Field Crops Webinar Series - Field Crops Webinar Tar Spot Management - Chilvers Damon

March 28, 2022

Video Transcript

- Hey everyone. I'm gonna cover a couple housekeeping things 'cause we are just a couple minutes from getting started. First, welcome, and thank you for registering for the Field Crops Webinar Series. This is always a pretty popular series we run, and we appreciate the reoccurring support. Also we'll be putting in a link at the end that's both gonna link you to the evaluation. We appreciate your feedback, this is the last one of the season, so if you kind of like the topics or the format we used this year, please feel free to give those comments kind of on your overall thoughts, maybe suggestions for our following year. We look at those before we start planning for the following year, so we always appreciate that kind of feedback. Both Jena and I are on the planning committee for creating this event, and so if you don't wanna put it on that, 'cause maybe you don't fill out our evaluations, you're also welcome to submit those into the Q&A for us, and we will have that data saved afterwards. We will be using the Q&A box to submit all the questions. During this, if you have a more question you just didn't wanna post on there, you're welcome to message me on the Q&A and then I can start a private chat with you separately. So, know that that is also open. But as we go through this presentation with Marty and Damon, we'll be primarily using the Q&A box. Otherwise, I'm just going to give you a friendly reminder again if you're logging on, and you don't have a name, you have a number, or maybe the name that you logged on is not your name, it's someone else's account, if you could please rename it to your name, that's how we confirm that you were on, and attended live for you to get those CCA and RUP credits. You do that by going to chat, oh, I'm sorry, by going to participants, finding your name, and then clicking more and scrolling over to the rename. Do you mind moving on to the next side for me quick, Damon? Thank you. So, as a friendly reminder, all of our MSU extension programs are open to all, we do ask demographic questions when you register, and frequently on our post evaluations we give out, and that is because we are a partially federally funded organization just like most of our land grants, and because of that, we have to ask these questions, so, you're welcome to complete them or not, it's up to you. Next. Today we're gonna be talking about tar spot, and we are right at 7:00. So, I'm gonna let Marty and Damon kind of kick it off and introduce themselves, but thank you again for coming on here. - Awesome, thanks Monica for that introduction and getting everything set up here. Yeah, I'm excited today to have Damon with us. So, we are very fortunate I think Damon to have a number of colleagues right around these states that we work with. And yeah, Damon's certainly one of these colleagues that we've worked with a lot, both on white mold, being from Wisconsin he deals a lot with white mold, and that's one of his babies as well, but yeah, with tar spot coming on the scene. Yeah, there's been a number of us but yeah, Damon's been one of the key ones here in as well. - There's been a lot of efforts in here, I think Marty and I are gonna be delivering some information from all across the Midwest. So, it's been a great team, and we're a little odd, we have fun with these projects, but I know it's a pretty devastating disease, and that's probably why you're all here. - Right, absolutely. So I guess with having said that, let's get started, and we do wanna reiterate, like if you have questions, we would really like you guys to put those questions out there. Damon and I have given this or a similar talk to this many, many times now, but we wanna make sure we get you of questions. And so, let's jump into it, you know, tar spot disease, as you're all probably familiar with now unfortunately, presents these types of symptoms on plants, they look like on corn plants, looks like tar has been flicked onto the plants, and it's caused by a fungal pathogen, Phyllachora maydis. Damon, would you like to go to the next one? And I asked Damon a little bit earlier this afternoon too, like, "Hey, do you guys also get mistakes being made with bug poop basically?" And yeah, it's not just Michiganders, so its like the folks in Wisconsin also occasionally make mistakes. So, I just kinda like this slide. How often do you think it happens Damon that people get out there and spray bug poop? - Oh, I say the first, probably the first two months June and July, you know, probably two thirds of what comes into our clinic ends up being bug poop. Yeah, so very common mistake, but you know as that video shows, you get a little water, you know, and pour it on the leaf and you can almost always rub bug poop off. So, that one's real common. And then on the right hand side here we have rusts. And late in the season, of course when tar spots just really blowing up, this is a common one that we get in the clinic as well, common mistake. Remember these rusts spores, they transition into a different spore type, and so they'll turn real dark black, and they appear like tar spots but have a very different appearance when you're looking at them in real life. I've been fooled by pictures, so make sure you're looking at the real sample. I thought for sure, you know, a couple years ago we had tar spot way up North, and they sent the samples down to the clinic, and I got fooled in the pictures that came in and it was just common rust. - Yeah, and just speaking of that too and maybe the host range piece of it, we've had people convinced