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Join the University of Minnesota Extension Crops team in addressing all your crop-related questions this growing season, from soil fertility, agronomics, pest management and more. We will tackle issues as they arise to help you make better crop management decisions this season.
Well, good morning. Welcome to our Field Notes webinar. My name is Dave Nicolai. I'm an extension educator in in field crops. Today, of course, as in always, these sessions are brought to you by the University of Minnesota Extension and along with generous generous support, from farm families across the state of Minnesota, including the Minnesota Soybean Research and Promotion Council along with the Minnesota Corn Research and Promotion Council.
Dave Nicolai:Our guests today are are doctor Seth Naeve, University of Minnesota Extension soybean specialist, and, doctor Debalin Sarangi, University of Minnesota Extension weed specialist for corn and soybeans. And with that, we're gonna get the ball rolling, and we'll have an opportunity to ask questions of these folks as we go along, and we'll give them each of a proportion of the program, this morning in half hour. So with that, I'm gonna turn it over to Seth, talk a little bit about soybean management and that situation with that. And and, Seth, last night, we got a good line of rain showers moved across the state, some rather intense, 03:00 in the morning. I know they they came through the Twin Cities area, but it came earlier in other places.
Dave Nicolai:And so there's these soybeans are still at a little bit of a tender age here. You can talk a little bit about management, overall effects of what you're seeing in terms of weather and and growth. Any other comments you have?
Seth Naeve:Yeah. Thanks, Dave. And just to highlight the variability we have in my house, I'm not that far from Dave. I we didn't get a drop last night. So it's been highly variable out there.
Seth Naeve:I think, you know what, the good news for crops overall is that we've kind of broken some of this, you know, long, dry spell under a high pressure. But what is coming, we're not we're not they're seem to be kind of poorly distributed across the state. And there's certainly some areas that have had really heavy rainfall over several day and week period in West Central Minnesota, and then there's parts of the state that are still quite dry. But overall, the crop really got off to a good start. I my general feeling is dry springs really benefit Minnesota farmers.
Seth Naeve:There's a lot of chatter about dry conditions based on, you know, NOAA, drought maps, and things like that from traders and other otherwise that really discount this crop. But it's really good for Minnesota farmers to have dry conditions at at at overall at planting as long as we get rain and and rain rain's coming. And so I think it really behooves us. But the devil's in the details, and we'll talk with Debalin about getting post op sprays applied in a timely way and and, you know, nitrogen side dressed in some of these areas can be a real challenge. I think, we did have, emergence is quite high this year.
Seth Naeve:I think we're 83% emerged on soybean, and I think that's compared to 60 some percent. I don't have the, I guess, 73% on average. So we're well above average in terms of our emergence rate. We're a 100% planted across the state. And soybeans, honestly, are pretty similar stage most places.
Seth Naeve:They're they're definitely bigger in the South. We're at b two to b three in the South and b one kind of in West Central, and then just emerging when we get up into the valley, further north in the valley, but things look generally pretty good. But for those farmers that aren't in a perfect environment or that had got nailed by some of these heavy rains and some small pockets or even some hail. I did wanna mention a couple things about replants and and and those kinda considerations. It's middle of June nearly right now, and so we're right in the middle of this really drastic decline in yield potentials in soybean that start about June 1.
Seth Naeve:So up until June 1, we're still, like, eighty eighty five, 90% yield potentials, depending, in June 1. But by the time we get to July 1, we're kinda down to half. So, basically, the way I look at it, we lose about 45% of our yield potential across thirty days. That's a point and a half per day. That's also about one bushel per day we're losing in terms of having to replan.
Seth Naeve:So if you start counting back the number of days in June and add a few more in May, we're quite a ways back in terms of yield potentials if we had to replant today. We're probably 70% yield potential if we could replant today. If you look at the populations required to to replant, to have kind of a yield parity, this isn't an economic parity, but a yield parity, we'd have to have populations down around 40,000 plants in order to justify replanting on a day like today. So stands would have to be really, really bad, in order to rip things up and replant. But then I think it turns into a weed question, and this is much more for Dublin, and we can talk more about that if if that topic comes up.
Seth Naeve:But, certainly, we're we're talking more about aesthetics, a little bit about the economics of the situation. So the reality is replanting shouldn't be a a difficult question at this time unless we've unless we have a real disaster out there. So, and I think that luckily, I think this year, that applies to very, very, very few farmers, but, of course, you know, not every farmer is average. In fact, I would contend that there's no average farmers in Minnesota, and so we're we need to provide the information for everybody. So that's kind of broad overview of what I'm seeing.
