Title: Weeds AR Wild, Ep. 14, Early Season Cotton with Tom Barber and Bill Robertson (6-2-21)

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

Tom Barber: Welcome to the Weeds AR Wild podcast series as part of Arkansas Row Crops Radio. My name is Tom Barber and I'm an extension weed scientist with the University of Arkansas System Division of Agriculture. Today for this episode of the podcast we are very fortunate to have Dr. Bill Robertson, our cotton specialist with the University of Arkansas System Division of Agriculture, as our guest. This was a last minute decision on my part, so Bill, I really appreciate you joining me today and thanks for picking up the phone at about 7:30 this morning. 

Bill Robertson: You're mighty welcome Tom. It's always good to visit with you and help out on things. I can talk about cotton anytime man. 

Tom: Well, I'll just start by saying it's been an interesting cotton year to say the least. And I'll just kind of turn it over to you.

Bill: Oh yeah, it's just been crazy. If we look at the two previous seasons, I thought well we just can't get any later than that because our optimum window for planting is, we always think about the first ten days in May and the two years previous to this we were only half planted when we got to the middle of May. We planted half of our crop in the last half of May. It really looks like our weather patterns are shifting, there's things that are going on. Year before last we had more units in September than we did August, but the last two crops we've had have been #1 and #2 in our books and they've been the latest we've planted. Well lookie here Tom, we've got a crop that's even later than last year. Not by much but still later. In Arkansas I think we're blessed to have a lot of different options and fourteen dollar soybean makes a good option. We have a lot of people that are locked in and don't have a lot of options other than cotton. I think we're really fortunate, weekends before we are right now, we had two really good weekends in May, we got a lot of farming done and so I was very surprised we got, I think we got about all the cotton planted that we wanted especially on the eastern side. Over in Southwest Arkansas, it seemed like every time you turned around those guys were getting a rain and some of them that had just a very, less than a handful of days where they would be able to plant cotton. So there's not as much cotton planted down there as what people wanted but we got most of it in but it's really late. Now then here comes the kicker. Look at all the temperatures this last few weekends. Some places it's forecasted to be in the upper 40's in Northeast Arkansas. I'm in Poinsett County right now Tom looking at some cotton that I looked at late Friday and you know it turned off cold this weekend and all that and looked at it today and I don't think it's moved any whatsoever. So in the last three or four days this cotton isn't growing, so I think that's really making a late crop even later. We've got a lot of things that are compounding problems right now.

Tom: I was just going to say absolutely, I agree. I've been looking at our plots that we planted about that 2nd week of May, got a lot of ours in and that cotton did come up within seven days but then it's just sat there because the cloudy weather, the heat units and one location we even rolled out poly pipe thinking it was going to dry out so quick before we could get a good root system. I don't know, it's been a crazy year to grow cotton off that's for sure.

Bill: The last few years we get a one to two day window during a calendar week to plant cotton. And we got all hands on deck planting and then we can cover a lot of ground with our planters behind that but then we're so focused on planting, we got some tools that we think we have and then all of a sudden we don't have and so our weed control a lot of times suffers because it's just so hard to even get the seed in the ground. That's kind of what I'm seeing, is that what you're seeing Tom?

Tom: Yeah, this year it's been hard to get the seed in the ground and then it's even harder to follow that with a sprayer because the wind has been so crazy. There were several days where the winds were sustained above twenty mph, sunny days that we would love to have for spray days, actually some people did spray on those and now I'm going around looking at the damage crops because they sprayed during that time. But we've had very few days to plant and I'll go back and say we've had even fewer days to spray. I've talked to a lot of guys this week or last week that they got the crop planted but they just didn't get that residual out there and they weren't really worried about it at the time because they thought they had the June 30 cutoff date, well now that's something to question whether or not we can use dicamba now. Fortunately we can still use glufosonate on those acres, which in most cases we can get everything under control, but it's just been a roller coaster ride of issues trying to get in the field this year.

Bill: And then again like I said, Mother Nature's compounded these with the temperatures we're seeing. Right now we're barely getting into the 60's today, cotton's not growing. I think our cardinal low temperature, the temperature which you get below where cotton doesn't grow and that's 60 degrees Fahrenheit. What do you think the cardinal low temperature for pigweed would be? As long as it's above freezing it's going to grow? That's what it seems like.

