Green Speed of Eight Creeping Bentgrass (Agrostis stolonifera L.) Cultivars

Green speed was evaluated of main creeping bentgrass (Agrotis stolonifera L.) cultivars used in Korean golf course greens. Eight cultivars of creeping bentgrass (CB; Agrotis stolonifera) were ‘Penncross’, ‘T-1’, ‘Penn A-1’, ‘Penn A-4’, ‘Shark’, ‘Declaration’, ‘Pure Distinction’ and ‘Pure Select’. Experiment was conducted on a 1 m×5 m plot with three replication (total plot size=120 m2) at Chunryong Country Club located in Jincheon, Chungcheongbuk-do, South Korea. Green speed was evaluated using by the stimpmeter under 4.0 mm and 3.6 mm mowing height on Oct. 27 in 2020, respectively after seeding on Apr. 17 in 2019. Significant differences of CB cultivars were observed in ball roll distance. As for ball roll distance of CB cultivars at 4.0 mm cut, it showed 0.55 m difference with 2.85 m (‘Shark’, the fastest cultivar) to 2.30 m (‘Penncross’, the lowest cultivar) among treated CB cultivars. On the other hand, Pure Distinction (2.80 m) and Pure Select (2.75 m) showed relatively fast ball speed when compared to medium high ball speed with ‘Penn A-1’ (2.70 m), medium low with ‘Declaration’ (2.60 m), low with ‘Penn A-4’ (2.50 m) and ‘T-1’ (2.50 m). In regard of ball roll distance of CB cultivars at 3.6 mm cut, it showed 0.15-0.30 m faster than ball roll distance at 4.0 mm cut. In this time, Pure Distinction was evaluated with the fastest cultivar on 3.10 m while ‘Penncross’ with the lowest cultivar on 2.60 m ball roll distance. On the other hand, ‘Shark’ (3.00 m), ‘Penn A-1’ (2.98 m) and ‘Pure Select’ (2.95 m) showed relatively fast ball speed when compared to slow ball speed with ‘Declaration’ (2.78 m), ‘Penn A-4’ (2.75 m), ‘T-1’ (2.70 m). Considering ball roll distance under 4.0 mm and 3.6 mm cut in this study, ‘Shark’ and ‘Pure Distinction’ were regard as excellent ball roll speed cutivars when compared to relatively high speed cultivars with ‘Pure Select’ and ‘Penn A-1’, relatively low speed with ‘Declaration’, ‘Penn A-4’ and ‘T-1’, and the lowest speed with ‘Penncross’.