Seth Naeve:I think everything's good. Oh, one more thing I wanted to mention. A lot of IDC in Western Minnesota this year, as early as I've seen seen it, it doesn't really bode well for us because early tends to kinda linger around. But sometimes things really turn around based on the weather. If we get the right patterns of rainfall and temperature, the beans can grow through that tough soil moisture and come through it pretty well.
Seth Naeve:We've had years that the weed looks really green at the beginning, and then everything's bad at the end. So I think, just keep our fingers crossed on this thing, but, looks like a pretty tough IDC here.
Dave Nicolai:You know, Seth, I have a a question. We we talked about this years ago from a replant perspective, and you've done some research and looked at this whether whether at this point in time, is it more appropriate to if we have a a a stand that's not very good, tearing it up versus trying to spike it alongside with another plant. And if you can move your planter over in that situation so you'll have differential, plants out there, what are some of the problems and so forth? We've also had crusting earlier in this year where folks had to, run a rotary hoe in some places in Southern Minnesota and, you know, the stands and so forth. But what are your thoughts or, you know, a couple of different ways to approach this?
Seth Naeve:Okay. To back up just a little bit with those kinda thinner stands, I think it's important to remember that we overplanned all of our fields in in preparation for some problems. We have research that says even down to as low as 78,000, we can have a 100% yield potential. This is that's not certainly what we'd want, and those would have to be really evenly spaced plants. But certainly down to a 100 or 90,000 plants that looks really, really thin out there, we can still do well.
Seth Naeve:So that's that's the first piece of that. Spiking in is really a logistics challenge for us. I think economically, there's no question that if a farmer at this point can spike in, pull back maturity by about a half of maturity group from what was planted, plant a stand that would give us a total of a 125 or a 150,000. So counting as the existing stand and then putting a number of seeds down to match that is economically gonna be the right way to go. It's it, We can maintain some of the yield potential from some of those existing plants, and we can cover some of our sins in those in those blank areas out there with with extra seed.
Seth Naeve:And this does us the most good with the least cost and the least damage. Ripping up an existing stand is really is really damaging because we've got if we start like I said, if we start over on yield potentials right now, we're at relatively low. We're we're at a lower yield potential level overall. We can only hope for about 70% yield potential overall. But, again, I think we'll go back to Debalin with this, and it's all about weed control.
Seth Naeve:What are the preeds? What kind of weeds do we have? Where are we at with those kind of things? If things if things really got away from us and we've got tough weeds out there, it might be better just to rip things up, start over, and start fresh. But, there's a lot of I think the majority of the question really is around managing weeds at this point because farmers can't afford to deal with, a whole season of of, tough weed control, issues out there, with a thin stand.
Dave Nicolai:I'll leave you with one last thing, and if anybody has a question about regrowth potential, you know, there's a lot of growing points on a soybean plant and so forth. But if you your cotyledons are there, maybe the unifoliate leaves, and but if you even if you knocked off the top and so forth, you still have potential there. Correct?
Seth Naeve:Yeah. I mean, look for green tissue. That's the that's the easiest thing. If you've got hail, look for green tissue. The more green tissue, the better.
Seth Naeve:The less green tissue, it just takes longer for them to come around. And if you just have a little stub sticking up, you got nothing. Corn, we're, you know, growing points pretty much above the the surface of the soil across most of the states, so we're in a different situation on the corn side than soybean side. But, with soybean, we just look for green tissue. And it's the same sort of a thing as I was talking about with thin stands.
Seth Naeve:We just have to really determine what we could do. But if we do have hail at this time, there is still an opportunity to spike in, if there is green tissue there. So we deal with it a little bit like having a thin stand, and there will be thin stands. So I think it's possible to get in, but I we'd I don't think we have the extent this year that we have in a lot of years at this time in terms of of hail damage, but I'm sure certainly, sure there are fields out there that are in this situation.
Dave Nicolai:If you're taking that final population, see how you did in planting or or stand, what any guidelines, a couple places in the field, the length of, counting beans in a particular area, what's more statistically valid or consistent, I guess?
Seth Naeve:Yeah. I'll turn that question on its head and, remind folks that they need to look field wide. There's a you know, we've we're all tied up with precision ag and technology and things like this, but the reality is if a farmer has 10 acres that are really at the far end of the field that are really suffering, the overall yield of that field can really be dragged down by by those acres. And so, it's important to know what's going on everywhere, and then make management decisions based around the whole field. It's it's very easy for me to say to get out of your truck and and go walk across fields.
