Extension Weed Specialist

(Jim) Good morning, folks and welcome to That’s My Farm. I’m Jim Shroyer your host. And today we’re going to be talking with Dallas Peterson our Extension Weed Specialist at Kansas State University because now’s the time of the year we need to be controlling those weeds in our wheat crop. So stay with us, we’ll be right back and we’ll be talking with Dr. Peterson in a moment.

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

(Jim) Good morning folks and welcome to That’s My Farm. I’m Jim Shroyer your host and today we’re in luck because we’re speaking to Dallas Peterson. He is a weed scientist in the Agronomy Department at K-State. Dallas, its wintertime, with snow outside but its supposed to be 60 or 70 tomorrow and I know there’s a lot of weeds out there in the wheat field so go through with us the weeds we need to be watching in our wheat right now. (Dallas) Well we have a variety of weeds that we can have in our wheat fields and probably the most abundant ones that we have in winter wheat are the winter annual weeds because they have a similar life cycle and there can be winter annual broadleaf weeds, as well as winter annual grasses and we also can have some summer annual weeds although they won’t be germinating and come up until spring. So right now the ones that are out there that we need to be cognizant of are the winter annual broadleaf and grass weeds. (Jim) OK, what are some of those? Let’s go the eastern third of the state. What are the main ones? (Dallas) Well probably the most abundant ones are the broadleaves. And in eastern Kansas things like Henbit, Bushy Wallflower, Treacle Mustard, Field Pennycrest, those would be some of the primary ones that we have. But we can also have a few other winter annual broadleaf weeds especial the mustards, things like Quickweed or Tansy Mustard. (Jim) We don’t worry too much about the annual grasses in this part of the state? (Dallas) Well in eastern Kansas they’re not a major problem because we have enough crop rotation. Crop rotation is probably one of our best management practices to deal with the winter annual grasses. Although we could have them especially as we move a little bit more toward the middle part of the state and we do a little bit more continuous wheat planting. (Jim) Segway into the central part of the state. What are the weeds there? (Dallas) Really similar although we probably don’t have as much of the Henbit, for example. The Mustards are probably our most dominant broadleaf weed there. Busy Wallflower, Treacle Mustard, Flixweed, Tansy Mustard, maybe even some Blue Mustard. Those would be our primary broadleaf weeds that we would have to deal with there. (Jim) Grasses? (Dallas) And the grasses definitely then become much more prominent in central Kansas because we do a little bit more continuous wheat cropping. So Downy Brome, Cheats, Japanese Brome, maybe even a little Cereal Rye in a lot of places. And if you get down onto the southern border perhaps maybe even a little bit of Italian Rye Grass. (Jim) Now will Italian Rye Grass be in the southeast part too? (Dallas) Right along the Oklahoma border both in southeast and south central and maybe even a little bit in southwest. But primarily in that south central and southeastern part. (Jim) OK real quickly, what about the weeds in the western part of the state? (Dallas) Well, weeds in the west would again be the Mustards primarily, Flixweed and Tansy Mustard. Also from the brass standpoint, Downy Brome is probably the predominant grass we have there. As well as Jointed Goat Grass which is another winter annual that can be very problematic in wheat. (Jim) A little Blue Mustard out there too, right? (Dallas) There is some Blue Mustard as well. (Jim) Don’t go away Dallas, we have to take a break right now. Folks, stay with us. We’ll be right back after these words from our sponsors.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer and with us we have Dr. Dallas Peterson, Extension Weed Scientist at K-State. We just talked about the weeds that are in the various parts of the state. Now let’s kill them, Dallas. So let’s go through the broadleaves first. What are some of our herbicide options that we can use. (Dallas) Well we have a lot more options to control broadleaf weeds probably than we do grass weeds. And to be honest with you, a lot of the broadleaves can be controlled fairly well and fairly economically. But there are a number of herbicides, we could start with our growth regulator type of herbicides. Things such as MPPA, 2,4-D and Dicamba. Timing is a little bit critical with those herbicides. Most of them will provide pretty good broadleaf control in general, although there are specific broadleaves they don’t control. For example Dicamba is very good in the spring for things like Kochia and Wild Buckwheat. But its not very good for the Mustards. So you would have to apply something else in combination with the Dicamba for the Mustards. MPPA and 2,4-D are both good in general for Mustard control. They are not very good, for example, for Kochia control in the spring. So we see that different spectrum of control from the different herbicides. MCPA has better safety than 2,4-D does. (Jim) Of Course that’s one of my favorite ones. (Dallas) Yeah, it is, and over the years we’ve felt that its probably been an under-utilized herbicide. In some cases it might not be quite as effective as 2,4-D on certain weeds, but again it has a broader window of application. (Jim) You can put in on in the fall and 2,4-D you shouldn’t. (Dallas) Exactly. MCPA can go on in the fall before the weeds are fully tillered. With 2,4-D we never recommend it in the fall because it can inhibit that tillering process. So we generally suggest that it not be sprayed until spring. And even in the spring you want to make sure your wheat is fully tillered before you spry with 2,4-D. (Jim) Because it stops tillering right there. (Dallas) Exactly. And it can result in yield losses. (Jim) Right. OK please continue. (Dallas) The Sulfonylurea herbicides in general also can provide very good broad spectrum broadleaf control. And some of those have a long residual activity and others do not. Finesse, for example, and Glean herbicides have been kind of standard treatments through central Kansas for many years and have provided in general very good broadleaf weed control. That’s good on the Mustard, they’re good on Henbit, they’re good on Field Pennycrest, they’re good on Wild Buckwheat. One of the issues, however, with that class of herbicides has been the development of certain species with resistance to that class of herbicides. (Jim) We’ll talk about that in just a minute. OK, continue some of the other herbicides that you can use. (Dallas) Yeah, there are other Sulfonylurea herbicides as well and again that list is fairly long. things like Rave which is a combination of Amber herbicide and Dicamba herbicide. Its a mixture of two active ingredients which is beneficial. (Jim) You’ve got to be a little careful on that one because if its jointed it will ding it. (Dallas) Exactly right, and we’ve talked about the timing with 2,4-D and MCPA, but that is also important with Dicamba. (Jim) Yeah, its a good herbicide, I like it but it can sure lay the wheat over. (Dallas) It’s a good herbicide and its effective early but you don’t want to spray it after that wheat starts to joint because that wheat will lay it over. (Jim) I think we’ve got to stop for a break here, Dallas, and keep those herbicides in mind. Folks, we’ll be right back after these words. Thank you.

