Crop Talk by IAS – 07/15/26

Corn and soybeans continue to grow rapidly across Iowa as heat and humidity push development forward. Across much of the region, corn is tasseling or nearing tassel, while soybeans are reaching key reproductive stages. This week, our agronomy team shares boots-on-the-ground insights on fungicide timing, disease pressure, insect activity, and what growers should watch as application season ramps up.

In this episode, the team discusses:

• Corn tasseling progress across Iowa
• Soybean growth stages and identifying the R3 fungicide timing window
• Gray leaf spot, common rust, eyespot, bacterial leaf streak, and early tar spot concerns
• Western corn rootworm beetle emergence and scouting reminders
• Fungicide timing recommendations for corn and soybeans
• One-pass versus two-pass fungicide strategies
• Disease pressure and how weather conditions influence development
• Ground rig, drone, and aerial application considerations
• Heat, humidity, and plant uptake during fungicide applications
• The importance of field-by-field evaluation before making application decisions

Featured this week:

Nicholas Giesseman - Host and Eastern Region Agronomist

Owen Heetland – Northwest Region Agronomist (Cleves)

Melissa Schumann - Northeast Region Agronomist 

Adrianna Herlache – Southeast Region Agronomist 

🎧 Listen now
Have a question for the team? Send it to CropTalk@InnovativeAg.com

To learn more about Innovative Ag Services and our agronomy services, visit InnovativeAg.com/Agronomy.

Produced by IAS Communications in partnership with My Four Creative.

Transcript

Nicholas Giessman 0:00

Welcome to Crop Talk, brought to you by Innovative Ag Services, and this is our Field Scouting Special. Each week from March through October, our agronomy team shares timely, boots on the ground updates from across the IAS geography. So you can make confident decisions as the seasons change. Today you'll hear a quick regional update from our IAS agronomist, including what we're seeing in the fields right now, what to keep an eye on next, and a few practical scouting reminders you can put to work this week. And to kick things off, I'm going to send it out to the Northwest region where we can hear from Owen. Owen, what do you have for us?

Owen Heetland 0:47

Thanks, Nicholas. This is Owen Heatland, agronomist at Cleaves location, covering Franklin, Butler, Grunde, and Harden County. We have really, really moved along with the heat since the last time we spoke. So most of the corn, I would say probably 50% is tasseling with the rest not too far behind. Beans are in the R2, 2R3 stage, are finding some beans that are ready for that fungicide and insecticide pass. We are having planes, drones, haggies, etc. moving on fungicide on corn. So the biggest thing that that I'm seeing is just, you know, fungicide timing. Have looked at a lot of crops and haven't seen a ton of disease. We do see some gray leaf spot out there. We've heard rumors of tar spot around. I haven't personally seen any yet, but I know it is around. Seen some eye spot, um, some bacterial leaf streak, and just a multitude of different diseases. I have also started to see a fair amount of rootworm beetles start to emerge. So it is very important that we continue to check the corn as we are spraying for fungicide and then making a plan whether, you know, if it's going to beans or corn, if we're going to beetle bomb, if there's going to be a first pass or a second pass when we apply that beetle bomb, and then, you know, continue to check for more emergence of beetles as time goes on. When we flip over to beans, you know, as we're looking for that R3 stage of the beans, we are starting to see that on some earlier beans, you know, anywhere from a 1-7 to a 2-0 or 2-1. The later beans are continuing to add growth at the top of the plant, so they aren't quite there yet. But I would guess with the heat over the next week, we'll see most of the crops by this time next week in the in the fungicide timing. So with that update, I will send it up northeast to Melissa.

SPEAKER_02 2:38

Thank you, Owen. Melissa Schumann here out of our Alcator office, covering the extreme northeast corner of Iowa for Innovative Egg. And here we are seeing some tasseling. A lot of fields are showing a lot of uneven tassels, very much lining up with that uneven emergence or the earlier stress we saw with some waterlogg soils. Lots of disease present anywhere from physoderma brown spot, gray leaf spot, a little bit of common rust, and a fair amount of eye spot that we are seeing. And then watching some fields that had a lot of wind damage earlier, we're seeing more significant goosenecking. So just kind of keeping an eye on those and having conversations about adding in microcomponents in with those fungicide applications and just kind of keeping an eye on it. We have not started fungicide applications here yet, but in the coming week, we'll likely see those helicopters fly in here. With that, I'm gonna send it down to Adriana in our eastern section.

