Managing issues after heavy May rains and early-season pests in 2023
Good day, this is Agronomy Update from the University Minnesota Extension. I'm your host Dave Nicolai along with my co host Doctor. Seth Nay from the University of Minnesota Extension. We welcome you here today to a little bit about our cropping situation here across the state of Minnesota, Certainly from an integrated pest management bent. Today is Monday the May fifteenth.
Dave Nicolai:The crop report Seth just came out from the USDA and of course they made a lot of progress from the previous week. We know that that corn planting on the report indicated that they were up into the area of 61%. Now we know that this report was done as of last Friday, certainly planting has progressed even far beyond that given the weekend and other opportunities for that. Soybean planting was also up was 30% but we know again a lot of soybean planting was done. But what about our historical average here, Seth, in terms of where we were last year on soybeans, five year average, things have changed.
Seth Naeve:Well, I guess looking back towards last year and if we can remember last year now, was, we had a pretty tough spring last year. So we were only at 10%. So we made some progress over last week. I think last week we were at 13%. So we're up to 30 on soybean this week.
Seth Naeve:So that was good. And we also made some progress relative to a tough year of last year. But the five year is 37, so we're just a little bit behind the five year. I think it's just like we always talk about farmers, when they have good weather, they can really hit the fields hard and make a lot of progress planting both corn and soybeans. But certainly we're gonna talk about the weather and its impact here coming up.
Seth Naeve:But certainly that that had a big fact, big effect, and it's gonna have a big effect for this coming week as well.
Dave Nicolai:I might say that the corn planting was at 61 and the five year average was 58% but we know that's probably even higher than that. But one thing that was in excess this last year particularly in some spots in South Central Minnesota and in other areas was moisture. When we look at even at where we are for topsoil and subsoil, our subsoil moisture was reported at 71% adequate with 21% surplus. So certainly but in some areas it was quite a bit higher. And so we needed someone on give us a bird's eye view of that and we've asked one of our coworkers, Bruce Potter to come in and give us a little bit more information.
Dave Nicolai:Now Bruce is with Integrated Pest Management Specialist and he hails from the Southwest Research and Outreach Center out at Lamberton. So good day Bruce and tell us a little bit about what's going on in that route of that area from, you know, in terms of everything from New Ulm to the Camprey to to Lamberton, what are people dealing with after this last week of excessive rains?
Speaker 3:Well, a lot of them are looking at pond ponded water in the fields. Most of the depressional areas are are filled up right now, some of the creeks and of course the rivers are are at flood stage, so it's it's been real wet. We've had anywheres from five to highest I've heard was 15 inches of rain over the since last Monday. So pretty unusual bout of bout of weather, and, you know, it kinda stretches from from a little bit west of here. The worst of it's kind of south Southern Brown County, Northern Walk county, but it this this wet streak over the last week has gone all the way, and they got quite a bit of rain all the way over towards Rochester.
Speaker 3:So kinda followed the Highway 14 core corridor, so it's wet, unfortunate. Would guys were making really good progress and pretty much got stopped last Monday.
Seth Naeve:Yeah. Last week's forecast, I mean, we had the whole state had, you know, small chances of rain, you know, thirty, forty, 50% chance of rain almost every day. And it just seemed like every one of these things ended up going through the same kind of path in in Southern Minnesota, didn't they?
Speaker 3:Yeah. Well, I guess I guess it pays to be optimistic. I don't know. But we get this we get these systems that kind of train through the same area. I was looking at the total precipitation maps, and it's almost like a line where the Minnesota River is.
Speaker 3:North of that, rainfall was moderate, and then south of that, it is where we got really really doused. So it's not not only did it bring up rain, but we we round up a lot migratory crop pests, cutworms, and armyworms. We had had a pretty non uneventful spring until last week, and and we're pulling are pulling in some big numbers now.
Dave Nicolai:Before we jump into talking a little bit about the insect movement, maybe just go back and talk Bruce a little bit. A lot of the crop that was inundated in here was it planted but not yet emerged? Was there any that you saw that was actually emerged at this point in time or was a lot of it, you know, in the soil yet in terms of that moisture, excessive in those lakes?
Speaker 3:Some of the earliest planted corn was was emerging. I hadn't seen any soybeans yet. A lot of the corn had not emerged yet. So, you know, even even over the weekend here now, I'm seeing on the on the higher ground, I'm seeing more corn poking through. But I'm I'm guessing that where the water standing, there's gonna have to be some replants.
Dave Nicolai:Talking about replanting here, Seth, from a soybean perspective, what's your your guidance when people ask about should I stick with the same you know maturity in terms of soybeans to go back in there or similar situation? If they're able to go back in the field later this week or next week if enough water has drained away. What do you you say in a lot of these areas of Southern Minnesota?
