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Hosts Anthony Hanson, Dave Nicholai, and Bill Hutchison at the University of Minnesota alert growers, ag professionals and educators about emerging pest concerns with Minnesota Field Crops, including corn, soybean, small grains and alfalfa. They offer useful, research-based pest management solutions.
Dr. Anthony Hanson, IPM Educator - Field Crops
Dr. Bill Hutchison, Coordinator of the MN IPM Program
Dave Nicolai, Crops Extension Educator & Coordinator of the Extension Institute for Ag Professionals
Good day, welcome to Agronomy Update from the University of Minnesota Extension. I'm your host Dave Nicolai. Today is May 8 and I just like to start off a little bit in terms of where we are in terms of planting corn, soybeans and other crops around the state of Minnesota. First of all, we made quite a bit of progress in terms of corn planting this last week. We are now according to USDA Minnesota State Ag news that came out at 38%.
Dave Nicolai:This is dramatically farther ahead than we were last week at this time we were only 5% but we're very very close to the five year average of 39% in terms of corn planted. My co host Doctor. Seth Nave, University Minnesota Extension soybean specialist is with me and Seth, where are we in terms of soybean planting and are we doing a good job?
Seth Naeve:I think we're doing a good job. We're catching up a little bit. We were at 1% last week and now we're at 13% officially. So certainly, you know, as on the corn side, we got a lot of a lot planted over the weekend. So this is all relative to Friday's census, believe.
Seth Naeve:Those numbers are usually taken. So we're we're definitely catching up. Last year, we were 21%. Or I'm sorry. And the in the historical average is 21%.
Seth Naeve:And last year, we were just at 2% this week. So, you know, we're I think we're doing okay. This is you know, we've had a little bit of a tough spring here with a lot of snow, cold weather going very late this season. So I feel really good about where we're at. We're definitely getting soybeans in along with the corn.
Seth Naeve:And so whether farmers are planting both simultaneously or farmers have just banged out quite a bit of their corn and now are are working on soybeans in some of these areas. It's a little bit hard to tell. But driving around the state last week, I did see a lot of soybeans going in in South Central Minnesota. So I think it's just gonna follow through Western Minnesota and then into Northwest as we get a little
Dave Nicolai:bit better temperatures coming up. Certainly we've had some hit and miss showers in some places in the state of Minnesota. We still had some of that snow that was melting up in Northwestern Minnesota. But the bottom line on the report indicated our subsoil moistures was still rated at 72% adequate and 14% surplus. So not too far off where we were the previous week.
Dave Nicolai:So where things are going well there. Sugar beet planting, I know talking to Doctor. Tom Peters out of our joint NDSU UofM weed specialist. Tom indicated that in some places Breckenridge and down into the Renville area, they had at least half of the sugar beets planted if not more. And you know they could rapidly close things off in the next week or two.
Dave Nicolai:Much farther though behind in terms of sugar beet planting when we get up to the Moorhead area and on north. So we wish those folks good luck in terms of that. What we'd like
Seth Naeve:to I just, you know, I'd just like to mention, I mean the forecast is not very good. We're not seeing a lot of sunshine on those little symbols our phones. And there's a lot of clouds and a lot of twenties and 30% chance of rain coming up for much of the state over the next week. So I think that's a big part of this question is, you know, farmers getting out there and taking advantage of working days right now while they have them and making some progress now. So I think that's an important piece of where we're gonna go.
Dave Nicolai:And that's an excellent segue to our next portion of the program. I'd like to introduce a gentleman that's fairly new here to the University of Minnesota, Doctor. Deblin Sarangi and Deblin is our University Minnesota Extension specialist in weed control primarily working in the crops of corn and soybeans. And we're gonna talk to Deblin a little bit more about some of that weed control that has to get started now even as you mentioned Seth in terms of these intermittent showers when we talk about pre emergence and so forth. But before we get into the subject matter, do you wanna talk, Devlin, a little bit about your own background?
Dave Nicolai:You know, how long you've been here at the University of Minnesota and a little bit more about what your work entails here?
Debalin Sarangi:Thank you. Thank you, Dave, and thanks for the introduction. And hi, Seth. So, yeah, so my background, I did my bachelor's and master's in a foreign country. It's in India.
