Effects of growing degree day based trinexapac-ethyl application on ultradwarf hybrid bermudagrass putting green quality and ball roll

Application of plant growth regulators to hybrid bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] putting greens is a common management practice used reduce clipping yield and improve aesthetic functional turfgrass quality. Growing degree day (GDD) models have explored the effects regulator application timing on ultradwarf yield. However, there need for research evaluating GDD-timed applications quality ball roll. A field study was conducted in summer 2018 at three locations (Knoxville, TN; Raleigh, NC; Starkville, MS) determine trinexapac-ethyl (TE) applied according GDD model green roll compared calendar-based treatment (i.e., weekly or twice-weekly). For applications, TE either 20 33 g ha−1. based were made once 220 (base 10°C) accumulated after each treatment. ha−1 treatments rate reduced 14 16 twice-weekly In all locations, GDD10C schedule resulted greater than equal that treatments. Ball distance slightly lower plots treated with every treatments, although differences may be negligible golfers (13 23 cm). negatively correlated (−0.37 −0.69). Turfgrass managers choosing regulate should consider applying rather interval achieve improved without sacrificing distance.