Barenbrug's Extreme RPR delivers "defining" moment at the home of golf.

The Castle Course at the Home of Golf, St. Andrews, has become one of the first golf venues to benefit from grass breeder Barenbrug's revolutionary RPR (Regenerating Perennial Ryegrass) technology.  

The Castle Course, which opened for play in 2008, offers a breath-taking cliff-top setting with stunning views over the "Auld grey toon", and poses a very different challenge (both in golfing and greenkeeping terms) to the hallowed turf of the famous links courses less than three miles away.  Visually, the course looks like a traditional links, but is actually built on predominantly agricultural land rather than the wind-blown sand of its neighbours.  

Whilst the pristine fescue/bent greens have thrived over the last five years on their imported sand rootzone, maintaining consistent growth of the fine fescues in other areas has been more difficult, particularly in the face of recent wet summers and cold winters on the east coast of Scotland.

Course manager Allan Paterson called in Barenbrug for some advice, and implemented an overseeding programme beginning in autumn 2012, primarily in maintained rough areas.  "We really needed to add definition and density to the roughs, which were providing very little growth, particularly in spring and early summer.  I gave Dave Greenshields, Barenbrug's research and development manager, a call and we were both in agreement -- perennial ryegrass was the obvious choice." 

Selecting the species was relatively straightforward, but choosing the right combination of cultivars was a more complex decision, as Dave explains.  "Perennial ryegrass is the most commonly bred grass for amenity use - there are literally hundreds of cultivars to choose from with a vast spread of genetic variation, which leads to a wide range of morphological and physiological differences within the species.  Allan needed a mix to blend visually with red fescue, and one which offered strong spring growth."  

The requirements at the Castle Course all pointed to a Barenbrug classic -- BAR EXTREME -- featuring top-rated fine-leafed varieties with a nice bright mid-green colour such as Bargold and Barsignum.   But Dave had another trick up his sleeve.  "At the time (BAR 7) RPR was in its first full season as a product for winter sports pitches and the feedback we were getting was fantastic.  I thought if we could combine the wear tolerance and regeneration potential of RPR with golf ryes like Bargold, we could really be on to something -- this is when EXTREME RPR was born."

Central to the RPR concept is the production of elongated tillers or determinate stolons, distinct morphological structures which Barenbrug varieties such as Barclay II can produce even during early establishment.  The structures allow RPR to "creep" (unlike other ryegrasses), enabling it to "fill in" worn or bare areas in the surrounding turf.  

Allan saw the potential of this advancement immediately.  "One of my concerns about the programme was how to successfully blend the new ryegrass with the existing sward.  I was going to disc-drill the seed in, and I really didn't want lines of new grass plants standing out for a long period.  RPR sounded like the perfect solution; it's great to work closely with Barenbrug and to be able to try new innovations early.  We got excellent germination, and the RPR quickly established to give a uniform surface.  This spring there was a noticeable difference -- more definition, good colour and a rough that offers a better experience for the golfer." 

Dave visited the site again recently and was similarly impressed.  "It was great to see the job Extreme RPR has done at the Castle, and I am really pleased that Allan was willing to go with the recommendation.  There's still a bit of a stigma attached to using ryegrass on golf courses, which is crazy really.  The species has developed so much in recent times that I would be hard pushed to think of any golf course that wouldn't benefit from its use in certain areas.  The key is to make sure you choose the right combination of cultivars for each specific job.  Extreme RPR has massive potential for golf courses -- for fast divot fill-in or high-wear walkways, I can't think of a better option!"