Debalin Sarangi:And then I moved to United States to do my PhD in Nebraska, and I worked on glyphosate resistant waterhemp, which was, like, that time, it was a big problem. Now we have more multiple resistant weeds there and palmaromerate there. But, that that was a time, like twenty thirteen, fourteen, when I started my PhD, glyphosate resistant waterhemp was the biggest issue. And then I moved to Texas A and M for one year to do some research fellow job, and I worked on palmaramaranth there, and then moved to Wyoming, and then came to Minnesota. And so, yes, waterhemp and palmer amaranth definitely, two biggest species that we are currently working on at U of M.
Debalin Sarangi:And, also, we are working on other species like giant ragweed and foxtails. So yeah, we are pretty much targeting the major weed species in the state.
Dave Nicolai:Now some of our audience might be aware of the fact that your predecessor in this position was here for many years, Doctor. Jeff Gonzalez, and so you're in a similar position as Jeff was. But I think your program also entails in addition to extension, have a research component. Yes. Graduate students, quite a few in terms of that.
Dave Nicolai:So you're balancing a lot of things.
Debalin Sarangi:Yeah. So we have three graduate students and we are planning to bring one or two more this year. So we are growing and we are doing a lot of applied weed management work and doing some cover crop work because we know that cover crop can do weed suppression earlier in the season. But in Minnesota, due to our unique weather and climate pattern, we don't have much cover crop acreages. But it is increasing, I can see that.
Debalin Sarangi:So there is a need from the stakeholder to work on that direction. Also, are working on some other novel technologies like harvest time weed seed control, and we are working on some remote sensing technologies. So we are trying to do some traditional applied work that will help the farmer today, and we are also trying to do something that will probably help the farmer in the future. So we are trying to balancing that out.
Dave Nicolai:Well as we indicated when we started the program here, we had quite a bit of corn planted. We're rapidly moving up that and same within soybeans. Is there a recommendation that you would give to growers? Know we're looking at the weather forecast and there's always a chance of showers sometimes more than others. How important is pre emergence weed control in the long run here in terms of managing our weeds?
Dave Nicolai:Are there things that we should be really trying to take care of, especially this coming week?
Debalin Sarangi:Yeah. That's definitely a good point. And so just to let you know, today my graduate student went to our Rosemont farm and sent me a picture of waterhemp coming up. So today, it's May 8, and waterhemp coming up. And lamb's quarter is already up.
Debalin Sarangi:Giant ragouti is already up. So so, yeah, like, we are rushing for soybean and corn planting, but weeds are also rushing to come up. And as I recommend every year that your sprayer should follow your planter, don't don't be too behind, and then you cannot catch up anymore. So the preemergence should be down, and it should be within three days of the crop planting. That's what we say.
Debalin Sarangi:Because most of the preemergence should be down before your crop emerges. And with the soil moisture and warm days, the soybean and corn will be up soon. So it is better to put those preemergence down. And I talked about waterhemp today. So waterhemp, like, it is it can emerge throughout the season.
Debalin Sarangi:It's not like the emergence is done. It's just started, and it will keep emerging throughout the season. So it is better that we put some prees down so that we can control some of the early emerging cohorts of waterhemp and some other weeds like lambsquarters. And then maybe we have to come back with post emergence in the future.
Dave Nicolai:How critical is having some rainfall? We know we talk about getting a pre emergent on but while we're concerned about getting that herbicide into what we call soil solution into that top portion where a lot of our smaller weed seeds are located in there. Briefly, are there some rules of thumb as to how much rainfall would be desirable if you could, you know, in fact order it up, but if you can get ahead of it. What's your feeling on that?
Debalin Sarangi:Yeah, so in extension we call like activation of the prees, so you need some water in the soil to activate the prees. But definitely, if you have more rainfall, then you know, those herbicide can leach down. So we say usually quarter to one inch rain is good for activating the pre's, but sometimes like half inch rain can work best for most of the herbicide.
Dave Nicolai:I know there's quite a bit of concern, know, when things come in that we might get, you know, behind. We've talked about weeds emerging a little bit later. I think one of the things that we're experiencing right now this coming week is warmer air temperatures, Seventies, some close to 80. Seth I did see that the temperatures, soil temperatures at Lamberton in fact had have jumped up quite a bit to in into the sixties. So you know it's it's good obviously for planting emergent soybeans but also weed seed at the same time.