Seth Naeve:Yeah, it's, you know, we've always recommended waiting until June 10 has been our date. You know, what we have noticed over the years though is that, you know, farmers plant a really, start with a really broad range of maturities that they're already running. Some farmers are really pushing for really long season varieties for their area normally. And some have some real short stuff because they want to get in there and get some soybeans harvested early, or want to get manure out, or things like that. So we really have to couch our decisions based on what we're starting with.
Seth Naeve:And so if farmers are already really long already, they probably need to pull that trigger and back up a little bit earlier, go with a half maturity group earlier, you know, maybe around the June. So we still got a lot of time. So I don't think we're in any kind of situation where we even need to consider that in soybean yet. I think corn might be a little bit of a different issue for us though.
Dave Nicolai:I think Bruce you've been involved in some of these studies. Know that our Doctor. Jeff Coulter, our corn specialist talks about that we have on University Minnesota website for corn production and talking about a percent of maximum grain yield and some of these studies were done at Lamberton. Some of the data indicates you know planting the May 20 probably around at least 9092% of the maximum grain yield and if you get later it's it'll obviously drop down on May 25 down to about 87%. And then of course talking about recommended corn hybrid maturities you know by May 22 you know perhaps considering after that for that week and they're dropping back to maybe five to seven relative maturity units.
Dave Nicolai:But I think you mentioned before we talked on the air, it depends a little bit I think Bruce on what you start out with, right, in terms of corn hybrid maturities?
Speaker 3:Well, yeah, it does. I mean, a lot of guys are already planning, you know, shorter than the full season corn just because they don't they're trying to make sure they don't have to dry anything. Sometimes it works, sometimes it doesn't. But I think the other thing to realize too is that, you know, how this all plays out and what can you know, how you're gonna be your maturity is gonna be affected for corn really is gonna depend on what kind of weather we have. You know?
Speaker 3:And last year too, guys got guys got away with planting real late because we had that the rest of the summer was real warm.
Seth Naeve:Yeah. We're we're probably jumping the gun on our, you know, discussing this, but we wanted to get some of this stuff out there. And I think both the weather in the next week and then, like you said, it's ultimately affected by the weather late in the season is what the big driver is. You know, the only other thing I'd like to throw in here is a reminder that, you know, variety selection for corn and soybean is really the biggest driver we have in terms of managing for yield. And it's, you know, we have to assume that we did the best job of selecting varieties the first time around.
Seth Naeve:And I think farmers should accept that when they switch varieties or hybrids that they're probably not going to get as good a stuff as they had the first time. And so there's going to be some nick that they're going to take in terms of yield potential. And then, you know, I think you need to figure that in with the drying cost on corn or maturing time on soybean as well. So it's pretty complicated, but I think we've, again, I think we have a little bit of time to think about that. I think a bigger concern probably is getting the corn and soybean out of the ground.
Seth Naeve:And Bruce, you mentioned crusting earlier. Certainly there's going to be some heavy there was some heavy pounding rains, and just the quantity and the number of days of rain is really going to make some of these fields really tough for the crop that has not emerged yet. So what are you thinking about how to how to manage some of those things for farmers?
Speaker 3:Well, I think if they can get into the field, if it crusts and they get in the field and they've got the the equipment to do it, I mean, I would take care of it. You know, rotary hoe is a really good tool. I think the other thing that I don't know how many guys push were pushing to get stuff planned before the rain and got caught, didn't get a pre emerge herbicide on on soybeans. That could be an issue for some guys too. So I think my concern is, you know, at least in this area here, and and by all means, there's there's areas in the state that still want some more water.
Speaker 3:The extreme Southwest corner of the state, for example, hasn't hasn't had had much at all. But I think think around here, I think the issue is gonna be that we've got so many wet potholes, that sort of thing, that it's gonna be hard to get out and and into these fields. Part of them are gonna be dry and fit and crusted, and maybe and and the other parts are gonna be still pretty muddy, so it's gonna be a little bit of a challenge, I think.
Seth Naeve:Yeah. We just farmers just hate this kind of thing. And it's, you know, I think we all think of those really good years when we can, you know, get the crop in, move across the whole field, can get it sprayed and, you know, get it harvested without farming around wet spots. But we know that there's a lot of those. If you travel around Minnesota very much in the summertime, you see a lot of these areas that were delayed or they replanted something in them or even put some soybeans into some middle of some cornfields.
Seth Naeve:And it's not it's not what farmers like, but I think most farmers, you know, understand it and and have to deal with it enough that they have a pretty good handle on how to how to take care of those things.
