• Response of Needle-and-Thread and Western Wheatgrass to Defoliation by Grasshoppers

      Burleson, W. H.; Hewitt, G. B. (Society for Range Management, 1982-03-01)
      Field and greenhouse studies were conducted to measure changes in plant growth resulting from grasshopper defoliation. All data indicated that as grasshopper grazing intensity on needle-and-thread grass increased, total root weight decreased. A greenhouse study with western wheatgrass showed that heavy grazing (80% removal of top growth) for a 16-day period reduced top growth 82%, root growth 85%, crown growth 81%, rhizome growth 100%, and depth of root penetration 49%. Field observations indicated that most grasshopper defoliation of needle-and-thread grass and western wheatgrass occurs after seasonal growth has been completed.