A first report of glyphosate-resistant goosegrass (Eleusine indica (L) Gaertn) in Malaysia

Goosegrass (Eleusine indica (L) Gaertn) is a noxious weed in vegetable and fruit cultivation in Malaysia. Goosegrass biotypes resistant to aryloxyphen oxypropionate and cyclohexanedione herbicides have been reported in localis ed areas of Malaysia since 1989. However, this weed could be easily control led by glyphosate at 720 g isopropylamine salt ha(-1). In late 1997, a frui t grower in Teluk Intan, Perak, Malaysia, reported that glyphosate failed t o give adequate control off indica in his four-year-old orchard. In respons e to the grower's feedback, an on-site field trial was initiated to evaluat e the efficacy of glyphosate at 720 to 5760 g salt ha(-1) for control of th e weed. Results from this trial confirmed the grower's observation. Glyphos ate at 5760 g salt ha(-1) gave only about: 25% control of E indica ('Teluk Intan' biotype). In an attempt to rule out environmental and other agronomi c factors, and to further quantify the level of resistance, seeds of the bi otype were collected and cultivated in our field station. In comparison to a susceptible goosegrass, the 'Teluk Intan' biotype: was found to be 8- to 12-fold resistant to glyphosate. (C) 2000 Society of Chemical Industry.