Managing soybean insects and weeds in June
The month of June typically brings new challenges for soybean growers in Minnesota. In this week’s episode, Dr. Bob Koch, Extension Soybean Entomologist and Bruce Potter, Extension Integrated Pest Management Specialist provided an update and reviewed management strategies for soybean aphids, grasshoppers and soybean gall midges. Because of the delayed spring planting season, soybean aphids are not present in significant populations but as the weather heats up there are some scouting procedures and insect biology to be aware of this spring. In addition to soybean insects the subject of alfalfa weevils was also discussed. The last portion of the program included Dr. Tom Peters, Extension Surgarbeet Weed Specialist for Minnesota and North Dakota. Tom provided an update of the Section 18 label for Ultra Blazer to control emerged broadleaf weeds in sugar beets which has similar weed control strategies for use in soybeans as well especially for other Group 15 herbicides. Tom also provided a review of the utility of pre emergence herbicides in terms of residual weed control as to longevity. We also reviewed current cutoff dates/crop stages and best application methods for growth regulator and glufosinate herbicides.
I'm Ryan Miller, crops extension educator.
Earlier this morning we recorded an episode of the strategic farming field notes Program. Strategic farming field notes is a weekly program addressing current crop production topics.
It is a live webinar hosted at eight AM on Wednesdays throughout the cropping season.
During the live webinar, participants can join in the discussion and get questions answered.
An audio recording of the live program is released following the webinar via a podcast platform.
Thanks, and remember to tune in weekly for discussion on current cropping and crop management topics.
David A Nicolai: University of Minnesota extension Minnesota are brought to you by not only the U of m extension and but also generous support from the Minnesota Soybean Research and Promotion Council.
David A Nicolai: Along with the Minnesota Corn Growers Research and Promotion Council i'm Dave Nicolai. I'm a regional extension educator in in crops.
David A Nicolai: In my co host and co moderator is Anthony Hansen we'd like to welcome today's guests, Dr.
David A Nicolai: Bob Koch from the University of Minnesota extension entomologist and Bruce potter from the.
David A Nicolai: Research and extension and outreach Center at Lamberton and integrated pest management and later on in the program will be joined by Dr Tom Peters.
David A Nicolai: University Minnesota and NDSU weed control specialists in sugar beets
And with that i'm going to turn it over to my co moderator and integrated pest management Anthony hanson so Anthony take it away.
Anthony Hanson: Thanks Dave and yeah we're going to be focusing a lot on the pests today here insects and then later on beads, so I think to start things off Bob.
Anthony Hanson: Basically we're dealing with soybeans have been planted.
Anthony Hanson: Know over a long period of time knows there's a lot of variability and what people have for.
Anthony Hanson: Growth stages, right now, so what is that, looking like for so even insects, in general, but the big question is always going to be so i'd be Nathan, what can you say so far, but we might be able to expect with that one.
Robert L Koch: yeah for soybean aphid.
Robert L Koch: I guess, maybe even.
Robert L Koch: Just stepping back a little bit with that here, regularity and planting dates.
Robert L Koch: Past like so i've been a bit been leaf beetle you know I think early on they're going to be referring those earlier planted.
Robert L Koch: So i've been field, sometimes as because all there is so it could be concentrating them there I haven't seen any soybean aphids yet i'm not sure if Bruce has, but I have seen some been leaf Beatles out there, not very many, but just a few here and there.
Robert L Koch: Another past where.
Robert L Koch: Planting dates could be important is.
Robert L Koch: So i've been gold image it's not a widespread or very damaging passed yet across much of Minnesota but it's an emerging issue, and I think Bruce will touch more on that later.
Anthony Hanson: So this is a little early for this question Bob but people have been talking about it quite a bit already come July or so.
Robert L Koch: When.
Anthony Hanson: We might be treating for so you Nathan.
Anthony Hanson: What alternatives do we have for court purifies and that's kinda reminder, we like to put out that the registration has been pulled for that that's no longer available for people to use.
