Population regulation of Rhodesgrass cultivars in sward conditions I. Genet density.
In order to describe the regulation of genet density of Chloris gayana and variations in this process, 7 cultivars were sown at 4 densities and the changes of genet densities were recorded during the year of sowing. Genet density generally decreased nearly exponentially with half lives of 0.8-1.8 months. During the sward establishment phase, genet mortality was positively correlated with the surviving genet density. The 8.0-fold range of sowing density converged into a 2.5-fold range of genet density at 58 d after sowing. Significant differences in mortality among cultivars were observed after the sward established. Genet mortality did not then correlate with the surviving genet density. While there were appreciable variations in surviving genet density and genet weight, attributable to both sowing density and cultivars at the end of the year, there was nearly complete compensation between the 2 traits in both sources of variation, which regulated the stand yield of the C. gayana sward to within a narrow range.