The first in-depth practical look at how to get the best results from the new growth regulator.
Making good turf great
The launch of Primo MAXX at the BTME Show in Harrogate last month created a surge of interest in new growth regulators and how to use them effectively. The product's makers, Syngenta, believe it will change the way course managers approach the whole course; for many the opportunity to create stronger, healthier turf and a better playing surface could prove as attractive as reducing the need for cutting.
Primo MAXX is a new generation of growth regulator, which works by blocking the grass plant's production of gibberellic acid, which is responsible for vertical growth. Where it is different to other growth regulators, however, is that it creates the block late in the growth cycle, which serves to stop cell elongation and keep shoots and stems short.
But Syngenta scientists, who developed the product in the US, report that this late block doesn't inhibit the plant's natural energy production, so all the potential is diverted into more lateral growth - creating a denser, healthier sward - and encouraging more root growth, which makes plants better able to withstand drought, heavy wear and stress.
Syngenta turf management specialist, Simon Elsworth, claims that harnessing the way this works makes it a valuable management tool for course managers on all areas of the golf course. "With Primo MAXX we are looking to achieve so much more than simply reducing the frequency of cutting and the volume of clippings, although they are extremely significant benefits in themselves.
"There is now the real opportunity for course managers to improve the quality and consistency of tees and greens, keep fairways looking green and healthy for longer under drought conditions, help grass to better withstand the rigours of year-round play, and enable the course recover quickly after competitions and heavy use." Recommended Programmes To best harness its traits, Syngenta and Scotts - which will distribute the product in the UK - have developed a specific range of recommended programmes for different areas of the course, following course managers' experiences of practical trials on a variety of playing conditions, including parkland, heathland, links, newly constructed and long-established courses last year.
On tees, for example, course mangers are advised to apply Primo MAXX at four to eight week intervals from mid-April to early September. For tees cut at 10mm, Mr Elsworth advocates rates of 0.8 l/ha, but increasing up to 1.6 l/ha for an 18mm cut height (see Table 1).
For greens that are cut tighter, down to 7mm, the application rate is just 0.4 l/ha, but should be applied every three to four weeks through the growing season. "Close cutting on greens removes most of the energy providing green leaf, which gradually weakens plants. Primo MAXX encourages more dense green leaf at a lower height and enhanced root growth, so plant health is encouraged - so the greens look and play better," adds Mr Elsworth.
The programme for recommended use on fairways can also be tailored, with application rates of 1.6 l/ha for fine turf fairways, but increasing up to 2.4 l/ha if turf is predominantly Perennial Ryegrass. Use on the fairways not only reduces cutting frequency, but with the denser sward balls sit higher, for improved playing conditions. Improved rooting also helps stave off the effects of drought, maintaining fairways in better condition for longer throughout dry periods and helping the recover faster when moisture becomes available.
Mr Elsworth adds that, generally, the tighter the cut the more frequent the need for application, but the lower the rate used; overall season-long use will remain broadly the same. "Applications are best targeted at periods of intense grass growth, and may be extended in dry periods if growth has slowed.
"In most years applications from mid-April to early October will provide season-long results, but course managers may need to start earlier or continue for longer depending on the weather and their particular course situation."
Grass growth should start to slow within one to two weeks of initial application, he reports, but the effects are cumulative over several successive treatments; hence the need for the programmed approach.
"On tees, fairways and rough areas the reduction in grass growth should enable cutting intervals to be extended over the course of the season. But for greens we recommend course managers continue to cut as normal; the key difference will be the healthier, denser grass quality, with reduced growth during the day - so greens putt far more consistently. There's also a significant reduction clippings to remove, so the operation is quicker."
Trials have shown up to 50% reduction in clippings over the course of a season, which could help reduce issues with composting under new waste management legislation. Mr Elsworth also points out the slower grass growth will minimise the impact of rain disrupting the cutting schedule, and provide greater flexibility in the cutting intervals.
In the US course managers have found Primo MAXX helps with what they term 'pre-stress conditioning'. Essentially they are aiming to enhance the health and vigour of grass before periods of stress - such as impending drought or a tournament where grass will be subjected to heavy use and spectator traffic - so that it will stay green and healthy for longer. Equally importantly, they report grass recovers faster and more completely when normal conditions resume.
Syngenta advises the PGR can be safely tank mixed and applied along with liquid fertilisers and nutrients. Tank mixes with herbicides and fungicides are also possible, but course managers should consult with their technical advisor before application. The liquid formulation has been specifically designed to be easier for operators to handle and measure than powders; the liquid also disperses quickly and easily in the tank, for faster spraying operations.
"All the trials have shown it is very safe on grass, so course managers should not see any adverse effects of yellowing when used at the recommended rates," according to Mr Elsworth. One useful tip, he adds, is that when treating a bent/poa mix sward, the bent grass tends to become a darker, stronger green more quickly than the poa after the initial application; adding a small amount of nitrogen to the tank mix will help to alleviate the difference.
The exhaustive trials by Syngenta and Scotts, to prove the safety to grass and the environment, also revealed that when used on over-seeded areas it encouraged the newly emerging seedlings to establish quicker and stronger.
With course managers under ever increasing financial constraints, along with the need to provide better and more consistent playing conditions, the routine use of Primo MAXX ticks the boxes to reduce course management time and costs, as well as producing better quality turf. "In fact, over 95% of golf course managers who used Primo MAXX in the UK trials last year plan to repeat its use on a wider scale for the coming year."
More information and literature is available from nationwide Scotts' distributors.
Putting the Principles into Practice
David Horn, course manager at the 18-hole parkland Sittingbourne & Milton Regis Golf Club in Kent, designed by Donald Steel, reports results of a trial where he made four applications of Primo MAXX to a non-irrigated fairway from early June, through to the end of August. "During this period I saw a general improvement in turf health, plus reduced seed head production and stalking.
Primo MAXX helped reduce the effects of drought and aided fast recovery on non-irrigated fairways at Sittingbourne
"I also observed a marked improvement in the drought resistance and tolerance, plus subsequent rapid recovery of the treated area after a prolonged drought period."
Mr Horn's comments on turf health were also identified by Rob Holland of the Birchwood Park Golf Club, Wilmington, Kent. After just two applications he said: "Primo Maxx has greatly increased sward density and drought stress tolerance."
Mr Holland added: "The treated fairway looks far healthier and less stressed than the untreated areas." With an 18-hole parkland course and a short 9-hole course to maintain at the club, along with a 41-bay driving range and other facilities, time is always an issue and any opportunity to improve cutting speed or reduce frequency would be warmly welcomed.
Caption: Sward density on the eighth green of Cranham Park Golf Course at Upminster in Kent (top) was significantly improved after three Primo MAXX applications through June and July, reports course manager, Barney Cameron, along with colour and general health of the grass, compared to untreated (below).