Seth Naeve:For sure. It's all it's a race. Know, last week we talked about pathogens and you know, the warm temperatures ramp up activity of the pathogens. They ramp up activity of the weeds along with our crops that we're planting. So, you know, I we I think unduly as agronomists put a lot of emphasis on temperature because, you know, we want we want our corn and soybean to get off to a good start.
Seth Naeve:But the reality is, you know, that cold temperature is also, you know, pushing down on some other things. On the other hand, when we we have conditions like now where we're in potentially a bit of a rainy period, but with warm temperatures, you know, it's good to have our crop out, but we also have to be concerned about those weeds that are under those same kind of situations or conditions and can, you know, push through as well. So I think that's this whole point about, you know, getting our pre out is that we don't know when we're gonna be held out of the field due to rain. And, know, these these pathogens, and and in this case the weeds, continue to emerge and push up.
Dave Nicolai:I want to go back to talk a little bit about PREs. And there was recently some research, Deblin, I noticed that came out of Missouri in terms of concerns over resistance in some of the HPPD inhibitors and waterhemp. And I think one of the comments in that those folks made was the need for a PREs that contain more than one mode of action so forth. You wanna highlight a little bit why you know even though we're not Missouri, is it still important here in Minnesota do considerable multiple modes of actions even in a PRE situation and for other folks that may not be familiar about, why do we care?
Debalin Sarangi:Yep. I'm I'm aware of this news that came out of Missouri recently regarding HPPD resistant waterhemp. And HPPD herbicides like Callisto, Loudaise, or Balance, those are definitely strong herbicides in corn, and that has a big presence in corn production. And if we lose those chemistries, that will be really big challenge for the corn growers to control weeds like waterhemp or palm aramarin. So that's why it's a big concern, and I'm aware of that.
Debalin Sarangi:And just on the same note, I just want to tell you, recently, one of our graduate students finished the screening of waterhemp population from Minnesota, and we screened about 90 population. And so far, my so far my results we are still analyzing the data, but so far, my results shows that we we have some HPPD resistant waterhemp in Minnesota, and it's like about twenty percent of the population came out positive HPPD resistant. So in the future, near future, we'll see that population will grow. So what I'm trying to say is, yes, I mean, relying on only those chemistries may not be a wise decision. So we may need to think about tank mixing them with other herbicide like atrazine or some metrolochlor type product like dual type product so that we get, multiple modes of action to manage those weeds.
Debalin Sarangi:And, you know, there is a big concern for, metabolic resistance with this, HPPD resistant waterhemp and things. And, you know, metabolic resistance, we probably don't have much time to talk today, but metabolic resistance is another level thing. So we so far, we know about target site resistance, which is our roundup resistance or ALS resistance like classic pursuit. But metabolic resistance is the next level thing where you don't know which herbicide it will be resistance. If it is showing resistance to HPPD, let's say, Calisto, it may show resistance to other chemistry.
Debalin Sarangi:So it's pretty complicated thing. So we should not allow them to grow. We should just control them at the beginning with multiple mode of action.
Dave Nicolai:So in the pre that you're perhaps purchasing for application, it may already have things but you know maybe consider those situations with that if you've been overly dependent on one mode of action you know year in year out. Even if you're in a corn soybean situation you know it's just every other year and you know so some folks would say that's not a real rotation because things come come back together again and certainly with that. So I guess to sum this up in terms of a pre emergence, you ordered up a perfect rainfall here, if we could get close to that half inch would be desirable. Quarter maybe but half half a little bit more in terms of getting it into into that soil solution. And so we can get that's basically what we're talking about is activation.
Dave Nicolai:Yep. And down in there and that type of thing with that. One of the things that we've talked about in the past was layering. Where say for example, you have a you know a really bad waterhemp situation. You might make one application but post but maybe come back with another one.
Dave Nicolai:You wanna explain real briefly what is that definition of layering?
Debalin Sarangi:Yep, so as I told you, waterhemp can emerge throughout the season. At least we saw this year, May 8, we saw some waterhemp emerging in the Southeast Minnesota. And also, we saw last year some of the waterhemp emerged close to late July. So there is a chance you get a big window for waterhemp emergence. So you need to have some kind of pre herbicide down.
Debalin Sarangi:Suppose you are spraying Roundup or Liberty as your post emergence treatment, it is wise decision to put some pre's with the post tank mix so that it will control the later emerging cohorts of waterhemp. So there are options available, for example, herbicide, comes in tank mix like Acurone or Acurone Flexi, you can split the dose because the label allows to split the dose and put as pre as well as part of the rate you can put as a post. So that is one option. And another option would be having some kind of product like Warrant or Dual or Outlook in the tank mix with your foliar applied herbicide and get it out in your post emergence timing so that it will give you a little bit more wider window for controlling that late emerging cohorts.