that they've had tar spot on sorghum, but so far we have not had any confirmations of that. So if you think you have task bot on your sorghum, please send it into the diagnostic clinic. We think that the host range is pretty specific to corn, that something that we're working on still. I think if it was gonna be a major issue on other crops we certainly would've seen that by now. So Damon would you like to advance? So, this has been the beast, hasn't it? Over the last, geez, we've got about eight years there now. Since that initial introduction in Northern Illinois and Indiana, we had that explosion around Southern Lake Michigan really that drew Wisconsin, Michigan, former colleague in Illinois, and now the Darcy at Purdue into this conversation. Unfortunately it's bringing more and more members in, nobody really wants to see that, but it's a disease that's been spreading, right? We don't really know how it got introduced to the US, right? There's a number of different theories, but it's here and we're dealing with it. - Yeah, it's gonna be, you know, I tell everybody here in Wisconsin, it's established here, so it's not a matter of, you know, are we gonna see tar spot in 2022, it's really when. And you can see at least with Wisconsin scenario basically all of our arable corn acreage is infested, we consider it established here now in the state. So, the pathogen side of the triangles there, and we got lots of corns, so we got the hose side of the triangle there, so two of those three important pieces are not really here in the Midwest now. - Absolutely, and I guess the final piece we're gonna touch on here, and that's the environment. And I guess I just say really quick, you know, we had those wet summers of 2018 and 2021, so we had the pathogen introduced in 2015, but then those wet summers in '18 and 2021, and that's where we've seen these explosions, and you know those reports of absolutely devastating yield losses. So yeah, let's talk about what drives tar spot. So Damon, we actually sent you guys some residue, right? You've got a great technician in your program and she did some work, do you wanna just tell us briefly what she did there? - Yeah, it was a really great experiment. So from the 2018 epidemic we basically had folks, colleagues all over the Midwest here, Marty included set material from Michigan, we had a couple locations from Wisconsin, Indiana, Illinois. So the material was from the 2018 epidemic, we let it go through the natural winter on each of those states, and then we had colleagues go out and collect that material after the snow came off and et cetera. And then that was all sent to my lab, and my research technician, she's really awesome and she figured out how to basically get the little tar spots to give up their spores, and she developed a technique where she could actually see if those spores would actually survive. So the spores are hard to transmit, but they do germinate if they're still alive, and they do germinate readily in water. So she worked out that whole technique, and we published a nice paper in early 2020, talking about the fact that, you know, there is a wide range of survivability, and we don't know this was just over one winter season, so we're not sure if you extrapolate this across the entire rotation, what this residue has in store for those future epidemics, but we do know at least for the one season we can have it over winter quite readily. There was a wide range in percentage of survival from 2% to 25%, but even at 2%, you're still dealing with millions of spores, so even 2% of a really large number is still a really big number. So, that's why I can say with confidence, you know, that the pathogens here, it survives the winter here in the upper Midwest, and we have resident inoculum here. It's not like rust, like Southern rust that has to be blown in from the Southern US, it's here and we'll initiate epidemics here. - And I think the other thing we can draw lines of evidence from as well is just, you know, that rapid spread of disease across the region. And you know, where we are seeing it over time, that really tells us something about that, it's here, it's sticking around, it's not going away, it's not blowing up from Down South. - Yeah, we're gonna show some data here talking about tillage, 'cause you're probably thinking about, "Well, what if I bury all that residue", but one thing, and it's here in the society, you all in Michigan have good familiarity with fusarium head blight., you gotta think of it like that, that particular type of disease, right? So you can have dispersal within the field, you can also have dispersal between fields. So, you know, at least here in the Midwest unless you have probably a 10 mile radius of tillage around your field, you're probably not gonna get ahead of this thing just from a residue standpoint, because there's lots of corn residue, and there's gonna be lots of tar spot inoculum around. - Absolutely. So, let's move on to the next slide. So you've got a slide here about, we all jumped into the literature pretty quick, right? As soon as this thing popped up, we're like, "Okay, so what do we know about it?" And thankfully there'd been some work done down in Central America where this thing has been around for about 100 years now, it was described in 1904. The map there was some work done to try and look at climate similarity for where they see disease in Latin America, and they predicted that this is probably where tar spot is gonna kick off. I guess the one thing I say Damon, that they probably didn't account for all the irrigation in Nebraska, right? (laughing) That's gonna be a hot mess I think once it gets in