Effects of Winter Foot Traffic on an Annual Bluegrass Putting Green.

Annual bluegrass (Poa annua L.) is the dominant putting surface in the coastal Northwest (British Columbia, Washington, Oregon, and North California).  In these regions snow fall and freezing temperatures are minimal, therefore, golf is often played year round.  During these winter conditions annual bluegrass traffic tolerance and recuperation is minimal; however, turfgrass managers are often blamed for the reductions in turf quality when these conditions are present.  Therefore, the objective of this project was to document the effects of winter foot traffic rates on an annual bluegrass putting green in the coastal Northwest.  Field research was initiated February 2014 on a USGA sand-based putting green with well-established annual bluegrass at the OSU Lewis-Brown Horticulture Farm, Corvallis, OR.  Experimental design was a randomized complete block with four replications.  Treatments were foot traffic applied at rates equivalent to 110, 220 and 440 rounds of golf per day, compared to a control, which did not receive foot traffic.  Turf color and quality data were collected using a 1 to 9 scale, with 6 or greater considered acceptable, from 7 January 2015 to 26 March 2015, and again from 13 January 2016 to 8 April 2016.  Foot traffic applied at the high rate (440 rounds per day) produced the greatest reduction in turf quality and color.  The control produced the highest turf quality and color ratings throughout the study.  Traffic at the high rate reduced turf quality and color to unacceptable values (< 6) in February and March of 2015, and turf color in March of 2016.  Regression analysis determined that putting greens in the Corvallis area will experience reduced turf quality and color in the winter months if golf rounds exceed 300 per week.