Corn and soybean yield updates

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I'm Ryan Miller, crop extension Educator earlier this morning.

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Anthony Hanson: These sessions are brought to you by University, Minnesota extension, as well as generous support from the Minnesota farm families through the Minnesota Soybean Research Motion Council, as well as the Minnesota Core and Research and Promotion Council. So we're glad you could join us for today's session on our agronomy Updates and can what to expect. For, you know, trying to predict, yield, and what might be happening. When we look at what to expect or when it comes to harvest time here.

Anthony Hanson: and my name is Anthony Hansen. I'm a regional extension educator and integrated pest management based out of Morris. And today we welcome both Dr. Jeff Coulter and Dr. Seth name our University of Minnesota extension agronomist, and both corn and soybeans.

Anthony Hanson: So with that, I think I will turn it over to Jeff to start off. We're gonna talk about corn first. I know you have to leave a little bit earlier, and then we will talk to Seth a little bit later here, too. So if anyone has questions specific to corn, please get those into the QA. Box, and we'll go ahead from there.

Anthony Hanson: Alright. So, Jeff, that's a start off. How are things looking overall for corn across the State so far in terms of just overall status to crop development to growth stages.

Jeff Coulter: Yeah, thanks, Anthony. Well, it's

Jeff Coulter: turned around. It's looking looking better. I would say. In general, it's quite variable across the State. We got areas that have had a somewhat timely rainfall, and we have areas that are excessively dry. Up until recently. And

Jeff Coulter: So we did lose a fair number of kernels at the tips of the ears around pollination. It was quite warm and dry during around pollination, and afterwards, so we had some kernel abortion or drying out of kernels near the tips of the ears. But recently we've picked up these rains and that has started to help us.

Jeff Coulter: Right now we're at the late milk to early dose stage, for corn and corn can continue to lose kernels through the end of the milk stage if they're stressful conditions. But after that, then the kernel number is set. So we're, we're basically at the point now where the corn is transitioning into the main grain filling period. So

Jeff Coulter: ech, sufficient moisture will help that green filling period and result in bigger kernels and drier conditions will just put stress on the crop and result in in smaller kernels, but not not change the number of kernels per year.

Jeff Coulter: basically, from this point onward.

Anthony Hanson: Yeah, I think that's a good point. We talk about Colonel Abortion. I've heard Lot folks talking about that lately where they've gone out into their fields earlier on pollination, and thought they had a decent size cob out there, and a lot of folks definitely noticing that abortion or die back on the tip there.

Anthony Hanson: So that kind of gets into one of the main questions people have this time of year. It's how do we actually go about estimating yield in corn? At least what we can expect and how valid are estimates right now compared to what you'll actually get. Come harvest time.

Jeff Coulter: Well, yeah, we could start taking yield estimates. Once we get into the DOE stage.

Jeff Coulter: because at that point the number of kernels per year is set. Basically the 2 yield components in corn or any crop is, how many kernels do you have? And what are the weight of those kernels? So for corn we would go out into the field and pick some representative ears, count the number of rows.

Jeff Coulter: and that would typically be 16, or maybe 18. And then we would multiply by the number of kernels per row on average. Excluding the kernels near the tip that aren't really a full kernel.

Jeff Coulter: and and may have aborted or have some other issues with them. So, and also maybe excluding some of the kernels near the butt of the ear, that

Jeff Coulter: aren't representative of a a a full kernel all the way around the cob. So typically that'd be like 16 kernels long around and about 34 kernels long on the ear. So you multiply those 2, then you would multiply by your final plant population, which in many cases might be around 33,000

Jeff Coulter: plants per acre, and then you divide that number by the number of kernels per bushel, and the number of kernels per bushel is something that you have to kind of guess on.

Jeff Coulter: If we have very good conditions for grain filling that would result in big kernels. That would be, you know, sufficient moisture, not too high temperatures, a long extended grain filling period. We can assume that there will only be 70,000 kernels per bushel. So those are going to be big kernels.

Jeff Coulter: On the other hand, if we've got droughty conditions, and the crop is under stress, and that grain filling period is compressed, then the number of kernels per bushel may be upwards of 85,000.

Jeff Coulter: So

Jeff Coulter: you have to kind of make an estimate here of what the kernel size is, and how many kernels per bushel there will be. So you know, you could divide that that numerator number, either by

Jeff Coulter: by the number of kernels per bushel somewhere between around 70,000, 85,000, and that's kind of a guess, and you know the difference in the yields between which value you use for number of kernels per bushel can cause yield swings of around the range of 50 bushels and acres. So it's important to think carefully about what you would use to

Jeff Coulter: estim what number you would use for kernels proposal. And it's it's essentially a guess at this point.

