Marestail Problems with Doug Shoup

(Jim) Good morning folks, welcome to That’s My Farm, I’m Jim Shroyer your host and today we’re n the Agronomy Farm at Kansas State University and we’re going to be talking with Dr. Doug Shoup. Doug is an Extension Specialist and he’s going to be talking to us today about a pesky weed problem we have in our row crops and that’s Marestail. So, stay with us, we’ll be right back after these words.

Closed Captioning Brought to you by the Kansas Soybean Commission. The Soybean Checkoff, Progress Powered by Kansas Farmers.

(Jim) Good morning folks, welcome to That’s My Farm. I’m Jim Shroyer, your
host. And today folks we’re in luck because we have Dr. Doug Shoup, a colleague of mine. He’s the Southeast Area Extension Specialist but truth be known he’s kind of a weed specialist as well. And we’re gonna be talking about some weeds. Although, Doug, thanks for being here. (Doug) Yea. (Jim) And Doug although we are on a foggy day here in winter time, planting’s a little ways away, there are a few weeds that farmers need to be thinking about right now. And I’m thinking one or two and so let’s have it. (Doug) OK. (Jim) Let’s talk about those pesky weeds. (Doug) Yea, exactly. So, it’s really cold out today and you don’t think a lot about doing spray operations in the winter, but if you haven’t done any sort of burn down applications this fall, really we need to think about the next two months of getting the sprayer fired up and controlling a couple difficult weeds. One would be Marestail. (Jim) That’s the big one. (Doug) That’s the big one. And we’ve done a better job over it the last several years, but it’s very inconspicuous this time of year and if you don’t get it controlled say before the month of April, it can really get away from you and then it’s really difficult to control. (Jim) That’s for all the crops not just one particular; it’s for all of them. (Doug) Yea. (Jim) So, what makes Marestail such a problem weed? (Doug) Sure. It’s what we consider a winter annual. And so what that means is it will germinate in the fall for the most part. Actually we found out that it germinates pretty much eight or nine months out of the year. The only times it doesn’t germinate is in the dead of winter. But most of the flushes of weeds come up in the fall. And they’ll over winter, is what we call is a rosette. And so you’ll see thistles… (Jim) There’s a few right here at our feet. (Doug) Exactly. So, they’re really inconspicuous this time of year, low, they’re very prostrate to the ground. And then in about the first part of April, last part of March when the temperatures starts to warm up, the day lengths get a little bit longer, they’ll start to bolt, or they’ll shoot their seed stock up. And once that happens, they’re really difficult to control. So, right now they’re a lot easier to control when they’re at a smaller stage or at a rosette stage. We can use a lot of different chemicals and have really good efficacy, but it’s around April 1st timeframe that it gets really challenging. (Jim) OK. So, let me kind of summarize that. So, we need to be looking at sometime the month of March basically. (Doug) That’s right. That’s right. I like to tell people before they start planting corn that they need to start thinking about burning down all the ground that they haven’t already burned down in the fall so they can get that out of the way. And then they can start thinking about planting corn and then they can have the fields clean and then they can start managing for other difficult weeds, like pig weed that germinate later in the season. (Jim) We gotta take a break here in a second. So, folks stay with us. We’ll be right back after these words from our sponsors.

