Weeds AR Wild Series, S3 Ep5. Wheat and Corn Updates (4/18/23)

Weeds AR Wild Series, S3 Ep5. On this episode, Dr. Jason Kelley joins Dr. Tom Barber to discuss wheat issues, corn planting progress, replants, and weed control options.

Transcript

Weeds AR Wild, Season 3, Ep. 5

[00:01] Intro/Outro

Arkansas Row Crops Radio: Providing up to date information and timely recommendations on row crop production in Arkansas.

[00:11] Tom Barber

Welcome to the Weeds AR Wild podcast series as part of Arkansas Row Crops Radio. This is Tom Barber, extension weed scientist with the University of Arkansas System Division of Agriculture. Today, I'm very fortunate and happy to have Dr. Jason Kelley, extension corn and small grains specialist with the U of A Division of AG here with me on the podcast. So welcome back to the Weeds AR Wild podcast series Jason.

[00:34] Jason Kelley

Well, thank you, Tom. I appreciate you having me on today.

[00:39] Tom Barber

Well, it's springtime is here. I think this week we might be doing a little farming. I'm not sure. What do you think?

[00:46] Jason Kelley

Yeah, I think so. You know, I mean, across the state, I know we got a lot of variation in rainfall and temperature in the last few weeks, but, you know, I was talking to several people in northeast Arkansas yesterday, and, you know, a lot of them are about done planting corn, done planting rice. And then you got other areas of the state which got a lot of rainfall or have had had more rainfall the last couple weeks that really hadn't got started much. So, yeah, every year’s different. This one is no exception.

[01:18] Tom Barber

That's right. I don't know what you know, we talk about it all the time. I don't know what an average year is, but, you know, it's kind of flip flopped on our planting progress. Usually, northeast Arkansas is a little bit later to the game. And like you said, it's crazy to me. In the matter of five or six days, we can almost have this crop planted.

[01:36] Jason Kelley

Exactly Tom, I think so. I think there's a lot of things going on. Of course, of course the equipment, gosh, I mean, we can get over the acres really quickly. And, you know, last fall was really dry. So a lot of those fields were prepped last fall. So, so when it got time, this spring it’s just a matter of dropping in and going instead of doing a lot of tillage work. So I think that’s really helped speed up planting, especially in northeast Arkansas.

[02:03] Tom Barber

Well, I agree, and I'm not going to complain. I mean, we've been able to get out at the field there at the Jackson County Extension Center there at Newport. We've been able to get out on that research station quicker this year than we have been, in I don't know when, I mean, this is one of the earlier starts we've had, so I'm not going to complain. I like it. You know, I know we've got a small chance of rain coming in Saturday, maybe, or over the weekend. And so by then we're going to have a lot done, though, I think in the.

[02:30] Jason Kelley

Yeah, I think it'll be interesting time. I know you know, we always talk about well we're going to plant corn first, rice, soybeans. You know, in a planting order. But you know, there's so much that's gotten planted in the last ten days, two weeks, and in northeast Arkansas. And of course, it's all going to be ready to harvest about the same time, right?

[02:48] Tom Barber

At the same time. Yeah. We might be wondering why we did that come August.

[02:54] Jason Kelley

At the end of August or early September. Yeah, yeah, yeah.

[02:59] Tom Barber

Well, let's, let's dig in here. And I know corn is going to be a main focus of our podcast today, but real quick, let's, let's touch on wheat. I know we've both been getting some questions on wheat and you've seen I think, you want to touch on some issues you've seen with the cold weather and anything else going on out there in the wheat crop.

