Weeds AR Wild Episode 13 Problems So Far 
Welcome to the Weeds AR Wild podcast series as a part of Arkansas Row Crops Radio. My name is Tommy Butts, extension weed scientist for the University of Arkansas System Division of Agriculture. Thank you for joining me this week for this episode of the Weeds AR Wild podcast series. I plan on discussing a few of the common problems I’ve heard of out there & some of the most common phone calls I’ve been receiving across Arkansas in the past few weeks. And just basically giving everyone a rundown on what some of those most common problems observed have been. And then hopefully provide a few recommendations to remedy some of these different situations. 
So one of the first topics I wanted to cover is the timing of our overlapping residual herbicide applications or the timing of those first POSTs or even second postemergence applications that should be going out across several of our cropping systems. And the best thing that I can tell you is, especially with our residual chemistries, it’s much better to spray sooner rather than later. Especially right now we’ve got some rain chances in our forecast in the next couple of days and even next week we have some slight chances here and there across different parts of the state. If we can get those residuals out, get them some of that moisture, some of that activating rainfall to get them activated, that goes a long way at reducing the amount of weeds that emerge out of the soil that we have to combat later with POST applications. And especially on things like rice where postemergence applications tend to be quite expensive, if we can get some of those residuals up front it saves us some money on the backend. So that’s the big thing if we can get some of those out a little bit sooner even if it’s pushing the envelope on the early side, because we’ve got some of these activating moistures coming right now, it’s really a good idea to get out there and get ahead of some of these weeds and hopefully save yourself a postemergent kind of salvage application later on in life. I’d also like to mention as our weather is finally turning here, we’re starting to get really hot, that plays into a lot of our weeds, especially our most problematic weeds to start germinating and really taking off with their growth rates. So I’m thinking barnyardgrass, Palmer Amaranth, we’re starting to get warmer temperatures here, those things are really, really just going to start going crazy now with these temperatures and so if we can make sure to get those residuals out in a timely fashion and make sure to get them activated, so like I said with some of these rainfalls or in a lot of areas of the state I know we’ve already turned quite dry, be ready to flush or run water down furrows for our different cropping systems, get those residuals activated, make sure that they are really working to our fullest capabilities. Again, don’t let those weeds out of the ground. It gives us better weed control in the long term, it saves us money in the long term from reducing some of those postemergence applications and it just reduces our selection pressure for evolving resistance to some of our postemergence herbicides. So that’s really what we can do there on the timeliness. Also if you have questions on the necessary moisture amounts for different residual products or kind of the timing of some of those moistures, make sure to listen to Dr. Tom Barber’s podcast from a couple of weeks ago, it was Episode 11. He goes into some really good detail, and provides a lot of really good information on moisture and activating our different residual chemistries. So make sure to check out that podcast if you haven’t on that topic. Also one of the last things I always really like to mention too when we get into this time of year and it’s getting late and we’re in a time crunch to get crops in the ground, always make sure that we’re not planting too far ahead of our sprayer. I know we get in a rush to get our crops in the ground but if we get too far ahead of our sprayer, we don’t get stuff burned down, we‘re not starting clean and we don’t get our residuals out in time, again it just creates a mess for us later on in the season where we end up spending more money trying to clean up because we just didn’t get our sprayers out in time to get those residuals and those burndowns out properly. So just make sure we’re doing that as well and as we’re planting try and keep an eye on that weather, for both rainfall but also wind speed so that we have good spraying conditions really to get all these applications out in a safe and timely manner, and keep up with how much we have planted in the ground, that we’re not getting too far ahead of those sprayers.
