Avoiding the pain of renovation

Glenn Kirbyin Technical

The journey is never over, from initial moves to firm up surfaces, to the wholesale change of turf grass species. The bigger the step that needs to be taken, the greater the disruption needed and the more severe the short-term pain writes Syngenta Technical Manager, Glenn Kirby.

Early season renovation to reduce organic matter

Renovation action is essential in the long-term transition towards playing surfaces that meet players' demands more consistently and can be more effectively and sustainably managed with good Integrated Turf Management practices.

The confrontation is that players want the end result but are largely intolerant of the disruption of the process to get there. More recently, the extra demand for rounds of golf through the Covid era puts extra pressure on resources and reduces opportunities for action, along with challenges of climate change that limit chances for renovation and can seriously compromise recovery from renovation.

STRI reports have shown greenkeepers have made great strides with appropriately designed and well-timed renovation practices over recent seasons. Year-on-year assessments of over 2,500 greens on 490 courses, covering parkland, links and heathland, showed an average of more than 14% reduction in organic matter on parkland courses over a seven-year period, and nearly 23% reduction on links.

Directly correlated to that was a 14% increase in firmness and 18% rise in green speed on parkland courses, with 12% firmer and 3% faster links' surfaces.

The research fully supports the relationship between lower organic matter (OM) content that will lead to firmer, better performing surfaces. Furthermore, measuring volumetric soil moisture content, surface hardness and levels of organic matter are key to producing year-round high-quality surfaces.

It also highlighted a significant rise in the number of assessed courses that were successfully moving into the optimum STRI target zones for average firmness, of 85 to 110 gravities for parklands and 100 to 130 gravities for links greens.

Assess soil organic matter levels to adapt renovation programmes / Firmness measures indicate needs for renovation intensity

Greens on parkland courses still had, on average, 30% higher organic matter in the surface 0-20 mm layer than the desired target of 3 - 6% OM. Links course typically had lower levels of organic matter, but were still, on average, 10% higher than the top-end of the target zone.

The good progress over recent years with organic matter reduction, along with a distinct shift to a higher proportion of finer grass species, is likely to be a combination of greater recognition of what needs to be done and the availability of better, more efficient machinery that can deliver greater results faster. Along with a better understanding of how organic matter is generated and what agronomic conditions drive its production, as well as the increasing demands from the customer for ever better and more consistent surfaces.

The Syngenta Golf Player Survey, referred to by the R&A as a benchmark for greenkeeping actions to meet players' demands, highlighted that 'smooth ball roll' was the number one requirement, with 'free of disease scars' and 'firm playing surfaces' also noted in the top four, along with 'free of weeds'. Managing and delivering on their expectations requires more 'out of the box' thinking on the renovation path.

Renovation practices vary from course to course and season to season, as conditions, requirements, labour, time and budget allows, but typically involves at least some removal of organic matter using hollow tines or intensive scarification.

Increasingly, course managers are using the opportunity of disrupted surfaces to follow this up with more solid tining, at varying depths, to increase air infiltration, help bridge any existing layers in the profile and increase opportunities to fully integrate topdressings. The more holes created and the more material removed, all needs more topdressing and more aggressive brushing in to ensure the holes are filled. Brush technology has developed significantly in recent years and, being able to work large quantities of sand into the surface, has contributed to the strides forward.

Sand top dressing improves surface quality but can be harsh on turf and mowers

At this stage, seed is often integrated into the surface, to aid faster recovery and transition to new species. Moisture is then used to help work the dressings in, speed up recovery and aid germination. Last, but not least, is the act of a suitable feed programme that will help to optimise the recovery.

These are all necessary actions to achieve the end objective. but even with the greatest care, there will be damage left behind. Damage on the leaf blade, additional stress imparted and turf sheared off by mower blades blunted by topdressing, for example, all make plants more susceptible to disease infection. Furthermore, the additional water and nitrogen often supplemented to aid germination and recovery, creates close to perfect conditions for disease to thrive.

To compound the difficulties, demands on the Club calendar often forces renovation timings into periods when weather conditions are less suitable for actions, and disease pressure is high or on the horizon.

Even when renovations can be squeezed into the playing season, historic disease records on the Syngenta Turf website show that this can simply stretch the period over which the plant is susceptible - making the disease window much longer than it would be without renovation. That can lead to high disease populations and more susceptible turf, just as the risk periods are increasing.

To help protect turf and encourage faster recovery, Syngenta and ICL have been successfully trialling a new strategy, utilising a combination of fungicide actions, in conjunction with innovative Ryder pigment technology. The trials have sought to optimise the rates of the fungicides involved and the application timing, to give long-lasting protection through the most vulnerable period.

Early season renovation to reduce organic matter / Sand injection and over seeding five days after works with new germination

Research on courses under real greenkeeping conditions, at Colne Valley in Essex and Notley Golf Club near Braintree, showed the consistently best results with the fungicide + Ryder combinations tested was for Heritage at 0.3 kg/ha; Medallion TL at 2 l/ha and a litre of Ryder.

That combination sought to give the best results, when applied pre-renovation, to help the turf grass cope with the additional stress imposed during renovation week. It takes advantage of the long lasting physiological benefits of Heritage, with the spore population reduction of Medallion. It further adds improved colour from and UV stress protection with Ryder.

At Colne Valley, for example, the combination of the two fungicides, at the lower than standard rates, gave significantly better disease control. The FR321 pack combination held disease in check at less than 0.5% surface area affected 14 days after treatment, compared to over 12.5% in the untreated.

In the Notley trials, the fungicide combination plots had less than 1% of surface area affected by disease four to six weeks after application, compared to 3 - 4 % with each of the component fungicides used alone. In the untreated plots, infection hit over 15% of the surface area.

With both trials, the combination of pack products tailored to the specific situation showed improvements in control throughout the challenging period. Furthermore, on both sites, the addition of Ryder gave a further reduction in the signs of disease damage and improvements in assessed turf colour.

Research has also shown the importance of application timing and the condition of turf going into renovation are important to get the best result possible. STRI trials have shown Heritage applications prior to disease symptoms being visible, but at times of high risk - resulted in 90% less disease scarring, compared to an application on established disease. Without treatment, levels of microdochium patch hit an unsustainable 25% of surface area, compared to 10% infection when treatment took place on established disease, but just 1% from the well-timed preventative application.

Renovation is clearly a big step in producing better long-term sustainable surfaces, and is delivering great strides in success for many. Time spent planning and preparing pre-renovation, along with flexibility to adjust the intensity of actions according to conditions, as far as practically possible, will enable faster recovery.

Article Tags: