Tank-Mixed Postemergence Herbicides for Large Crabgrass (Digitaria sanguinalis) and Goosegrass (Eleusine indica) Control in Bermudagrass (Cynodon dactylon) Turf

Abstract

A two-year experiment was conducted to determine if tank-mixes of postemergence (POST) herbicides would consistently control large crabgrass and goosegrass in common bermudagrass turf compared to herbicide alone treatments. Tank-mixes of MSMA plus quinclorac at 2.2 + 0.6 kg/ha effectively controlled large crabgrass (≥ 81%) for 10 to 11 weeks during 1993 and 1994. The control from MSMA plus dithiopyr at 2.2 + 0.3 kg/ha was higher during this period than when each herbicide was applied alone at the same rate. There was no increase in large crabgrass control from tank-mixes of MSMA and diclofop applied in a single application, when compared with two applications of MSMA applied at 2.2 kg/ha. Goosegrass control at 9 wk after tank-mixed treatments of MSMA (2.2 kg/ha) and diclofop (≥ 0.3 kg/ha) in 1994 was lower (12 to 28%) than when diclofop at 1.1 kg/ha was applied alone (85%). Tank-mixes of MSMA with quinclorac or dithiopyr did not control goosegrass. In general, common bermudagrass injury was no higher from herbicide combinations than when each was applied alone. An exception occurred at 1 wk after treatment in 1993 when common bermudagrass injury was higher from tank-mixes of MSMA plus diclofop at 2.2 + 1.1 kg/ha, than when either herbicide was applied alone.