Seth Naeve:But I think the reality is that's that's the important piece of this and because there are these things are very streaky. We've got low spots and high spots, and hail obviously comes in streaky patterns. Soil types differ for in terms of emergence issues. So, getting a good handle on the whole field and and getting a mental idea about what areas what proportion of the areas were affected and how traffic might work if if a farmer was to go plant replant a portion of it or the whole thing. Those are all things that farmers have to run around in their head.
Dave Nicolai:Super. Any last things? Otherwise, we'll, switch it over to Debalin at this point.
Anthony Hanson:Dave, there is one question.
Dave Nicolai:Oh, we have a question? Yes.
Anthony Hanson:Yeah. In the Q&A . Just wanna make sure we get that. Someone did ask how much more rain do we need for a good bean crop in 2026? There you go.
Seth Naeve:All of it. It's we're we're gonna take a lot. It's gonna need we're gonna need a lot of rain, and it depends on soil types and where you're at, but it's we're gonna need consistent rainfall, especially because we're not we're not full. But I really look at this on the other side is that we lose a lot to drowning out in Minnesota every year. And even on tiled fields, we have a lot of years where ditches are full this time of year, and even tiled fields don't drain well.
Seth Naeve:And so being a little bit short I I know I'm kinda being repetitive on this, but being short this time of year puts us in a very good spot. We just have to get those rains as as the questioner asked. The rains have to come, and so we've gotta get good measured rain. So, I mean, all I want is another inch of rain every week for the rest of the summer, and then we'll be fine. But beyond that, let's just, see what we can get.
Dave Nicolai:Alright. Very good. Well, as, we've talked a little bit about, Debalin, as Seth mentioned, it's it's critical in a lot of these considerations to think about weed control, especially in terms of moving the soil around, timely pre's and so forth. But there's a number of things that I I know that you would like to address because this is a very critical time for, any options and and strategies for post emergence there in terms of that in soybeans. So I'm just gonna turn it, the platform over to you, and, we'll go from there and see what kind of questions we have.
Debalin Sarangi:Dave?
Dave Nicolai:Yes.
Debalin Sarangi:Yeah. So you can hear me. Yep. So I think Seth set up the stage regarding the precipitation, in Minnesota this year. And I was, digging into some, precip data from Southern Minnesota from different locations starting from Lamberton, Waseca, Rosemont.
Debalin Sarangi:I was kind of trying to figure out how much precip we got. And we are way below than the historical precipitation in our growing season. So this year, I mean, we got, like, a little bit rain in last few days, but but in May, it was extremely dry. So what I have observed in the field is waterhemp emerged, back in, June 15 when, my students and staff member, they were traveling across Minnesota, and they found they spotted the first waterhemp around June 10, but it was very tiny. And for some reason, the oh, sorry.
Debalin Sarangi:Not June 10. Sorry. May 10. I'm sorry. May 10.
Debalin Sarangi:And those waterhemp somehow didn't survive, maybe due to the dry condition or something. Then we saw the robust emergence of waterhemp on May 15. And that that waterhemp survived, and they are probably right now, three inches tall. But the thing is waterhemp loves water. The the name waterhemp has water in it, and it loves water.
Debalin Sarangi:So we got a flush of emergence around May 15. And since then, we didn't see a major emergence for waterhemp, at least in the Southern Minnesota. So but if you look at the other weed species, like giant ragweed, lamb's quarters, or velvet leaf, they are right now at the stage, where you should spray your post emergence. So if you have other weed species than waterhemp, probably this is the time to, go out with your boom and put some post emergence herbicide because, lamb's quarter, velvet leaf, and giant ragweed, they are, getting taller. I mean, I checked a couple of the fields yesterday, and they are somewhere between three to five inch right now.
Debalin Sarangi:So probably at the stage of getting the post emergence. So then the question comes, what will happen to waterhemp? Because we got some rain, in last few days, and we're expecting a few more, incidents of precipitation in next few days. What will happen? So water waterhemp will come because with the soil moisture, it will trigger the waterhemp emergence.
Debalin Sarangi:So right now, the pre emergence is, pre emergence herbicide, if you put it, it is losing its efficacy. Now waterhemp is not there yet, but it will start coming with, the soil moisture. So I think it is a good strategy for this year to go out with the layering residual approach. Because if you put your, post emergence right now, a tank mixing with some group 15 herbicide like Warrant or Outlook or Duo will help you or Zidua, it will help you managing this upcoming waterhemp flush for next one month or so. And after that, it will be all on the canopy.
