area; the only supplemental irrigation Duplex and Primer Select were also in the top group. This difference is applied to plots occurred following likely related to the fact that wetwetting agent applications. ting agent performance is affected by Treatments that often provided thatch and organic matter, as well as a softer surface in 2015 as measured putting green maturity. with the clegg hammer include: Sixteen90/Dispatch Sprayable, Aquiflo, Volumetric water content, turfCascade Plus (3 or more of 5 ocgrass quality, chlorophyll index currences in the lower 30% of treatments). Treatments that often provid- Volumetric water content was ed a firmer surface include: Duplex, not significant on any rating date in Aquicare, Primer Select (4 or more 2015, and this is surprising given of 5 occurrences in the upper 30% the differences in surface firmness. of treatments). Clegg Impact Values There are two potential explanations on the dates of June 18th and August for this: 1) the 4.8 inch probes tar20th, 2015 reflect these observageting the bentgrass rootzone were tions (Figures 1 and 2). The untreated too deep to pick up shallow moisture control was often near the center of which influences firmness, and 2) the each data set, indicating firmness reported accuracy of the Spectrum differences based on surfactant type. TDR 300 is Âą 3% VWC, which may Other wetting agents varied in firm- not be accurate enough to pick up ness values throughout the study or small differences in soil moisture. performed closer to the untreated Still, general trends were made becontrol. tween high water content and softer surfaces. Some wetting agents behaved differently in regards to surface firm- Chlorophyll index and turfgrass ness from Year 1 to Year 2. For quality ratings were only significant example, in 2014 the firmest treaton one date each, June 18th and Auments under adequate soil moisture gust 9th, respectively in 2015. When conditions were Aquicare, Fleet, significant, high turfgrass quality and Cascade Plus, and Sixteen90/Dischlorophyll index ratings generally patch Sprayable. In 2015, Aquicare reflected those plots that were the was still a firm treatment, however softest and held the most moisture
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