Dave Nicolai:Now we've been cold and we're finally warming up, Seth, towards warmer. We talked a little bit about that but you know a lot of people say we're gonna have things simultaneous come up with that. I know you've been down to your drainage site in Southern Minnesota. Maybe it's a bit on the early, you're going down there this week. What do you hear from folks in there?
Dave Nicolai:I don't think we've got too much corn that's emerged other than Southeast Minnesota.
Seth Naeve:Yeah, that's right. There was a few fields that went in in that area of South Central Minnesota that were able to get in during that April period. But I wasn't able to row any of the corn yet. I'm sure there's there is some corn that is coming up. So there is some some corn out there.
Seth Naeve:But most of the corn went in last week and and the weekend before that, as I think the vast majority of that area where there was a lot of rapid planting going on at that time. So, you I think the question that we're really running into, and I kind of have question for Deblin about it, is if there is a weather forecast that's looking for slight chance of rain over a full week period, if we have 40%, 50% chance of rain every day for a week, you know, farmers are out there trying to get in those last soybeans in Southern Minnesota and maybe get in some corn in Central Minnesota. How do you balance this question about planting versus getting a pre on? And how do they make those kind of choices at that level? Because, you know, we've got a lot of farmers that are farming a lot of acres, but they may not have the help to be able to do both operations at once, or they may not have a co op that's able to spray for them.
Seth Naeve:So how do they make those choices of operations, planting? I guess it really comes down to planting versus spraying in some of those situations.
Debalin Sarangi:That's an excellent question, Seth. So usually when you talk about pre's, those prees should be down before your weeds and crops emerge. So that's by definition. But some of our prees that are allowed to be sprayed when the crops are emerged too, so from emergence up to certain stage, you can spray those breeze. So you still if you pick those herbicides, which has a little bit wider window for spraying and give you some residual control in the soil, you still have some some option left.
Debalin Sarangi:And sometimes, you know, if you as you said, like, sometimes they don't have enough help. But if you have enough help or if you can plant and spray together, like, it's best idea to do it so that your sprayer does not fall behind from your planter. But, you know, we understand the situation of the farmer. They have to work around the nature and the climate and weather, everything. So yes.
Debalin Sarangi:And if in case, like, you really wanted to put a pre down, but you could not due to some circumstances, maybe come back with a early post emergence application so that the weeds cannot rob your yield and the weeds are really tiny to get controlled with those herbicides, because we always talk about less than four inch tall weed to be controlled with the post emergence application. And then in the tank mix, you can put some soil residual herbicides that will give you a little bit more control in the future.
Dave Nicolai:I think that's a very good point because we're probably going to run into that in a lot of areas, maybe Northwestern Minnesota and some other areas of the of the state as well. Because if if you're in a situation where you can't plant, you get rained out and maybe have part of the crop planted, part of it not. And by the time you get back there are emerged weeds probably in what I would call the seedling stage or that one to two inch. And you know you might have to consider that because we talk about reach back with some of these pre's and I think it's very limited when we get much size on in terms of these weed sizes. So I wouldn't count on that you know situation certainly you want to continue maybe with the PRE but you have to think about other things.
Dave Nicolai:If it turns dry which it doesn't appear to be and only we can go back to rotary hoeing and incorporate the PRE. But right now I think we're looking at our weather forecast and according to what you talked about earlier, Seth, not having those little sunshine icons out there on the weather map.
Seth Naeve:Yeah, think so. And you know, as you guys were talking, it kind of reminds me that it's a good reminder for folks to study their weeds 101. Because, you know, knowing what species they have in their fields and knowing what's resistant and not. I mean, we've got species out there that grasses and things like that that we know that we can hit with our Roundup, you know, those things can be cleaned up pretty easily here in this early season. But if you've got resistant weeds, then you're going to have to be more selective with your chemistries, especially if we get, you know, into a post emergence kind of a situation.
Seth Naeve:So, you know, it's all about managing risk and it's understanding where we're at. But I think that knowledge base helps reduce some of the risk that we've got when we get into these situation, potential situations where we've got some rainy periods coming on.