Robert L Koch: Right so click your files containing products, you know or mixtures that have a fear of us are no longer in our toolbox for slaving aphid management, but fortunately we do still have some other effective.
Robert L Koch: Chemical tools available.
Robert L Koch: Some of the newer products like transform sub antos safina have proven to be pretty effective against slavery in a fits in our research trials and, from what I hear from the limited number of growers that I know that have tried any of those.
Robert L Koch: And those three products are all they all have the benefit of being more gentle on the natural enemies so they're they're toxic to the aphids.
Robert L Koch: But less toxic to some of the beneficial insects, you know, and especially for pest management that includes the predatory insects like lady beetles and even the tiny parasitic last that attack the aphids in there are you know still the pyrethroids but keep in mind, you know over.
Robert L Koch: Whatever we going on, or six or seven years we've got reports of resistance I retried resistance in the soybean eight bits so use of a you know pyrethroids might be kind of.
Robert L Koch: A risky choice for your first application against the sleeping naked infestation.
Anthony Hanson: So, in a lot of years we do talk about the seat treatment style and how effective that might be.
Anthony Hanson: When we're getting too late plan thanks now where some people are planting past the insurance dividing of June 10 are they going to see potentially benefit for server David or is that still a period of time, where I see much ravens yet and you're not getting as much use out of that.
Robert L Koch: I think in a in a typical year by the time you know with regular planting dates with the seed treatment.
Robert L Koch: By the time the eighth it's colonize those fields, a lot of the insecticide within those plants has dissipated, so you might not get much of.
Robert L Koch: An impact on the eighth of populations from that new niche annoyed in the plants, however, with later planting you know you could be creating a situation where you might have higher concentration, so that insecticide in the plants, when the aphids show up, so in that case you could get.
Robert L Koch: You know, maybe a higher chance of getting a return or an impact of that insecticide of the best population growth, do you have any thoughts about that.
Bruce Potter: or I think that's right, I mean typically you know by v3 stage soybeans.
Bruce Potter: Africa have any nicks are pretty well gone out of those see treatments.
Bruce Potter: But later planning yeah if you can hit them hit them as they're moving into soybeans I think actually right now about they should be, they should be starting to move off a buck foreign we've got.
Bruce Potter: The earliest beans or v3 out there, right now, we're darn close to it, so I think we're.
Bruce Potter: we're going to see some a if it's fairly quickly, I think one of the things the seasons weather is shaping up like last year hot and windy when that movements taking on and I don't think these small beans I think that's pretty hard on on those aphids trying to colonize soybeans.
Anthony Hanson: For their births or Bob I do we have any insects that could show up that we normally don't see for soybeans, especially because of the lake planting either.
Anthony Hanson: let's say low ground that was potentially flooded, just like planting or possibly something to do with how things are planted to have newer rose going in people using drills.
Anthony Hanson: All of these things are in the mix could that be affecting and sex, you can think of that might just be sporadic fest or maybe some we think about too much.
Robert L Koch: um you know one issue that comes to mind Anthony might be, you know if there have been weed control issues, due to the weather, you get a lot of grassy weeds that could you know be attractive to some of the caterpillar pass.
Robert L Koch: off the top of my head.
Robert L Koch: Bruce do you have any other.
Robert L Koch: Any other there are Anthony did you have something.
Anthony Hanson: Not.
Anthony Hanson: Tom Peters actually is asking about grasshoppers and I think that's one that we expect for soybeans possibly later in the year more August, if we're going to see them.
Anthony Hanson: Right now i'm seeing some grasshoppers out there, but low numbers, I think, are wet spring definitely help those ones out quite a bit, but yeah I think that's just the recurring question of being an odd year for planting so what other unexpected things might happen.
Robert L Koch: yeah I think for the grasshoppers you know the they're really favored by the dry weather right so conditions are pretty dry the last couple years so.
