Influence of Nitrogen, Trinexepac-Ethyl, and Mowing Pattern and Frequency on Putting Green Speed and Plant Health on a Creeping Bentgrass Putting Green.

Ball roll distance on golf course putting greens is a major factor in putting green playability. Changes in the management of the putting green turfgrass, such as fertility, growth regulation, and mowing have been utilized by turfgrass managers in an attempt to manipulate ball roll distances. The objective of this study is to determine the effect of nitrogen fertility, plant growth regulators and mowing pattern and frequency on ball roll distance. A field study was initiated in 2016 at the Joseph Valentine Turfgrass Research Center located in University Park, PA. The trial was conducted on a mature ‘A-4’ creeping bentgrass (Agrostis stolonifera L.) grown on a USGA putting green. Plots measured 1.2 x 2.7 m and were arranged in a split plot design. The studies consisted of three replications with the main factors of nitrogen fertility, plant growth regulator, and mowing pattern and frequency. For the main effect of mowing pattern and frequency individual plots were mowed with either a single cut, a double cut (two passes at 180 degrees from each other on the same pass), or a cross cut (two passes at 90 degrees from each other). For the effects of nitrogen fertility and plant growth regulator, sub-plots were treated with either 6 kg N ha^-2 from urea (N), 0.4 L trinexepac-ethyl ha^-2 (PGR), N plus PGR, or no N or PGR on a 14-day interval for a total of four applications. Data collected included ball roll distance, quality, and color. Results from morning BRD showed a PGR x N interaction on one rating date and that PGR was significant on only one rating date. Mowing pattern was significant on 7 of 12 rating dates with mowing patterns of cross cut and double cut having the greatest BRD on 5 and 7 rating dates, respectively. Afternoon BRD data revealed that PGR and N were each only significant on 3 of 12 ratings dates and that mowing pattern was significant on 4 of 12 rating dates with more frequent mowing resulting in greater BRD. During the trial, there was no significant reduction in plant health based on quality or color ratings.