Jeff Coulter: but it does give us an idea of where we're at, and I think it is helpful to know what you have for rows per year and kernels per road and final plan population, just as a reality check, for you know what is really there, because that's kind of the framework for what you're gonna get yield. But at the same time it is a guess and you know, we really don't know for sure until the combine rolls through the field.

Anthony Hanson: Yeah. So one of the things you brought up. There is basically just the length of the growing season if that gets compressed, and I hate to bring the subject up. But this is one of our this is our second to last session, so we won't be covering things in fall, but

Anthony Hanson: we'll be thinking about frost, and maybe a month here. So and

Anthony Hanson: kind of for corn at least, what is our main concern for temperature there, where we're definitely looking at? The die off of the crop there versus what can it tolerate to some degree there? Well, still, get them some dry off and maturing of the corn kernels in there.

Jeff Coulter: Yeah, when the air temperature gets to like 28 degrees, that's really starts to shut it down. That's typically a killing frost. But yeah, when we when we also, when we get these nights that are unusually unusually cool, you know, in the first part of September. Those also help to kind of

Jeff Coulter: help to turn that plant to

Jeff Coulter: kind of shut it down a little bit to get it, sensing that the end of the growing season is coming. I think at this point we're really not in a situation where we need to be concerned about frost. Most of our crop is about 10 days ahead of normal, in part due to the warmer conditions during the early vegetative period, and also due to the drier conditions. I just kind of accelerated the maturity status of the crops. So I don't think we really need to be concerned about frost this year. If we can continue to help

Jeff Coulter: have the type of temperatures we're having now, like, early this week, where it's the, you know, highs and the

Jeff Coulter: low to mid-eighties and sufficient moisture if we can extend that as long as possible, and just have a very comfortable weather. That's good to help to result in large kernels especially given that. We've had some tip dive back on the ears where we've lost some of those kernels on the tips, so there aren't as many kernels as there would be in a season where we had excellent conditions right after pollination, and therefore I think we got good potential to fill those remaining kernels quite well.

Anthony Hanson: Well, one last little bit about weather, but we've been talking about hail a lot this year starting in July especially, but into August year, too. So there have been some folks that have gotten hail earlier on some just last week, so what could you expect? And corn, at least for those that have had hail damage. And they're trying to work with her adjusters and trying to figure out just how much damage they're seeing.

Jeff Coulter: Yeah. Well, the worst time to receive hail is right at tasseling, because at that point you haven't set any colonels. You haven't filled any kernels, and all of the leaves are exposed as we go beyond tasseling, it's still not a good time to receive hail, because all the leaves have been exposed. But at that point. The further along we get into growing season, the better it is for the crop, because essentially.

Jeff Coulter: you know, the kernel. More of the kernels have been set, and they're starting to fill some. So we received some hail over the last weekend. In some areas it was quite severe.

Jeff Coulter: you know the good news is is that the number of kernels were essentially set at that point, or almost set completely. So. But the bad news is all the leaves are exposed, and there's no more leaves that are gonna come out and compensate for the ones that are lost or damaged. So the hail that we had recently could have a a very big impact on the yield. You know that looking at the yield reductions

Jeff Coulter: could vary greatly based on the amount of leaf loss and stock damage and whatnot. But you know, losses in the 30 to 50 range are not uncommon

Jeff Coulter: for the hail this time of year or greater. So you know that's not good. And

Jeff Coulter: Then we get the stock bruising that comes with it, and that can result in poor stock quality and lodging potential later on, which can result in down corn difficulty getting that harvest at the end of the year. For growers that are having issues with down corn. I would in where it looks like it could be really challenging with harvest. I would suggest. Looking into some of these specialized reels or sweepers on the corn heads.

Jeff Coulter: I know they're expensive and maybe difficult to get with short notice. But they can really help with the getting those years. So we have less harvest losses.

Jeff Coulter: Some other things are, you know.