Robert L Koch: We heard more and more of you know, increasing grasshopper populations, but you know, like you said Anthony the weather conditions, this spring might might be helping to knock some of those populations back and to see how.
Robert L Koch: How conditions play out.
Bruce Potter: yeah well, they should there should be there should be hatching know early hatching species like two stripes definitely.
Bruce Potter: Read legs, maybe you're going to be a little bit later, but you know grasshoppers really like a most of them like a balanced diet some grasses some form, so I suppose, possibly, if you have some weeds in that field it'll it'll be a little more attractive to them, but.
Bruce Potter: Really, you know catching them early any infestations early in in the in the field, or on the borders is the way to go, get him out of there when they're small easy to control.
Anthony Hanson: Suppose i'll pass this one over to you.
Anthony Hanson: So in Gaul Mitch, what is kind of the plan for this year with that one where do you keep an eye out for what were you looking so far and what people mean.
Anthony Hanson: My my veggies plan.
Bruce Potter: about your two different things and I don't know I don't know what they're thinking.
Bruce Potter: So right there's a there's a multi state project.
Bruce Potter: funded by the North central soybean research project.
Bruce Potter: program and we've got we're looking for emergence of adults as they come out of.
Bruce Potter: Last year soybean fields, they are catching goal image right now in in southern nebraska and southern iowa I haven't caught it in Minnesota yet.
Bruce Potter: So we're still trying to sort it out if Minnesota is the at the edge of their range and that's why our populations are as high maybe as they get them in nebraska.
Bruce Potter: Or if it's just a matter of they haven't populations haven't expanded and build up here as well, so a lot we don't know about this insect it's it's been a big puzzle.
Bruce Potter: So we're going to be looking at emergence and those are on the web, if you go to soyabean goal image.org there's a map it'll show you when and where adult emerges or emergency has happened.
Bruce Potter: I think one of the things about planning date is, if you have an early planning date with respect to the gold image they do better, they.
Bruce Potter: tend to lay their eggs in in these growth of visitors on the soybeans damn lower stem where as that soybean plant grows the stem expands and you get get these cracks in this down that's where they seem to prefer to lay eggs so early larger soybeans are a little more attractive.
Bruce Potter: Late planning if it's real late planning, you might miss that colonization for last year soybeans just because of the this year soybeans are going to be too small for him to do well.
Anthony Hanson: I think we got a couple months i've been questions coming in here one we got asking about feeding on V2 to be five corn seen feeding, but no bugs and site, at least so any ideas, probably Bruce on what could be showing up in that room.
Bruce Potter: So it could be leaf feeding by.
Bruce Potter: Maybe small cut worms.
Bruce Potter: You know if it's a real late flight we had some stuff in early May that those cannot relate may rather those caterpillar should be pretty small yeah that would be one thing.
Bruce Potter: depends on what the feeding looks like if it's just holes in the leaf, or if it's a series of holds cross the leaf may you know it was no till maybe maybe maybe some stink bugs or something like that can be out there, too, but.
Bruce Potter: My first guest is going to be is going to be a caterpillar of some sort or grasshoppers possibly.
Anthony Hanson: One other question I know various we've been talking about this in the past, but a little bit this morning before the meeting alfalfa we've all.
Anthony Hanson: People are having issues with some parts of the state and basically what you've been hearing so far about what's been happening with that one.
Bruce Potter: Will from what i've been able to gather so far it's kind of kind of where we had snow cover when we had that cool snap this winter.
Bruce Potter: Where the snow cover was to the north, just really issues are, as you get South where it was more open during the winter, the populations are lower, and the other thing I am hearing is there's been some concern guys have treated with pyrethroids and.
Bruce Potter: For before cutting and it's not working very well they're having some issues under the under the window so there's possibility, we might be dealing with some peripheral resistance in that population.
Bruce Potter: It happens it's not it's fairly common out West in the western states, but we don't know what the status of resistance is in Minnesota for sure, yet i'm awful suspicious, though.
