Has flaxleaf fleabane developed resistance to glyphosate?
An extensive random survey of flaxleaf fleabane in southern Queensland and northern NSW showed that populations differed in their response to glyphosate when grown under the same conditions. Notably, all populations from cropping paddocks in southern Queensland and most from cropping paddocks in NSW required a significantly higher glyphosate dose (3 to 6-fold higher) for similar control than populations from non-cropping situations remote to cropping areas. It is highly likely that these cropping paddocks had a history of glyphosate use for fallow weed control. In contrast, the non-cropping situations were not likely to have been treated as extensively with glyphosate.
