Spotted knapweed (Centaurea maculosa Lam.) is a noxious plant that has invaded many native ranges in the Northern Intermountain Region. Although the use of livestock to control knapweed is intuitively appealing, feasibility of the strategy has received little attention. This greenhouse study was conducted to evaluate response of spotted knapweed to defoliation, light, and competition. Although total knapweed biomass (g/plant) was not altered by defoliation treatments, several of the more severe treatments adversely affected root, crown, and final harvest foliage. Root and crown growth were also adversely affected by increasing competition from bluebunch wheatgrass (Pseudoroegneria spicata). Foliage, root, and crown growth of spotted knapweed increased significantly when plants received full, rather than half light. Spotted knapweed was less sensitive to defoliation than was bluebunch wheatgrass. Although the feasibility of using livestock to control spotted knapweed cannot be completely disregarded, data suggest that the knapweed would have to be selectively and repeatedly grazed during the growing season. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.