Prevalence of cross- or multiple resistance to the acetyl-coenzyme A carboxylase inhibitors fenoxaprop, clodinafop and pinoxaden in black-grass (Alopecurus myosuroides Huds.) in France
Article first published online: 25 SEP 2009
Copyright © 2009 Society of Chemical Industry
Pest Management Science
Volume 66, Issue 2, pages 168–177, February 2010
How to Cite
Petit, C., Bay, G., Pernin, F. and Délye, C. (2010), Prevalence of cross- or multiple resistance to the acetyl-coenzyme A carboxylase inhibitors fenoxaprop, clodinafop and pinoxaden in black-grass (Alopecurus myosuroides Huds.) in France. Pest. Manag. Sci., 66: 168–177. doi: 10.1002/ps.1851
- Issue published online: 5 JAN 2010
- Article first published online: 25 SEP 2009
- Manuscript Accepted: 22 JUL 2009
- Manuscript Revised: 30 JUN 2009
- Manuscript Received: 20 FEB 2009
- Syngenta Crop Protection
BACKGROUND: Repeated use of acetyl-CoA carboxylase (ACCase) inhibitors, especially fenoxaprop and clodinafop, since the late 1980s has selected for resistance in Alopecurus myosuroides Huds. (black-grass) in France. We investigated whether resistance to pinoxaden, a phenylpyrazoline ACCase inhibitor to be marketed in France, was present in French black-grass populations. We investigated pinoxaden resistance conferred by five mutant ACCase isoforms. Using 84 French black-grass field samples, we also compared the frequencies of other mechanisms endowing resistance to fenoxaprop, clodinafop or pinoxaden.
RESULTS: ACCase mutant isoforms Leu-1781, Gly-2078 and, likely, Cys-2027 conferred cross-resistance to pinoxaden, while isoform Asn-2041 possibly conferred moderate resistance. Other mechanisms of resistance to fenoxaprop, clodinafop and pinoxaden were detected in 99, 68 and 64% of the samples investigated, respectively. Cross- or multiple resistance to fenoxaprop or clodinafop and pinoxaden was not systematically observed, suggesting a diversity of mechanisms exist.
CONCLUSION: Pinoxaden resistance was observed before pinoxaden release in France. Only a fraction of the mechanisms endowing fenoxaprop or clodinafop resistance also confer pinoxaden resistance. Pinoxaden resistance was likely mostly selected for by ACCase inhibitors, and, in some cases, possibly by herbicides with other modes of action. This illustrates the necessity to use metabolisable herbicides cautiously where black-grass has evolved non-target-site-based resistance. Copyright © 2009 Society of Chemical Industry