[03:18] Jason Kelley

Yeah, yeah, we do have some issues, Tom, and I think, you know, we've got a few more acres this year. I think they the latest mass crop estimate was estimating about 230,000 acres. So acreage is up a little bit. And so that may be part of the reason why portion calls. But yeah, we've got several little things going on. I think back in mid, mid-March, we had some low temperatures, a freeze that that did cause some concern and we are finding a little bit of freeze damage even north to south. I mean, we've had some freeze damage in Greene County up at Paragould. I was down Ashley County earlier this week, had some freeze damage down there. So wheat, wheat in a late freeze is always a concern. And, you know, the wheat that's always further along always seems like it gets the freeze damage. And so you know looking around, I would say most of the wheat, we don't have that much freeze damage in. But you know, those early varieties that that take off a little bit early, those are the ones that that got hurt a little bit. And so, you know, any time we're in the boom stage or, you know, close to that reproductive, sensitive reproductive stage, you know, 28 degrees, somewhere in there. And then we had some areas colder than that and maybe a little bit warmer. But, you know, we were seeing some damage there. And of course, you know, it's easier to see a month after the event seeing some white heads, some dead heads week after that happen. And it's pretty difficult to really, to diagnose what's going on. But as time goes on, it is becoming a little more evident that we did have some freeze damage out there.

[05:01] Tom Barber

But what do you expect on yields when you see something like that? Is that something that's easier, easy to recover from, or are you just, you know, know you're going to take a little yield hit on it?

[05:11] Jason Kelley

Yeah, I mean, you just you know, the further along it is, the plant has less ability to compensate. So if you get your heads already out and you lose a third of those heads, you know, that plant just doesn't have a way to compensate. So yeah, unfortunately that, that's the way the freeze goes. And yeah, I mean there are some yields are going to be off a little bit and you know, I was over at Marianna the other day looking at a variety test and I had some early maturing varieties that had, I don't know, 50% damage probably, and then a plot right adjacent to it later maturing had zero damage. So, you know, selection's pretty, pretty important in wheat.

[05:54] Tom Barber

Yeah. So it's just all a matter of how lucky you got I guess.

[05:58] Jason Kelley

Planting date, maturity. Yeah, well, that's very important.

[06:04] Tom Barber

Well, and I know we both are, really, but because we've shared some pictures back and forth. But as usual, during our typical burn down window, you know, there's always the random glysofate drift, pictures here and there. And this year's probably no different with that. And so I do feel a little bit better, you know, being able to recover from glyphosate drift, I think. But it, it all just depends on how heavy that drift is, I guess. And that rate that, that, you know, gets onto the wheat crops.

[06:33] Jason Kelley

Yeah. And that's the thing, I think we've got a lot of pictures and everybody wants to know what, what's the impact on yield. And you know, that's really hard to say. But you know the, how much when, when the drift occurred and I think a lot of it was probably, what, a month ago?

[06:48] Tom Barber

Right. Yeah, yeah, yeah.

[06:50] Jason Kelley

And so, you know, the plants got a little bit of time to metabolize that. But, you know, a lot of times the short flag leaf, twisted up flag leaf, that's pretty indicative of a, of the glyphosate drift. And, you know, I've seen some wheat that looked fair, had some symptoms and cut really good. And then I've had some that, you know, a little bit later on had, you know, probably more yield damage than what I thought there might have been.

[07:16] Tom Barber

Right. And, you know, that's just no way to really guess that. But like you said, going back to that flag leaf, if we start stunting that flag leaf, making it short and messing it up, I mean, that's, we're affecting that flag leaf significantly. I feel like we're losing, losing some yield in those situations. So just based on my experience. Alright, what else in wheat do we need to cover?

[07:40] Jason Kelley

You know, quickly, Tom, I mean, I get questions on diseases, foliar diseases, and I've been telling everybody, you know, glyphosate drift, you know, some gramoxone spots. I get, get a few calls on those. But you know, stripe, rust leaf rust, we haven't found any in the state. I saw some information in Louisiana the other day that they hadn't even found these stripe rust. So, you know, so far the foliar disease levels have been very, very, you know, nonexistent. We do have some septory out there, but really, that's, that's the only foliar diseases we're seeing right now.

[08:15] Tom Barber

All right. So fairly light disease years out. Yeah. Maybe we can escape that.

[08:20] Jason Kelley

Yeah, exactly.

[08:21] Tom Barber

All right, well, let's move on into the spring and summer crops. Let's talk corn. What, what are you hearing out there? What's going on?

