Perennial ryegrass

Perennial ryegrass
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NOTE: The information in this Agnote must be read in conjunction with Introduction to selecting and using pastures in NSW, which covers information on areas of adaptation, sources of variability, species mixtures, and important issues related to animal health and the conservation of native vegetation.

Pasture type and use	Perennial grass, growing mainly in winter and spring. Dryland or irrigated for grazing, hay and silage.
Area of adaptation	Central, Southern and Northern Tablelands, South West Slopes, coastal and irrigation areas.
Min. average annual rainfall	700 mm (southern NSW) to 800 mm (northern NSW), and 900 mm (coastal).
Advantages	Excellent seedling vigour and therefore easy to establish. Good winter growth provides palatable nutritious feed ideal for fattening. Rapid recovery after grazing. Tolerant of acid soils but less so than fescue or cocksfoot. Suited to fertile soils in areas where summers are cool and the rainfall evenly distributed. Free-seeding ability enables it to regenerate readily after a dry spell and after cultivation.
Disadvantages	Low drought tolerance because of shallow root system. Prone to insect damage (cockchafer, grass grubs). Its free-seeding ability can result in it becoming a weed for newly sown pastures or crops. Seed reserves can be depleted by heavy stocking (the green seed heads are readily eaten by stock) or by regular dry spells. Most cultivars are susceptible to rust. Production is more erratic and persistence declines rapidly in conditions other than cool summers and even rainfall distribution. High soil aluminium may affect root growth.
Soil requirements	Best suited to highly fertile soils, but will persist on lower-fertility soils as well.
Varieties	Select varieties on the basis of maturity, plant type, rust resistance, endophyte level, and local production and persistence data (where available). * Denotes that this variety is protected by Plant Breeder’s Rights. Very early maturing diploids: Boomer * Fitzroy * Kangaroo Valley Matilda Meridian * Meridian Plus AR1 * Skippy Early maturing diploids: Ausvic * Camel * Kingston * Roper * Victorian Mid season diploids: Aries HD * Avalon * Bronsyn * Bronsyn Plus AR1 * Cannon Cannon AR1 Embassy Extreme Grasslands Nui Lincoln * Prolong * Samson * Samson AR1 * Late season tetraploids: Grazmore * Quartet * * Denotes that this variety is protected by Plant Breeder’s Rights. See Agnote DPI-283 Short-term ryegrass for hybrid varieties that have a high percentage of perennial ryegrass (i.e. Grasslands Impact, Grasslands Supreme, Horizon, Grasslands Greenstone, Banquet).
Sowing rates:
- as only species	3–20 kg/ha
- in mixtures	2–6 kg/ha
Sowing time	Autumn/early winter (March to June). In high-altitude high-rainfall tableland districts, spring sowings (August to September) can be attempted.
Companion species	Legumes (white, red and subterranean clovers, lucerne, lotus) and other temperate grasses (fescue, phalaris, cocksfoot).
Inoculation	N/A
Major nutrient deficiencies	Nitrogen, phosphorus and sulfur.
Main insect pests	Ryegrass pastures are sometimes seriously damaged by blue oat mite, redlegged earth mite, field crickets, pasture scarabs, army worms, slugs and snails.
Main diseases	Stem rust and flag rust are the main diseases, although other diseases can occur, including downy mildew and leaf spot.
Management	Yield, persistence and feed quality are optimised by grazing when ryegrass reaches the 3-leaf stage, grazing down to 5 cm high. Autumn: Remove dry residues, encouraging new tillers. Don’t graze new growth too hard (keeping more than 1200 kg DM/ha). Winter: Graze between 800 and 2500 kg of green DM/ha to maintain winter and spring growth (i.e. graze at 3-leaf stage). Spring: Maintain between 1600 and 3000 kg of green DM/ha to delay flowering, and keep the plant productive for longer. If trying to increase plant density, reduce stocking rate to allow a higher percentage of plants to run to head. Summer: Don’t graze hard (below 2 cm or 600 kg DM/ha), otherwise plant death will occur. In hot areas (mean temperature >30°C), spell pastures over summer.
Livestock disorders of particular note	Ryegrass staggers, endophyte ill thrift, ergot of rye poisoning.
Additional tips	Varieties not listed above and available are listed in the Agnote referred to below.
Further information	Agnote DPI-234 New pasture grass and legume varieties. Agfact P2.3.9 Endophytes of perennial ryegrass and tall fescue

Acknowledgment

Advice on livestock health disorders was provided by Dr Chris Bourke, Principal Research Scientist, NSW Agriculture, Orange. His contribution is gratefully acknowledged.