Adrianna Herlache 3:40

Thank you, Melissa. I'm Adriana Hurlash, covering the southeast region, mainly Jones County and parts of Delaware County. Over here, we're wrapping up a couple of resprays, mainly though again out in front of growers trying to have those fungicide conversations, as it is right around the corner. Corn is tasseling or about to tassel, and soybeans are R2 for the most part, some more pushing R3. Disease pressure is starting to become more prevalent. Again, I'm seeing some gray leaf spot. I haven't seen tar spot yet, but it doesn't mean that it's not here. I'm also seeing a lot of insect pressure among bean fields, you know, between Japanese beetles, a couple of aphids showing up as well. With that, I will kick it back to Nicholas. Thank you.

Nicholas Giessman 4:23

Thank you very much for that, Adriana. Uh sounds like, you know, kind of uh bring it all together. Either we're seeing tassels or they're already out there and we're already spraying. Beans are right around the corner. Um, when it comes to fungicide, optimum timing. We always talk tassel or slightly before is kind of my rule of thumb just to make sure it's getting out there. Is that how you're approaching it year in, year out? I know I had the conversation with the grower yesterday. Well, it's hot and dry. That means tart spot's not going to come in. Should I wait? You know, how do how do you handle those conversations and make those decisions?

Owen Heetland 4:55

So the the trials, the reps, almost everything would tell you that tassel is the is the time you want to spray. Um, some seed companies, some varieties, maybe you would push it a little bit later. But the reality is if you're spraying one time, tassel is where you're always gonna get the most bang for your buck. Now, out this way, because southern rust was so bad last year and it was so wet, we had issues getting fungicide on. There is a lot of two pass going on. And so some of that has actually been pushed earlier. To me, as long as the flag leaf is up and emerged, that means you can get good coverage on all your leaves. That's when that first pass is happening, and then the plan is roughly 21 to 28 days later, we'll go in and make that second application of fungicide.

Nicholas Giessman 5:42

Yeah, I think uh staying with the with the data that's out there that proves you know, tassel is going to be your best unless you're making that that two pass application. Doing one a little earlier never hurts there. If you're gonna come back, you know, in 21 days, like you said. Looking at beans, do you have any you know herbicide, fungicide guys going out trying to do these passes together? Or is that something you kind of try to shy away from, or is that even a conversation that people are having?

Owen Heetland 6:07

Uh it's something I would really try and shy away from. I mean, for the most part, now rows are closed. You're not gonna get good coverage on herbicides. I know that it it will happen and does happen in some cases where you've got to clean stuff up and you're making the pass. But if we're gonna plan on making a herbicide pass, that you know would have been done a couple weeks ago. Now we're really looking at crop stage for fungicide, which is R3 on beans. Unlike corn, beans will continue to grow taller. So that R2, R3 stage may last a long time because you may be almost to R4, and then all of a sudden, bean adds another node and it's still in R3, or vice versa. Same thing with R2. So you really gotta look at the beans and then uh you know see where they're at and kind of go from there. We are actually gonna be spraying some 18, 119 beans over this way today that are ready or you know, well into being ready. And I've looked at some two eight beans over here that probably aren't still a week and a half to two weeks off. So you really gotta just look at each one and and kind of make a game plan of where to go and what to spray and what not to spray.

Nicholas Giessman 7:11

I would assume out in the flat country you are ground rigging these soybeans.

Owen Heetland 7:15

That is correct. Most guys have ground rigged them for herbicide. The tracks are still there, especially if they're 15-inch beans and the tracks are there, you follow the same track. But we will have some that are done with an airplane, especially if we get into some weather events that tangle them up. You can pull a lot down going down a 30-inch row. So, just another reason to get out there and look and figure out what way you want to go with them.

Nicholas Giessman 7:38

Are you running 15 gallons per acre on the ground rig? I know helicopter plane 99% of the time is two gallons. When you run a ground rig, you can adjust your rate of gallons a lot easier without the cost there. What's your optimum when you're running the ground machine? What do you shoot for?