[08:30] Jason Kelley

Well, you know, kind of the same scenario we talked a little bit about earlier, Tom. I mean, parts of northeast Arkansas have missed some of these rains and there's a lot of a lot of producers that are, are done or will be done by the time the weekend rolls around. So they've had a really good planting season. Everything's went pretty smooth. Further south you go, we get a lot more rainfall. And, you know, there some areas down there that, you know, southeast Arkansas and Southwest too is probably that, you know, four or five inches of rain this last round. And we got some corn we're going to have to replant, unfortunately. So. And, you know, I think that, that always brings around a lot of different questions. I know, Tom. I mean, how do we how we're going to go about killing that first crop if we have to replant?

[09:19] Tom Barber

Well, and I'm probably talking to the same folks you've been talking to. And so just to see if they get different answers, probably. Yeah, that's all right. That happens a lot. You know, I'll be right to the truck with Tommy and the same person will call us back to back. So it's fine, but it doesn't hurt to get as many opinions as possible before you make a decision. But yeah, and so I'm getting those as well. You know, the biggest thing in my mind when we talk about taking out or controlling a current spotty corn stand is coverage. You think about those little corn plants, you know, spike into one leaf. Uh, the number one thing I always ask, are you sure that you don't just need to wait longer and make sure more corn is not coming? You know, and I think, you know, in most cases, they have a pretty good handle on whether or not, you know, they're going to get a stand or if there's corn that just hasn't made it up out of the ground yet. But that's always the first check list item for me is just make sure we don't need to wait a little bit before we make the, you know, the call to take out the current stand. And, and the other thing, you know, we've talked about weather and some issues that may have caused some of these replants and the rain, the heavy rain. But I've been hearing birds too. Issue with birds pulling out the corn plant, small form sealant, corn plants and, and reducing the stay. And so whatever the reason may be, you know, the options that we have, we've got them in the MP44, Gramoxone not by itself. If you just spray Gramoxone by itself, you're not going to be happy taking out the corn stand that you have. So Gramoxone plus a PS2 inhibitor. In most cases. I like the metribuzin, it's just a little easier to work with. Three ounces of metribuzin with a quart of paraquat or Gramoxone is one recommendation that I make pretty frequently. The biggest thing on that, though, is coverage. Got to cover those small plants in order to take them out. We can reduce the rate of select max equivalent and use that and, and replant fairly quickly, but it just makes me nervous on a couple of different levels because select can cause some injury from a pre emerge standpoint to the corn. And then again we start reducing the rates and we mess up on coverage a little bit. We're not going to be happy with that. So I tend to like the quart of Gramoxone plus PS2 inhibitor like metribuzin as being my favorite option I guess. But uh, but, but we could, you go the select route if, if folks don't like that. And then like we talked before the podcast, you know, some just want to go out and knock the top of the beds off and take out the little seedling plants that way. And if, and if we can get low enough to get to that growing point, I think, you know, that can be an effective way as well.

[12:10] Jason Kelley

Yeah, I think that's, some of the fields I looked at earlier this week, Tom are probably going to be replanted. I guess the question is, you know, like what you talked about, I mean, there are still corn coming and, you know, I mean, you had 25, 26, 27,000 uniform plants. You know, I mean, in early April planted, I think I might tend to keep something like that. You know, you're down there below 20,000. And Skippy, you know, I think that may be a no and easy decision to make on replanting. But yeah, I mean, I think, I've seen some in the past that I probably would have kept and you know you get another rain on it and then you get, you're almost in the same boat as you were the first time just a month later. So. Right. But yeah, I think, you know, farmers that are wanting to replant sooner than later, you know, we got a rain chance coming in this weekend and, you know, got corn that's just spiking. I mean, I don't see an option for herbicide, using a herbicide to remove that stand besides tillage, would you Tom?

[13:13] Tom Barber

I don't. I think, you know from a, I've walked a lot of complaints behind either gramaxone or Select, would just spike and corn they're just not enough surface area to really get good coverage and you know, but I go back to what we just talked about a bit spiking to me, we haven't waited long enough to make sure we’re going to get that stand. You know, you don’t want to pull the trigger too early and get a, you know, too far ahead because like you say, you may have enough, you know, where the, you know, to hit that mark that you were talking about. 