Now on another topic, we’ve also had several calls in our rice tank mixes of trying to find some different mixes with Propanil, especially since there’s numerous reports of Bolero kind of being in short supply. Prowl is honestly a really good option that can be mixed and kind of fit somewhat of the same roll as Bolero, especially with our grass control. It doesn’t have the flatsedge activity that Bolero has but it does at least have similar grass activity like in row rice, Prowl can take care of goosegrass just like Bolero can, it’s still good for barnyardgrass, it’s good for several of those other grass species. But there is just something to take note of with tank mix issues with Propanil and Prowl. Prowl H20 and Propanil in the tank together, they just don’t play nicely. There’s kind of an antagonism there, they like to gel up a little in the tank. That’s just not a good combo. If you are going to do this Propanil/Prowl mixture, especially if you are trying to find a replacement for Bolero, make sure to get a Prowl EC formulation. That oil formulation really works a lot better with Propanil out there. Also with that Prowl you see that oil can help heat up that Propanil a little bit more too like Bolero typically does. So just be aware of that if you are looking to do that mix in rice. We’ve already had some phone calls of Prowl H20 and Propanil kind of acting against each other, so make sure you can get a Prowl EC formulation if you’re going to do that tank mix with Propanil. 
One of the other phone calls that I’ve gotten a lot on is horseweed or marestail control across our cropping systems honestly. In just about every cropping system I’ve got a phone call on trying to get horseweed under control this year. So there’s a lot of different options and at the same time it’s pretty limited. So the other thing I’m going to mention here with my recommendations because of the recent injunctions or stays on our dicamba rules, at this point we’re not really sure where our dicamba rules are going here in the state of Arkansas right now at this point when I’m recording this podcast. So I’m just going to kind of skip over any dicamba recommendations because like I mentioned, we just don’t know where we’re going to end up here with the rules at this point in time so the recommendations I’m giving here for the horseweed and marestail control is excluding any dicamba options just again because we don’t know where those rules are going to end up here in the near future. But if we’re looking in soybeans, there’s a couple different options here. If we’re in Enlist E3 soybean, Enlist One plus Liberty should be a really good option. The 2,4-D and the glufosonate both working on that horseweed, will do a great job at melting that down. If we have E3 and XtendFlex soybeans systems, either one of those. Sequential Liberty applications, Liberty is really hot honestly on horseweed, so having sequential Liberty applications should do a very good job at burning that horseweed down. Also on soybeans, one of that ALS inhibitors, FirstRate is actually good on horseweed as well and so we can mix in FirstRate if we have a real bad horseweed population out there and that will help meltdown those horseweeds plants out there. 
Now on rice I’ve also had several calls on trying to get horseweed or marestail under control, particularly in row rice. And the best thing that I can tell you there, is especially if it’s early, if the rice is pretty little yet, one maybe two leaf, I would tend to say I’d like to lean towards the one ounce rate of Sharpen first to try and burn down some of that horseweed a little bit. I’m not saying that’s going to kill it but it’s at least a starter especially when the rice is that little. I tend to try to avoid throwing a full gallon of Propanil at it when it’s that young. So if we can do an ounce of Sharpen that can help burn down some of the marestail. After that a Grandstand/Propanil mix, again trying to burn down some of that marestail more and then finally kind of at the end of it all is hopefully that will take care of it, great, but if not, if we still have some stand-in or some escapes or a little bit of foliage left, Loyant should also be pretty decent on it as well. If it’s less than eight inches tall, it definitely should completely control it, if it’s a little bit bigger than eight, it’s more likely a suppression type thing. But Loyant is also an option in there as well. And so depending on the rice stage and where you’re at in close to canopy and those types of things those are kind of the three options I would tell you that you could rely on and give or take on your certain situation, you could kind of sub in one or maybe you only need one or those different types of things. But those would be my three options on row rice that would be most effective at trying to get rid of that horseweed in row rice. 
