MOWING HEIGHT AND VERTICAL MOWING FREQUENCY-EFFECTS ON PUTTING GREEN QUALITY

Lowering mowing heights to increase creeping bentgrass (Agrostis palus tris Huds.) putting green speed (i.e., ball roll distance) is a common practice. This practice can increase turfgrass susceptibility to heat and drought stress. Other cultural practices might be used to improve putting green quality and speed without additional stress. In this st udy, vertical mowing was used as a grooming technique to potentially i mprove putting green quality and speed. A 'Penncross' creeping bentgra ss turf, established in 1986, was mowed daily at 3.2, 4.0, and 4.8 mm in combination with vertical mowing frequency treatments of 1 and 2 ti mes per month, and a check of no vertical mowing. Mowing height and ve rtical mowing frequency effects on ball roll distance, turfgrass color and quality, and root production were evaluated in this study during 1989 and 1990. Vertical mowing treatments did not affect ball roll dis tance, turfgrass color and quality, or root production. Ball roll dist ance decreased by 0.2 m in 1989 and 0.4 m in 1990 as mowing height inc reased from 3.2 to 4.8 mm. Relative putting green speeds were rated as fast (i.e., > 2.6 m) across mowing height in 1989, and medium-fast to fast (i.e. 2.3-2.6 m) in 1990. Turfgrass color, quality, and root pro duction increased with mowing height in 1989 and 1.0 unit in 1990. Tur fgrass quality increased by 0.4 rating unit per mm increase in mowing height in 1989 and 1.0 unit in 1990. Root production at two soil depth s of 75 to 150 mm and 150 to 225 mm increased with mowing height in 19 90.