Effects of Mowing, Rolling, and Foot Traffic On Root Morphology of Creeping Bentgrass Putting Greens.

Many researchers have demonstrated reductions in turf quality and coverage with low mowing or increased traffic in individual studies.  Authors suggest that reductions in rooting are likely to occur, but few evaluate rooting characteristics directly.  Root scanning technology produces a multitude of data and intricate measurements of rooting characteristics.  This technology may be able to more clearly identify treatment differences expected among low mowing and high traffic treatments.  The objective of this study was to evaluate root morphological characteristics of ‘Penn G2’ and ‘SR 1020’ creeping bentgrass subjected to mowing, rolling, and foot traffic during summer months.  Two random samples were obtained from each plot in June and August of 2010 and 2011.  Cleaned root material was placed in a scanning device to obtain an image of roots that was processed with the WinRhizo software resulting in cumulative root length, surface area, and average root diameter.  Following scanning, root samples from a single plot were combined and dried to obtain root dry weights.  Few significant differences were observed for Penn G2; however, foot traffic and mow by roll interactions were identified for SR 1020 in August with respect to cumulative root length, surface area, and root dry weight.  Although not all parameters resulted in statistical significance, plots maintained at 0.100 inch with or without rolling had numerically lower cumulative root length, surface area, and dry weights compared to higher mowing heights.  From June to August in both years cumulative root length and root dry weights decreased by 75% and 80%, respectively, whereas root diameter was diminished by 30% following treatment combinations in summer stress.  These data indicate the usefulness of scanning technology to produce quantitative data that demonstrated a potential trend of reduced rooting with lower mowing heights and increased traffic during periods of environmental stress during summer months.