The Ability of Barley to Compete with Weeds

AbstractThe influence of crop plant density and variety on weed growth was studied in spring barley at a biodynamic and a conventional farm in two years. There was ample germination of weeds at both test sites. but the population of weed species was more diverse at the biodynamic farm.A reduction in barley plant density from normal to half or quarter density resulted in a 2-5 fold increase in shoot weed dry matter at harvest. The gain in grain yield obtained by herbicide treatment was 13.24 and 34%, respectively at normal, half, and quarter barley density. Normal plant density of barley was more important for the ability to compete with weeds than it was for obtaining a high grain yield.The amount of weed dry matter varied twofold between some of the barley varieties. This variation was not statistically significant within any of the experiments, but the reported high and low competitive ability of some of the varieties was confirmed. There were significant. Negative correlations between grain yield and w...