Tom: Yeah I think this time of year if it doesn't get a frost on it, it's probably growing a little bit. Now you know when we get cool, like this weekend we had low's down in the 40's, which is crazy, Memorial Day weekend. There's probably not a whole lot of stuff's not going to be growing during that time. But pigweed definitely is a lot more hardy than cotton as far as the range of temperature. It can grow, so the questions I'm getting now, you know we may or may not have a free day either way, but now a lot of people are wanting to go over the top of this cotton with a lot of different herbicides in the mix, so I always get questions on how much burn am I going to get, how much can I expect, you know, and generally I don't like mixing glufosonate or Liberty with a Roundup if I can help it just because of all the solvents that are in that system and all the burn we can expect. And then if you throw a Group 15 in there like Metolachlor, Dual Magnum, Outlook. I mean that can just increase that burn even more. And then you know Bill, there's a lot of times we're throwing an insecticide in there too, so now I got three, potentially three herbicides with an insecticide going out over the top of all this sickly cotton. I mean what do you think the result of that's going to be?

Bill: It's not going to be pretty. Like they say about the University of Texas football team, they never pass and said there's three things that can happen when you pass and two of them are bad. A lot of those are going to be bad on this because the cotton's not growing. We got the weeds that are growing. Our thrips are growing. The time clock on our thrips protection on seed treatment, that clock starts ticking when we put it in the ground. And we hope that the plant can get enough size to it that it can start outgrowing the thrips when the chemistry runs out. Well, it's been sitting still so our plots ticking so it's going to run out of chemistry before the plot gets some size on it. So, you talk to Gus, the thrips are there. They're out there, they thrive on technology's working. They love that technology and I'm excited for us to get it but we don't have it yet. But we got thrips coming, we got pigweed coming, the cotton's just sitting there and I don't think it's going to take a lot of extra pressure before it starts letting us know pretty quick that it's hurting. Because it's just not growing. So I hadn't thought about that and we're going to have a lot of things that are needing to go out and I don't know how long we wait. Because I talked about a while ago about our minimum temperature being 60. Well it's not like flipping a light switch to turn growth back on as soon as it gets above 60. It's going to take a few days. And so I really feel like you know normally when we plant cotton the last half of May Tom, you know on our target development curve, we figure about thirty five days from planting to squaring. But usually when we plant in the last half of May we're getting a ton of units. Cotton is growing and not looking back. And so a lot of times we get to squaring in thirty days. Well I think we're probably back to thirty five days and it may take forty days. So if we do that, if it takes us thirty five days to get squaring on May 17th, I jotted down some days on the calendar a while ago, that puts us thirty five days to squaring, it's going to be the 21st of June. And then it pretty consistent, you know we get from squaring to flowering in twenty five days. So if we were having normal heat units, then we could still have flowers a few days after July the 4th, if we were getting good heat units, but we're not getting good heat units. So we may be looking at the middle of July before we start having flowers. And so we got way more time for the pigweeds to, the cotton's not up over the pigweeds, it doesn't grow fast when it's early, so this has the looks to be a pretty tough season right now.

Tom: I agree and I think it's going to take, I just wouldn't recommend spraying a large amount of herbicide and pesticide combination over this cotton, all at once anyway. I think, you know we've done some work with Roundup, Liberty and Dual over the years with all these different cotton varieties and to me separating those applications out is really a better way to go than mixing them all together. If we could, if we got bad thrips and bad pigweed, and we need to do Liberty plus an insecticide, I think we probably ought to leave the Dual out over some of this sick cotton and then maybe come back in, in two or three days with the Dual or other Group 15, whether we're using Dual, Outlook or Warrant, just to get some of that solvent out of the system to help alleviate some of the burn. And then if we need Roundup with that second application we can put Roundup in with it then as well. If we don't have the thrips, then maybe do just the Liberty/Dual, or a Liberty/Outlook or a Liberty/Warrant, but I just wouldn't recommend a three way herbicide combination right now with or without insecticide I don't think. 

Bill: Yeah and that's a good point, you're thinking further down the road than I was, because I wasn't thinking about this, but we've given up some days on the cotton by planting late, and now then we're giving up some days on cotton because we're not getting any heat units. We can't afford to give up any more days so it may take us longer to get it sprayed but we have the luxury of giving up time more so than I think the cotton plant does because we can't do anything to slow the cotton plant down. But those are some really good points that I hadn't really thought about. 

