A screening programme for crop variety competitiveness would ideally be based on only a few, non-destructive measurements of key growth traits. In this study we measured the weed suppressive ability of 79 varieties of spring barley in two ways: 1) directly, by weed coverage assessments under weedy conditions at three Danish locations in 2002-2004, and 2) indirectly, by non-destructive measurements of varietal growth traits under weed-free conditions in 17 other experiments in Denmark in 2001-2003. Based on just four varietal growth traits (reflectance, leaf area index, leaf angle and culm length), we successfully developed a method for indexing the weed suppressive ability of spring barley varieties. The suppressive index ranged from 12% in ‘Lux’ and 55%... |