Species Watch: Ryegrass
This month I want to discuss the general attributes of Ryegrass ( Lolium perenne L.)
This species is characterised as having bright green, keeled leaves that have a very shiny underside. A distinguishing feature is the purple or reddish emergent sheath at the base of the plant. This turf grass is often referred to as amenity ryegrass or dwarf ryegrass to distinguish it from its cousins, the pastoral ryegrasses as it does not grow nearly as quickly as its agricultural relatives.
The first dwarf ryegrass cultivars were introduced to the market place in the early 1970's and since this time they rapidly garnered popular support for use in domestic lawns and sports fields globally because of their fast establishment rates, rapid rates of recovery, attractive colour and high wear tolerance. Plant breeders have continued to make significant progress in the development of this plant with the new varieties retaining some of the key characteristics such as speed of germination but they now include traits such as slower growing, darker green colouration and more resistant to fungal disease, particularly “red thread” which blighted some of the earlier cultivars such as “Elka” and “Imagine”. There are now more that 200 registered dwarf ryegrass cultivars and they vary significantly in their performance features. Those that are bred for sports-fields tend to grow faster in winter and have a stronger vertical growth habit. PGG Wrightson Turf dominates this end of the spectre producing varieties with Mediterranean genetics whilst the latest varieties out of Europe and the USA tend to have higher tiller densities, finer leaves and grow less rapidly. This later group from the US based plant breeders in particular also tend to have a darker green colouration. Ryegrass is the subject of a great deal of effort by plant breeders both locally and internationally and vast advances in the quality have been achieved. Even in the last decade the improvements have been highly tangible.
In Australia it’s predominant use today is in sportsfields or for use as a cover crop for the establishment of warm season grasses. It is also used to over sow warm season fields in autumn to provide an appropriate winter sports surface at a time when warm season grasses are less prominent. This technique is most common in the cooler parts of Australia but it is also used in New Zealand.