(Jim) Welcome back to That’s My Farm on this chilly morning. I’m Jim Shroyer and with us we have Doug Shoup. He is an extension specialist and he likes to work on weeds as well. And we were talking about Marestail. Cause Doug, has Marestail always been a problem? (Doug) Yea. So, not really. I’ve been in this job about seven years and when I came into this job Marestail was a really hot topic then. So, it’s a really difficult weed to control. One of the reasons that it’s been a fairly new weed problem to Kansas farmers is that we’ve reduced really Glyphosate to no till or reduced till operations. So when we were back tilling the ground two or three times really Marestail… (Jim) Four. (Doug) Yea or more, exactly. Marestail really wasn’t a big deal but this was a weed that really thrives in reduced tillage type operations. So, the folks that really have problems with Marestail are the ones that are no tillers for sure. OK. So, they’ve really learned the hard way how to handle controlling Marestail and they’ve done for the most part, a better job over the last several years. I think one of the newer type of tillages that we see that are getting really popular is vertical tillage, OK. And vertical tillage has some advantages. They chop up residue really well, they make a very nice seed bed. But one thing that some vertical till machines don’t do a very good job of stirring the soil very much. OK. And so when they have that kind of tillage operation a lot of weeds get through. They might knock a few out but so, the folks that do like a straight vertical tillage with minimal soil disturbance, they really have to treat that field like a no till field. (Jim) Right. (Doug) So then you have to start incorporating a lot of the no till type practices, fall burn down, early spring burn down or using herbicides that have a little bit more residual. Exactly, because we just don’t get the weed control with that operation. The other thing that’s been the one trend that’s really moved us to having a more difficult time controlling Marestail, the tillage side of things. But the other thing has been glyphosate resistance. And we’ve really relied on glyphosate a lot. (Jim) Just a tad too much. (Doug) Maybe just a tad too much. And we’ve developed a resistance. So, anytime you do put pressure on a weed species with a specific herbicide you’re gonna develop herbicide resistance. And so, Mare’s Tail resistance was first discovered probably in the early 2000’s in Kansas and then it really exploded over a lot of the part of the state. And one of the reasons is that it’s a wind blown seed, OK. So, you can do a lot of management in your own field, but this wind will carry seed miles and so it’s a really difficult thing to control locally. And so that’s really aided in the spread of glyphosate resistance. And really glyphosate wasn’t that effective at controlling Marestail even when it was susceptible, when it actually bolted. But when we developed resistance we really eliminated that tool from our tool box to control Marestail. (Jim) OK. Doug, we’ve gotta take another break here, so hang on. Don’t run off, we’ll be right back. Folks, now’s the time to go get a cup of coffee, we’ll be back in just a few minutes.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer and with us we have Doug Shoup and we’re on the Agronomy Farm in Manhattan. And on this cold foggy day, my ears are getting a little chilly here. (Doug) My nose is running too, so… (Jim) So, Doug, let’s talk about corn cause that’s the first thing that farmers are gonna be planting here in a couple months, so let’s talk about Marestail control in corn. (Doug) Sure. OK, so the… like what we mentioned before, the goal is we need to control Mare’s Tail when it’s small in the rosette shape. It’s just easy to control now. Fortunately we have a lot of great options for herbicide use in corn. (Jim) Now, are you talking the whole thing or for the first burn down? (Doug) Just for… really the whole gamut, from the burn down all the way in through season, we have a lot of really nice options, OK. And so the easiest option, the option that I’ve liked the best, Kansas is really unique, we have a label for fall applied Atrazine, OK. And just really small rates of Atrazine. Now you could probably get effectiveness with a half a pound of Atrazine in the fall. So, you know, we don’t need an excessive application but three-quarters of a pound will do a lot of good, OK. And so when I say fall applications, really it’s a nice opportunity after producers get done with fall harvest through the months of November, even easily into December, we can still get really good control. So throwing a half a pound to a pound of Atrazine out in the month of November and December we really get almost 100 percent Marestail control. (Jim) And of course some other things that may be coming in too. (Doug) Exactly. So you know we’re standing in a field here of old soybean residue. There’s a lot of henbit out here. So, fall applied Atrazine gets a lot of the mustards, henbit, does great on Marestail and a lot of our winter annuals. (Jim) But we’re past November and December. (Doug) We are. We are. And you know there’s almost a no man’s land, couple months in here in January and February where rarely we have a really good time to spray, so really the next step is OK. In the month of March, definitely before I start thinking about planting corn, we need to get our burn downs put on. And again, Atrazine even in the month of March is really effective as well. (Jim) Again, will you use the half to three-quarters rate again? (Doug) Yea, and actually if we’re in the month of March, we’re close enough to corn planting time in most of the state that I would just… if you wanted to put a heavier rate, we’re allowed two pounds of Atrazine a year, what we’re allowed to us use, I would be fine with using that rate in the month of March. Just be cognizant of later herbicides you put on later, you have to stay under that. Kansas restriction. (Jim) Right. That total two pounds. OK, so let’s continue then. If you’re applying some here in March, how long is that gonna carry you? You alluded to it there. You can go with a higher rate with other things but… (Doug) Well, for Marestail control it of course depends on the weather and it depends on soil type, how long Atrazine’s going carry you. (Jim) Right, ph. (Doug) But what it’ll definitely get us past that April flush. OK. And so, if Mare’s Tail gets away from us, if it starts to bolt, then we need to look at other chemicals in corn that work really well. There’s a lot of bleachers that work excellent and there’s also some growth regulators that work excellent like Status is one that comes to mind that works really good, it’s a Dicamba product. (Jim) Hang on, we gotta take a break here. (Doug) Sure. (Jim) Folks, let’s take a break. We’ll be right back after these words.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer. We have Doug Shoup with us and we’re talking about weed control and we talked about corn. So Doug, let’s talk about two divergent crops here. Let’s talk about grain sorghum and wheat. Marestail control in those two crops. (Doug) Sure, let’s start with grain sorghum cause we just talked about corn because they share a lot of the similar herbicides and actually the spectrum of chemicals they use in sorghum has shrunk considerably compared to corn. (Jim) Right, right. (Doug) But still we’re allowed to use Atrazine, OK. And again that fall burn down is the perfect time to even… fall burn down is the perfect time to use Atrazine ahead of sorghum as well. OK. We do typically plant sorghum a little bit later. A person could actually have some flushes get away from you but again we can use some growth regulator herbicides in crop that might not work very well, but they should provide a little bit of control. OK, things like 2,4-D and Clarity. Another product that’s fairly new in sorghum production’s been widely used actually over the last couple of years is Huskie and that is a bleacher herbicide that we can get very good control with post emerge. So Huskie actually works really good on Marestail, even after it’s bolted in sorghum. Now with wheat really the Marestail itself is not very competitive and so we don’t really want to control… we like to control weeds right, but it’s not really costing us a lot of yield loss, but the one thing that is important is controlling Marestail in wheat, because if you don’t control it and then you have a problem in the fallow. Or folks that do double crop. Double crop milo… (Jim) It’s gonna hurt you down the road. (Doug) Exactly. And so again, that thing will germinate with wheat in the fall. It will survive through the winter and then it will start to bolt, as the wheat starts to joint and get a canopy going. (Jim) Right. (Doug) So, things we can use for Marestail control in wheat are Finesse, a lot of those SU type herbicides- Glean, Ally, Finesse. They work very well. The other thing is again Huskie, actually was the product that I just mentioned on sorghum but it was originally released for wheat. (Jim) For wheat. (Doug) And so it has a really nice fit for that. And there’s a nice flexibility window when we can actually spray Huskie or Finesse in the spring. The wheat can actually get some pretty decent size on it, just as long as it’s not in the boot stage or there’s no flag leaf showing, there’s a nice window of application time. And we can get really good control. Finesse probably will work better in the winter when it’s in rosette stage. And Huskie is really kind of a rescue treatment if it gets away from you. (Jim) This time on… basically February, March. (Doug) Huskie we could probably even use into April and… (Jim) That’s kind of revenge isn’t it? (Doug) That might be a fault. (Jim) At that particular…. OK. We’ve got one more crop to cover and we’ll talk about soybeans after we take this break. Folks, stay with us. We’ll be right back.

