Weeds AR Wild Episode 27 
Title: Wheat Weed Control
Date: November 23, 2021


Welcome to the Weeds AR Wild podcast series as a part of Arkansas Row Crops Radio. Arkansas Row Crops Radio, providing up-to-date information and timely recommendations on row crop production in Arkansas.

My name is Tommy Butts, extension weed scientist for the University of Arkansas System Division of Agriculture. Thank you for joining us again for another episode of the Weeds AR Wild podcast. Today we are going to be talking about wheat weed control. Joining me today is Dr. Jason Kelley, wheat and feed grains extension agronomist so we can hammer on a few different things dealing with our weed control in wheat and some other small grains and then answer some of the most commonly asked questions that we’ve already gotten this fall, so we just wanted to cover a few things there. So, with that I wanted to introduce Jason and actually I’ll just turn it over to him to hit on a couple of topics right off the bat with planting and fertilization and some of those things, so thanks for joining us today Jason. 

Jason: Alright. Well, thank you Tommy. It’s a pleasure to be here today. Yeah, wheat time, definitely middle of November here, where we are at right now, we’re about 80% planted according to the Ag Statistics Service and in reality, that may be a little bit higher than that number. I mean wheat, it always seems like the weather dictates the final planting date and that’s what’s probably going to happen again this year. I know there’s some wheat being planted this past week. We got rain a few days ago so we got some fields wet. I don’t know whether there will be some more planted or not, but there still may be some planted. So about 80% planted, which is probably about right on course where we normally would be. I know some of our soybeans were a little bit later harvested so that did delay some of the planting intentions a little bit this year.

Tommy: Just along some of those lines Jason, what’s it looking like our total acres of wheat is going to be this year? Are we up? I know last year we were kind of up. Are we up again this year, is it about the same as last year, are we down some?

Jason: Yeah, I mean you look at the grain prices. Grain price and weather dictates a lot of things on wheat planting. And last year it was up a little bit, still low from our historical acres, but last year we planted about two hundred and ten thousand acres which was up pretty good from the previous few years. This year, you look at the grain prices. I looked yesterday at the Memphis Markets there on the Mississippi River, you could book wheat for eight twenty-four I believe, so that’s a really high price. We haven’t had that type of price in ten plus years, so you think that good a price people would be wanting to plant, get some more wheat planted, but we’ll talk a little bit more about the fertilizer. Fertilizer taking some of the fun out of that. I think overall the acres probably be up a little bit. I’m getting a lot more calls this fall about wheat and so you know, will it be three hundred thousand? I don’t know, but I think it will be over two hundred thousand. 

Tommy: So just along those lines you mentioned the fertilization part of that, and I know we’ve been preparing for high prices for next summer for corn and everything else. What’s it looking like for our prices for wheat right now as far as fertilizing? Is it just as ugly? 

Jason: Yeah, it really is. I mean you know I think that’s the elephant in the corner. What’s these fertilizer prices going to do, and we all know they are going up, have been up dramatically So you know our wheat budget, fertilizer typically accounts for about 40% of that budget. So last year in our wheat verification program we spent close to a $100 an acre in fertilizer. So just automatically given the prices this year, if we did the same mixes, vary field by field, how much P and K fertilizer we’d need to put out, but you’re probably going to double those prices. So, you know, yeah, I mean going from $100 per acre for fertilizer to potentially 200, that’s, all of sudden $8 wheat is not really $8 wheat and so I think that’s what has tempered the excitement of wheat, just these fertilizer prices. So, yeah, I mean like always, $8 wheat sounds good but then you run the pencil to it, you still need to have sixty, seventy-bushel wheat to make ends meet. And I think most of our producers have the capability, seventy, eighty-bushel wheat if things go right and we place that wheat in the right field. Good weed control and a lot if things go the right way for us. So, you know, what can we do about the fertilizer and of course I know a lot of producers that they called earlier this year and ok, well the P and K, maybe I’m just going to plant and see how much, make sure I get a stand and I don’t have a soil sample and so you’ve still got time to go get some soil samples even though maybe you’ve already planted. The phosphorus we can apply that January, February even and still not be a yield drag on us. I’d rather do that. Figure out what kind of numbers you’re really looking at if you don’t know and then apply accordingly , not just a blanket, well I think this will get it covered, so trying to do some educated guesses there to save some money on phosphorus for sure. 