Debalin Sarangi:If your soybean and corn, it will close the canopy. It will take care of the water emergence in in July and onwards. So I think for this year, probably this is the time we should go out with first post emergence. If you see your weeds are close to three to four inch tall, but if you don't see much waterhemp, make sure you put some layering residual approach. Put some group 15 herbicide in the tank so that, you can control the future flush of And so another thing I want to remind folks is, you can always do the second post emergence.
Debalin Sarangi:If it is, if the field condition is good, if it permits with your economy, definitely, you can plan on coming back with second post emergence and maybe targeting waterhemp at that point. But depending on how much waterhemp emergence you got and how much waterhemp control you get from the layering residual approach. Now I know that glufosinate application is happening, and it is happening pretty widely in Minnesota. I want to remind folks about couple of the things. Number one, we recently confirmed glyphosinate resistant waterhemp in Minnesota.
Debalin Sarangi:So we found one population of waterhemp from Southeast Minnesota, which is register which is surviving the one times level dose of glufosinate. So I would remind the folks that relying on only one option, which is glufosinate, is not a wise decision. Maybe we should think about tank mixing another herbicide. It could be your L list. It could be something else.
Debalin Sarangi:But tank mixing, another mode of action or side of action with glufosinate will help. And another update, is not very pleasant news for us, the glufosinate resistance case that we found, it looks like it is metabolic resistance. We we have not confirmed that yet, but it is definitely not target site resistance. So if it is a metabolic resistance in the future, it will be very difficult for us to manage glufosinate resistance if the glufosinate resistance thing, become widespread in in our state or in this region. So, I would remind few things.
Debalin Sarangi:Glufosinate is still a good option for waterhemp management, and we should always, consider this fact that we should preserve this option. Right? So don't break glufosinate. So follow the, labeled restrictions for glufosinate. So don't spray any weeds which are more than four inch tall.
Debalin Sarangi:So always the weeds should be less than four inch tall because, because glufosinate is a contact herbicide. And if the weeds are too tall, you may, burn the top of the plants, but still the, plant will survive. Second thing is, using AMS. We have seen in the past using AMS, 1.5 to three pounds per acre. That definitely helps with glufosinate absorption and glufosinate activity.
Debalin Sarangi:Temperature and humidity. So, there are enough evidence that if the temperature is, eighties in eighties and humidity is high, glufosinate tends to work better. Sunlight. Don't spread glufosinate earlier in the morning or late in the afternoon because we need at least few hours of sunlight for glufosinate to works properly and the plants to absorb glufosinate. So, these are the things I want to remind the folks that please consider when you are spraying glufosinate tank mix and consider putting some AMS into that and consider the weed height, temperature, humidity, and sunlight.
Debalin Sarangi:Okay. Last thing I want to remind, folks about the dicamba application. So, I was talking to few people, with with with this year's dicamba option is back. Some people are using dicamba on soybeans, but I want to remind that dicamba restrictions is coming up. They're coming up because the the date for the application is June 12.
Debalin Sarangi:The cutoff date is June 12 in the South Of I 94, and June 30 for North Of I 94. And our state specific restriction is if the temperature forecast is more than 85 degree Fahrenheit, you you should not apply Dicamba. So I was checking the forecast for temperature next few days. It looks like next one week would be very good because our temperature is below, 85 most of the days. However, remind remember about the cutoff date.
Debalin Sarangi:If you're in the South Of I 94, June 12 will be the cutoff for you. And then record keeping is needed for Dicamba. And, please check the labels because you need to apply, volatilization reducing agent, VRA, and drift reducing agent, DRA, with Dicamba. And, also, check the label because you need to use the nozzle that will produce only coarse droplets. So no fine droplets are allowed with dicamba application.
Debalin Sarangi:And, also, there are some restrictions about the downwind buffer. Please check the label and, apply Dicamba properly so that we can reduce the drip top Dicamba. I think those are the updates I wanted to give out. Dave, any questions?
Dave Nicolai:Well, yeah, one quick question. When we deal with, herbicides that are more broadly perspective, and I'll just use Enlist as an as an example here. And you mentioned about lambs quarters, and I've noticed too, and some of these weeds are growing very rapidly. Is there a point I mean, these products are not the old Roundup or glyphosate when we're talking about situations. There is a proposed or rule of thumb limit here on height in there.
Dave Nicolai:Any mention about that? These would be weeds aside of waterhemp per se.
Debalin Sarangi:Excellent question, Dave. So last few years, I got couple of the phone calls that people showed me picture, people send me pictures, people send me seeds of waterhemp. Those survived two forty or at least one application. And I when I looked at the picture, my first impression was probably it was sprayed when the waterhemp lamps quarters, they are too tall. And we tested some of those seeds if those waterhemp is resistant to two four d.