Anthony Hanson: yeah i'll be curious to with that one one question can I this using FLEX Star and herb side effect insect pressure so a barbarous if you want to comment on that one a bit they're.
Bruce Potter: going to be because you've got that leaf injury.
Bruce Potter: My guess is it'll be a little less attractive for soybean aphids at least until that new growth comes out but I don't know if there's any been been any real definitive studies on that at all.
Bruce Potter: You know that the the flex our injuries is fairly fairly temporary as long as you've got good growing conditions.
Robert L Koch: yeah.
Robert L Koch: i'm not a i'm not aware of any direct impacts of that herbicide on the insects.
Robert L Koch: The other possibility could be you know knocking down the weed hosts that certain insects might be feeding on, and then they could move over to the crop.
Robert L Koch: In an indirect effect.
Anthony Hanson: All right, I think I got one last question that came in here Bruce that's actually a good segue over to.
Anthony Hanson: Tom Peters afterwards here, I recently talked a little bit about having some insect issues and sugar beets so it's kind of wondering what's been going on that works, we don't always cover sugar beets as much on this webinar but every now and then we'll get some in there.
Bruce Potter: Well, we have been given just over the last week or so will be getting some reports of black couple rooms in sugar beets in ranville meeker county area.
Bruce Potter: And that that the timing fits the size, the size of the cutler and spits.
Bruce Potter: So in there and talked to one guy yesterday one consultant yesterday, and he was saying they were taking off some fairly large beats, but they were cutting below ground so.
Bruce Potter: it's more than likely black cup rooms that are doing that makes a little harder to control and cut worms if they're if they're not coming above ground.
Bruce Potter: You know insecticide they have to come in contact with insecticide so.
Bruce Potter: Sometimes you know cultivation, if you can do that helps get that insecticide down, where the cut worms are get some little more active or some rain will get them to move to the surface.
Bruce Potter: So it's a we're starting to feel the lack of laura's ban and a couple crops and sugar beets and fell for other two were having problems, just because of.
David A Nicolai: Okay, well, thank you Bruce and Bob any more questions that it came in Anthony at this point in time.
Anthony Hanson: I think we've.
Anthony Hanson: got nervous cleared out so far.
David A Nicolai: So.
Anthony Hanson: If anyone has additional questions feel free to add them to the Q amp a box and we'll get them address for you okay.
David A Nicolai: Well, if those guys will hang around a little bit we'll see if we have any questions that have come in in the other remaining part of our program but i'm going to jump over to week control.
David A Nicolai: And with this Tom Peters is the extension we control specialist for university of Minnesota and North Dakota State University primarily working in this in the sugar beet area I should say not primarily, but he is.
David A Nicolai: But it gets questions from from all over and those types of things and Tom you certainly been busy of us last year, maybe just segue a little bit about.
David A Nicolai: We talked about labels all the time, and we have an older herbicide at least older because it relates back to what I am as as as older and and that's a Su floor ruffin.
David A Nicolai: Are blazer and and you have a section 18 of all crops in in sugar beets and maybe tell the folks a little bit by in terms of weed control.
David A Nicolai: Why are you doing this and why do we need a blazer and a sugar beet crop here in in Minnesota maybe a little bit of background i'm gets into a little bit on on our wheat spectrum but.
David A Nicolai: what's what's the reasoning behind this.
Tom Peters: Dave you're right.
Tom Peters: All blazer or ultra blazer or ask the flat earth and is indeed an oldie but goodie it's been around for many, many years.
Tom Peters: it's primarily a broad leaf herbicide and it is primarily a pig weed herbicide so not much activity on lambs quarters, if you have kosher needs to be small.
Tom Peters: But the reason why we're interested in in in blazer in sugar beets is, we have a lot of glyphosate resistant water hemp and in some years we have escapes escapes from our soil applied herbicide program so I want to make sure our listeners are clear.
Tom Peters: laser is not our our number one program for water hemp control the idea of blazer is to control escape weeds from those other programs.