Dave Nicolai:I think the weed ID is certainly important. Think, Devlin, you mentioned before when the grad students saw small waterhemp come up. We know I've talked to the folks in sugar beets farther west in Chippewa and Renville the same thing. You know giant ragweed will be the other one that comes up comes up early. I think the thing about waterhemp was we used to say well don't worry about it'll come up later but now this the last couple of years, it seemed to come up very early in with a with a sawworm.
Dave Nicolai:So it comes up early and just stays with us.
Debalin Sarangi:Yep. And I'll go back to that comments about early post emergence. So be careful if you're thinking about applying the post emergence. It should be down ASAP because within a within a day, the water ramp in a warm day, like 85, 90 degree days, they can grow like one inch per day. So that's another thing you should consider when you are thinking about early post emergence.
Debalin Sarangi:It should be really early if you skipped your pres.
Dave Nicolai:Okay, rapid growth. Seth, as we kind of close into the end of the podcast here on
Seth Naeve:these No, have a niche kind of question or comment. I guess it follows my question earlier about getting these PREs out. So what about these farmers that do have cover crops out there? What would you talk what would you say to farmers that have a cover and are planting soybeans maybe into a green situation and about, you know, terminating some of those covers? What advice might you give them in this kind of a situation where we do have warm temperatures coming and potentially some a bit rainier period coming at least?
Debalin Sarangi:Yeah. That's a good question. So one of our graduate students right now is investigating this cover crop thing and how we can adapt this cereal rye cover crop in Minnesota in a best way. So we did one year research last year, so this year will be the second year, then we can kind of conclude it. But I can tell you a few things we saw in the first year.
Debalin Sarangi:Number one, that if your cover crop gained a lot of biomass, that definitely helps with your weed control, especially the early season weed control. But we also saw that in soybean, it's going fine, but in corn it does not go well because that much biomass corn cannot handle, probably with our equipment and with our soil condition and environment. So if you're planting corn, yeah, my best suggestion would be terminating cover crop in a tillering stage, which will gain some biomass, not really too much biomass that will shade out the corn. However, for soybean, you can probably little wait a little bit, go for planting green that we saw that there was no yield hit compared to, like, regular tillage and herbicide methods. And if you can put like, when you are terminating your cover crop, if you can put a pre down with that, that's the perfect choice because that gives you more time for your postemergence treatment.
Debalin Sarangi:We saw that with waterhemp, lamb's quarters, and giant ragweed. We saw exactly same thing that if you have a cover crop, gain substantial biomass, suppose you're planting, like, late May soybean, and then you have a pre down with Roundup when you are, like, when you are terminating the cover crop, perfect choice. And we saw like it gives more window for weed management.
Dave Nicolai:Again, use of glyphosate obviously is I think part of the part of the question in there. Any last comments of anything else in terms of weed control, weed science that you want to make here as we close out?
Debalin Sarangi:Just watch out for your weeds to emerge because you know like there are are weed species that are coming up. Giant ragweed up in the Southern Minnesota, waterhemp is coming, and lambsquarter, I saw a lot of lambsquarter. Woolly cupcress, I saw a lot of woolly cupcress right now. So, yeah, please check what are the species coming up and based on that, select your pre's. Because sometimes those pre, like, let's say you are using dual or warrant, they cannot control the emerged weeds.
Debalin Sarangi:So in that case, maybe something like like which one has, like, some foliar activity, like Acuron type product that can be a best choice, especially for corn growers. So, yeah, check out what are the weeds right now in your field. Maybe you have done your tillage two weeks back or one week back, so there is a substantial time that weeds weeds started emerging. So check out that and happy planting and we'll get back to you in middle of the summer probably with post emergence recommendation.
Dave Nicolai:Well good advice to stop what you're doing sometimes and take a look at those fields that have already been planted. If you're in the middle of planting somebody else can scout, if you can't scout but someone should be taking a look at these fields as we progress and go forward with that. With that we'd like to thank again Doctor. Deblin Sarangi, our our new University of Minnesota Extension weed scientist. I shouldn't say new but I've been here for a while but it seems that well since COVID so we really appreciate you stopping by here for the podcast for this week and then on behalf of Seth Naeve, my other co host here, we'd like to thank Devlin for coming by and providing that information here on Agronomy Update and with that stay safe and have a good day.
Debalin Sarangi:Thank you, thanks to both of you.