Debalin Sarangi:It turned out those are not resistant to two four d. So those plants were spread when they're, like, six inch tall. So although two four d is a systemic herbicide, it's not like Liberty or glufosinate that it is is a systemic herbicide. But still, we have seen that when you spray Elast one, it is better to spray the weeds which are four inch or less. Because if you wanna get proper control of pigweeds or other weed species, always try to spray them less than four inch height.
Debalin Sarangi:Because this is from my experience. My students tested at least six or seven samples in last two, three years where farmer were pretty much confident that they got two four d resistance in their on their farm. And when we tested them in the greenhouse, it turned out those plants were absolutely sensitive to two four d. So that means those are sprayed when they're a little bit too tall. So or another possibility could be those plants were getting sub lethal dose of two forty because they are hiding under the canopy.
Debalin Sarangi:So, yeah, that's a very good point. So lot of people thinks that two forty is a systemic herbicide. I can kill the I can kill the pigweeds just like Roundup when they are even six inch, eight inch tall, but it doesn't work that way for two forty.
Dave Nicolai:Well, that's gonna critical because we have very warm temperatures this week. We had some moisture in some places, and and we're gonna get rapid weed growth so that that window is closing fast
Seth Naeve:Yes.
Dave Nicolai:Here hereby this this weekend in in terms of that. As we get towards the end, Seth, anything else that you thought of that you didn't mention before or any any comments? We didn't really have any other questions that that came in or any, words of wisdom you wanna leave with people?
Seth Naeve:No. I don't wanna dilute the conversation. This has been very good.
Dave Nicolai:Okay. There in that that type of thing. Deblin, anything else that we didn't, touch on? The only other thing I heard this spring concerns earlier on poor grass control. There was more of of foxtails and grass, more annuals.
Dave Nicolai:I I shouldn't say perennials. Some of that may be the the the mistiming in terms of soil activation of a pre versus when they emerge. And so that can typically occur, but there are some other herbicide options, obviously. There's a limit to how well glufloxacin will work on on larger grass, but something to watch out for. Any comments about that?
Debalin Sarangi:Yeah. So this is something I have also observed this year that we we we are getting more grasses than I would would say what I can recall from my last six years of experience in Minnesota, I would not say this is the the most, like, grass problem this year, but I would say this is one of the year when I have seen more grasses than other broadleaves. So, yeah, I mean, there are some options. I checked some of the fields yesterday, like, when we put Acetylchlore. Acetylchlore was controlling grass better than its competitive, like Pyroxasulfone or or Dual or Atrazine.
Debalin Sarangi:So, yes, I mean, grass control is a concern, especially if you're not using Acetylchlor. This year, I have seen as a pre emergence. But, again, those grasses are still under four inch, I believe. So if you need to go out and spray some Roundup because Roundup still works very good on the grasses. So if you want to put some Roundup or some SelectMax, maybe this is the time because I have seen those grasses like Uli cup grass, Foxtails.
Debalin Sarangi:They are, like, three to five inch again. So that I think this is very good time to control those grasses this time of the year. And and as I told you, I expect some waterhemp will come up. So when you clear up those grasses, it will make the way for waterhemp. So you should have some contingency plan for, late season waterhemp management this year.
Debalin Sarangi:Because with the rain, I expect the waterhemp will, keep coming.
Dave Nicolai:Okay. Very good. Comments to keep in mind, especially this week as, we approach the, end of the week and still have good crop and wheat growth. Well, we'd like to thank those people today for attending our University of Minnesota extension field notes and participants here, this morning. We also wanna thank for support the Minnesota Soybean Research and Promotion Council along with the Minnesota Corn Research and Promotion Council.
Dave Nicolai:We will be back again next week, next Wednesday morning with a very couple of timely, topics in terms of diseases, maybe a report to a little bit on on some other crops, as well in the in the sugar beet area. It's often used as a rotation, and we'll talk about some of those things as we go farther along. Thank you for attending today with that. So thanks again to Seth and to Debalin, and keep looking at your crop e news accounts, or you can just go and search for crop news. And we're trying to do is keep timely articles about their especially if they're weather related and other types of things, and other information that that comes through, from fertility, etcetera.
Dave Nicolai:So crop news is a good thing to check, when you have a chance or opportunity. Otherwise, that's that's all I had. I wanna thank, Anthony Hansen, this morning here for lending a hand, with the production. So we appreciate that, and we will see you folks again next week. We'll start at 08:00, next Wednesday.
Dave Nicolai:Thanks for attending.
Debalin Sarangi:Thank you for having us.
Dave Nicolai:You bet.