Tom Peters: Use of outlook, the S matola Clark products or warrant or at the fumes eight which goes by a number of names North tron ethan tron neck tron.
Tom Peters: So what we're doing is we're using ultra blazer to get the escapes so and sugar beet, that means sugar beets that are at least at the six leaf stage and we're making one application of a pint per acre.
Tom Peters: blazer with a non Ionic surfactant because we think the oils are too harsh and then under extreme conditions will add glyphosate to the mixture as well and we're getting some adjutant you know contribution from the glyphosate formulation to so it tends to be a little bit hotter.
Tom Peters: That that application is.
Tom Peters: approved and it'll be in effect through the month of July.
David A Nicolai: You know, you can we can translate that really easily I think Tom over to soybeans because you use the same type of reasoning, when we talk about.
David A Nicolai: You know, putting the pre on it in a soybean situation, but now you know, I was out down to the Rochester area and observed, you know, a whole host of land lambs quarters that are emerging, etc.
David A Nicolai: And we talked about you know whether it's whether it's not just blazer and ultra plays which you can use, and so I beans, but we have other products that are that are group and so forth, that would be applicable in soybeans or post emergence.
David A Nicolai: Maybe back up here a little bit and talk about all of those that particular site of action or mode of action when we talk about weed height and also you know axillary buds and so forth, I mean there's a limit here to what we can expect you know it's not certainly glyphosate.
Tom Peters: And I have to I think you're making a good point Dave and I have to temper everybody's expectations so ultra blazer is most effective on pig we that's less than four inches tall.
Tom Peters: So the other thing that's really key is you've got to get good coverage, which means you've got to use a lot of water and i'm thinking 15 gallons i'm thinking.
Tom Peters: there's guys that use 25 gallons of water to get good coverage now The other thing going on Dave, especially on bigger sugar beets is sometimes the sugar beet partially.
Tom Peters: covers the weed and you know how pig weed is water hemp is there's so many growing points sometimes the the water hampel recover from the other side of the plant that didn't get good coverage.
Tom Peters: So you're absolutely right ultra blazer is not glyphosate 2.0 it's a it's a a fix that we have to try to clean up or get some of the escapes in these fields.
David A Nicolai: So I guess My point is well taken in about any of the other group 15 years I mean they're they're going to have a similar activity it, regardless of the crop when we talk about that that we that we growth correct, even in a situation.
Tom Peters: Absolutely and and you, as you said it, the strategy is really the same and soybean and and sugar beet and, to be honest with you.
Tom Peters: The whole program came from Bob hartley at iowa state, I mean he was the one that started talking about a layered approach and soybean and I thought heck if it works and soybean let's give it a shot and sugar beets.
Tom Peters: So that we're using a pre an early post and elite post plural a seat of my program now and sugar beets to control pick weed.
David A Nicolai: We have a lot of traded soybeans out here, and some of the enlist and so forth, that even have a fascinator liberty trade.
David A Nicolai: Just a little bit about that, I mean we're getting into post emergent situation, even with glue fascinate although maybe not doesn't fit you know some of these other categories as a as a true.
David A Nicolai: group 15, but we still have a weed size we've got cut offs.
David A Nicolai: In here in terms of our height, when we talk about and in our one on particularly even on so I beans, where we have to when we bought something and I.
David A Nicolai: There is a really good publication I think phyllis is going to put it up here in the in the box here and in the chat box, a little bit out of.
David A Nicolai: purdue and also another one out of out of Illinois that I came across one of them is on a growth rate of growth stage cut offs for herbicide applications and corn and soybeans I our good friend.
David A Nicolai: Down bill Johnson and producer puts this together, and I like to use sometimes gets a little bit ahead of where we are.
David A Nicolai: and so forth, so this has been out there, but since we're behind a little bit typically on our where our crops are emerging, I think it's still a clickable.
David A Nicolai: The only thing is that that kamba obviously has a different situation in Minnesota here and then also.
