Soybean Update and Crop Diseases (including tar spot) on the radar

and for those few fields that are irrigated in a managing irrigation, to minimize how long the leaves are wet. Dean K Malvick: and just to get one little example, this is from some data, and northern part part of Indiana, where they have a lot of tar spot. And Dean K Malvick: again. This timing. In this case it showed this doesn't show the disease, but it shows the yield Dean K Malvick: preservation associated with funding side applications in a tar spot invested field. Dean K Malvick: So if you look at the bottom. Dean K Malvick: the 2 tallest bars are 2, and our 3 applications Dean K Malvick: is when they have the best deals. Dean K Malvick: They also had the greatest suppression Dean K Malvick: of Tar Spot. Dean K Malvick: I haven't seen any significant data that would show that we have much of a benefit after our 4. I mean, soon after R. 3. Dean K Malvick: So there's more and more data is coming in every year. But that's what the information is saying. Now Dean K Malvick: let's let's get it on between Bt and in our 3, Dean K Malvick: if we need it. Dean K Malvick: There's more information on the disease, and that will be available to you. Lizabeth A Stahl: and I want to just touch. Briefly, can I can ask you a quick question. And and just to let our our listeners know too, if you're listening on podcast we'll have those links available on the recording and we'll pull some of those up in the chat as well. So you can pull it up later. But just wondering. You you talk about the timing What would make you pull a trigger on a fungus side application? What level of pressure out there. Dean K Malvick: that's a really good question. Dean K Malvick: I know there's there's kind of 2 2 ways to look at this, I think. Dean K Malvick: and there are folks out there doing it both ways. There are many that have already made the decision that they're applying Dean K Malvick: in mid July regardless of the status partly based on past past years, experience Dean K Malvick: and perceive risk and some field. Some areas have a much higher risk than others. Dean K Malvick: But back to your question, if we're going to try to scout for it and then pull the trigger. Based on that information from scouting. That's not an easy decision. Dean K Malvick: if it's in a field where I've never seen it before. Then maybe it's a little easier. Dean K Malvick: and because if you don't see it Dean K Malvick: and you're out in Western Minnesota, your risk is really low right here in southeastern Minnesota, south and east of Rochester. Dean K Malvick: A lot of those fields are much higher risk. So we see it start developing here in mid July. Dean K Malvick: and we think there's a reasonable chance of some regular rainfall, which which we are all hoping for. Of course, you know, then, and we might want to lean toward it. I don't think there's any magic formula right now. Dean K Malvick: you know, one spot is not a big deal Dean K Malvick: 20 on an early, you know, that's becoming something that's really worth paying attention to and maybe reacting to. If we have relatively cool, wet weather in the in the forecast. Dean K Malvick: Yeah, a lot of things plan a role in that decision. Thanks thanks for that, Dean. But I'll let you move. Still figuring that out with all the research to, I suppose, to. Dean K Malvick: We've had limited numbers of years to really collect data, but we certainly have a lot more knowledge now than we did a few years ago. Dean K Malvick: And then, just very briefly, just to remind you, this is the time when white mold tends to really get going in soybeans, if it does. Dean K Malvick: But where we have our drought conditions, of course, this disease will be essentially non-existent. Dean K Malvick: but what's surprising. Dean K Malvick: of course, every year. Excuse me. Dean K Malvick: Some reason Dean K Malvick: what frees up on you there? Lizabeth A Stahl: Maybe a few. Oh, there you go. Dean K Malvick: So what conditions favor this? It's not that different. In a sense, the entire spot. Dean K Malvick: relatively cool temperatures and wet conditions. Dean K Malvick: Now, ideally, we' to paint the ideal situation for white mold. We get a saturating ring in an inch or 2, you know last week or this week. Dean K Malvick: Then we'd have periodic rains and do that. Keep the foliage wet for saturating main helps stimulate the fungus in soil to grow out of the soil, produce spores and go into the plant. Dean K Malvick: keeping the can be web, and and it has this infection and spread. So it's always surprising to me as we hear about drought situations. But then we have certain areas where they had timely rains, you know, early to mid July. Dean K Malvick: and then just periodic enough rain, and they get severe outbreaks, like many of you out there might have seen it this way. So even though we have dry conditions, there are a few areas that have had enough rain, but could be favoring this. Dean K Malvick: And I think many of you also know which fields are most prone to this problem. Dean K Malvick: Now, if you think