(Jim) Welcome back to That’s My Farm. We have Doug Shoup with us on the Agronomy Farm here and we’re still talking about Marestail. Cause that little pesky critter. And we need to talk about control in soybeans. So, what do farmers have in their toolbox? (Doug) Sure. And that’s the most important crop really, that we’ve had…at least the most difficult crop that we’ve had time to control Marestail ahead of, OK. And so again, just like what we mentioned with the previous row crops, fall burn down is the best. Right? And really again cause it’s so small we can do a really good job with, I still like to have Round Up in it, Glyphosate in it, cause there’s a lot of other weeds that Glyphosate does a good job on. But something with a 2,4-D or a Dicamba product in it, those growth regulator herbicides we can get really good control in the fall. (Jim) Again, in that November, December time frame. (Doug) Yea. Exactly. So but you know we can’t use Atrazine of course ahead of soybeans but it’s been a… that’s a really easy, flexible…there’s a lot of other options too. There’s some sulfonylurea type herbicides, but just a straight 2,4-D or Banvel plus Round Up works really well. Now, again as we enter the spring and it starts to bolt, that’s when it become really difficult to control and so again, you can still get some control sometimes with 2,4-D and Round Up but the problem is when you’re using 2,4-D and Banvel, and you get closer to the planting window for soybeans there’s plant back restrictions. (Jim) Oh sure, sure. (Doug) Exactly and with Dicamba products a lot of ’em, it’s a 30-day residual that you can’t plant soybeans and it’s a pretty significant deal. So, that gets producers a little bit jumpy on what product to use. And so then as you get closer to planting time you have to switch your product up. (Jim) But still we’re talking about March for the burn down in the spring. (Doug) I would still consider March time, we can still kill it with a 2-4-D and glyphosate. But I’m thinking more as we get into April if you let it slip away from you and as you move into April and you have Marestail and it started to get knee high, hopefully it’s not that high or at least boot top high then that could be a problem. (Jim) OK. Well, let’s continue some of the later herbicide application closer to planting time. (Doug) Sure. OK, and so then planting windows become important as you get closer to planting time so then you have to start focusing on herbicides that we can still get good control of, big Marestail they don’t have plant back restrictions. Sharpen would be one that can work. Sometimes it can be a little inconsistent, but Sharpen we’ve had some success with a Sharpen product. It’s a burn down, burner type herbicide so you’ll need high gallonage and MSO additive. One that we’ve had the best luck with has been Liberty really. And Liberty you hear of and Libertylink crops, but Liberty had been a really good herbicide for us taking down really big Marestail. Again, it’s a contact herbicide. High gallonage is going to be important. Hopefully we don’t get into that problem, but that is kind of a rescue treatment. (Jim) OK, any others real quick? (Doug) In crop a Round Up and First Rate, we have found to be the best solution in crop if you’ve already planted it and you have big Mare’s Tail. It’s just really slow to work, but it’s our best product. (Jim) OK. Doug, I tell you what I really appreciate you taking time… (Doug) You bet. (Jim)…and then stopping by the Agronomy Farm and talking to us about Marestail. Folks, thank you for being with us and don’t forget next Friday, this same time another issue of That’s My Farm.

Closed Captioning Brought to you by the Kansas Soybean Commission. The Soybean Checkoff Progress Powered by Kansas Farmers.

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