Jeff Coulter: if for corn that was damaged by hail this time of year. Some people think that would be good silage corn to use for silage if they weren't planning on it earlier, and that is true. But there are a couple of things that one might want to take into account, you know, first off that silage may have a lower grain to stover ratio. Just because the grain yield reduction may be greater than the reduction in green biomass

Jeff Coulter: and therefore it's probably gonna have lower starch levels lower quality. We could also see some micro toxin issues potentially in the ears. If there were hailstones that hit on those ears and cause some bruises there and open things up

Jeff Coulter: and then there is also potential for nitrate high nitrate levels in the silage and that can happen when we don't have a a large year on the plans. And

Jeff Coulter: there's really

Jeff Coulter: and the nitrates essentially cumulate in the plant because we're unable to translocate as many nutrients into the year, and that is also exasperated when we have droughty conditions later in the season, so that may be a concern if the drought persists especially for hail damage corn to avoid potential issues. With that one can raise the height of the cutter bar up to like 10 to 12 inches.

Jeff Coulter: I know that reduces your tonnage, but it does avoid, or it avoids harvesting that lower part of the stock which can really accumulate the nitrates and then things to think about. If you have this poor quality silos that you're trying to use is to, kinda you know, dilute it with better feed stuffs, so that the overall quality of the of the forage that you're feeding or the diet isn't

Jeff Coulter: reduce that much. So a lot of things to consider. But yeah, I think that kind of summarizes the hale situation.

Anthony Hanson: Yeah. And that gets into one of the questions we had coming into that you just covered was based on the silence side of it, then drought to nitrogen. So yeah, that definitely helps a lot. And your other comment on this corn ears are those getting bruised? I can remember a few years ago, and some fields I was in. It's sure, distinctive smell when you get in some of those fields, and you can smell porn for the kernels actually fermenting out. They're the ones that got bruised.

Anthony Hanson: So it's not something that people will notice if they actually did have a damage on that there. So again, thanks, Jeff, I know you have to run here quick. So yeah, it was great to kind of get a overview of kind of our last steps here hopefully for corn before harvest there.

Anthony Hanson: So with that, I think we'll switch over to Dr. Seth native, and we'll talk about what's going on with soybeans here. So yeah, I think it's been a variable year for our sorrybeans, too, hasn't it?

Seth Naeve: Alright? Yeah, it's I think you know, Jeff basically summed the year up pretty well. And I. You know, we we

Seth Naeve: the things that we talk about in corn basically follow along. Does soy Bean pretty well?

Seth Naeve: So I think you know, I think there's some some nuances to it, of course. And I think

Seth Naeve: soybean just reacts a little bit different. It's it's seed filling period. And the way the the plant is is built. and what it mobilizes to the seed at the end of the year makes things a little bit different, and and Soybean is also a crop that

Seth Naeve: is more photo period dependent than heat dependent.

Seth Naeve: But not entirely. So I there's some really interesting things going on with the crop in terms of maturation, and and through the stress and drought, and you add the heat into it.

Seth Naeve: So there's a lot of lot of interesting things happening this year, for sure.

Anthony Hanson: Yeah. So one of the questions I've had coming in prior to this is just it's the variability question. So I mean there's been some fields to just seem like. So even instead, take off canopies never really quite closed, and so so on irrigated ground in some cases. So it wasn't just the drought and have you heard many reports of that, or kinda speculation on what might be

Anthony Hanson: causing this kind of failure to perform soybeans. There's not obvious disease or high drought stress situations.

Seth Naeve: Yeah, I've gotten. I've have. I've had more questions this year about just odd, poor development and ugly soybeans than I've ever had in any year previous. So that's and I've been here 25 years or so. So it's it's been a really interesting year, and of course it's easy for me just to to blame the drought universally.

Seth Naeve: You know. But when we do have those fields that are irrigated. You know it. Really it it. It shows my ignorance pretty clearly. That that these things aren't all related to soil moisture. But I think

Seth Naeve: definitely. We had an the the year that we had this year with with quite a bit of water early, and then drought hitting right away right after planting was was kind of a perfect storm for us to really

Seth Naeve: it really exposed a lot of our weaknesses in terms of fertility in terms of you know, early soil, soybean development.

Seth Naeve: no, till soybeans looked really crappy this year. We had really poor development in no till soybeans, even though

Seth Naeve: theoretically we should have maintained some soil moisture there longer. They still didn't look good. You know, and there's lots of streaky fields that that farmers are relating back to some sort of nutrient application in previous years.

Seth Naeve: We can see some things lining up. But yet the soybeans weren't able to, to, you know, capture anything from some new fertilizers in some cases. So an Idc, of course.

Seth Naeve: So lots of early season problems

Seth Naeve: the the one that's really interesting to me recently, and II know I'm not giving you any good advice on these things. Except for that, II do think that there was a lot going on this year in terms of

Seth Naeve: rooting. Ii really look at this thing relative to where those active roots are, or or where the roots are active in the soil relative to soil moisture.