[13:48] Jason Kelley

Well, yeah. So if you get going too fast and you're going to use Gramoxone and you replant and I've seen many instances as you as well, that first stand you get more plants there and what you thought you did and you didn't kill them and then you get a perfect second stand and then you get way too many, right?

[14:06] Tom Barber

That's right. I've had that call before, too. And so I, you know, I think we just, you know, hold the brakes, give it some time, make sure we're not going to get, you know, that stand of that population. Mark, what did you say it was? 20, 25,000?

[14:21] Jason Kelley

Yeah, I mean, you know, normally we're shooting for 30 to 34,000 plants. And, you know, a lot of these hybrids, I mean, you know, there's, there's a curve there. I mean, if you're 25,000, you're probably going to have a yield loss. You know, if you're closer to 30, you know, a lot of times you're hitting that plateau where, yeah, a few more might help, but what are you going to spend to get that that perfect stand? And, you know, early planting is beneficial a lot of times. So an early planted stand at 28,000, 27,000 could be better than a perfect stand planted two, three weeks later.

[14:57] Tom Barber

Right? Yeah. So there's just a lot of information to take in there. But I agree with you 100% on the spike in corn. If we're just can't stand it and we've got to, I think we need to start over. Oh, just shaving the top of that bed off to get rid of those populations is probably the best, best way to go where we can do that. So well, you mentioned anything on hybrid selection. I know. You know, really until we really get a little later in our planting window, I don't know that it even matters when we're talking about replants and hybrids selections.

[15:29] Jason Kelley

Like, Yeah, I mean, you know, I think if we were having these conversations in early May, then I might just, you know, maybe we'd have a conversation about, you know, changing hybrids something a little bit. But I think, you know, we're still in April, I mean, north to south. I mean, you know, even in far south Arkansas, April 25th is the deadline for full crop insurance. So we still got, what, 10, 12 days before we hit that. And, you know, if I had whatever hybrids I had lined up, I'm not changing my plans on hybrid selection at this point. You know, we had some studies last year, some really late planted corn. And, you know, those full season adapted hybrids is what, what probably gave us the highest yield in late planted. So, you know and that's probably typically what we're plant, planting anyway, so you know hybrid selection, I think I'm going to stick with what I got right now and letting, you know, I guess the one exception maybe was if you were going to have a, you know, some refuge corn, you know, hopefully we get you know, typically we'd like to get that planted first and then plan our stacked corn later on. That might be the only exception. 