Tommy: That’s a good tip. Are there any other tips? I know I’ve already had a couple of calls on some thinner stands or maybe some a little bit weaker wheat. You know if we can’t spend all the money on fertilizer because there’s just such high prices, are there other things that we can do to try and either help our stand out or just increase the vigor going into the winter a little bit? Is there anything else you would recommend there? 

Jason: Well, I mean typically you know if we had thin wheat or late planted wheat, like I said there’s still some wheat being planted. Last week I planted some myself and so typically late planted wheat we would think about applying some fall nitrogen to help stimulate growth and tillering. Some years that makes a difference, some years it may not, depending on the weather and all that. If we’re following rice, we’d probably need a little bit of nitrogen to stimulate some growth there, but you know, I mean late planted, I would typically probably go ahead and plant. You know, make sure you got a stand before you put some nitrogen out there. A little bit of nitrogen, it is key. We don’t need too much. You know twenty or thirty units the fall is plenty. I had a producer the other day, he was concerned about availability of nitrogen come February, March, the normal top-dressing time and he had some available now and he was wanting to put some out. I said well you know, you can but from an efficiency standpoint yield wise I really don’t want to put too much fall nitrogen out. We can get more growth than we need and then when that plant really needs the nitrogen, that nitrogen may not be there. So I think from a nitrogen standpoint, you know, the prices are going to be high. We know that but I think spreading the risk out, maybe split applying. I can do probably just as good a yield with 90 to 120 units by applying timely, correctly vs even higher rates if I don’t have the time quite right. So spacing it out, applying based on growth stage is really pretty important.

Tommy: Perfect. I appreciate that. That’s good advice right there. Moving on from kind of the planting and fertilization side of things and jumping into the actual weed control portion, first thing I always want to talk about when it comes to wheat and really one of our main conversations anymore with a lot of our crops comes down to Italian ryegrass again. You know it’s ryegrass, ryegrass, ryegrass. It’s what we always got to hammer on. Right now we actually, Dr. Tom Barber does have a graduate student that’s working on some ryegrass projects moving forward, so hopefully over the next few years we’ll have some more up to date data and some more advice and recommendations going forward, especially with the resistance concerns across the state and then trying to optimize some applications. But right now where we’re sitting, we’re kind of making some educated guesses as what we’ve seen in the past. And I can tell you as far as the resistance goes, glyphosate and ALS resistance is pretty widespread. We see the ALS inhibitor resistance quite a bit across the board and it may not be as common as we originally once thought, but it’s still enough and it’s difficult to distinguish I guess the distribution of that I don’t typically recommend the ALS’s for ryegrass. It doesn’t seem to be a consistent recommendation I can make so I tend to avoid that. Glyphosate resistance seems very widespread. I’ve had calls from south of I-40, north of I-40, the river valley. Basically there’s glyphosate resistance in all of those populations that I’ve seen, so that’s pretty much out as far as ahead of planting. And I do know that Tom’s student has just recently found, this isn’t officially confirmed yet, and it’s not all completely done, but he does have some initial findings of clethodim resistance down in south Arkansas, kind of down around Lake Village area, down around there right across the Mississippi border basically. So we may have some ACCase inhibitor resistance at least already in the state as well. So I say all that to say especially burning down trying to get it killed ahead of wheat planting can be very tough. We’ve got to use things maybe like Gramoxone, lay down residuals. Residuals are super important because POST we just don’t have a lot of good options. Now again with the time of year that we’re already in, we’re kind of getting a little bit behind there. Hopefully our ryegrass either hasn’t come up yet, or we were able to get those residuals out, like Zidua. Zidua is my #1 option because it’s really good for ryegrass control and has a good residual length and I’ve just had really good control out of it. Now we typically do recommend that it’s applied delay PRE, that’s based on the label. There is a potential for some injury if it goes out PRE or sooner, so just be aware of that. But that is a great option from the residual standpoint. If we talk about things like Prowl, or even Axiom, and Axiom whether we spray it POST or PRE, those two are really more suppression herbicides to me than actual control. Ryegrass is real small, one leaf or so, Axiom might be able to get us some control there, but on the whole those tend to be kind of suppression type herbicides to me. So what it really boils down to as far as ryegrass is trying to kill it. Once it’s up it gets really challenging because we just don’t have a lot of options and really it’s Axial Bold from a POST perspective that we got. And I don’t know about you Jason, but my recommendation is typically, if we can, at all costs, avoid spraying the Axial in the fall and save it for our spring because we got to have something to either get a second flush or just to finish to crop out or anything else, so I typically want to try and save it for the spring, but if we’ve got absolutely nothing killed in the fall, we didn’t get rid of that first flush with tillage or anything else, we have a huge population out there, we may just have to bite the bullet and spray Axial in the fall, try and lay down some Zidua with it so hopefully it will carry us through to spring and go from there. But that’s not the best-case scenario. 