Tom: Yeah and so I think that, hopefully we'll get some of these clouds out and get the cotton off and growing and maybe we can get some of these weeds under control. One thing about if we're not using dicamba due to this whole injunction, or whatever it is from the court, you know Liberty's going to be an option on most of our acres. I think you and I've talked before, I think you said what, ninety plus percent planted in XtendFlex variety. Does that still hold true?

Bill: Yeah, we're going to be about ninety percent XtendFlex but you know there's a few people that are growing some non transgenic cotton, but other than that we can spray glufosonate over everything. Tom it would be hard to imagine having to grow cotton without using glufosonate over the top. That's a pretty tough challenge I think. 

Tom Well it is and you know we found a couple of populations that where we found some resistance so I don't think those are widespread obviously in those fields or that general area we have a lot of concern, but we're fortunate to have that as an option. Now it doesn't work as good under cloudy conditions generally. We need to spray that herbicide during banking hours. We don't need to spray it after dark or real early in the morning. It just doesn't work as well. And I think that's going to be a key since we've missed some of these applications and some instances we don't have residuals down. Liberty application's going to be key. And timeliness of that and not just the first application but coming back on some of these acres that have a lot of weeds coming back within ten days and hitting it with a second application. But again we have to watch the growth and development and make sure we're not, like you say, losing more days because I don't want to set the clock back any more than it already is right now. 

Bill: Yeah and Tom I don't know what you're seeing but a lot of people I work with and visit with have put Break in their mix and I think that's going to be something that's going to save a lot of people. If we didn't have that in there we see a bunch of really grown up fields right now. I know a lot of people are using that product.

Tom: I agree. I think the pint of Break plus a pint and a half of Cotoran this year has been really good because in most instances we've got good rainfall to activate it. I also think that the pint of Caparol and pint of Cotoran that's been going around on our sandier soils has worked real well for us this year. So for the ones that did it, you know I think that was obviously the right decision. That's what we recommend. For those that weren't able to get the residual out, we're in a little bit of a hornets nest in some of these fields. So any other hot topics going on right now in the world of cotton Bill? I know we try to keep these fairly short but do you have any other pointers before we wrap this up?

Bill: We're seeing a little more cover crops here and there and I've run into some situations. Some growers seem to have snails more so and it's not widespread but obviously with one grower he's got one spot in a field that he has snails every year. And I've got a grower, sent me a video and I put it on social media, just like twenty five, thirty snails. When you first look at it, it looks pretty thripy, but you turn that plant over and you look and those snails are everywhere. A slug, when slugs go through, when they eat, it looks like we shot it with a shotgun, because there's shotgun holes in the leaves and they just keep eating on it until there's not any leaves left, but the slugs, a lot of times they get up under the leaves, so it kind of makes it thripy looking and last year we counted in a field where the farmer had done a little bit of tillage on one side of the field, no slugs. Where he had the residue in the field he still had the slugs. A good number of slugs just like what I showed on the video here over the weekend. We counted nodes. No difference in nodes but there was a height difference early. But by the time we got into bloom and all that you could see a difference and one farmer I visited with over in the central part of the state said he has those slugs every year but it always makes good cotton. So it makes it look bad but I'm not sure that we're having any impact on yield. So those are some of those things that we're seeing is some of the cover crops that are emerging right now and hopefully those slugs won't be an issue. We just need to get some warmer weather. That's going to take care of a lot of things and get this cotton to growing so we can kind of stay ahead of everything that's trying to pull it down.

Tom: Right. Well I agree. I mean I think sunshine & heat units solve a lot of our problems in every crop really. 

Bill: Yeah if we had a jug of liquid sunshine boy we'd be millionaires wouldn't we?

Tom: Yeah that's right. Well look Bill, I really appreciate you joining us today for this episode. Thank you for taking time out of your day. I know I'm at Tillar. You said you were driving to Poinsett County I think's where you said you were. So I appreciate you taking time out of your day today and being our guest on our podcast series. So thanks everybody for listening today and again special thanks to our guest, Dr. Bill Robertson, our extension cotton specialist for visiting with us. Join us next week as Dr. Jason Norsworthy will be discussing some current weed issues. Just things that have popped up over the last couple of weeks. Thank you for joining us for this episode for the Weeds AR Wild podcast series on Arkansas Row Crops Radio. 


End notes: 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.