Dave Nicolai:Maybe we should jump back and talk a little bit that Bruce you started off on on terms of some of these weather systems moving in, insect movement migration. I know that you've been involved in helping to coordinate you know a fairly good sized network here in the state of Minnesota when it comes to black cutworm trapping, pheromone traps, armyworm, etc. I know I have a couple out at Rosemont, but maybe give the folks a little bit of background what our attempt is this year and and what we're finding.
Speaker 3:Well, I think the thing the reason we've got these traps out is to first detect when moths are coming in, and we could kinda, once we know that and where they're arriving, we can kinda start looking at degree days and and give guys a little bit of a window on when to maximize scouting, when when, in the case of cutworms, when corn cutting will start, and then just as importantly, when those larvae are gonna start to be large enough that they're gonna quit feeding, so when you kinda get out of the woods on things. So what we do is we have a bunch of cooperators out there with pheromone traps, they check them once a day, and as these moths migrate in on weather systems from the South, the unmated males are attracted to the pheromones, they get glued into a trap, and and we get to count them. Like I said earlier, it's been it was pretty uneventful for the first part of the year when we had this last batch of weather come in. So last week, we started to pick up a lot of a lot of black cutworms, so we could have some issues with those.
Speaker 3:There's specific fields that guys are gonna wanna focus attention on, scouting fields that don't have BT in them, fields that have a lot of early season weeds, those sorts of things. And probably a little more concerning than the cutworms even are are the number of armyworms we're catching, and I got my I've been trapped looking at light traps since the seventies, and I set my personal record last Friday, a 193 in one night. So it usually means there's gonna be a problem somewhere as there's a lot of things that have to happen as far as egg hatch and larval survival and that sort of thing, but it's an insect we're gonna have to have to watch out for. So probably two or three weeks, you're gonna start larvae are gonna be big enough we can start finding those.
Dave Nicolai:Would you say the what crops from an armyworm perspective we really have to monitor and and be be aware of?
Speaker 3:The armyworms that we're dealing with here, the true armyworms pretty much only feed on grass. They'll maybe take a bite out of a soybean if they have to, but they can't they can't develop on on on non grass crops. So it's small grains. They like they're liking lush grass, so anything where you got a dense gross growth in a in a roadside ditch or something like that, pastures, winter cereals, those are preferred egg laying sites. Where corn gets into trouble a lot of times is if they've got a lot of grass weeds in there or or they're planting corn into a rye cover crop, those are the ones that really have to be scouted.
Speaker 3:Black cutworms were worried about corn and I think the other they have a wider host range than than the armyworms do.
Dave Nicolai:Any geographical area? I don't know. Maybe it's a little presumptuous here to talk about it from a black cutworm that people might need to be aware of. And, you know, sometimes we find more black cutworms along that I 90 corridor in set, but, you know, we're not quite out of the woods yet.
Speaker 3:Well, no. We're definitely not out of the woods and and stuff that fields that haven't been tilled when those moths arrive, those are kind of prime egg laying spots, especially if they've got weeds in them. And we had some earlier significant captures, one in Martin County, one in and several in Rock County. Those are those early flights, those are probably hatched now, and the guys are out scouting weeds, those sort of stands, those sorts of things. Look for leaf feeding on the corn, look for leaf feeding on the weeds.
Speaker 3:Those larvae are gonna be big enough to cut corn plants in well, probably the very last week of May, you'll you'll start to see some larvae large enough. And this last week now, we've got anywhere as long that South of the Minnesota River, and then anywhere we're starting to pick up high camp captures of black cutworms all the way into Olmsted County.
Dave Nicolai:So if people want to stay up to tune and say catch with this, I know that you are involved in a regular almost weekly newsletter. Can people access that and just go to the the Lamberton site if they're not already registered and receiving the electronic newsletter?
Speaker 3:Sure. You can you can just do a search on black cutworm trapping networks, Minnesota black cutworm trapping network, or go to the the Southwest Research and Outreach Center and and look under research, and and you'll find that site there.
Dave Nicolai:Alright. Sounds good. Maybe a little bit more we can should talk we talked a little bit earlier about diseases. We mentioned crusting already but are we still concerned and with this wet environment and seed treatments and so forth things to be aware of and and watch out from your perspective?
Speaker 3:Well, I think anytime you have, you know, flooded soils or saturated soils, you have the an increase definitely have an increased potential for seedling diseases. Some of those things like sudden death syndrome, they're infected now, if those seedlings are in wet soils, but you don't really see the symptoms till later on. Some are more immediate, things like pythium, fusariums, and I think we're probably warming up to even start seeing some phytophthora as these soybeans emerge. But
Dave Nicolai:Those are probably some of the some of the key wins, like you said before, fusarium, you know, and I think Dean Belvek mentioned about Pythium, you know, but kinda it depends upon the the temperature too, doesn't it, in terms of that? What we
Speaker 3:would say? Pythiums tend to be, you know, there's exceptions because there's a lot of species of that of that genus fungus, but Pythiums tend to like a little bit on the cooler side, Phytophthora is a little bit on the warmer side. Fusariums are kind of multifaceted or multi they're pretty adventitious.