Jason: I think so too Tommy because you know if you got a lot of ryegrass and there’s some fields, I’ve had some calls as well that, ok, I intended to put Zidua out at planting or delayed PRE, it didn’t happen. It rained, it cooled off, now all of a sudden I have two leaf wheat and three leaf ryegrass that’s really thick so something like that. That ryegrass is really competitive so if you’ve got a lot of ryegrass, yeah you would typically like to hold onto that Axial Bold application until in the spring but with that much competition I think you have to go ahead and pull the trigger on that one just to take out the ryegrass because if you don’t you’re going to be losing a lot of yield just from competition all winter. And the Axial Bold also Tommy we just got one application per season so that’s I guess probably why we always want to hang onto that because that’s typically been our most effective herbicide for ryegrass.

Tommy: Yeah, that’s exactly right. And at least in my research it still does a really good job and I don’t think we have, at least not widespread resistance to those herbicides yet across the state in our ryegrass, even though we may have the DIM resistance in south Arkansas. With Axial Bold it’s not a DIM part of the ACCase group, it’s a PROP and a FOP I believe is the other one in there. Or pinoxaden so it’s a different one in there. Anyway, either way it’s not in that necessary same exact class as what clethodim is, so we still get some activity out of it for the most part. 

Jason: And I know in the past Tommy we’ve had some instances where we thought, ok, we didn’t think that Axial XL at the time was working very well, but you go out there and look and look at the misses, the escapes, well you know if you’ve got a plant that’s six inches in diameter and twenty tillers and it’s cold and not growing, you know, you’re probably going to miss some of that and so, and of course that leads to other issues, resistance issues anyway, but there’s some like you say that it’s got to be actively growing. Things are a lot more tender right now or even up to December than sometimes first of March when it’s cold and things have been hardened off.

Tommy: Yeah, that’s a 100% right. And that’s why we again, just to rehash that, our recommendation for ryegrass is get that first flush killed. Whether that’s through tillage, burndowns, laying down residuals, whatever it is, that’s the most crucial thing. If we miss that first flush, it’s going to be playing catch up and fighting it the rest of our wheat growing season and even going into next year, it’s just going to be there, so if we can get that killed out with whatever method there first, that’s the most important. And then if we missed it or we haven’t gotten it and we have a real bad thick population out there, then like we said, you probably need to shoot your Axial Bold shot but also lay down residuals to hopefully carry you next spring so you don’t have a huge flush in the spring then either that you have to deal with through harvest. 

Jason: So Tommy we got seems like a lot of questions on metribuzin here the last month or so. Great herbicide, offers some flexibility there. At this point, the 18th, or mid-November, we’ve got ryegrass up, we got PoAnna up, is just straight metribuzin, two or three ounces, is that going to be effective for us?