(Jim) Welcome back the That’s My Farm. I’m Jim Shroyer and with us we have weed scientist, Dallas Peterson. Let’s continue the conversation about broadleaf herbicides. (Dallas) OK, well, again, there are a number of different broadleaf herbicides available. Each has a little different spectrum of control, timing, safety and different modes of action. One of the newer broadleaf herbicides that’s been introduced in recent years is called Huskie. And Huskie is actually a pre-mix itself. Its a combination of a bleaching type herbicide, so that’s a different mode of action than we’ve talked about, along with Buctril, old Buctril herbicide. And that actually helps to synergies the bleaching herbicide. And so that’s actually a good alternative, for example, if you have ALS resistant weeds because it des provide a different mode of action, has very good safety both as a fall or a spring treatment. One thing is it doesn’t have a lot of residual activity. So like most herbicides that don’t have residual activity you want to spray it when the weeds and the crop are actively growing. they probably would not be a good candidate right now but as soon as that wheat starts to green up in the spring, then it would be a good time. (Jim) So we’re talking a March time application. (Dallas) That would be a good time. (Jim) So what are some other ones? (Dallas) Again in many cases we might look at different combinations or alternatives such as the Starane type of herbicides. Starane is a very good Kochia type herbicide. (Jim) Good for out west mainly. (Dallas) And the one advantage it might have over Dicamba, which is another good Kochia herbicide, is that we can go on a little bit later in the season. Again with Dicamba we don’t want to be spraying after that wheat starts to joint, but the Starane products can go on a little later. You want to make sure you can still get good coverage, but it can provide very good Kochia control. (Jim) OK, we’ve flirted with the issue of resistant weeds. Let’s talk about resistant weeds. What are they? And now we’re going to be talking about some combinations. (Dallas) Right. Herbicide resistance occurs over time, generally when we use an herbicide repeatedly. And again we’ve gotten into a little bit of trouble with some of the herbicides and most notably those ALS inhibiting herbicides that I was talking about. Things like Finesse for example. We’ve used them a lot over the years and consequently we did shift our population and now we are starting to see some ALS resistant weeds. And the primary ones we’ve seen to this point in time are the Mustards like Bushy Wallflower and even Flixweed and Tansy Mustard. The most recent one that we actually found has been Henbit. That’s one of the reasons that its a good idea to tank mix those herbicides with other modes of action and to rotate the herbicides among different modes of action. So with Finesse for example we almost always recommend now that you tank mix it with an MCPA or a 2,4-D to get that second mode of action in that treatment. (Jim) Of course crop rotation will help too because now you’ve got your herbicides for your row crops in there as well. (Dallas) Well absolutely crop rotation is one of our best management practices for weed management in general including herbicide resistance because it does break up that growing season and it allows us to use different herbicides with different modes of action. (Jim) Dallas, we need to take a break right now. Folks, now’s the time to go get a cup of coffee and we’ll be back after these words from our sponsors.

