So, what’s new for wild oat and millet control in wheat? Not too much actually. Sure, there have been several new names launched during the last couple years; names like Wildcat, Axial, Nufarm Clodinafop, Tundra, Slam’R, and Hellcat. Each of these will do a great job at controlling your annual grasses when sprayed at the right time. However, they are all variations of the Group 1 and 2 grass herbicides that we have been using in wheat for years. In fact, all the grass herbicides for wheat which have been introduced in recent years are based on these two chemical families.
At last count wheat farmers could choose between 52 separate post-emergent herbicides to control both wild oats and green foxtail (wild millet). Unfortunately 42 of these 52 herbicides are Group 1 modes of action and the other 10 are Group 2.
The good news is that these current herbicides are very effective and if applied at the correct timing and with a little help from Mother Nature, you can expect 90%-95%+ control from most of them. The fly in the ointment though is the steady rise in weed resistance. This should be no surprise to anyone, since the farm media has been writing about resistance management for quite some time. The spread of biotypes of wild oats and green foxtail which are resistant to Group 1 and Group 2 herbicides is well known.
For wheat growers though this can be an especially critical issue since we don’t have the option of using an in-crop burndown product like glyphosate or Liberty. So what are the options? (1) Rotate herbicides between Group 1 and Group 2 chemistries, (2) Rotate into a crop such as canola where a non-Group 1or 2 can be used, (3) Consider using a soil-applied herbicide on suspect fields, and (4) Consider fallow or forage to break the cycle.
One caution though when choosing a different mode of action. Many of the new herbicides available, especially the co-pack ones, may list several modes of action on their labels. To be an effective weed resistance management tool, these different modes must be effective on the target weeds – wild oats and millet. Unfortunately that’s not the case, since these other modes of action are typically aimed squarely at broadleaf weeds and not grasses.
Perhaps the most effective tool though is you. Keep an eye on suspicious escapes, document them, prevent them from seeding, and then make a game plan to stop the spread next year.