Different combinations of perennial ryegrass and white clover phenotypes do not affect mixture yield under cutting management during establishment

Abstract

Abstract A field experiment was conducted for 12 months under irrigation and cutting management to determine if interactions between perennial ryegrass and white clover cultivars of different phenotypes could affect pasture yield and botanical composition during establishment. Four ryegrass and four clover cultivars, differing in leaf and tiller/stolon traits, were grown in all combinations (n=16), along with monocultures of each (n=8), as sub-plots under two nitrogen fertiliser levels (100 or 325 kg N/ha/ year). Dry matter yield and botanical composition were measured on nine occasions and ryegrass and clover population densities were determined four times. Total annual yield was similar for all mixture combinations due to substitution between the sward components. While there were significant yield differences among ryegrass or clover cultivar monocultures, these seldom explained differences in mixture yields. Mixtures yielded more DM than ryegrass monocultures under both N treatments (+1.3 to +3.9 t DM/ha/year). Keywords: perennial ryegrass, white clover, dairy, dry matter yield, nitrogen fertiliser, phenotype, competition