Seth Naeve: and I think we just had a different

strata in the soil or profile in the soil. We've we had roots chasing that moisture down into the soil.

Seth Naeve: We didn't get any that replenishing rain that we normally have at the top.

Seth Naeve: and that we. We were just pushing those roots down deeper in the soil, and I think I think we have some stratification, some of our nutrients.

Seth Naeve: You put that, together with lack of mineralization in some of those zones where the roots where we might have some water, but not enough to really mineralize any nutri nutrients.

Seth Naeve: and I think it caused us some problems or exposed some issues that we wouldn't have seen otherwise.

Anthony Hanson: Reliable. Hopper. Sure.

my recommendations for

Seth Naeve: for estimating yields and soybeans by just telling them not to do it. I think it's it's all you know, these folks that are out there estimating yields are really

Seth Naeve: They claim there's a lot of science behind this, but what they do is they count a lot of pods and then they adjust by what they. It's the same thing that Jeff recommended for corn. Exactly. It's a little bit more complicated because

Seth Naeve: we don't have ears, and we have larger number of plants, and so it's not. It's not quite as clean for estimating yields. It's not not quite as easy to estimate yields and soybeans or seed number. I should say it's not as easy to estimate seed number on an acre basis and soybean.

Seth Naeve: But then these folks that go out and estimate yields. They basically apply a fudge factor that says, well, we're going to have larger, smaller seeds at the end of the year.

Seth Naeve: And that fudge factor is what's creating the yield out there, that's what's that's what's giving them above or below trend line yields. and that's all the stuff that we can see ourselves by looking at these fields? Do we have good canopy? Do we have nice tall plants?

Seth Naeve: Do we have good soil moisture? What's the 1014, 30 day forecast. Those are the things that are gonna create seed size for us. And you don't have to count seed in order to know what we've got.

Seth Naeve: Soybean has an amazing of capacity to increase seed size. I'm sure farmers have seen soybeans that have come from fields where the the seed codes actually split.

Seth Naeve: So we can have. We can have the soybeans that actually grow so much at the end of the year that they split out of their seed codes

Seth Naeve: we can add at least 25% to our yield by just increasing seed size at the end seed.

Seth Naeve: And I'm I'm working with my crew this year. And we're we're really. I'm really hellbent on determining

Seth Naeve: or exposing this idea, that seed that Soibi yields can be seed, limited, seed, number limited

Seth Naeve: and and identify where those occurring. I don't think that occurs very often in fields. We're almost always limited by seed size, because we just aren't able to put on enough at the end of the year. So if we have perfect conditions.

Seth Naeve: we can, you know, it's just like everybody says, you know, August makes means it's absolutely true. We did take the top off of our yield. the potential yields out there because we don't have really good

Seth Naeve: tall soybeans with good canopy closure. We did not capture all of the light necessary throughout the year to build that machine.

Seth Naeve: to now put that into place, to to manufacture those beans here at the end. So we don't have. We're not gonna be above trend line on these yields. But we have an opportunity to have really, really good yields out there if things continue.

Seth Naeve: And again, I'm rambling. But the caveat here is is that we're seeing some weird things relative to maturation. And I mentioned. The soybeans are are photo period dependent, and that that affects, you know, the the maturity, the soybeans.

Seth Naeve: But I'm getting some calls on some soybeans that are targeting, starting to yellow up. Mostly, I would say that that's probably a combination of stress and heat. And again, it's probably just cause. I don't really know what it is, and that's that's my best guess.

Seth Naeve: But the heat is definitely pushing soybeans. We we know we can look at the crop reports, the the weekly crop reports, and we can see that soybeans have have more than caught up for any any delay that they had early on.

Seth Naeve: So the heat is definitely pushing them.

Seth Naeve: The problem is is, if it pushes them through maturity, and we have a quick seed filling and things end up earlier than we would like out there and match mature early because we have really high temperatures. And it sounds like we've got really warm temperatures coming next week that could add to this

Seth Naeve: that could really reduce our our yield potential. So even with good water.

Seth Naeve: if if the heat really pushes these things in maturity. We're we're in in a bit of a bind. And the only thing that might save us at that point is some really long maturing maturity soybeans that some farmers, have been been pushing the maturity envelope a little bit.

Seth Naeve: and they may actually come out the other side on a year like this a little bit better. So, anyway.

Anthony Hanson: maybe you could slice and dice that a little bit.