there, and I'm sure it's gonna be in North Dakota. Credit to them though, you know, it was a helpful piece of information as we were getting started. - Yeah, it was actually an eerie foreshadowing experience for us, you know, had we, you know, this came out actually right before the 2018 epidemic. I don't think any of us really paid much attention. We all saw the article and we saw the maps, but didn't pay much attention to the fact that, you know, it could really blow up in a favorable year like this. But you're right Marty, we sort of sit in a climatic zone here in the upper Midwest, it's really quite perfect for this pathogen. You can see the various parameters that have been sort of worked out in the mid 90s. My lab does a lot of modeling work, and we've looked at these parameters in depth, and you'll notice that four of the five parameters that are all wedding parameters. So, that's a key clue right there that it's wetness wedding events. Yes, temperature is important, I'm not gonna rule it out, but we learned in 2021 that it is not as important or at least the high temps aren't as lethal as people had assumed. It can sit there and sort of just remain a little bit inactive but survives just fine. And so when the weather conditions do show back up that are favorable or, you know, we start to really irrigate a lot, you know, the pathogen will take off and move pretty quick. - Yeah, and you can go to the next slide if you like, but- - I do have a question, sorry, (indistinct) - I saw that one, I was gonna deal with that one breeding one. Let's save that for a minute. So, just on this whole thing about water and temperature and whatnot, you know, we saw reports of it in Georgia. It was fairly late in the season I think, but I called Bob Carmel right about that like, "What is going on down there with you guys?" Like, "Why have you guys getting tar spot? It's not supposed to be a Southern problem," right? He told me it was unusually wet, but also you are unusually cool for them, not much above 90 degrees Fahrenheit. Again, I agree with Damon, I think the leaf moisture is the more important piece, and we'll learn more as we do more studies to figure out those temperature pieces. But, I mean, I think this picture, and thanks again to Dan for sending this into us, really demonstrates unfortunately, you know, leaf moisture is critical for this disease. - Yeah, and I think it's, you know, in my opinion just as an epidemiologist, and looking at these things mathematically, it's really the nighttime leaf wetness that I think is the important piece. Daytime wetness, you know, that stretches into the early noon hours, I mean, the other cause is really important, but fungus is probably doing a lot of its work in terms of germination, and you know, how it keeps moving along and expanding during the night when those leaves are wet. And so, pay attention to that when we're good and cool at night, and we've got plenty of moisture around, it's raining a lot, good leaf flatness, I mean, those conditions are really important for the movement. - You wanna go ahead to the next slide there Damon? I mean, again, this is one that just drive home that like, why did we have a problem in 2021? Well, you know, above normal precept, right? Once we actually have a canopy out there. So I just pulled up by June to August, and I think this really pretty demonstrative of what happened. And I guess I'd note as well, our colleague in Indiana did see a band, that sort of Northern band where they didn't have as much, but the very top of Indiana and the Southern part a little bit more tar spot from what she was telling us. And Damon, what was your experience in Southern Wisconsin there, where you had a little bit less moisture, was it a little less disease? - Yeah, it was really strange, you know, 2018 that Southwestern quadrant. I don't know, can you see my arrow on that Marty? - Yes. - Yeah, so this was sorta of, traditionally had been the epicenter of tar spot here in our state, the Southwest quota, and this is our drifts region, we've got a lot of valleys and things over here. And in 2021, actually this inverted U band right here, this coincidentally is actually where a lot of our irrigated corn acreages as well, including sweet corn and canning acreage. And this was sort of a double whammy and this inverted U here, because not only were we irrigating, but we had excessive amounts of moisture, and this is where the epidemic was just absolutely phenomenal in 2021. And ironically the Southwest portion, the traditional, you know, sort of epicenter really wasn't much yield loss at all tar spot, we were actually in a drought, actually we're still in a drought in that part of the state. So again that's wedding thing, and when precipitation is above average and we all know when that's happening, that should be the light bulb and the alert that, you know, "Hey, this thing could really start to blow up." - And I think that's really important too in thinking about yeah, like the potential for losses, and whether we gonna put a fungicide down or not, and when we're gonna do that. So, keep that in mind as we go through this, Damon's got some nice stuff here. Damon, do you wanna... I'm glad you're here 'cause I definitely make a mention of task spotter, but I don't normally bother getting into too many of the nitty gritty details. So, do you wanna give us a bit of a run through what you've got going on here? - Well, first are you using Tarspotter Marty? - I am, most of the time. - On a regular basis? - That's the important key. - Fairly regularly. - So, you know, this is a great tool, it's based on our spotcaster framework, and some of you're probably familiar with that white mold tool that we developed a few years back. When the tar spot thing developed, we quickly realized that, you know, this is a really flexible framework, and we can retrain it using similar modeling approaches here, and build this new Tarspotter tool. So, we're not using the same weather parameter, we retrained it, we pulled in the per weather parameters for tar spot, we pulled data from Michigan from Marty, and we have Wisconsin, and Indiana, and even Iowa in this. And the Wisconsin corn promotion board helped fund this as well as the National Corn Growers Association, and really were able to help get this up and running. And we ran a few beta versions of this, and some of you may have helped us test those. And early on the models weren't great, this is the thing about machine learning exercises, is that you have to keep adding data in. And so we've continued to do that, and in 2021 we were able to generate a new set of tools which we call Field Prophet, which is actually related, it runs the same models, but these are a little more at tune in terms of the items that we deliver. So, in this particular tool we're actually pulling down seven day trend lines. So we also learned from our white mold experience that, you know, we can look instantaneously today and get an idea what the risk might be, but it's a lot more informative if we can look back in time and see what the seven day trend was, how has the weather been leading up to today, and then we also have seven day forecast built into the Field Prophet tool. So, this tool will run free for this season, so, there's the QR code, you can scan it and pull that down. And just to show you kind of the successes we've had with Tarspotter, this is just one location, but what we're showing you are the instantaneous daily risk indexes. So, these are on a 0% to 100%, this is analogous to basically a rain forecast, so today might be a 50% or 60% chance of rain, well, today could also be a 50 chance at tar spot occurrence. So this is exactly what this is doing. And then we set these action thresholds, and the way to interpret these action thresholds basically is, again an analogous to the rain example. If it's a 50% or 60% chance of rain today, you're probably gonna bring your umbrella, right? So, that's how you would interpret this 40% action threshold. Once we reach that 40%, now it's time to start get out to scout, if you're in that kind of VT, V10, VT, window, maybe start thinking about those fungicide applications lining the airplanes up and those sorts of things. And you can see here's real world data, we're going through time, you can see we had a really big area here where we had high probabilities, and we actually found tar spot in this particular location right around that V10 growth stage on the 9th of July. And then it got hot and things kind of tailed off, and then we started getting favorable again with frequent rain events, and you can see things popping up and down, and then it just kind of came off the tracks as we went through August. So a nice way to sort of visualize this. But again, I'll just reiterate that, you know, this Field Prophet tools out there, it's a lot of useful information, I would download it to your phone. And you know, you're not gonna be charged this year, so you can wipe it off your phone at the end of the season, and you know, don't need to worry about that, but you can actually run the white mold tools in this tool as well. We're showing you how to actually go through and set up a forecast here. So we're actually gonna go down to Florida and find a nice tar spot field down there, 'cause it's the springtime, we don't have a lot of corn here in the Midwest. So we're actually gonna use the map function here, drop a pin, and now we're actually gonna run a forecast here, and you can see all the different locations that were set. To answer a couple of pieces of information about the crop, run the model, and those things gonna run really fast, and you can see that nice trend line there. So you might say, "Hey, I'm gonna wait" based on that trend line, but now we're gonna go in and run a seven day forecast and look ahead, and I might be getting my plane ready when I see a trend like that. So, you know, the next six outta seven days is pretty high risk there, and you might wanna do some things like scouting at least or try to get things lined up. It also has a nice map function, you can back out, I drop pins usually all over mine, and I can back out and look at the different areas of our state just to see what the risk is here, and you can actually do that with all the different models that are loaded into Field Prophet. And then your dashboard there also gives rolling trends as well. So again, just a tool to try to help folks anticipate this, and make some decisions on, you know, what should I be doing? Am I in the right growth stages? Has it been conducive? Should I get the fungicide out? All those sorts of things. Just to show you what it looks like in action. Here we have basically some plots out at Arlington, Wisconsin where we add a non-treated plot, and then fungicide treated plot according to Tarspotter, and you can see those plots on the right look pretty good. There's tar spots in there taken on the September 7th, but you know, things look really clean. I would take those spots on the right all day over the stuff on the left for sure. So, just to show you how it could be used in action, and to make those spray decisions. - Cool. - So I'll turn it over to you Marty, to talk a bit about - Sure. - some of the agronomic practices here. - Thank you, thank you very much Damon. So, yeah, I mean initially when