[16:41] Tom Barber

Yeah, I guess. Okay. Well, good deal. One, one I guess pet peeve of mine and soapbox item lately has been on Italian ryegrass. And although I think you know this year we've done a lot better whether it was the fall weather that helped us or just the fact that, you know, farmers realized they really needed to get some residuals out this fall on the ryegrass population. Overall, I think we've done a much better job managing ryegrass as a whole. Now, there's still some problem fields out there. We still have issues. I get calls on it a lot, but when we move in to planting this corn crop, I've already seen pictures with corn coming up in a pretty full stand of Italian ryegrass out in the field and we're losing, you know, we're just planting into a losing yield situation when that happens. So we really need to make sure we try to kill that ryegrass or do the best we can to get something out there on it before we roll that planter out in the field, whether we're talking about corn or any of these other crops, really. But corn and rice especially, we can see a pretty substantial yield loss if we have a large population of ryegrass out there. So my recommendation this time of year for ryegrass is basically the same as it was to remove that corn stand. Paraquat, a quart of paraquat, a 3lb Paraquat ? , but a quart of that with three ounces of, of metribuzin dry equivalent metribuzin, is in my opinion, probably the best method to try to take that ryegrass out. The bigger the ryegrass is, the harder it's going to be to kill. But you know, burning it back before that corn plant comes up out of the ground will at least help us compete with the ryegrass plant. So it'll, it'll help to protect some of that yield early on versus just planting straight into it green. So I really think that, again, we've done a better job this year but still don't need to let our guard down. If we're planting into a pretty big population of ryegrass, we're, we're planning to lose some yield in those situations. But you know, along those lines, the other questions I get from a burn down standpoint would be horseweed or marestail. I've had several questions about that. I wasn't able to get the burn down out on the field for whatever reason. And so what are the best options there? And although supplies might be limited, Verdict, which is a combination of Sharpen and Outlook, but it's a different formulation than the Sharpen product itself, is very good on horseweed or marestail control. And so if we can put that out, we can put it with Roundup, we can put it with glufosonate or Liberty, actually Liberty, it might be a little better on the horseweed in general, but if we put those together, we can get a pretty good burn down program out ahead of planting this corn. And, you know, if you've got a question of whether or not, you know, if you lose your stand and you want to plant with beans, we need to keep that Verdict rate down to five or seven and a half ounces of Verdict. But usually in our work, you know, we can go seven and a half and replant beans, you know, within seven days if we need to. So usually we'll have that much time anyway to determine if we're going to have a corn stand or not. But in corn, you know, from a pre standpoint, it's really good, it buys us some time. And, you know, I really like the ten ounce rate of Verdict, but it can do two things. It can take away and go ahead and control our winter annual weeds that are out there at planting. And, and it can also give us some important residual control, you know, till we get to B3, B4 to put our, you know, mix herbicide combinations out, whatever that may be. So, you know, that's pretty much what I have for early season weed control. The other thing I'll say is now our general recommendation is to go out with the pre-emerge product, even if you don't have a winter annual vegetation in the field pre-emerge product, it can be as simple as a dual two magnum or s metolachlor. We can use, you know, something like Zidua. You can go out with a ? two magnum that has little atrazine in it. But, you know, usually we like to save our atrazine for in-season so we can get a little better activity on our morning glories and, and pigweed populations then. So, but we need something to get that corn off to a good start. We just talked about how fast the planters are rolling in the field. A lot of times we get ahead of ourselves planting and we can plant a lot of these faster and then we'll be able to go back and spray them. And so providing a residual will give us some time to get back and do some timely post-emerge applications and protect our yield again from early season weed competitions. So I don't really have a specific program early. We just need to do something and to buy some, you know, 2 to 3 weeks where we can get back in with our post emergence weed control program. And you know, Jason, I mentioned earlier, I was talking to Daniel Stephenson, my counterpart down in Louisiana this morning, and they have seen some injury because of the rain and cool weather down there with some of their corn premix products. And I think that's something common that we've seen from time to time. If we put a big mixture of corn herbicide out there, you know, like Acuron, Halex GT, anything that's got a lot of different actives in it from HPPD’s, group 15’s, like Dual 2 Magnum, glyphosates, atrazine. You know, we put a lot of those products together and it gives us extra weed control. But if we put it ahead of a big rain and cool conditions, that corn is just not able to metabolize those herbicides as well. And so we'll get a get a bleaching effect for a week or so. But most of the time, in the cases I've seen that we've seen that corn recover fairly quickly after that. So, you know, the only thing I'll also talk about from a weed control standpoint, I guess as we wrap this up, you know, there's been a lot of talk from a lot of, I guess, and social media and popular press about EPA restrictions moving forward on products like atrazine, as the re-registrations take place with the Endangered Species Act and so on and so forth, and just want to let everybody know that is still occurring. But for the 2023 season, we don't see any changes in the way we're able to use these products for 2023 or this growing season. So, you know, we need to stay on top of that and so pay attention to some things we put out later in the year, you know, fall, winter, we might have some different recommendations moving forward for 2024. But as of right now, we're not going to see any changes that I'm aware of anyway for 2023. So, Jason, what else we need to talk about? Well, you got any thoughts?

[23:56] Jason Kelley

Yeah. I mean, I think it's uh, I know, what you're talking about weed control, Tom. I know some, some people are, are done planting. Everything is going really smooth and I'm getting a few calls or how early can I put out my, my big or my main herbicide program and you know v1 corn, not 2 million is need to you know if you get something out there right now maybe even a shot of Roundup, a little bit of something just to keep that burnt back and you know main application two or three weeks from now v3, v4,v5 corn, would you agree?

