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GreenCast in UK and Ireland - Knapsack guidelines for Rescue application

Application
08.09.2010

New guidelines for the knapsack application of Rescue will help greenkeepers achieve accurate application and the best possible results this autumn. The innovative selective herbicide has proven extremely effective in removing rogue Ryegrass from fine turf swards, whilst leaving Fescues and Poa annua unaffected.

 

Rod Burke of Syngenta highlights that knapsack application is quick and convenient for treating relatively small or inaccessible areas affected by Ryegrass infestation, such as green surrounds, bunker faces or patches encroaching from rough areas into fairways. "Excellent results can be achieved with knapsack application, but it is important that sprayer operators are following best practice in the calibration and spray pattern," he advises.

A new knapsack application technical update, available to download from the Syngenta website - www.greeencast.co.uk - provides full details of calibration techniques, practical spraying tips and appropriate Rescue application rates. 

"The recent wet weather has made conditions ideal for Rescue application," reports Mr Burke. "Growing conditions are now excellent and we are entering the autumn flush of grass growth, which will ensure optimum uptake of the herbicide into weed grasses to achieve a high level of control.

"Furthermore, soil temperatures are still warm and there's sufficient moisture to ensure good seedling germination and rapid establishment of over sown seed, to aide surface recovery where the weed grasses have been removed," he adds.

Knapsack operators must hold the lance at the correct height above the target zone to ensure even coverage - which will be different for Rescue application on greens or in rough (above). Fixing a length of light chain on the lance can act as a useful guide (below). Also remember that walking through dense rough will be slower, which will influence application rate.

In extensive user trials the autumn applications have proven the most successful in achieving effective control of Ryegrass and some other coarse grasses, including Yorkshire Fog, reports Mr Burke. Experience has shown under some conditions Bentgrass, especially Highland Bent, may be affected by Rescue application, but in good growing conditions typically recovers in a couple of weeks.

He highlights that it is important that greenkeepers and turf managers have a good understanding of the turf species composition of areas being treated, and appreciate how much turf cover will be lost. "With current conditions greens over sown with Fescue and Bentgrass species will quickly recover once the invasive Ryegrass has been removed.

"We are increasingly seeing turf managers using Rescue as a routine part of their autumn renovation programme, with over seeding using desirable fine grass species every year to enhance playing surface quality."

For spraying larger areas of fairways, greens and rough, Mr Burke advocates the use of a conventional boom sprayer, fitted with the Syngenta Turf Foliar Nozzle to maximise spray retention on the target leaf and minimise the risk of spray drift.

Primo Maxx over seeding success

The success of autumn golf course renovation programmes can be significantly enhanced with the application of Primo Maxx growth regulator five days prior to over-sowing, advises Mr Burke.

"Primo Maxx will slow down the growth of existing turf, and thus reduce competition for light, moisture and nutrients that will enable new seedlings to establish more successfully," he says. STRI trials have shown there is no adverse effect on seedling germination rates from Primo application.

A follow-up application of Primo Maxx is recommended once new seedlings reach the two-leaf stage, to encourage tillering and stronger rooting that will help to quickly fill gaps and achieve a more consistent playing surface for the winter.

Mr Burke highlights that Primo Maxx and an appropriate liquid fertiliser must be applied separately to any Rescue treatment.

What is your experience with the best timing for Rescue application? How much is applied with a knapsack or conventional boom sprayer? Post your thoughts and ideas for others on the GreenCast Forum.