Tommy: That’s a great question Jason. I’ve had those same calls too. And for the most part, in the majority of the cases I’ve been called on, I said no. You know, it’s not going to be effective at this point. It’s too late in the game. Metribuzin is really a lot better as a PRE residual product than it is a postemergence product for weeds, so if our ryegrass and PoAnna is already emerged, it’s already a little bit behind the eight ball there for the getting the best control out of it and at this point on most of the calls I’ve gotten, the PoAnna’s already getting some pretty good size to it, the ryegrass is maybe tillered already, it’s just not going to work at that point. It’s not worth the money at least in that case. So that’s where I’ve been on that too. It’s a great product, just a little bit closer to planting when we don’t have stuff up, but right now it’s not in the cards to help us anymore at this point. 

Along the ryegrass side of things too, I’ve had, I don’t know about you Jason, but I’ve had several calls on some other small grains like oats and cereal rye and things like that. And there’s some herbicide options for those crops, but the vast majority of the herbicide options that are labeled are for broadleaves. There’s really nothing labeled to control ryegrass in those crops. And so there’s nothing that we can recommend or tell you or that can help with ryegrass management in those. We’re pretty much, if you’ve got those crops up and you’ve got the ryegrass already up, we pretty much got to live with it because there’s nothing that I know of that’s labeled. Is there anything on your end?

Jason: Yeah, no, I get the same questions as well and there’s more oats planted this year. I think last year there may have been eight or ten thousand acres, which was more than what you might think there would be, but yeah, I mean, people ask about ryegrass control on oats. My first recommendation would be find a different field. (laughing) But you know, we already got those planted, we got the ryegrass up, then yeah, we’re just out of options for ryegrass control there. 

Tommy: Cool. Yeah, that’s where I’ve been at too. I just figured it was a good conversation piece there to have. So, that pretty much hits on the ryegrass side of things. Like I mentioned, there’s limited options there at this point, so that’s kind of where we’re at as far as managing that.

The next weed that I’ve gotten a lot of calls on too is managing in our wheat is PoAnna or our Bluegrass out there. Now generally I’m not too concerned about PoAnna in wheat. It’s a low growing crop, it’s really not super competitive. Normally our wheat can grow up, get over the top of it and out compete it very easily, so in most cases I’m not super concerned with it. The problems come in as if the PoAnna density is very high, it starts turning into a blanket on us across there and then maybe our wheat stand was a little bit thin or we’re having some issues there. And so then it can be a problem and we might need to think about controlling it. But the first recommendation I always make is double check it and make sure you know just how bad it is. If it’s only a couple of patches, if it’s not really a blanket, if your wheat stand is actually fairly decent, then I really wouldn’t worry too much about the PoAnna at that point, especially from an economic standpoint, but if you are in a scenario where it’s real bad density, you’ve got weak stand, then you might need to consider some methods to control it a little bit. Now the best one that I always lean on first is probably Osprey. It’s one of our best recommended ones from a POST perspective. Now the metribuzins to Axioms, things like that, have pretty good activity on it PRE, or also as a, like if it’s real small, just one or two leaf, those can be good options there, but the calls I’m getting now, it’s no longer that size, it’s bigger, there’s more concerns now, so I tend to lean Osprey route at that point.

Jason: I think so too. Because it’s just, the PoAnna, if it’s got tillers, even though maybe it’s half inch tall or an inch tall, it looks fairly small, but if it’s got tillers it’s going to be pretty tough to control. Even a higher rate of metribuzin.

Tommy: Yeah, 100%. And the Osprey actually does work real well on it. The one major thing I like to tell people is to double check that label because Osprey does have some pretty specific requirements as far as adjuvants and fertilizer carrier and things like that. So double check those recommendations and if you apply it accordingly it should do a pretty darn good job on that PoAnna out there. 

