braunschweig-Volkenrode under treatments of two densities (100 and 400 seeds m 2) and two nitrogen fertiliser regimes (0 and 80 kg N ha"'). Significant genotypic variation was observed for all traits studied in all groups, except straw nitrogen content (old cultivars, new crosses). Nitrogen had significant effects on all the characters except on nitrogen harvest index in the new crosses. In all germplasm groups, grain yield exhibited a moderate to strong positive correlation with nitrogen uptake and nitrogen utilisation efficiency as well as with nitrogen harvest index. Grain nitrogen content on the other hand was negatively correlated with grain yield. The new germplasms while having superior nitrogen harvest index and nitrogen utilisation efficiency exhibited significantly lower grain and straw nitrogen contents. This seemingly …