this thing hit, okay, we we'll certainly tackle it on the fungicide front and the variety hybrid front, we'll talk about that in a minute. So we also thought we should ask some questions about standard agronomic practices, and a couple of the things that we looked at there is nitrogen rates, which is probably quite topical at the moment too with unfortunately very high nitrogen prices, and the other thing we looked at was planting population. So Damon, if you wanna go ahead to the next slide here. So we looked at, you know, basically low, so what we might consider a base nitrogen rate and a high nitrogen rate, we looked at this across five different locations, and we could not drive tar spot with too little nitrogen or too much nitrogen. It's not to say there may not be some subtly facts from nitrogen or other fertility type treatments, but certainly we're not gonna be able to... Well, on the nitrogen side there really doesn't seem to be a strong driver there. So, that doesn't really appear to be a major factor here in terms of management of tar spot. The other thing you'll notice, we've got kinda two set, there's three and three bars together, and what that is showing is two different sets of hybrids. So that allegan chart there in 2019, you've got three bars close together and then another set of bars that are close together. Thank you Damon. So, the difference there is hybrid, surprise, surprise, that's what drives things, right? I mean, Damon will preach this all day as well, you know, variety selection is so important for managing disease, and that's what we saw when we ran this nitrogen trial. Try to go to the next one Damon, please. This one was a little bit interesting, right? So like we sort of said, you know, we've done a lot of work on white mold and with Damon, we've looked at row spacing, planting population, and fertility there as well by the way. And we know from white mold, and I think all of you are very familiar, if we push population, push row spacing to be tight, that's when we develop a microclimate underneath that canopy, and that's really great for growing white mold, and bad in terms of trying to manage the disease. We actually saw the opposite with tar spot which is kind of neat, and maybe a little unexpected initially, but thinking about it more it does make sense when we're out scouting where we find disease. If we're walking a field, it's typically easier to pick up along that field edge, or if we've got skips within the field, you know, blank areas, that's where we tend to find it a little bit easier. So, in those low plant populations of 28 to 34,000 plants per acre, we actually had a little bit more disease than we did compared to that high plant population, 40 to 46,000 plants per acre. But again, the major difference, especially when we start looking at yield data, is actually that hybrid tolerance or susceptibility, whatever you wanna call that, the one on left hand side there had less disease than this more susceptible hybrid on the right hand side, and that was really the big driver especially when we start actually looking at yield. So yes we can drive disease a little bit by planting a lower plant population. Does it actually matter in terms of tar spot management? It really doesn't. So, don't buy into, you know, the seed salesman, pushing more seed to try and manage tar spot, that's not gonna be a solution. Then we see subtle differences, but the most important thing again is to find those hybrids that have better tolerance. So we wanna move forward Damon? - Sure, yeah, yeah. So I can talk a little just about how this thing moves in the canopy, which is pretty interesting, and it also helps guide sort of how we, you know, where we scout, how we think about things. Before I dig in though, I do wanna just mention how we typically rate for tar spot, and we use these standard area diagrams. So these are pixel counts from a computer, these are not humans making up these percentages, so these are a true 50%, 10%, 5%. And we do actually take in, in some years take two types of ratings, one is for this fish eye, and then the other would be the tar spot coverage. Interestingly in 2021 there weren't a tremendous amount of fish eyes around, so there's some discussion on why that was. But I'll say most of what we're gonna show you here is gonna be basically tar spot coverage. And if I threw these up in front of you and didn't have those percentages, I bet folks would actually estimate that this 50% was closer to 80% or 90%, that's usually what the human eye tends to make things a lot worse than they really are. The reason why we stop at 50% is, it's hard to find leaves that rate any higher than 50% to 60%, by that point the plant is pretty much shut down and dead, and the fungus has moved on to other green material. And that's a really important piece is, this fungus is like green material not brown material, so the longer there's green material out, that's the window of opportunity for the fungus. So this is just to dig in a little bit and try to tie back into the hybrid and residue questions that we get a lot. We had some coordinated trials across many locations, Marty's our location, one of them we had some here in Wisconsin, I think there's gonna be seven site years of data here that I'm gonna show you here in a second in a summary slide. But what we're doing here visually is we're taking you through the various growth stages. And this was our location that was very high tar spot pressure here, the blue ratings here is basically the ratings for the resistant variety, and then the red is for the susceptible variety here. And we split the canopy in three levels just to track