Physiological Effects of Intensive Management Practices On Creeping Bentgrass Putting Greens.

Putting greens are commonly maintained at lower mowing heights and undergo traffic from equipment and golfer foot traffic. These lower mowing heights and implementing light-weight rolling are effective means for increasing green speeds with little concern of soil compaction and wear. Many turf managers increase mowing heights and incorporate rolling to maintain green speed and improve the physiological health of the turf during environmental stress. This philosophy seems logical, but no research has been performed to verify that increased mowing heights with rolling will produce physiologically healthier turf. The objective of this project was to evaluate photosynthetic rates and carbohydrate levels of ‘SR 1020’ and ‘Penn G-2’ creeping bentgrass managed at different mowing heights, rolling frequencies, and foot traffic. A closed-system photosynthetic chamber was used to determine environmental parameters and photosynthetic rate simultaneously. Carbohydrate analysis was performed on random samples collected in June, August, and October. Individual carbohydrate fractions were determined for foliage, crown/stems, and root material using colorimetric methods. Few significant differences in photosynthetic rate were observed among treatments; however, trends indicate higher rates on plots maintained at the highest mowing height. Foot traffic significantly reduced photosynthetic rate of Penn G2 in mid-summer compared to non-trafficked plots. The majority of significant differences in carbohydrate levels were observed with rolling treatments on Penn G2, but those differences were not consistent over sampling dates or plant portions. Similar to performance data collected throughout this project, few physiological differences have been observed with intensive mowing, frequent rolling, and foot traffic. Dry conditions and low humidity throughout the summer of 2011 may have helped maintain the physiological health of creeping bentgrass.