Effect of root and shoot competition from established hill-country pasture on perennial ryegrass

Abstract

Abstract The effect of root and shoot competition on perennial ryegrass seedlings transplanted into patches of paspalum in a Wanganui hill-country pasture was examined. Seedlings were transplanted in late August and treatments implemented on 30 September 1986 (Day 0). Root competition from the surrounding pasture was prevented by inserting a metal tube into the ground around the transplant, whereas shoot competition was limited by weekly clipping of the surrounding pasture. Growth and development of the perennial ryegrass plants were restricted by both root and shoot competition, with root competition being more severe than shoot competition. The size (tiller number × height) of plants subjected to root competition or to both root and shoot competition was smaller than those of plants subjected to shoot competition or no competition from Day 14. The results suggest that reducing root competition should improve the establishment of perennial ryegrass seedlings in hill-country pastures at Wanganui.