this really intensely over time, and we're in a high residue situation. So this was corn on corn, had tar spot in the previous season, we no tilled into it, so lots of residue there. And you can see, as you might expect, the fungus moves from bottom up, and we get kind of an exponential increase really late in the season. So as these plants approach maturity, you can see how the disease is really ramping up really fast. So there's a long lag phase, and then a really fast exponential increase, which is sort of classic for these polycycles or diseases that have many cycles per season, that's kind of a classic thing that happens. So our goal here with our management is to try to keep things in this lag phase, we wanna maintain this phase as long as we can, and try to delay this entry into the exponential phase. So we were really interested, you know, how does residue sort of play in to this scenario? So all the locations that ran this also had companion fields where we ran the same hybrids, we did everything exactly the same, except we changed how much residue was there. And in Arlington at this particular location, this was actually soybeans the previous season and till, it was really hard to find any corn residue other than a few stock pieces in this particular field. And you can see really surprisingly, the track of the disease is pretty much the same pattern. Yes, the overall severity is a bit lower, so by the time we get to the final increase there, it is a bit lower across all levels in the canopy, but the fungus still moves from bottom up, okay, and we still have a lag phase, and then into the exponential increase of the disease. And so, if we look at all the seven site years that we had up to this point, we can cook that down into some statistics here just to look at what those real effects are. And yes, here's the residue effect high versus low, we can actually pick up a statistically significant difference, but that difference is really actually quite small. When you have a lot of site years, you have a lot of power to find differences between you know, in small increments, and you can see us some reduction there, but where we get the best reduction almost 50% is actually from the resistant hybrid, and so that really is key, and that's why we keep pounding that home that we have to use that resistant hybrid. We could do some tillage, but it's only gonna get us part of the way there, and really, you know, in Wisconsin, we are very conservation tillage minded here in the state, and we would not wanna abandon our conservation tillage just to give up a small increment in terms of our tar spots severity. So, I'm telling folks to go ahead and continue with their no-till, maybe do some rotation, and definitely work in the hybrids, there that's really gonna be key. And, you know, unless again you have that 10 mile radius around the field, even if you did till you're probably not gonna have a huge effect, 'cause the fungus can still either come from outside in, or we're starting to suspect that even really small pieces of leaf material that aren't visible, may still be able to actually, you know, harbor the fungus in the soil. So, just be aware of that, and again, put energy into finding those resistant hybrids there. - Yeah, I completely agree Damon. Before you had this data set to set a point to, you know, I was going off some anecdotal evidence I guess that we're hearing from different growers, and some of them hadn't had corn in a field for five or seven years or something, planted corn, and in an epidemic year it had moved in and just decimated the field. So there was plenty of evidence I think to, you know, it is great to have this data, but evidence outside of this just to show that... Yeah, I mean, you could mobile plow all day, but it's not gonna the save you. - Right, yeah, I mean, - (chuckles) right? - again, you gotta think like fusarium head blight, you know, even if we rotate away from corn, and we get, you know, our rotation just right, we can still have good fusarium head blight if you got a susceptible variety out there, those spores are just moving long distance, so make sure you have that mindset in place as you're thinking about management here. - That's right. - Before we move on to management, there was a couple questions about the apps that you had shown, is there an Android version of the field of it? - Yeah, the Tarspotter, the fully free version, the true Tarspotter one does have an Android version, we're working on an Android version for the Field Prophet, Field Prophet is only for iPhones at this point. So if you're an Android user, I would go ahead and just download the Tarspotter version for now, hopefully we'll have the Field Prophet ones coming along sometime soon. - Okay. - Thanks Monica. - Yeah, and there's another one in here too, "Is there an app that will give us a similar analysis in the field?" And I- - I think what you were talking about there I think that might have been Eric, like asking about the number of spots on a leaf. There is actually, so leaf doctor will do that, something that one of my former PhD advisors put together, you could put that in the chat. I don't know how easy it is to use, but that is an option. - And so that looks at the spatial, and gives you the estimate? - Yeah, I mean, basically, you know, you can take a leaf, and take an image of a leaf, I think the problem is you might have to be on a black background or something so it's got good contrast, and then it'll basically pick out the black spots versus the green tissue. And I know Addie Thompson here, our corn geneticist, for now this person is playing around, and private companies playing