Goosegrass (Eleusine indica (L) Gaertn) is a noxious weed in vegetable and fruit cultivation in Malaysia. Goosegrass biotypes resistant to aryloxyphenoxypropionate and cyclohexanedione herbicides have been reported in localised areas of Malaysia since 1989. However, this weed could be easily controlled by glyphosate at 720 g isopropylamine salt ha−1. In late 1997, a fruit grower in Teluk Intan, Perak, Malaysia, reported that glyphosate failed to give adequate control of E indica in his four-year-old orchard. In response to the grower's feedback, an on-site field trial was initiated to evaluate the efficacy of glyphosate at 720 to 5760 g salt ha−1 for control of the weed. Results from this trial confirmed the grower's observation. Glyphosate 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 agronomic factors, and to further quantify the level of resistance, seeds of the biotype 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.
© 2000 Society of Chemical Industry