The NDSU Extension weekly podcast In the Pod: Soybean Updates delivers timely insights and expert advice on soybean production.
You're listening to In the Pod, Soybean Updates, a weekly trek into the latest soybean information from NDSU Extension. Weed control in soybean may be even more challenging this year, according to Joe Ikley, NDSU extension weeds specialist. Joe, is there a particular weed that is the most challenging in soybean?
Joe Ikley:Even though it is January, the day we're recording this, there's a blizzard warning up north. And so what does that mean? Well, one of our worst weeds, kochia, is a tumbleweed. So there might be some of that blowing around. That's been our number one weed for a while now that we're dealing with. Very problematic in soybean. Primarily due to resistance to some of our most popular herbicides. Glyphosate probably being one of the biggest ones we think of. But certainly we have some more resistance to things like dicamba and we have resistance to our group 14 herbicides. So a suite of herbicides we typically like to utilize in soybean that kochia is finding ways to get around.
Bruce Sundeen:Joe, you mentioned dicamba. What's the big challenge this year?
Joe Ikley:Yes. So one of the biggest challenges is we've really utilized the dicamba or the extend Technology System since 2017 when that technology was launched. About this time last year, a court decision in Arizona vacated those labels. And that basically means that those herbicide registrations for and the products here are Extendimax, Genia and Tavium. Those products don't have a label right now, meaning we cannot utilize them. So one of our most popular products that we like to use for kochia control in soybean, not a viable option this year. And so that's kind of one of the big talking points this winter is what are we gonna do if we can't utilize dicamba for kochia control and some other broadleaf weeds as well.
Bruce Sundeen:Joe, can you explain how the label affects the use of dicamba?
Joe Ikley:The main thing is we have those three products, XtendiMax, Ingenia, and Tavium. They've been the only dicamba products with a label that says we can apply pre plant, pre emergence, or post emergence in Xtend or XtendFlex soybean. So, those three off the market, the older dicamba labels, products that we can still utilize this year in other areas, don't have a use pattern for extend soybean. And since that is not on there, we can't make a labeled application and the label is the law. That's why we can't utilize those older products in the same fashion we utilize XtendiMax and Ingenia.
Bruce Sundeen:What are the alternatives?
Joe Ikley:There are still options for kochia control, and part of that does start with knowing which resistances you have. For the most part, we're gonna have a baseline assumption of glyphosate resistance, so you're not gonna control your kochia populations with that molecule. Group 14 resistance is fairly widespread, but we still have plenty of populations not resistant to this group 14 herbicides. So what does that look like in a burn down situation that some of our popular products like Saflofenacil, trade name is Sharpen. If If you don't have resistance to that, still a very effective option for us in the burn down situation prior to planting. Otherwise, if you do have group 14 resistance as well, it does get a little bit trickier. So what's left for the burn down market for soybeans, we can still utilize Paraquat, Gramoxone being the main trade name. Still very effective on every population that we have tested. There are some risks with handling it, so some folks don't feel comfortable using it. But if you're comfortable using that product, one of the best options we have for kochia Control prior to planting. Then when we get into planting, that's when we really do have to focus on the use of residual herbicides. This often is older chemistry as well. We've highlighted metribuzin a lot over the past couple years. Still very effective on kochia. Older chemistry, but still very effective. So utilizing that is one of our core products that we're focusing on for kochia control, but blending in some other mixtures as well. So we always talk about tank mixes. There's things out there you can do like a metribuzin, a group 14 plus a group 15 like Zidua. Always wanna have a couple of effective modes of action in that residual. And the goal there is to really get us into the growing season, manage that early kochia that's going to try and germinate to emerge after soybean planting. And then, we need that effective post emergence chemistry. One of the biggest ones we're gonna utilize for kochia is glufosinate or Liberty being the main brand there. And so that is still also very effective. Folks that have utilized that product know there can be some variability based on the year. If it's a dry climate, that product does not work quite as well. So we need to have warm conditions, humid conditions, and sunny conditions the day of application to really maximize the efficiency of that product. It is effective, but we also need to have a little bit more consideration about when and how we apply that one to make sure we get the best efficacy we can out of that product.
Bruce Sundeen:Thanks, Joe. Our guest has been Joe Ikley, NDSU extension weeds specialist. You're listening to In the Pod, Soybean Updates, a weekly trek into the latest soybean information from NDSU Extension.