• Establishment of Diffuse and Spotted Knapweed from Seed on Disturbed Ground in British Columbia, Canada

      Roze, L. D.; Frazer, B. D.; McLean, A. (Society for Range Management, 1984-11-01)
      The rangeland weeds diffuse and spotted knapweed (Centaurea diffusa L. and C. maculosa L.) were sown at densities of 208 to 1,504 seeds/m2 on disturbed rangeland in Westwold, British Columbia, in 25 × 25-cm plots. Both species established well to the rosettes stage at the lowest sowing densities, but only 5% of the diffuse knapweed rosettes bolted in the second year compared to 45% of the spotted knapweed rosettes. Intraspecific competition appeared to decrease the number of spotted knapweed rosettes bolting at the higher sowing densities.