Jason: Yeah, and Tommy I agree with you too on the wheat. If you’ve got a good stand of wheat and the wheat come up and got ahead of the PoAnna, I’m like you, I don’t see typically a need to spray it. The instances and I’ve got a few calls this year where maybe they planted no-till or stale seed bed and maybe didn’t get that burned down out ahead of planting and all of a sudden, we got PoAnna up ahead of the wheat, so in that instance I think it can be fairly competitive in combination if you’ve got a poor stand. One thing we’ve also seen in the past is geese feeding. So the canopy whether it’s corn, soybeans, anything, wheat, can end up having a good thick canopy is good for weed control. So our problem sometimes in wheat is the silly snow geese come in and they mow off our canopy and that PoAnna that was shaded out, being competed with pretty well, all of a sudden it comes back alive. So there is some that probably gets sprayed maybe because of the geese feeding. 

Tommy: If you’ve got a problem out there with snow geese feeding on your wheat, give me a call because I’ve got plenty of friends in Wisconsin that keep calling me about going snow goose hunting. So we’ll come down and take care of it for you, let me tell ya. Just give me a call. 

Jason: I don’t know Tommy, there may not be any ammunition left. I hear of all these ammunition shortages.

Tommy: That’s also a good point, so maybe it won’t work, but hey, just give me a call and we’ll try and set something up for sure. So moving on from our ryegrass and PoAnna, which tend to be our two worst grasses in our wheat crop out there. We also can have some broadleaf problems, you know and stuff like buttercup, vetches, all kinds of ranges of different broadleaves that pop up there. Mayweed, things like that. Typically I’m of a mindset that I’m not super concerned with those broadleaves in the fall. I normally want to save my broadleaf control measures for the spring and take care of them all in one application. And there’s normally several different good options still for managing broadleaves out there. I see PowerFlex as a great option because it’s really a broad-spectrum type herbicide. It can get a lot of different broadleaves under control with just one herbicide which is helpful. If you have a really bad henbit or horseweed problem out there, Quelex is probably our best option there. Quelex does a great job at managing those couple of weeds. Harmony Extra and Peak are also a great options for a variety of different broadleaf weeds and will also help us with our wild garlic or wild onion if you have a bad problem with that out there. Those are some good options there. The one note I wanted to make though with Peak is that if you do apply that, especially in the spring, even in the fall it’s still not going to work, but you won’t be able to double-crop soybeans behind your wheat crop. The plant back after Peak to soybeans is ten months and so it’s just not going to work for that plant back if you do apply that to try and double-crop our beans. Even with STS beans the label is still ten months. STS beans, non-STS, it doesn’t matter. It’s still ten months you are not going to be able to do that double-crop, which is a little bit of a hindrance, so that’s a little bit of a problem there. 

The other thing that we wanted to mention too is there has been some instances of ALS inhibitor resistant Mayweed around. The PowerFlex, the Harmony Extra, the Peak, all those that I talked about, those are all ALS inhibitors and so if we have some resistance in our broadleaves out there on those, we need some different options. Well again, we do have 2,4-D in the spring that can be a great option at hammering a lot of these broadleaves. Quelex is not an ALS, it’s another growth regulator, so that can be a good tank mix partner. Dicamba I know is used out there a little bit as well, so that can be an option. And maybe do some mixes of these different herbicides as well to get a more broad-spectrum approach. There’s several different options that are available to get our broadleaves under control and like I said, I typically recommend to save those in the spring application and hit them then. Did you have anything different there?

Jason: Yeah, no I agree Tommy. I mean you know before long it’s going to be getting cold and things are going to be shutting down so those spring applications a lot of times those broadleaf weeds aren’t that competitive unless like you say you’ve got a thin stand or some other reason there, but yeah, I mean, one pass maybe you got some garlic or onion, maybe it’s up and going, probably spraying it now wouldn’t do you any good. So, yeah those spring applications make the most sense and yeah, the one that we’re finding more and more is that ALS resistant Mayweed population. I know there’s some around Brinkley, over towards Marianna. Some of my plots a couple of years ago we sprayed some and you know, February I think we sprayed Harmony and about two weeks later we went back and it’s like, man, I don’t think they sprayed this. (laughing) But then you get to looking and there’s one dead and one right next to it is pretty healthy, so adding some 2,4-D, the Quelex, some other different mode of chemistry in there is what we really need on some of these populations.

