 Greetings, this is Brian Janks and ESU Research Center weed scientist in Minot. Today we're going to discuss COSHA control. We're going to look at options for fall applications as well as trying to make those spring burn downs more effective. Unfortunately we know that throughout the state we do have COSHA that is resistant to roundup and now we cannot rely on post-emergence roundup to control COSHA anymore. Also we have starring resistant COSHA or COSHA populations that are more tolerant to our starring applications. So we have to find other methods to control COSHA. So I want to look at four steps here. First step, fall applications that provide residual control that will reduce the spring density. We want to be able to burn down fewer plants in the spring. Hopefully 20 plants per square foot instead of 80 plants per square foot. We want to have more effective burn down of those emerged weeds. We also want to have residual control of weeds that emerge later and then minimize any escapes that we can hopefully control with post-emergence herbicides. This is a picture of a farmer farmers field where he applied Valor in the fall in just the center strip and outside of that strip you see COSHA dominates the field. This shows that a fall Valor does have enough residual to control COSHA in the spring. We've seen this with multiple studies as well as farmer experience. It isn't 100% though. We don't rely on a fall application to give a season-long COSHA control. Here's another picture from Tom Gardner with Valent where they applied Valor in 2-4-D in the fall. You can see on the left the field is much cleaner than on the right. This is a study we conducted in 2018-2019 where we applied fierce. Now fierce is a combination of Valor and Zidua and if we look at this higher rate fierce plus Clifus-8 this was six ounces plus 32 ounces of Clifus-8 this was applied in the fall. By May 14 we still had 97% control and by July we still had 82% control where we had fierce followed by Spartan charge in the spring. So four and a half ounces of fierce in the fall followed by five ounces of Spartan charge in the spring. We essentially had a clean field the entire year. Now I wish we could say that this happens every year but it does not. I have shown this slide to many of you and what this slide shows is tank mixing AMS and MSO with group 14 herbicides enhances immersed COSHA control. So our group 14 herbicides would be Sharpen, Spartan, Valor, Thorady MTZ is a Spartan metribusin and here is Spartan, Sharpen and then Spartan charge which is Spartan plus AIM. So in each of these pictures it shows that when we tank mix the group 14 herbicide with AMS and MSO it provides much better control than the herbicide by itself. Those were greenhouse pictures now let's look at some field pictures here is Spartan charge plus MSO on this side compared to glyphosate plus AMS over here. This was a glyphosate resistant population. On this side we have authority MTZ plus glyphosate plus AMS plus MSO compared to on the right Zidua plus glyphosate plus AMS. Again I wish these herbicides were this effective all the time but unfortunately they are not. So fall applications we want to consider Valor. Valor generally has provided good COSHA suppression but we don't always see it so I want to call it suppression rather than control. Want to mention that Spartan and metribusin which are very effective herbicides but they've been less effective in the fall in my experience than in the spring. I would rather see these herbicides applied in the spring. We still can get control with saunan and prowl which can reduce COSHA densities. With spring applications again Spartan has been more effective than Valor in the spring. Spartan and metribusin is a good combination because it gives us two different modes of action. Authority MTZ is a premix of Spartan and metribusin and these have generally been very effective in the spring but of course even more effective if we have adequate rainfall. Another combination that has worked well is grimoxial plus metribusin in a burn down which unfortunately provides much better control on small COSHA than larger COSHA. We might be able to under some conditions still get control of three inch COSHA but we have seen much better control of smaller COSHA compared to the large COSHA. Some different options and this is not an all-inclusive list of options for spring burn down of COSHA. Roundup alone generally isn't going to do it for us so we need something else in the tank such as a Roundup plus Sharpen, Roundup plus Spartan Charge, Roundup Spartan metribusin or Authority MTZ, Grimoxial plus metribusin. These are some options for spring burn downs. Now one of the things that I've noticed or some of the things I've noticed with COSHA is I've tried to determine what's going to influence better control. Definitely smaller COSHA. When the COSHA is smaller generally see more activity on those plans. Also higher temps. I know you can't control this but generally we see better COSHA control when we have warmer temperatures. Good soil moisture, not drought stressed. We've seen that when plants are drought stressed we don't get as good a burn down. Sunny conditions definitely help and then of course we need some rainfall afterward to activate these soil applied herbicides. So these are some things to consider for burning down COSHA starting with reducing the COSHA population through fall applications and then using some effective herbicides in the spring. Hopefully on smaller COSHA warmer temps, good soil moisture, sunny conditions. Hopefully this will give you some help in reducing the COSHA population in your fields. If you have questions about any of this please feel free to give us a call. Thank you for your time. you