David A Nicolai: Out of Illinois is there was the residual soybean herbicides, where you can apply those posts emerged over the top, if you haven't haven't got those on So those are in the in the boxes as well, I think we have some questions that came in Tom.
David A Nicolai: Any you had a chance to look at those a little bit you want to comment on.
David A Nicolai: On some of those that we received already.
Tom Peters: Well, you know we've been talking a lot Dave about pre herbicides and because of circumstances, because of the lateness because of the need to make sure we get planting done not everybody gets a pre emergence herbicide out.
Tom Peters: So and i'm going to switch over to soybean now, because that would be a bad day and sugar beet so in soybean what do I do if I have broad leaf weeds.
Tom Peters: And I didn't get a pre emergence herbicide out and i'm going to say you better be scouting weekly keep an eye on those fields, because they change it's incredible with these moisture and temperature situations how our fields are changing and make sure that you're.
Tom Peters: spraying small weeds you know what traits are in your product, you know what other Co herbicide mixtures are available you're sure that you can assess those problems.
Tom Peters: Our products this year that they're available to to purchase and you already alluded to a Dave in southern Minnesota you're done using you're done using.
Tom Peters: The guys north of interstate 94 we still have 15 days but we're going to give five days away because we've got a couple of days of wind and then we've got a couple of days of hot temperatures so we're starting to get limited here a little bit.
Tom Peters: um one good news is it's a perfect season now for liberty herbicide liberty likes he liberty likes humidity liberty like son and we're certainly getting all three of those so i'm expecting good performance from liberty herbicide.
David A Nicolai: Well, and certainly you have to keep in mind using enough water, I think, in those situations where we've had problems in the past.
David A Nicolai: And of course it really likes those warm temperatures, as you alluded to Tom you know it's going to work that much better under those conditions.
David A Nicolai: You know that we're going to get really hot here Monday we're we're talking forecasted high 99 is there anything that we need to be careful about poster merchants when it gets that warm.
Tom Peters: I don't like to spray when it's in the 90s, to be honest and I don't think our products are.
Tom Peters: They don't perform the same way when it gets excessively hot so first of all, I would encourage our listeners, not to spray when it's 9095 degrees.
Tom Peters: The response on the crop is going to be unacceptable and, quite frankly, our weed shut down so they don't grow and.
Tom Peters: And a lot of these products that interrupt different pathways in weeds well they're not working so we're not we're going to be disappointed in in the control.
Tom Peters: Now, if you have to spray Dave I would prefer that you spray in the evenings take advantage of the cooler portion of the day, as compared to getting out early in the morning and then have that product be during the hot part of the day.
David A Nicolai: A couple of questions that came in Tom one was how long will residual herbicides be effective and I know that's it's a little bit of a crapshoot opinion to find when they were applied, but typically there's a limit that's the reason why we do layering.
David A Nicolai: But if you look at you've had experience, obviously with outlook.
David A Nicolai: And a lot of different crops what's your expectation for product like that in terms of efficacy going forward yeah.
Tom Peters: So if you can get it in the ground remember these products are they need to be incorporated into the soil.
Tom Peters: So if you get rain on them, I think they're three week products Dave and that's one of the reasons why we layer them, because we know we need more than three weeks of control, so the coral a seat of mines in my book, are three weeks products, maybe for for lucky.
Tom Peters: jumping into the some of the soil applied PPO inhibitor products and soybeans so i'm thinking about valor and I want to contrast that to.
Tom Peters: Some of the authority products authority is a longer residual product, I think you can get eight weeks, maybe 10 weeks out of that one valor is is a shorter residual product probably four weeks, maybe five if you're lucky.
Tom Peters: Some growers are using metro buzan in soybean and that's another four or five week product that we get residual control from.
Tom Peters: So the short answer Dave is it's going to be dependent on environmental conditions, certainly getting rainfall to get it activated and then the chemistry itself.
Tom Peters: And we haven't talked about some of the long residual ALS inhibitor herbicides, but some of those are full season herbicides they're not used as much as as as the ones that i've mentioned.
