| Abstract: |
Several field trials were conducted in 2005 on Riviera, Princess 77, Savannah, and Yukon bermudagrass (Cynodon dactylon) varieties at the Turfgrass Research Center in Blacksburg, VA to evaluate Certainty (sulfosulfuron), Monument (trifloxysulfuron), Revolver (foramsulfuron), and flazasulfuron for broadleaf, grass, and sedge control when mixed with herbicides such as 3-way blends, Drive (quinclorac), Quicksilver (carfentrazone), Manor (metsulfuron), and Confront (triclopyr plus clopyralid). Effects on bermudagrass injury at greenup, annual bluegrass (Poa annua), and smooth crabgrass (Digitaria
ischaemum) control were evaluated.
Treatments for smooth crabgrass and annual bluegrass control were applied during bermudagrass greenup and included Revolver at 0.2 and 0.4 fl oz/1000 sq ft, flazasulfuron at 1 and 1.5 oz/A, Certainty at 1 and 1.5 oz/A, and Monument at 0.33 and 0.56 oz/A each alone or mixed with Drive at 1.0 lb/A, SpeedZone at 4 pt/A, Confront at 1.5 pt/A, Manor at 0.5 oz/A, and Quicksilver at 1.5 fl oz/A.
Treatments containing Confront, SpeedZone, and occasionally Drive injured bermudagrass turf at greenup. Confront was most injurious (40 to 60%) while other products never injured bermudagrass greater than 20%. All bermudagrass eventually recovered. Revolver and Monument controlled annual bluegrass 100% regardless of tank mixture. Flazasulfuron controlled alone controlled annual bluegrass 90 to 100% and was minimally affected by tank mixtures. Certainty alone controlled annual bluegrass 90 to 100% and control was reduced to 50 to 65% when mixed with Confront or Manor but not when mixed with other herbicides. Regardless of tank mixture, smooth crabgrass control was excellent with Monument or flazasulfuron and variable with Certainty. Revolver controlled crabgrass 25% when applied alone and control increased to 95% and 78% when applied with Drive and Manor respectively. |