When we move to corn, we honestly have some very limited options POST in corn to try and get rid of that marestail. Halex GT is a decent option. It does do an ok job and we have up to 30 inch corn to spray that. Normally we always like to mix Atrazine in with our Halex GT, but just realize that our Atrazine has a cutoff of 12 inches which most of our corn should be, if not past that, they’re getting pretty darn close to passing that across the state, so we’re kind of hitting our limits there. Resicore is actually another option too out there that would be pretty decent for horseweed control. Once again this is a 12 inch corn cutoff, so we’re kind of hit or miss on that for most of our corn in the state. We’re probably past that cutoff in a lot of areas, but if you are still under that 12 inch corn, Resicore can do a pretty good job at burning down some of our horseweed out there. One other thing to note with Resicore though, there is a 12 month plant back to cotton so if you plan on going to cotton the following year in that field, just be aware that it does have a 12 month plant back. 2,4-D is an option as well again 12 inch corn cutoff unless we’re using drop nozzles and then we can go a little bit taller corn. Just be aware also that 2.4-D, there are certain counties in the state still have restrictions on that being allowed, on the limitations on that being sprayed and so make sure and check the Arkansas State Plant Board website for the current rules and regulations with the 2,4-D as well in corn and if it’s banned in your county or not banned in your county at this point in time and that kind of thing. Then the final option in corn is again back to the Liberty option and that cutoff is up to V7 corn, so again we’re probably getting close to, if not already past, that cutoff as well. The other major thing with Liberty is make sure you have a dual stack hybrid out there, that it is both Liberty and Roundup resistant. You don’t want to spray Liberty on Roundup only corn and then kill off your entire field. So just be aware of that and make sure you have that dual stack. But again Liberty is a pretty good option as well for killing horseweed. 
If we move to cotton, once again very limited options honestly in cotton, but Liberty is one of our best options there, especially Sequential applications of Liberty and then also after cotton reaches five leaf, Envoke actually has some pretty good marestail activity and so that can be a pretty good option. Just make sure that cotton is at five leaf or after. If it’s before there’s some pretty good crop response that can occur if that Envoke gets sprayed too early.
Finally in peanut, one of our last remaining crops where I‘ve had a couple of calls on horseweed as well. If the peanut is not emerged yet, Strongarm is actually probably our best option because it does have a POST activity on horseweed and we can use that as a PRE then in our peanut crop as long as the peanut’s not emerged, but it will burn down any horseweed that’s emerged ahead of that crop. Now I’m sure in a lot of or areas our peanut is already out of the ground and so then we get limited and it pretty much gets down to just Paraquat as an option POST to help burn down some of those horseweed/marestail problems out there. So again very limited on peanut as well. If the peanut’s not out yet Strongarm can be good, otherwise we’re pretty much are relying on Paraquat POST in those peanuts to be successful.
One of the final topics I really wanted to hit on that is probably been the majority of my phone calls coming in is just different tank contamination issues and then also spray drift issues. So basically crop response from a variety of different herbicides of where either the sprayers were not cleaned out properly. We had chemical left in the boom or even chemical completely left in the tank that got mixed in and sprayed on the wrong crop and spread across the entire field or also like we mentioned with some of the high wind speed applications were going out in twenty mile per hour plus wind and we’ve had significant drift onto fields causing crop injury. And so mainly I just wanted to highlight again to make sure we’re paying close attention to all of our applications that are going out. Let’s thoroughly clean our sprayers and the entire boom, the tank. Triple rinse them, those type of things. Let’s also just have really good communication amongst all of ourselves so we don’t get wires crossed and think we’re going into a field that has a certain herbicide trait technology and it really doesn’t. My best example there is we had one where there’s just some miscommunication. The sprayer thought they were going into a Clearfield rice field and it was really a conventional rice field and they hadn’t cleaned out the tank and ended up spraying Newpath over the top of conventional rice and pretty much killed off about three or four acres of rice. So just things like that and communication, make sure we’re cleaning out thoroughly and then with the wind speeds again avoiding those high wind speed days, setting up our applications to avoid physical drift. All those kinds of things. Really paying close attention to those applications and setting them up for success is really important as we move forward to cut down on some of these incidents that we’re seeing. 
Really those were the main things that I wanted to hit on this week. Like I said these have just been some of the main phone calls and complications that I’ve been hearing about, so I just kind of wanted to hit on some of the main recommendations and remedies that we can kind of implement to hopefully help us out with some of these situations while we’re still in the heat of the growing season.
As always if you ever have any questions please don’t hesitate to reach out and get ahold of me or any of our weed science team for that matter. I also just want to thank everyone for their continued support of the Weeds AR Wild podcast series and for continuing to listen to our episodes and everything there. So once again any questions please let me know and next week please tune in for another episode of the Weeds AR Wild podcast that will be hosted by Dr. Tom Barber. He’ll bring up the series next week and with that, thanks for joining us for this episode of the Weeds AR Wild podcast series on Arkansas Row Crops Radio.