Perenial Ryegrass

  • Good persistence (AR37)
  • Excellent dry matter production at key times 
  • Mid-season maturity (+7 days)
  • Low aftermath heading for improved late season quality
  • Sowing Rate 15
  • Heading Date Mid
  • Days to Grazing From 55 To 85
  • Growing Seasons Autumn,Spring,Summer,Winter
  • Grazing Seasons Spring,Summer,Autumn,Winter
  • Grazing Method Rotational Grazed – Long Term
  • Number Of Grazings + 3
  • Tetraploid/Diploid Diploid
  • Rainfall Minimum 650mm per annum
  • Pasture Life 5 years+

Excess AR37 is a diploid perennial ryegrass with a mid-season flowering date of +7 days (compared with Nui). Excess AR37 has the added feature of being available with AR37, a novel endophyte which offers excellent insect protection. AR37 allows for increased potential for the plant to persist over many years and offers increased forage yield at key times of the year (summer, autumn and winter).

Aftermath heading (AMH) is a trait that offers real benefits due to its effect on feed quality late in the season. Plant breeders at PGG Wrightson Seeds put a lot of focus on low aftermath heading to maintain high quality feed late in the season and after plants have gone reproductive. Excess AR37 was selected for the trait of low AMH so as to keep the quality of feed high later in the season.

Like any other cultivar, a plant with low aftermath heading will produce seed heads when it goes reproductive. But, it will revert to vegetative growth quickly (providing moisture is available), thus minimising the period when forage quality is low.

Grazing Management

Excess AR37 perennial ryegrass will produce and persist better under rotational grazing. Avoid hard set-stocking during periods of stress (e.g. droughts, low fertility and insect attack).

Grazing Excess AR37 for the first time is the same process as with any new pasture. Look to implement the “pull test” before introducing livestock onto the paddock. This will indicate whether or not the grass is well anchored and able to handle the pressures of grazing for the first time.

Careful grazing management is required during drier periods as this can affect persistence through the constant use of key energy reserves of the plant which, if not replenished, will result in lower plant persistence. With the introduction of the North West Spanish germplasm into the breeding of Excess AR37, it is a key feature that when there is available moisture, the grass will grow and produce good levels of dry matter, regardless of the time of year. It is important to carefully manage Excess AR37 through the summer – autumn period in a dryland situation in the event of any “out-of-season” rainfall events. If this situation occurs, be sure not to graze for extended periods of time or the grass will run out of the energy reserves which allow it to regrow after grazing. If grazing is required, it is recommended the grazing period is brief and some leaf area is left behind to allow the plant to continue the process of replenishing energy reserves ready for the next opportunity to grow.

Sowing & Establishment

Excess AR37 diploid perennial ryegrass seed is smaller than tetraploid seed, so sowing rates should be between 15-30kg/ha.

Excess AR37 is an ideal companion grass in a pasture mix that may include a tetraploid perennial ryegrass, clovers and chicory. This will ensure a balanced pasture diet that offers high quality feed for as long as the seasonal conditions allow.

It is important to note with any small seed that good seed to soil contact is required to enable even germination, quick vigour and therefore ease of management in the year of establishment. If this is not achieved, then processes such as weed control and first grazing can be severely affected.

To ensure the success of establishing a new pasture and the introduction of a novel endophyte is achieved, it is recommended that a full renovation program is implemented prior to sowing the new pasture. This will give time and opportunity to get weeds to a manageable level as well as eliminate any ryegrass plants that contain standard endophyte so as to enhance animal productivity.


Excess AR37 was developed within the PGG Wrightson Seeds internal breeding program utilising elite genetics that have proven successful in Australian conditions. The selections were made from a combination of elite North West Spanish and New Zealand genetics with a focus for mid-season maturity. With North West Spanish germplasm as the platform for Excess AR37 (similar germplasm used for Banquet II and Base AR37), the performance of Excess AR37 really suits Australian conditions and Australian farmers.

In breeding Excess AR37 there was a clear focus to specifically target key traits such as rust resistance, persistence, dry matter production at key times and low aftermath heading. Persistence is largely gained through the AR37 novel endophyte and the insect protection that it offers.


Minimum 650mm rainfall per annum unless irrigated

AR37 novel endophyte has been shown to provide superior resistance (over SE or AR1 endophyte) to a wide range of insects that cancause real damage and yield reductions to ryegrass pastures in Australia. These pests include adult Black Beetle, Argentine Stem Weevil Larvae, Pasture Mealy Bug and Root Aphid. However, under extreme insect infestations the pasture may require an application of additional insect control. The protection offered by the AR37 endophyte enables persistence to be a key feature of Excess AR37.

Rust resistance for Excess AR37 is very strong and one of the selection traits that was used to identify it as a potential variety. Management will assist in preventing rust, so fertility and general health need to be monitored and supported to ensure the onset of rust is delayed and/or prevented. Conditions that are conducive to rust are those in key coastal areas of NSW and where irrigation
is utilised.

Each time the cows entered the paddock they ran to the freshly allocated Excess AR37 and the recovery from grazing was excellent

Share this page