Observations on the spread of perennial ryegrass by stolons in a lawn

Abstract

Tufts of perennial ryegrass tillers excavated from a deteriorated Agrostis tenuis–Festuca rubra lawn were interconnected by underground stolons. The morphological character and induction of these structures are discussed in relation to reports of ryegrass stolons, rhizomes, and aerial tillers. Systematic excavation of all plant shoots from an area 1.2 × 0.8 m centred on a perennial ryegrass patch showed that ramets of perennial ryegrass genotypes identified both morphologically and by isoenzyme band patterns occurred across a patch 0.8 m diameter. Other genotypes formed smaller patches. When grown as spaced plants those genotypes which had spread to form patches had vegetative tillers with elongated internodes on the periphery of the tiller clump. These observations contradict the assumption often made in studies of the population dynamics of ryegrass that spread of the species by vegetative means is insignificant. Agronomic application of vegetatively spreading ryegrass is considered.