Water aid for seedling growth

With the immense pressure on groundsmen to renovate pitches between the close of one sporting season and the start of the next, successful seed germination and fast establishment is key to getting surfaces back in play.

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In many instances, there may be just five weeks available for complete renovation. And that applies at levels from premiership football and rugby - including restoring stadiums used for concerts over the summer and training ground preparations for pre-season work - right through to schools changing over from cricket to winter sports.

Not only do the pitches have to look good for the start of the season, but they have to be well enough established to withstand the wear and tear of the whole season and the inclement winter weather.

Now, results of new research at the STRI in Bingley, has shown that germination and establishment of turf seedlings could be enhanced by the use of Qualibra wetting agent before or at the time of renovation.

The research, investigating the effects of hydrophobic rootzones on seedling establishment, clearly demonstrated that all grass species tested germinated faster and established stronger with the Qualibra treatments, reported Syngenta Technical Manager, Marcela Munoz.

The results showed up to 250% increase in the germination rate of ryegrass, with a corresponding increase in surface coverage and development of the overall plant biomass as an indication of stronger rooting and plant health.

Reporting the work at PitchFocus 2016, held at the Tottenham Hotspur Training Ground facility in Enfield, Marcela highlighted that the results were particularly evident with ryegrass seedlings, which could offer extremely valuable extra days of strong growth to get pitches back in play.

The widespread use of sand rootzones for sports pitch constructions could increase the risk of hydrophobic conditions occurring. The build-up of natural waxy deposits on the sand grains acts as a repellent to water and eliminates its soil moisture holding capacity. Even if extra irrigation is applied, the water cannot physically work through the hydrophobic area, which makes it impossible for any seedling to germinate or survive.

On a small scale, water runs around the hydrophobic area and penetrates in columns, leaving affected areas dry that would lead to patchy establishment. On a larger scale, whole areas of dry patch with little or no grass cover could occur.

The trial used commercial sports turf seed of Ryegrass, fescue and bentgrass species, sown into rootzone sprayed with Qualibra, at different rates, either five days before or at the time of sowing - compared to untreated. The rootzone was taken from an existing sports facility in the north-west, and used directly in the pots for the trial with no amendment or alteration.

STRI Study Director, Tom Young, commented: "The germination of perennial ryegrass, fescue and bentgrass was significantly quicker for all Qualibra treatments compared to untreated controls.

"Also, the percentage coverage of pots with all grass species was significantly increased in all Qualibra treatments," he added. Further assessment of turf height and growth, calculated from clippings, highlighted the continued extra vigour and strength of seedlings from the treatments for over 30 days of study after sowing.

Marcela Munoz highlighted the research confirmed Qualibra treatment at the equivalent of 20 l/ha gave the best results in terms of long-lasting performance, but that a half rate of 10 l/ha did achieve significant short term boost to seedling germination and establishment.

Monitoring of rootzone moisture in the trial 'consistently showed a positive dose response to Qualibra application, with greater levels of moisture observed as the rate increased', according to the report.

"What we have seen is that Qualibra is extremely effective in holding moisture in the rootzone that can aid seed germination and allow it to establish more successfully, specifically in hydrophobic rootzone conditions," she advised. "That could have hugely beneficial implications for renovation programmes and helping to get faster recovery and coverage on sports turf for winter pitches and golf greens."

"Importantly, the unique combination of penetrant and polymer in Qualibra ensures that the surface stays firm and dry - which is good for playability - whilst seedlings and existing turf plants are well placed to make best use of any irrigation applied, with the desired soil moisture held in the rootzone."

Creating a greater root mass at depth is vital to improve the surface stability of a newly renovated pitch. And is essential to aid recovery from stress and damage during games over the winter. For the vast majority of pitches, without the luxury of undersoil heating, there is typically just a couple of months from sowing to get the root system established.

Marcela added that groundsmen and greenkeepers will still need to ensure the management of the renovation process was geared to fast germination and growth, including assessing seed quality, soil nutrition, irrigation and the use of germination sheets, for example.

Timeliness is always a factor to get the seed sown quickly after the pitch becomes available for renovation - whilst not compromising getting the conditions as perfect as possible for germination. But, as an insurance policy, the research shows Qualibra treatments could help assure more consistent results.

Further research, with STRI and in practice with groundsmen, is now looking at its use in renovation on a wider scale, and in conjunction with Primo Maxx programmes and fungicide treatments to further provide solutions for faster and more successful seedling establishment.