about management again, resistant varieties help. And again, hopefully, we can get some information from some variety trials this year. Dean K Malvick: and as far as this year, though, that the key thing is we can use fungicides. I think everyone knows that the challenges they really to be most effective need to get on at R, one r, 2 Dean K Malvick: already picked, one timing. I would go to R, 2, Dean K Malvick: we need to go on before we see much disease developing, because the later we get it on, the more disease that's out there. Dean K Malvick: the less we can really stop it from spreading. Dean K Malvick: So again, we need to beat the disease and prevent it more than we can stop it once it's really gotten going. Dean K Malvick: So that's my only point there. But white mold. Dean K Malvick: And see here. Dean K Malvick: I want to talk a little bit about stem diseases. Dean K Malvick: and not not to go into this in great detail. But you know, you can see. I I made this little Dean K Malvick: chart here of diagnostics. Dean K Malvick: We have white mold, and we get to dryer conditions. Dean K Malvick: Chuckle, rod, pot and stem-like and stem. Cancer can become important Dean K Malvick: now for plans to be in the stem kick, and we need some rains again on the stems to help an infection. But we don't need it to continue. Dean K Malvick: and oftentimes we see some very severe outbreaks of those under very dry conditions Dean K Malvick: and pods. Tabloid is recognized by these kinds of linear spots and rows on the stems Dean K Malvick: and infection can occur throughout the season. Most of it's probably done by now it's happened. And again, why, a warm, wet conditions favorite, but Dean K Malvick: later on the stress seems to bring it on it Dean K Malvick: more so than what conditions. Dean K Malvick: And here's an example. I'm going to mention charcoal rot. In a minute. I thought this field had Circle Rock because it was very dry. Dean K Malvick: Some of the symptoms look similar, but it turned out to be pod and stemline. Dean K Malvick: So again, these 2 diseases can be confused Dean K Malvick: and circle rot. A number of folks have been asking about this because Dean K Malvick: people know that it's associated with hot drive directly conditions. And we know it's in Minnesota. It's never been a really big concern in many places, but I think we don't have a really good understanding of how widespread it is, or how common it damaging it is. Dean K Malvick: so this is something we'd like to know more of again. If you see suspected samples. Dean K Malvick: you know, please send pictures ideally, send samples. and we can diagnose it and try to figure out where this is a for me. Dean K Malvick: because I suspect, is we continue with more summers with, you know, throughout prone areas or drought Dean K Malvick: and hot weather. we're going to probably see more of this in the future. Dean K Malvick: And one way you can help help diagnose this. You can actually see this with the handling. If you cut open Dean K Malvick: the root or lower stem. You can see black specs where it's where the charcoal right name comes from. Looks like specs of pepper. Dean K Malvick: and I will stop there. Lizabeth A Stahl: Yeah, we got a couple of questions here. One was talking about. Do you have any moisture day models for these plant diseases to inform the decisions to apply. Dean K Malvick: You know, people have worked on that for years and trying to put together all the variables. Dean K Malvick: And it's not. They're still not as predictive as we'd like. Dean K Malvick: I think this work have that. Many of you know. There's a forecaster Dean K Malvick: prediction to a lot of Wisconsin for white mold. and that's useful to look at. but it also doesn't always. It doesn't take in real local conditions. I guess the answer is, no, we don't have any hard and fast rules, because Dean K Malvick: even though people have done a lot of extensive measurement or weather variables matching this up to the disease development, it's been very difficult. Lizabeth A Stahl: Hmm. Lizabeth A Stahl: it depends right? A lot of factors. and then here's another question, when does the window close for effective treatment at our spot? So, for example, what date is the appearance of Tar Spot not going to affect? Yield? Lizabeth A Stahl: You know much. Dean K Malvick: Yeah. Dean K Malvick: I think we're still learning that one, too, because it can progress so quickly. But I I think it's somewhere past. Dean K Malvick: I don't. I don't have a good date, actually. But I I would say our 4 R. 5. Dean K Malvick: We don't see it by then. In that crop growth stage. Dean K Malvick: I see the risk of Dean K Malvick: seeing really, high levels are low. Yeah. Lizabeth A Stahl: I know we're getting a little over time here. Sorry, but we'll got some other questions in here. what are your thoughts on Sdn and Sds for this? You're given the dry conditions. Dean K Malvick: Hmm. well, scm, of course, is favored by direct conditions. Dean K Malvick: Yes, yes, is not there by dry conditions. But you know, some fields. We had enough