Tommy: Yeah, perfect. That’s just good resistance management anyway. Just trying to get away from some of the same mode of action every time. Get something else mixed in there, that’s just a great option anyway. From there, those were the main weeds I wanted to chat about. Are there any other weeds or different things that you wanted to mention in there Jason?

Jason: No, I mean you know like I say we always talk about it, but we’re talking about broadleaf weeds or ryegrass, I mean all these, they need to be growing. So if we delay our applications until February or March, if it’s been cold and things aren’t growing and we get one day of 70 degree temperatures, that’s really not enough to get going. So I always like to say, well, it’s been a week of warm weather and specifically warm nights, things start growing better, you’re probably going to get a little better weed control with that instance instead of one day at 70 degrees, things aren’t very actively growing yet. 

Tommy: Excellent point. It’s always good to always bring that up and remind people that as we get into these winter months that that’s really critical to help with our weed control.

Jason: I think the weather is an issue Tommy and you’ve gotten some calls as well. This supply chain disruption, I mean I’ve gotten several calls this fall, ok, well I wanted to use Axiom or whatever product it would have been and we can’t find it. We can’t get it. Someone the other day, they wanted some Osprey and if I remember correctly, they said it was going to take two weeks to get in. Well, you know if you’re wanting to spray something tomorrow, it’s going to take two weeks, that’s really not an option. So unfortunately, wheat products, probably even our spring crop protection products, we’re going to have to do a little ahead of time planning to figure out what we need and not just last minute. 

Tommy: Yeah, I just want to reiterate that point, is making a plan. Let’s get our plan in order and if we can’t follow through with a plan, that’s one thing but at least have it in order, maybe have a back-up plan. Have some different things there kind of in the works so we know what we’re doing because right now with them, like you said, the supply chain issues, we can’t just go pick stuff up anymore and have it readily available and spray that same day. It’s just not going to happen. I’ve heard the same herbicides, Axioms tough to get ahold of. I know last year Osprey was real tough to get their hands on and so I’m just assuming we haven’t really improved our supply chain over the past year, so I’m assuming Osprey is going to be tough. I think PowerFlex was in short supply last year too, so it may be in short supply again this year.

Jason: Part of our problem if we don’t have a lot of acres, the retailers don’t want to bring in a lot of product that’s not going to get used, so that’s another issue we’re fighting. 

Tommy: Yeah, 100%. So basically what we can say is just try and make a plan. Have a rough idea, from field history, what you’ve maybe dealt with in the past and try and start putting some of those orders in, even if you’re not going to use it until the spring. Say you want the Harmony, and you want Axial in the spring, well if you know you’ve used those in the past, you know you have those problematic weeds, try and start talking to your retailers now see if you can get it on the books or get them working on getting it in so you have it in the spring kind of thing. The more planning we can do, the better off you’re going to be. With that Jason, was there anything else that you wanted to hit on? Any other topics? I think that pretty much covers it.

Jason: No, I think that covers it. Like I say we’re, I think this year’s going, 2020 was challenging, 2021 in many ways was more challenging, so I think it’s going to be another challenging year in many ways.

Tommy: Got to keep everybody on their toes. That’s right. That’s just what we’ve got to do anymore.

Well I did just want to say thanks to all of our Arkansas commodity board funding out there. All of that commodity board funding that we’re able to receive goes a long ways to contributing to the different research that drives our recommendations that we discussed today, but as well provides a lot of Extension opportunities such as the Weeds AR Wild podcasts where we can get some of this information out to you. So I just want to say thank you to the checkoff dollars and all those commodity boards that help distribute those funds to us. With that I really didn’t have anything else to hit on, so I just wanted to say thank you to Dr. Jason Kelley for joining us today and then thank you again to all our listeners out there and continuing to support the podcast series here. If you ever need anything please don’t hesitate to reach out to Jason or I. If you have any more wheat questions just let us know. So once again thanks for joining us for this episode of the Weeds AR Wild podcast series on Arkansas Row Crops Radio. 

Arkansas Row Crops Radio is a production of the University of Arkansas System Division of Agriculture. For more information, please contact your local county extension agent or visit uaex.uada.edu.