The effects of severity of defoliation and soil moisture stress on Desmodium intortum

Abstract

The responses of five introductions and one cultivar of Desmodium intortum to two defoliation intensities under stress and non-stress soil moisture regimes were studied in a pot experiment. Both heavy defoliation and moisture stress reduced yield. Significant line X defoliation interactions occurred, including differences among the component lines of the cultivar Greenleaf. Evidence was found that genetic shift has occurred in Greenleaf in the direction of the lower yielding components which were more adversely affected by severe defoliation. The wisdom of releasing mixtures of 'pure' lines as commercial varieties of perennial pasture species is questioned.