Grass species and cultivar effects on establishment of grass-white clover mixtures

Grasses may differ in their compatibility with white clover (Trifolium repe ns L.) during establishment. We conducted greenhouse and field experiments to evaluate the compatibility of early- and late-maturing cultivars of pere nnial ryegrass (Lolium perenne L.) and orchardgrass (Dactylis glomerata L.) with 'Will' white clover during establishment. Monocultures and binary mix tures of each cultivar with white clover were established from seed in pots in two greenhouse studies. After an initial harvest at 6 wk of growth, pla nts were harvested el erg 2 or 4 wk at a 4- or 8-cm height for 8 wk. The sa me monocultures and mixtures were planted in field plots and harvested twic e at 4 or 8 cm after an 11-wk establishment period. White clover produced m ore (P < 0.05) stolen + leaf mass and clover proportion of herbage yield wa s greater when grown with early-maturing than with tate-maturing grass cult ivars in the field and greenhouse. This indicates that early-maturity grass es were more compatible with white clover. Individual perennial ryegrass pl ants had about twice as many tillers per plant (P < 0.01) and yielded 24% m ore (P < 0.01) dry matter than orchardgrass in mixture with clover. Perenni al ryegrass-clover mixtures yielded 20% more herbage and had 40% more tille rs per unit area than orchardgrass-clover in the field. Clover plants in mo noculture were heavier and more complex in structure than plants in mixture in both field and greenhouse. We conclude that maturity of grass cultivars has an effect on white clover establishment and that early-maturing cultiv ars of perennial ryegrass or orchardgrass are more compatible with Will whi te clover during the establishment phase.