around with that as well. And folks are looking at drones, right? There's a lot of interest in this space for sure. - I guess on the topic of app, someone asked if there was an app for a farm or garden layout, I'm assuming like planning, 'cause of course we don't really worry about tar spot, like this is for corn. So, is there cross, I don't know, is there crossover into corn you would plan in your garden? - Well, sweet corn. - Yeah, sweet corn. Actually our sweet corn folks here are very worried about tar spot because, maybe the canning, the preferred canning hybrids that we grow here in the State are quite susceptible. (clears throat) What's interesting about that, and we didn't talk about it too much here is that, the timing of planting also is really important. So, late planted corn tends to get hit a lot harder than early plant corn, and we learned that painfully here in Wisconsin last year, we have our late planted sweet corn crop going as late as the end of June here, and that crop got absolutely pounded last year, so that is something to keep in mind. You know, if you're dealing with sweet corn, different crops are gonna have different levels of susceptibility even if the hybrids are the same. So, our early crop, like it's planted in April, usually not hit very hard, but definitely in the mid and late crops hit real hard. - Yeah, we're seeing the same thing here as well in Michigan of course, I mean, no surprise, right? So let's move forward I guess into management, 'cause this deals with the next question. And that was, "What have breeders been doing over the last 10 to 15 years in screening hybrids that do not carry resistance for this disease?" So, I think really, you know, breeders have been doing what breeders do trying to shoot for yield, right? Like that's primary, that's what makes you guys happy too when things are working out well, because this is a new disease. We're sort of stuck with what we have at the moment, there's certainly everyone's companies are working at screening material. I think the big thing that's happened is they've tried to pull out stuff that's really susceptible and take that away from market, but, you know, I know we are doing screening for companies as well to try and help them identify material that's got better resistance. - Yeah, this is the hundred million dollar question, I think if folks can get some really good resistance in there, we can start to actually get a handle on what that resistance is through good quality data that's gonna be key. Because I think you can see effects pretty clearly here when you have a susceptible versus a moderately resistant hybrid and the payoff that you can get. And we've looked at that in terms of yield reductions too, you know, with multi-state work this includes Wisconsin and Michigan data, as well as Illinois and Indiana, where we just looked at yield loss here. And we split up into sort of shorter day relative maturities and then higher day relative maturities over on the right hand side. And what's really interesting here is, both get hit pretty hard, but the longer RMs get hit a little harder, so the yield loss that line's actually a little steeper, and we can actually solve for the slope here, and we know that for every about every 10% increase in these short relative maturities we lose about five bushels of grain yield, and the longer RMs that's about eight and a half bushels for every 10% increase. And yes, the yield potentials a little higher, but this is another really important piece is, if you're trying to dig your way through resistant and susceptible hybrids, also consider that relative maturity, and is it really appropriate for a location? I'm seeing folks sort of back off just a little bit on pushing the relative maturity thing. And I think that's smart because, when we have a bad tar spot year we can get hit really, really hard, and the benefits that we might have seen in terms of yield potential in that long relative maturity may not pan out in these heavy tar spot ears. And I had a really interesting conversation with a farmer in Illinois this winter, and he's sort of rethinking his whole philosophy on how he chooses hybrids, and he's actually thinking about, you know, "Do I really need that high yield potential hybrid because I have to put so many more inputs into that hybrid? Maybe I give up a little bit on the yield potential, I don't have to put so many inputs in it, I get something with a little more resistance with less inputs." And from an economic standpoint, he felt like he might come out ahead in that situation. So those are some other considerations as you sort of slog through the resistance thing. I don't Marty if you had any other comments there before we- - No, I think that sums it up pretty well, I guess let's keep moving into the fungicide piece. - Sure. - So, this is kind of fun, right? So this is some work that's multi-state here, and essentially what we've been doing is looking at, what's typically sort of marketed for tar spot management, and essentially having a look at efficacy. What comments other than that do you have here Damon? - Yeah, I think the key with this data set here is just to keep in mind that we were just purely running this trial for just, you know, what are the of efficacious products, these are all applied at the tassel timing, we'll address the timing thing here in a second, but we really wanted to separate efficacy from timing, and try to get a lay of the land, so I think that's a really important piece with this data set. And I think at the end of the day Marty we see a lot of things that have really good efficacy, right? - Right, absolutely. - And this data