Anthony Hanson: Yeah, the last question I have for you is kind of same. I asked Jeff, too. But yeah, what about hail scenarios? And when growers are working with their jesters, what should they expect? Whether it was the last hailstorm we just got, or case with our family's farm. It was back in July. We got hail and just it up. I'm gonna wait till August and we'll come back out later and see how things look.

Seth Naeve: Well, it's it's the same way that I, you know, same follows the same theory that I did with, you know, yield estimations of soybeans as we really don't. It's really difficult for us to predict

Seth Naeve: but you know there's been a lot of hail studies, and we know what that does to the crop, and it is, I think, a nice contrast or caveat relative to Jeff. And and the timing is that

Seth Naeve: soybean. This is absolutely the the most critical time for leaf removal in soybeans right at R. 5.5. That's 5.5 is when we have. It's easy to see in the field. It's basically when those laughs, little leaflets appear at the very top of the plant kind of at this terminal racem at the top of the plant, when we've got a bunch of little leaflets, and then maybe hopefully, a few pods starting to show up at the very top of the plant.

That's R. 5.5 when the soybean quits developing any new leaf area. So it's halfway between beginning seed and full seed, which is R. 5 and R. 6. So R. 5.5.

Seth Naeve: And so this is the period that's most sensitive to hail, and so study after study have demonstrated that you know, if if you remove a hundred percent of the leaves at this period, and and you just leave the stems out there. We we have about a 75% yield loss.

Seth Naeve: But if we go down to about 50% defoliation, we can still get by with about 80% of our yield potential. So there's still a lot of potential to come about. There's a lot of yield to occur and accrue, I should say.

Seth Naeve: from here on out. So there's a lot of opportunity to rebound. But. on the other hand, this is the most sensitive time. So this is the time when soybeans are are most affected because it both removes that machine that's going to be utilized later for photosynthesis and create that seed.

Seth Naeve: But also those leaves are really rich resources of of protein that would be translocated to the seed late in the season. So we lose both a storage unit of yield

Seth Naeve: as well as actual that machinery to make the yield. and I would just pile on by saying

Seth Naeve: that I think a lot of us forget that that a lot of that yield in Soybean is actually in those leaves, and so that I call that yield in the bank.

Seth Naeve: So as long as we can maintain those leaves

Seth Naeve: and the bigger canopy that we've got that's yield that we've already is right there, and all we needed. All we need to do is help that plant move that yield from the leaves stored in the leaves into the seed.

Seth Naeve: and we've got a significant yield there at the end.

Anthony Hanson: Yeah. One last question related to that. I had been getting calls, too, where people got in hail earlier on their beans and leaves look pretty beat up but a few weeks later, then they're start to turn yellow. It looks like localized disease. And is that something we are concerned about over the whole plant? Or is it just gonna be a rough looking plant where just those leaves that got hit by the hail are just gonna not look as good.

Seth Naeve: I think the latter, for sure. I'm not really overly concerned about, you know, disease and those things. I think that the soybeans able to pretty much wall off those injuries for the most part.

Seth Naeve: if they are seeing excessive yellowing. I kind of pushed this back into that old camp of just a stressful year and and and issues nutrition related issues and other things. So

Seth Naeve: plants a little short on energy. So it's it's not sending a bunch of it's actually pulling a lot of resources that would normally go to the roots. And so it's it's trying to put a few leaves back on the top of that plant for these earlier hail hail storms.

Seth Naeve: So we we could be in a nutritional deficit in those areas just because we're not able to tap into the right nutrition at the right time to help support that new leaf development. So

Seth Naeve: it's I think it's, I think a lot of this is is a complex. It's all somewhat intertwined that we're seeing this year, but

Seth Naeve: I'm sure field by field are are different nuances of those same kinds of things.

Anthony Hanson: Alright. Well, thank you again, Seth, for joining us on the soybean end of things, and we wanna again thank everyone for attending this University of Minnesota Extension Field Notes program today. Also. Wanna thank our sponsors Minnesota Soybean Research Motion Council and Minnesota Corn Research Motion Council.

Anthony Hanson: Again, there'll be that quick survey. When you log off today, and next week we will be covering green marketing. So we're definitely getting into kind of the harvest theme a little bit, and what to expect for the rest of the year, pretty much in terms of what we might see with markets. And then maybe another topic to be decided, possibly looking more at green storage and equipment there. So with that. Have a great rest of the day, everyone, and we'll see you next week. And again thank you. Seth and Jeff Coulter, for being on talking about the

Anthony Hanson: comedy side of things today. Have a good morning. Everyone.

Corn and soybean yield updates
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