Tolerance of Seashore Paspalum (Paspalum vaginatum) and Bermudagrass (Cynodon dactylon) on Putting Greens to Xonerate (amicarbazone)

Abstract

On seashore paspalum and bermudagrass putting greens maintained at 7/32" at the Turfgrass Field Laboratory at Tarleton State University in Stephenville, TX, Xonerate 4 SC (amicarbazone) was applied at 2.8, 5.6, and 11.2 fl oz/A, and Xonerate 70 WG was applied at 4 oz/A on 6/03/2013.  All treatments included a 2 week sequential application except 11.2 fl oz/A, and 5.6 fl oz/A was evaluated with and without a 2 week sequential application.  Plots were evaluated from 6/03 to 8/15/2013 for chlorophyll indices and visual quality and for visual injury from 6/03 to 7/12/2013.  Although no treatments caused unacceptable injury, there may be some susceptibility issues in seashore paspalum since plot boarders that received spray treatment overlap were injured.  Xonerate 5.6 fl oz/A with a sequential application was the most injurious treatment followed by Xonerate 70 WG.  Seashore paspalum was more susceptible to amicarbazone.  Amicarbazone may have plant growth regulator properties as a period of rapid growth followed a 3.9"rain event resulting in scalping in bermudagrass near the end of the trial.  Amicarbazone appeared to have a long soil residual as broadleaf weeds were suppressed greater than 60 days in an area where remaining spray solutions were applied.