We report here the first case of field resistance to HPPD-inhibiting herbicides in R. raphanistrum (wild radish), caused by 12 years of continuous reliance on that mode of action.
For the first time, resistance levels to stand-alone herbicides and binary mixtures are geographically ranked across the Australian continent by benchmark statistical analysis of resistance frequencies and distribution. The extension of these results will raise awareness of rapidly emerging patterns of herbicide resistance, encouraging the adoption of cost-effective modes of action and integration of diverse strategies for weed resistance management.
This study provides examples showing that target-site resistance to POST herbicides and non-target-site resistance to PRE herbicides can be overcome by offering direct evidence across many L. rigidum populations screened. Evolved resistance to binary herbicide mixtures in individual plants may require the accumulation of multiple traits (at least two genetic traits) conferring resistance to each herbicide component applied at the maximum recommended dosage.
With the ever-increasing evolution of resistance to post-emergent herbicides there is in several parts of the world an increase in pre-emergent herbicide use.
Global grain production is under threat from the escalating evolution of herbicide-resistant weed populations. Worldwide, herbicide-reliant grain crop production systems have driven the proliferation of herbicide resistant populations of major weed species.
The widespread evolution of resistance in rigid ryegrass populations to the highly effective, in-crop, selective herbicides used within southern Australian grain-crop production systems has severely diminished the available herbicide resource.