 Greetings, this is Brian Jencks, weed scientist and ESU Research Center in Minot. We're going to discuss today the concept of controlling winter annual weeds with fall herbicide applications. Winter annual weeds, of course, emerge in the fall and then over winter and continue to grow the following spring and set seed and die the following year. Some of the most important economic winter annual weeds that we're facing are horseweed, narrowleaf hawk's beard, percolatus and false chamomile. Horseweed, of course, is a challenge because it has become round up resistant. Narrowleaf hawk's beard is a challenge because of how easily the seeds just seem to blow all over the field. So I'm going to focus mostly on horseweed and narrowleaf hawk's beard today. This is what narrowleaf hawk's beard can look like across fields. It might just be a few plants in one area of the field one year and then the next year it may be completely across the entire field. Here's a picture of the rosette. This is what you want to be targeting in the fall. These rosettes may germinate anywhere from late August. We've seen it through late October germinating as well. Horseweed, on the other hand, is one that we must also target in the fall. Here are the small rosettes. These pictures were taken in September. Here are some rosettes grown in the greenhouse. I want to give credit to Aaron Fromke, an NSU graduate student. Here is a study that Aaron conducted in the greenhouse and what we want to show here are the early rosettes. The picture that I just showed you are the early rosettes where they're small like a couple inches in diameter compared to the late rosettes which are much larger and then the bolting plants which may start to shoot up a stock. In this slide we show herbicide control at either the early rosette stage, late rosette, or bolting. The orange bars are early rosette, yellow bars, late rosette, and blue bars are bolting. With each of the herbicides used here you can clearly see that the early rosette stage, the horseweed is much easier to control. You look at 93% control with 2,4-D in the early rosette, extended max 99, Elevore 93, Sharpen, Liberty, and Gramoxone. So much easier to control in that early rosette stage which you will find typically in late September and early October. So one of the things we say though is you'll hear us say use Valor in the fall. We're not using Valor in the fall to control immersed weeds. So here's the concept that we need to understand. We've got weeds that exist in the field that have emerged. Those are best controlled in the fall say with 2,4-D or Sharpen. Those are the weeds that are already up. But there are other weeds that are going to emerge later and that's where Valor comes in. In that it will not control the weeds that are up, but it will control the weeds that will emerge later in the season. This is shown in this slide where we have extended max controlling 76% or providing 76% control of horseweed by itself. So it's controlling what's emerged, but it's not going to control everything completely, especially those that emerge later. So when we tank mix extended max plus Valor we get 99% control. With Sharpen we do get excellent control whether it's applied alone or with Valor. But with Gramoxone we get 64% control by itself, but when we tank mix Gramoxone with Valor 99% control. So those herbicides that don't have soil residual will not provide control of weeds that are going to be germinating much later. So that's where we get that one-two punch. So say we control something in the fall with Gramoxone or 2,4-D then we tank mix with Valor to help us control what emerges later. So for fall applications of horseweed we want to consider Glyphosate plus 2,4-D, Glyphosate plus Sharpen, possibly a Glyphosate-Sharpen 2,4-D combo. Also Glyphosate dicamba, dicamba actually controls horseweed even better than 2,4-D, but we have to be aware of rotation restrictions, especially in the western part of the state where we're growing lentils. And also maybe the best treatment might be something like a Glyphosate Valor plus 2,4-D. In controlling narrowleaf hawksbeard the herbicides of choice are very similar. We can go with Glyphosate plus Express plus a 2,4-D, the Express product or it can be any product that has Express in it or Trebenuron. Something like Paniflex. So we tank mix a Glyphosate plus Express plus 2,4-D, Glyphosate Sharpen 2,4-D, Glyphosate Sharpen by itself or with dicamba or Glyphosate Valor 2,4-D, but the concept is the same. We need something, a herbicide like Glyphosate and 2,4-D to help control what's emerged in the fall and then a Valor to control what emerges later. In the spring with narrowleaf hawksbeard, if we're going to use Sharpen in the spring it has to be in that very early rosette stage otherwise it's going to blow right through it and not control it. So Glyphosate plus Sharpen in the very early rosette stage, Glyphosate at higher rates and in crop we do have several options. So these are some things to consider for controlling winter annual weeds such as horseweed and narrowleaf hawksbeard and if you have any further questions please feel free to call us. Thank you very much for your time.