Site‐related set‐back by weeds on the establishment of 12 biomass willow clones

Ten commercial clones of willow and two breeding clones were studied for their ability to compete with weeds during the establishment year at three different sites in southern Sweden. Cuttings were planted according to commercial practice in April, and the two treatments, ‘Weeded’ and ‘Unweeded’, were laid out in a strip‐plot design. Weeds in the ‘Weeded’ treatment were removed mechanically and by hand hoeing. Willow plant shoot weight and plant mortality were measured after the first growing season to evaluate the initial effect of weeds. In addition, weed flora, weed aboveground biomass, soil properties, shoot damage and soil moisture were assessed during the growing season. Plant mortality was