David A Nicolai: will certainly that state of stale ALS and then they talk about metro abuse and there was a question that came in from one listener about metro abusing and Atrazine.
David A Nicolai: Evidently, this is a rotating ground so i'm considering that probably corn or soybeans are involved, but using one or both with pre's on rotated ground in there i'm always a little concerned about soil pH and where they're where they're from, but I would be kind of caution to.
David A Nicolai: use both of those in a rotation situation what's your what's your feeling.
Tom Peters: Well, first of all they're part of my arsenal there in my toolbox, so I love Atrazine I don't know as much about metric abusing.
Tom Peters: But, but we see it in soybeans lot as well it's in some of the pre mixes that we have so i'll focus my remarks, a little more on Atrazine.
Tom Peters: I I like to use Atrazine i'm very cautious about the rate so pay attention to the rate you're using.
Tom Peters: And, and you hit hit it on the head Dave you've got to be aware of your soil, how much organic matter how much what's the texture your soil and, of course, what the pH of your soil is.
Tom Peters: So under high pH conditions, these products are going to be more active immediately under low pH is and by low I mean maybe 7.2 or less they're going to be bound to soil and they're going to be more likely to carry over.
David A Nicolai: I think what.
Tom Peters: Genes one last thing good try as things are broken down by microbes Okay, so if we get good rain and i'm thinking six into the rain and and June, July and August we generally get microbial degradation of those products and they don't cause any problems to our rotation crops.
David A Nicolai: One of the last questions I wanted to get to and there was another one that came into Q amp a box i'm going to respond separately with that one.
David A Nicolai: But that is, we have a lot of enlist soybeans and I know that situation if we just look at growth regulators, whether you're in northern Minnesota can still use a di camera or whether you're using.
David A Nicolai: More than list and listen to all products, you know what with glyphosate.
David A Nicolai: talk a little bit about weed height when it comes to that, and you know we've got oftentimes weeds coming up in variable height So how do we deal with a field.
David A Nicolai: That has variable height, I mean some big some small are going to average that targeted what's a strategy in there because we're going to grow pretty darn fast here with this kind of temperature.
Tom Peters: yeah that's that's a tough question Dave.
Tom Peters: there's always going to be a range and part of that is species related so common ragweed and maybe lambs quarters, is going to be bigger.
Tom Peters: Because they emerged sooner they emerged earlier than the pig weeds so I, as a rule of thumb like to say, four inches.
Tom Peters: But I know that sometimes it's six inches or seven inches and I think that gets back to what we talked about earlier about coverage.
Tom Peters: If you want to kill these weeds you got to get coverage on them and I don't care that you're using oxygen herbicides, I still want to make sure that we're getting coverage on them, even within lists.
Tom Peters: herbicides so so let's be realistic about him sometimes weeds are bigger than we want them to be, which means you've got to use full rates.
Tom Peters: get good coverage select the right nozzles that are designed for the herbicides that you're using and try to get out there under the the right wind and air temperature conditions.
David A Nicolai: On our good friend Greg doll just.
David A Nicolai: offered here, please get great coverage to kill every growing plant on the planet, I think that's correct here.
Tom Peters: Now, and I meant to say that with water hemp.
Tom Peters: that's the nemesis with water hemp is on a planet six or eight inches tall there might be 20 growing points there might be 25.
Tom Peters: So what that means is you got to kill every one of those those buds to kill the plant and if you don't kill them all, we get regrowth and sometimes that regrowth is as bad as the original plan.
David A Nicolai: i'm going to the last question, I am going to answer this and Tommy Can you help me out here, if you think about perennial weeds we don't often talk about that, but perennial weeds.
David A Nicolai: And this person has alfalfa voluntary alfalfa coming up he's got extend soybeans it's about six inches high it's it's always been a tough one for for me for controlling you know in that situation any any thoughts in terms of that or we're dealing with somebody with a rich system.
Tom Peters: I thought you were going to answer.