water early to create the early season infection of Sds. Dean K Malvick: But then, if we don't have sufficient soil moisture through July. Sds. Doesn't really develop very much. Lizabeth A Stahl: all right. And we did that one question that we talked about earlier, too. I know there's been some hail damage. And, Seth, maybe you have some thoughts on this, too. I know a lot of people look at Lizabeth A Stahl: you, you can hear, hey? At hailed. So let's use a fun just side. What are your do you have any thoughts you can share on on that. And is this worth the investment? You know? What? What are some things a person should consider for pulling that the that trigger on that. Seth Naeve: you know, Dean, is Dean is really the expert on this. but I would say, just don't do it. Don't be talked into it. There's it's almost criminal to claim that these products are providing these health advantages to soybeans when when there isn't really any evidence that Seth Naeve: fungicides, you know it's it is a little bit disingenuous to claim that these products do things widely beyond what their label is is written for. Seth Naeve: And and that's really how a lot of these things are being sold to farmers right now. There's some some folks are really desperate to sell product, and they're they're pushing these things in any any cases. I I just had a farmer Seth Naeve: in a very dry area. He wanted to spray fungicide, and I talked him out of it on on his soybeans. But he said, I really want to get the fungicide, so I can get the insecticide. And I said, well, didn't you get a spider might flare up last year because of your insecticide? He said. Yeah, we lost like 15 bushels. Seth Naeve: because we we put on insecticide early. Seth Naeve: and it flared. Our Flared our spider mites. And I said, Well, aren't you concerned about that this year? He said, well, yeah, but I just feel better if I get all this stuff sprayed on my crop. And and so there's real deep psychology that goes into this and marketing And I think farmers really need to think carefully before they put a lot of these things out. because it's not just the cost of investment. It's not just the environmental impact. But there, there's actual real can be real negative yield effects of some of these things, too. Dean K Malvick: Team, yeah. And just a couple of comments. I agree with what sets said and also to think about, for example, corner soybeans. Dean K Malvick: the diseases that would be enhanced by but by hail really aren't really managed effectively by Linda sites. at I think about corn could be, say, smuts and goss is built, and then neither of those are controlled effectively. Dean K Malvick: My bunch of sides so overall we have not seen a lot of evidence. Say it really does provide a big benefit to hail damage crops. Seth Naeve: Show me the data. I will. I will change my tune if anybody has. If any commercial folks out there have real good data on where these products affect under stress conditions like this and and can really show it to me. I'm I'm happy to Seth Naeve: happy to gladly listen. And maybe maybe I could change my tune a little bit on these things, but I'm I'm pretty pretty negative. Dean K Malvick: I feel the same way I'm I'm always looking for more information. Lizabeth A Stahl: excellent points, and I'm sorry we had one question that came in early, but I wanted to wrap this kind up at the end here. What can we expect going forward this with the plan stresses here in 2,023 any thoughts on that here. Lizabeth A Stahl: you know, if we get the drought. Anything we can expect moving on here, or Seth Naeve: I'll just take it. The the Gronomy side of it real Seth Naeve: broadly, and just say, you know, we're basically living, you know, it's like living paycheck to paycheck right now on the soil moisture. So it's all about soil moisture, as far as I'm concerned. getting the crop going. I think I would say the disease piece of this is secondary and soybean Dean K Malvick: because we just need the soy. We need the moisture for the crop to develop and yield. Well, I'm happy to take any diseases that come with excess moisture at this point, because we need the rain to get the yield first, so you know, I'll I'll let Dean take over some of the other stresses. Dean K Malvick: most diseases, I think, as we all know rain favors them. Dean K Malvick: There are a few that are favored by drug conditions, and I mentioned a couple of those. But in overall, when we have dry conditions. We have fewer diseases that that take any eel off the top. Lizabeth A Stahl: Oh, no. Well, thank you guys very much for some excellent information. Today, Dean and stuff. We appreciate that very much, and thank you all for joining us today. And of course, again, we thank our sponsors, the Minnesota Soybean Research and Promotion Council. Lizabeth A Stahl: we'll have is corn root worm. Getting your corn down. We'll have Bruce Potter, our Ipm specialist out of the Southwest Research and outreach center at Lambertton, and then our new corn entomologist, Dr. Faye, will be here as well. And anyway, have a great week, and thanks for joining us.