The occurrence of herbicide-resistant Avena fatua (wild oats) populations to ACCase-inhibiting herbicides in Ireland

Following growers’ reports of herbicide control problems, populations 30 wild oats, Avena fatua, were collected from the south-east main arable counties Ireland in 2016 and investigated for occurrence potential resistance to acetyl-CoA carboxylase (ACCase) inhibitors pinoxaden, propaquizafop cycloxydim, as well acetolactate synthase (ALS) inhibitor mesosulfuron + iodosulfuron. Plant survival ?20% was considered discriminating threshold between resistant susceptible populations, when plants treated with full recommended field rates ACCase/ALS inhibitors. Glasshouse sensitivity screens revealed 2 out cross-resistant all three ACCase While both pinoxaden propaquizafop, additionally, two only. Different degree cross-resistance suggest involvement either different point mutations or more than one mechanism. Nevertheless, including seven ACCase-resistant equally ALS inhibitor. An integrated weed management (cultural/non-chemical tactics judicious use herbicides) approach is strongly minimize risk evolution.