The use of Primo Maxx could enhance the efficiency of nitrogen fertiliser utilisation and reduce overall season-long requirements on greens by 25%, according to results of trials in the US and published in Crop Science magazine.
The trials’ premise was that removal of grass clippings with mowing had been shown to double the nitrogen (N) requirement of turf to maintain plant health and surface quality; therefore reducing the clipping yield with a growth regulator programme should correspondingly make more efficient use of fertiliser inputs, whilst maintaining turf colour and health.
Undertaken by William Kreuser of Cornell University and Douglas Soldart of the University of Wisconsin-Madison, the three-year trials on bentgrass greens showed that in normal growing conditions the Primo Maxx programme enabled a 25% reduction of N application, from a typical 15kg/ha to 11kg every two weeks, without affecting turfgrass colour or the residual balance of fertiliser input to nutrient removal in clippings (the input-output N budget).
Furthermore, the researchers concluded that ball roll distances may likely benefit from the reduced clipping yield as a cumulative effect of lower N nutrition and regulating turf growth.
They also noted that untreated plots suffered a significant decrease in colour index, which was attributed to greater soil N reserves on the Primo Maxx areas, where less N was being removed in the mowing clippings.
Whilst the trials demonstrated that lower N fertiliser per se could limit turf growth, it confirmed that the nutrient is an essential factor of turf colour and visual quality. It was only the combination of reduced N and the use of Primo Maxx that was able to maintain the desired colour and surface quality. Kreuser and Soldart concluded that, to simply cut N to the point that it would have a similar effect to Primo Maxx in reducing the clipping yield, would: “severely reduce putting green colour, result in an unsustainable N budget, and likely lead to collapse of the putting surface during stressful conditions.”
Commenting on the reports publication, Syngenta Turf Technical Manager, Dr Simon Watson, told The Landscaper, “These results confirm the recommendations we have been making to include a high quality liquid N feed with every application of Primo Maxx, but that overall there is potential to make more efficient use of fertiliser programmes over the course of the season.”
Typically Dr Watson advocates a greens programme starting in May with Primo Maxx at 0.4 l/ha plus Everris Greenmaster Liquid High N 25-0-0+2MgO+TE at 40 l/ha. To maintain consistent growth regulation and turf health, this application would typically be repeated at four to six week intervals, with the precise timing and application rate varied according to turf species and prevailing growing conditions.
The Greenmaster Liquid options available with this season’s Everris/Syngenta Ultimate Offers can be adjusted to use NK 10-0-10+TE or Spring & Summer 12-4-6+TE, to accurately match specific growing requirements. A 40 l/ha application in tank mix with the Primo Maxx puts on between four and 10 kg N/ha, depending upon the fertiliser used.
“Primo Maxx can enable turf managers and agronomists to be more accurate in their use of fertiliser applications that are better matched to growing conditions and the specific requirements of the turf to maintain high quality playing surfaces,” he advised. “More efficient targeted use of nitrogen will prove to be cost effective and good for the environment.”
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