David A Nicolai: that's my view.
David A Nicolai: um.
Tom Peters: Well, I just want to add to your observation or our listeners observation i've seen them a lot of fissile this year and, to be honest with you i've had more this'll questions in.
Tom Peters: than my 10 years combined, so there are systems out there there's dandelions out there out in the western part of the state in my area here we've got leafy spurge as well, so so these perennials are more problematic this year than other years you're absolutely right Dave.
David A Nicolai: So, but and in terms of that you have what's called you know, obviously the labelled rates in situations.
David A Nicolai: With alfalfa and perhaps six inches if you still can use a diet kamba I mean that's certainly an option, you know in in there.
David A Nicolai: You know, life is saying to but you'd have to use a very high rate, I think.
Tom Peters: yeah I i'm not we better be careful, on what we say about alfalfa not i'm not sure I don't know that you can even use a di cam but shouldn't be anywhere close to nfl food my opinion.
David A Nicolai: Well, this is volunteer in soybeans.
David A Nicolai: Coming Oh, I see what yeah so he's controlling voluntary alfalfa so.
David A Nicolai: I think you got to really look back at those labels and if you have a traded, so I mean or you can use it, I know that I remember the glyphosate label as to me.
David A Nicolai: At a high enough let situation here and there, but check your labels in terms of rates but certainly the bigger, it is the tougher tougher it's heavy to control and so, if it's six inches I think sooner the better, I think, in time, at this point.
Tom Peters: hey can I talk about a couple of things that are on my mind.
Tom Peters: Questions that i've got lots Atrazine so lots Atrazine is a very common treatment in in corn and.
Tom Peters: At least in central Minnesota West central Minnesota sometimes latisse Atrazine is on corn ground that's in rotation with sugar beets.
Tom Peters: So my rule of thumb is the 15th of June so it's the 15th of June today so we've got to start moving away from largest Atrazine.
Tom Peters: If we're worried about our our rotational crops, so I called out sugar beets, but it could also be soybean in the case of of lot us as well, so I just want everybody to be wary that the later growing season is starting to butt up against some of the rotational restrictions that we have.
Tom Peters: And then Dave you know, one of my favorite topics is is how herbicides breakdown and and there was a question about the season.
Tom Peters: And since we're applying our products later if that means we've got to worry more about carry over and and I don't think so, and here's the reason why.
Tom Peters: Our herbicide breakdown degradation occurs during the month of June, July and August and that's a combination of the temperature and the rainfall conditions that we get in those months.
Tom Peters: So just because we're applying things three weeks four weeks later than we normally are.
Tom Peters: i'm not overly concerned yet about while we're going to shift everything back and we're going to have a lot of herbicide carry over concerns so.
Tom Peters: I I would use these products to get your weeds control your weeds because that's our number one objective here and let's see what our rainfall conditions are air temperature conditions are during the month of June, July and August, to see if we get the microbial degradation.
David A Nicolai: Okay, thank you very much, Tom and with that we're going to end our program for today we'd like to thank you for attending strategic farming field notes there's a very short for question survey when you leave.
David A Nicolai: there's the sponsors, we want to thank again and Minnesota Soybean Research and Promotion Council, along with the Minnesota Corn
David A Nicolai: Research and Promotion Council next week we'll be back again Wednesday, that will be June 22 at eight o'clock with current crop topics in that situation so Anthony any last words otherwise that's all I have.
Anthony Hanson: that's most of it, I got to think through set a quick comment on that corn feeding.
Anthony Hanson: Maybe think about if you had BT corn that was in six need to feed a little bit first actually just the toxins and that's possibly what's going on there to just a little bit of reading, but the crop may have taken care of that issue.
David A Nicolai: Again, and thank you again for attending to survey certainly enter in any questions and so forth on fun thoughts about next week as well, so with that from the advertisement oh so essentially it's a Dave neckline, thank you for attending this week we'll see you next week.
Anthony Hanson: Thank you everyone.
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