| Abstract: | Take-all (Gaeumannomyces graminis Sacc.] Arx & Olivier) infection was measured over 7 years (1968–1974) in a long-term tillage experiment involving deep and shallow ploughing, tined cultivation, no-tillage and 4 rates of N. Average infection increased from 4% to 15% and 9% to 35% over the 7 years for June and August samplings respectively. The severity of infection was light and did not change over the years. Increasing N rate consistently reduced infection. In the early years, shallow ploughing and tined cultivation gave greater infection than deep ploughing and no-tillage. In the last 2 years infection levels were the same for all 4 tillage treatments in both June and August, except that in August the no-tillage system continued to show a much lower incidence of infection. The take-all appeared to have little effect on yield because the relative yields from the different tillage treatments did not change with the change in relative degree of infection. Lack of take-all decline was possibly due to the relatively low incidence and severity of infection. |