Owen Heetland 7:52

We are running 20 gallons here. Um, we've got the tips to do so, and so that a lot of times is what it comes down to. But the I guess outweighing to running the beans over is better coverage. And obviously, if you're running 20 gallons versus two gallons, you're gonna get better coverage. But if you're in an airplane, you're not gonna pull beans down and run them over. So those are kind of the trade-offs, and we will be doing some you know, kernel boost, micro boost trials. Um, it makes it a lot easier with a ground rig to split the field just because they aren't having to come back.

Nicholas Giessman 8:22

I think I think that kernel boost is gonna be a big push here going into the fungicide timing, just with what that product offers. Definitely excited to see some yield trials. I know I'm gonna have a few. It sounds like you're gonna have some out there. So that's some some stuff definitely we're gonna have to swing back around to come fall and come harvest time.

Adrianna Herlache 8:37

Nicholas, do you want to touch on with it being hot? What is our fungicide response, whether it's corner beans, the pros and cons? Do you want to break it down?

Nicholas Giessman 8:46

Oh, and is there any negatives to doing it while it's super hot? The plant's still gonna, you know, get good coverage, you're gonna get a good uptake as far as it being hot or you know, if there's moisture on the leaves. Do you have a little better insight on that?

Owen Heetland 8:57

Yeah, I so I would say my biggest worry would be a drying before it gets intaked into the plant, but it appears, at least over here, that it's gonna be very humid while it's very hot. So it shouldn't evaporate super quick. That's my my worry about when it's really hot. Now we're supposed to be 90 for the majority of the time for a high, and so I would assume you guys would be the same. We start to get into the upper 90s into 100. I worry a little bit about the plant shutting down and not taking product up, but I don't foresee that being a problem. And and if it is, you're probably talking from three to five in the afternoon when not a ton of the fungicide's gonna get sprayed. Um, I would guess for us, we're gonna spray most of it as soon as it dries off in the morning and then you know try and be done by early in the afternoon. Airplanes usually are the same way. I mean, they'll probably spray through, but like I said, unless it's really hot and dry, I don't foresee a huge problem with that. On the other side of the question, the fungicide, once it's in the plant, it should help with the respiration, stress, etc. So it should help regulate those things that we're worried about if it is hot.

Nicholas Giessman 10:02

Yeah, I would agree with that. You're gonna get it out there. The likeliness of evaporation problems, or especially with the way Iowa weather seems to be, is it's when it's hot, it's humid. It's it's muggy out right now. It seems like it's just an Iowa July, not very pleasant to be walking around working outside. Does that kind of answer your question, Adriana?

Adrianna Herlache 10:19

Or yeah, absolutely. I just I figured it'd be good. You know, I've got a couple guys asking, is it worth it, you know, being so hot and humid as it is? And you know, I definitely think it is.

SPEAKER_02 10:29

Another thing I would add to that, Adriana, is to make sure that if they are doing it themselves, that they're adding the components to help offset any of the heat, such as your adjuvant, to make sure we have canopy penetration and that helps with controlling the droplet size and stuff so the plant has the maximum opportunity to uptake that fungicide as we can't control the weather, but we could control what's in the tank.

Adrianna Herlache 10:55

Yes. Thank you, Melissa.

Nicholas Giessman 10:56

You can only control so much. You can't out guess Mother Nature and you can't change what's what she's doing. So making sure that we got you know the right adjustments, run the master lock at the right rate, whether it be ground rig or aerial, making sure you got those products in there. If you're making that pass, adding in a foliar to help give it a little boost, if you will.

Owen Heetland 11:14

Yeah, I would agree with all of that. Anything that you can do to help make sure and get that product into the plant quicker, better, um, easier for the plant is is a good thing. So definitely, like you said, the master lock. And then to me, that's where the ground rig may have a little bit of benefit is you're gonna get a little more volume, a little more coverage. But I know the planes and the drones do a good job too of pushing that product down into the canopy. So the big thing is is the master lock, like you said, to make sure that those droplets penetrate deeper down into that canopy.

Nicholas Giessman 11:46

That's all for this week's Crop Talk by AS. Thanks for tuning in. If any of our listeners have questions, feel free to email them to crop talk at innovativeag.com. Be sure to like, follow, and subscribe so you don't miss next week's update. And if you know a fellow grower who'd value a quick field snapshot, share this episode with them. For more agronomy resources and to connect with your local IAS team, visit Innovativeag.com and follow Innovative Ag Services on Facebook, Instagram, YouTube, and LinkedIn. We'll catch you next week on Crop Talk.