(Jim) Welcome back to That’s My Farm and with us we have weed scientist Dallas Peterson. You’ve given us some good advice about the various weeds and the herbicides for broadleaves, now let’s kind of shift to grasses. I think those are a little bit trickier myself. So tell us about the grasses and herbicides. (Dallas) Well certainly the grasses have been more of a problem over the years, when we have them. Now they’re not quit as common because if we’re in a good rotation of crops, some are broadleaf crops or grass crops, generally we can keep those down. But where we tend to grow a lot of wheat, we tend to have some problems with the winter annual grasses. (Jim) In that central corridor mostly. (Dallas) In that central corridor and because they have a very similar growth habit to the wheat and its harder to develop selective herbicides that will take a grass out of a grass. But we have seen some herbicides introduced over the years that can selectively control grasses in wheat. So again, we’re primarily looking at Downy Brome, Cheat, Japanese Brome, perhaps Jointed Goat Grass and Italian Rye Grass. So all the herbicides that have been developed to control grasses in wheat do belong to that ALS inhibiting class of herbicides. So primarily at this point in time we have Olympus herbicide, Empower Flex herbicide, and then if you plant Clearfield wheat, you also have the option of using Beyond herbicide. But you cannot use Beyond on any non Clearfield wheat. (Jim) It will nail it. (Dallas) It certainly will. And i now you have some experience with that yourself. (Jim) Let’s not talk about that. (Dallas) OK. So with the grasses again they are harder to control in general than the broadleaves in many cases. And timing can come into play there. We generally get our best grass control with fall application. So we’re talking about a mid-November type of time frame when hopefully the wheat is starting to tiller but those young grasses have not started to tiller. And that’s usually when we get our best performance. But we can also apply them in the spring but the key there is not to wait too long. You want to get those applications on as soon as that wheat and those weeds start to go and actively green up in the spring. (Jim) So we’re talking about late February if we get a good warm spell which we’ve been having all winter long, but into early March maybe? (Dallas) Yeah, probably late February at the earliest, again we want things to actually take off, but you want to get them before we develop a lot of canopy. That’s going to give us our best results. (Jim) So let’s talk a title bit about Beyond again. (Dallas) Beyond actually has broader activity than Olympus and Power Flex. Olympus and Power Flex are pretty good on the Cheat grasses, if you will, Downy Brome and Cheat and Japanese Brome. But they are not very good for example on Jointed Goat Grass or Cereal or Feral Rye. And really the only herbicide that will control those two grasses is Beyond. And again, beyond has to be used in Clearfield wheat only. the timing is very similar as far as performance is concerned. Fall applications generally work the best. But if we can get that application on early in the spring, just as its starting to take off we can get good control of those species as well. Usually Beyond does a better job on Jointed Goat Grass than the Rye. Rye has been a little bit inconsistent. So we have to be a little more aggressive with those treatments for Rye. (Jim) Folks, we’ll be right back after these words.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer and with us again we have Dallas Peterson in our last segment. Dallas, let’s talk about carryover and applications with fertilizers. (Dallas) It’s been very popular per the years to apply a lot of our herbicides along with nitrogen fertilizer carrier. The advantage there of course is you eliminate a trip across the field, but you have to make sure that the herbicide is compatible with the fertilizer and you also want to think about the optimum timing of the two applications. they may or may not be compatible. So the long lived residual Sulfonylurea herbicides probably have worked best in that weed and feed type of operation. Again, things like Finesse and Glean and Amber and Rave because they have soil activity as well as foliar activity and they are compatible with the fertilizer. And from a timing standpoint, those actually work quite well if we apply them for example even in January and February and early March. AS you get later, you may want to back off of some of those combinations. And its also very important that you read the label in regards to how to mix it and whether you need to add surfactant or not. And again as you get later sometimes the issue us adding surfactant along with that fertilizer can increase the risk of burn and injury to the wheat. Just make sure you follow the label guidelines. (Jim) OK. And also we talked about later on you’ve got carryover issues for the next year. The advantages of those residual herbicides is that they do give us residual weed control. But of course that also means they are persisting in those fields maybe even beyond the wheat harvest. Again, that can be an advantage or disadvantage. It can help provide control even post-harvest. On the other hand you just have to be aware of what crop may be susceptible that you would plant after that point in time. So we’re looking at those same herbicides as far as having some crop restrictions, Finesse, Glean, Amber, Rave as well as even a couple of post-emergent grass herbicides Olympus, Power Flex and Beyond also has some crop rotation restrictions. So just make sure you’re aware of what those are and abide by those label guidelines. (Jim) Yeah, I know one of the issues we have when we have coarse sand out there and weeds coming in, well do you fertilize it? Do you put on a herbicide? And then if the crop fails, then what do you do? (Dallas) It really is a dilemma because you hate to invest too much money in a poor crop but yet if you’ve got thin wheat you need to have a herbicide out there to give you good weed control as well. (Jim) Hopefully if it fails you can come in with beans or something like that. (Dallas) And that’s when you need to think about what those rotational limitations are. (Jim) You’ve got the handbook there in your hands. Tell us briefly about this. (Dallas) this is the Chemical Weed Control Guide and we revise it each year to add the newest herbicides that have been introduced into the market. Or any label changes that have come about. It also has guidelines on all our major crops as well as some pasture and range land for noxious weed control and even non cropland. We think that its a very useful guide for growers. It doesn’t substitute for labels. But it should provide good information to help select those herbicides. (Jim) Dallas, I really appreciate you taking time and thank you. I know you’ve got to go to a meeting here in just a minute so I appreciate it. And folks, thank you for being with us here this morning. And don’t forget, next Friday we’ll be here at the same time.

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

No Comments Yet.

Leave a reply

You must be logged in to post a comment.