Trinexapac-Ethyl and Overseeding Effects On Shear Strength of Four Bermudagrass Cultivars Grown On a Sand-Based System.

Bermudagrass (Cynodon dactylon L.) is often used for athletic fields due to its wear tolerance and recuperative ability. Studies were conducted May 2007 through November 2008 in Lexington, Kentucky.  The cultivars ‘Quickstand’, ‘Tifway’, ‘Riviera’, and ‘Yukon’ grown in a sand-based medium were used to investigate differences in shear strength.  Trinexapac-ethyl (TE) was applied at label rates and frequencies or untreated. Overseeding treatments were perennial ryegrass (Lolium perenne L.) at 0, 612, and 1225 kg PLS ha^-1. Shear tests were conducted using the Clegg shear tester once wk^-1 August through October. Significant differences (p<0.05) in shear strength indicated Quickstand= Riviera > Tifway =Yukon (2007) and with Riviera ≥ Quickstand > Tifway = Yukon (2008).  Significant differences (p<0.05) in shear strength due to overseeding were not observed in 2007 and only for the last three observation dates in 2008. Applications of TE did significantly improve turfgrass quality, but were not significant (p>0.05) in either year for shear strength.