[24:31] Tom Barber

Absolutely. That's the you know, that's kind of the standard plan is just to get something out there to buy us some time till we get to the, the v4v5 stage. You know, a lot of our premix products that's going to be close to their cutoff anyway. And so that, that's usually the goal or the target to hit. Now, if we don't get a residual out there and we don't, you know, we don't buy the time that we need to get to that point, I would not let the weeds grow until that point. We need to be out there a little earlier around v2, v3. You know, I don't like hitting Spike in or one leaf corn with just a slug of herbicide. But I mean, you know, that's why to me it's much easier on the corn just to put something, you know, a little out for residual up front. It seems to be easier on the corn than hitting it real early with a large pre mixture of herbicide. So that corn plant can tolerate the herbicide in my opinion, a lot better on that. v3, v4 growth stage. And like I said, by the time we get to v5, that's the cut off point for several products anyway. We do have a publication out there online that talks about herbicide cutoffs and all of you can Google it either just through, you know, the search bar or you can go to our website at uaex.uada.edu and type in herbicide cutoffs in that search bar and should be able to pull it up. But, but you know, that's going to be real close to our cutoff Tommy for a lot of these herbicides. And you know, the questions I get a lot not now, but later in the year are going to be morning glories. I get them every year. Uh, we have some problem fields out there that seems to be problems every year in corn. And the question is, what can I do to reduce, you know, these morning glories late season? And the answer for me is pretty easy. It's not popular, but it's easy. And it's the answer is drop nozzles. And I might as well, you know, it's about like flushing rice. That's a four letter word, you know. So nobody wants to flush rice. Nobody wants to use drop nozzles in corn because it slows us down. And it it's kind of a pain in the butt to put them on and that kind of thing. But if you really have a morning glory issue in corn and you're really serious about not having that issue this year, then we need some drop nozzles on the sprayer and we need to put some materials out below that corn canopy where we get good coverage of the soil. And it's going to have to be later in the season, you know, around that 30 inch corn mark or a little, you know, a little later or whenever we can still safely get over the top of it without tearing too much up. So, you know, putting that material down below the canopy, we can use more atrazine, we can use Callisto or more mesotrione. We can put some herbicide out to reduce some of those later season germinating morningglory plants. But until we're able to get those drops on there, I just don't see us really attacking this problem very well Jason, so

[27:40] Jason Kelley

Yeah, I agree.

[27:43] Tom Barber

But okay, well, anything we leave off?

[27:49] Jason Kelley

I can't think of anything Tom. I think everybody's rearing to get everything in the ground and get off to a good start this season.

[27:58] Tom Barber

I agree. Well, and you know, as we move along and most of you probably know both of us, you know, if you're listening to the podcast, but you can always contact your local county agent if you have questions on anything we've talked about today. They can, you know, they know how to get a hold of us and we'll be happy to answer any questions that you have. And I always say at the end of our podcast, I always welcome comments and feedback. We got a lot of positive comments from and feedback from last year. And if there's any hot topics out there that we're not discussing in the future, just send a note our way and we'll be hap, we'll be happy to try to tackle some of those topics, but you can always email me at @uada.edu for any of those comments, questions or, or topics that you'd like to see us cover. Well, with that, Jason, I just want to thank everybody for tuning in and I want to thank you for joining me today, taking time out of your day. I know you're trying to get around and get all your corn plots planted and we're trying to get started this week as well. And so everybody's busy. But I think it's important to just take a minute, sit down and talk about some of these things, because usually if one person's having an issue, it's an issue for a lot more people as well. And so I appreciate you being part of the podcast.

[29:23] Jason Kelley

Yeah, I appreciate it. Tom. Appreciate the invite.

[29:25] Tom Barber

All right. Well, we're wishing everyone a safe and successful start with the 2023 season. And thanks for joining us for this episode of The Weeds AR Wild podcast series on Arkansas Row Crops Radio.

[29:35] Intro/Outro

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.