EVALUATION OF POTENTIAL ADMIXTURES TO IMPROVE POSTEMERGENCE SMOOTH CRABGRASS (DIGITARIA ISCHAEMUM SCHREB.EX MUHL.) CONTROL IN COOL-SEASON TURFGRASS WITH MESOTRIONE

摘要

Mesotrione is an herbicide registered for use on cool-season turfgrass.For complete control,mesotrione often requires multiple treatments,but previous research in agricultural crops indicates tank mixtures with mesotrione may improve weed control in single applications compared to multiple treatments.Three field trials were conducted in 2005 and 2006 in Blacksburg,VA in cool-season turfgrasses to control smooth crabgrass (Digitaria ischaemum Schreb.ex Muhl.).Mesotrione applied once in combination with bentazon,bromoxynil,or carfentrazone controlled smooth crabgrass better than any of these herbicides applied alone at all sites rated 24 days after initial treatment (DAIT),but control decreased by 35 DAIT unless a sequential mesotrione treatment was applied.Adding mesotrione to MSMA or quinclorac improved smooth crabgrass control to MSMA or quinclorac applied alone at only one of three sites.Although some herbicide admixtures were synergistic when mixed with mesotrione in the short term,these mixtures did not overcome the need for sequential mesotrione treatment to achieve acceptable smooth crabgrass control.