Dave Nicolai:Now you might be talking about this in about another week or two, but alfalfa weevil, other alfalfa insects, is it is it too early? I mean, we're getting warm temperatures. I I know the alfalfa in other places has really picked up. Things that you would suggest people be watching for?
Speaker 3:Well, last Monday, we started to see the adults moving into alfalfa here at at Lamberton. And so it's it's time to get out and start scouting, and, you know, you're gonna notice some some of the feeding on foliage, but a sweet net's the a tool to take out there, and and you can see if you've got larvae or or adults present, and then a a little more detail scouting to figure out if you've got enough to worry about.
Dave Nicolai:For the alfalfa weevil larvae, correct? So Yep. Correct. You know, they can always look up on Alina, think on your site you've had some other information about that, you know in the past and in in terms of that. Anything else about crop stand or just making those assessments out there if if you're gonna go out in the in the field as as far as you know population and things to be mindful of depending upon the soil type and cloudy.
Dave Nicolai:Any other suggestions if even if you're not in an area perhaps that that had excessive rainfall. Is this a good time to go out there and try to make those stand assessments, or would you want to be up one two leaf here?
Speaker 3:Oh, no. I think as soon as the crop starts emerging, you should be starting to take a look at it because you're gonna want to look at, you know, pre emerge weed control. You're gonna wanna see if there's a problem early. The earlier you find it, the, you know, the better off you are if you have to do some replanning. One thing in the case of stand reducing insects like black cutworm or other other cutworms is, you know, we're looking at percentage of cut plants, those sorts of things, but it but it kind of depends on where you're starting out at.
Speaker 3:And if you've got already have a thin stand, you can't tolerate the the cutworm feeding that you could if you got it have a have a good emergence.
Seth Naeve:Yeah. And the only other thing I'd chime in on this is that, you know, to encourage farmers to get out and and scout whether they're whether they're stuck watching watching the the their crop kind of dry their soils kind of dry out to to get back in there to plant some more or whether they're in an area where they're actually going pretty hard. We we didn't spend a lot of time talking about kind of Western Central Minnesota and Northwestern Minnesota, where it's been a little bit drier and they've had a little bit better luck. But I think farmers really need to continue to think about getting out there and getting across all their land. Remember that those fields are really highly variable, and there's a lot going on beyond just that field road or the gravel road that goes beside their farm.
Seth Naeve:And get out and scout. You know, a lot of these folks have really nice side by sides. It's a good time to go cruise around and check things out and make sure that they got what they think they're getting and that it's uniform across their whole field. Because it'd be a real shame if they have something that doesn't go diagnosed here early on that they could actually correct. This is a good time to correct some of those potential problems with planting or, you know, other disease or insect related issues.
Dave Nicolai:I just want to echo, Bruce, what you said before about the early season weeds. I was talking to doctor Joe Eichley out of NDSU and you know already up in the valley there's quite a bit of waterhemp that's emerged. We've got you know Rosemont area and of course Central Minnesota. So they're gonna come up right away with that and if you don't get a pre on you know you consider you know there might have to be post emergence options you know here you know all right away even sooner than you expect depending upon the situation or if you haven't on maybe a layer. But it it doesn't take long and and in terms of that especially the next couple of days here, the temperature is back in the seventies.
Dave Nicolai:Your soil temperatures, I presume Bruce have warmed up at Lamberton. So Well a lot of weed seed germination.
Speaker 3:Yep. Seen a little bit of everything already. So a little bit of waterhemp, but and and fox starting to see a few foxtails coming up. Definitely, the lamb's quarters are doing real well right now. Ocean.
Dave Nicolai:We've seen a lot of lamb's quarters really even here on Saint Paul campus. You know, it's quite thick as a matter of fact. So it doesn't doesn't take long in terms of that. Well, at this point in time, we want to thank Bruce for coming on board and being our guest today here on Agronomy Update. We appreciate that doing these things on a weekly basis.
Dave Nicolai:So we might want to mention that we're also engaged in a various webinars including air field notes, which is a Wednesday morning program that runs from eight to 08:30 from the University of Minnesota Extension and you both will be guests or have been and will be in the future on that's a little bit different tactic. We we do with those and again those are our weeklies too and we can have a little bit more visual but this is a this is a podcast on the go Seth in terms of that. So thank you very much again Bruce for coming by. We appreciate that. We thank you to Seth for running the operation here, getting things going, and we look forward to visiting with you again next week on Agronomy Update.
Dave Nicolai:Thank you.
Speaker 3:Thanks for having me.