set, yeah, 2019, 2020, those weren't really heavy tar spot years, we had eight environments in this data set, but you can see everything gave us a nice reduction relative to non-treated. Yeah, there's some things over here with ease that are, you know, obviously a little better than some of the stuff here in the middle pack, but you've got a lot of options here. Most of these are mixed mode of action products, but there's a lot of tools here, and so, in some respects I think that's a good thing, we got lots of good options. I don't know if you had anything else to say on this before we move to the yield. - No, go to the yield and I'll make a comment there. I mean, guess the other thing just to point out too, Damon mentioned it, and I guess we've got a slide to deal with that, is that our concern for fungicide resistance development. We don't necessarily want you using a single mode of action product, or if you really have to do that, please rotate it. This is a disease that has many cycles during the season, has a lot of inoculum potential out there, and it could be a very high chance for fungicide resistance development. So we prefer you to use a mixed mode of action product, that means it's got two different, at least two different modes of action in the jug. - Yeah, great point Marty. And you can see here the yield translates not quite as clean as that previous slide that the yield translates, you know, usually things that give us some decent efficacy, give us some yield, especially in years where we have high pressure, so pretty good data set there. We did dig in a little bit further just to try to ask some questions just about, you know, how fancy do you really have to be in terms of your product choice? Can you sort of just say, "Well, I'm just gonna go after a two or a three way mode of action that's labeled on corn, and is that good?" And so we did, we dug into that data set a little further. Darcy did a nice analysis here just looking at the non-treated versus single modes of action, two modes of action, three modes of action that we have typical in corn. And the work really, you know, everything gave us a nice reduction, but the work really is being done by the two and three way modes of action. You can see over in the right hand side here with yield, those are the two places where the yield, you know, we got good yield preservation over that non-treated. So, I think at the end of the day, especially when we're looking at fungicide shortages this year, and potential hard to find products, you don't need to be super fancy, you got lots of opportunity out there, find what you can get ahold of, and then what's reasonably priced, I think is really the take out of that analysis. - Yeah, and we just had a question along those lines come in, right? Joe was picking up the Veltyma and Delaro, perhaps looked a little bit better than some of the other products maybe. And he said the availability of those particular products isn't here right now, so do we have recommendations on substitute? We have two more slide decks, why don't we go into those and let the data speak for itself I guess, right? - Yeah, I think there are some other opportunities. Yeah, I mean Veltyma and Delaro Complete tend to continuously float up to the top, but I mean, here we are with good old fashioned Headline SC. I still really like Headline Amp, and my trials here in Wisconsin. Approach Prima doesn't look pretty bad, and this is 2021 data outta five environments, and you can see how much higher the tar spot pressure is here. So, a couple of comments here, I would say it was nice to see consistency on our data sets even in a really heavy tar spot year. So that was the first thing that was really nice. And I think the second thing is that, yeah, we do have lots of options there, there are things that are, you know, the best, but if they're hard to get ahold of, you know, there's some really good stuff in there that statistically is pretty comparable. And again, I think looking at some of those options is good. If at the end of the day you gotta do a single mode of action, you know, something like tilt, that's gonna be better than something else, but as Marty points out, it's gonna be better than nothing. But as Marty points out, just be careful with that fungicide resistance thing, and we're gonna wanna work on rotating the next time we need to spray in that situation. And we can look at the yield there. This year was a great year to get yield data out of these, we saw nice swings and it translated pretty well. Again, you know, Revytak, Veltyma, Delaro Complete up there in the A group, but we got from a statistical standpoint lots of things that are statistically similar from a yield preservation. So, again, you don't have to be super fancy, just see what you can get a hold of, try to go after the two and three way modes of action if you can, if you can get a hold of them and they're reasonably priced. But you know, again I'll stand by Headline Amp and Headline, and some of these Approach Prima, some of the stuff that's been around a little while, still really good on tar spot. So, we'll just jump in here. So, we've got some efficacious products, right? I think that's pretty clear out of these data sets. So, the other question now is, what's the optimal timing? What's that window of opportunity? And we actually looked at this over a couple of seasons, and we continue to look at it, but I'm just gonna show you the 2019 to 2020 years, 'cause that data set was summarized pretty well. And in this data set, what we did here is we just had one product. So at the time that we initiated this driver pro was kind of the go-to product, We used the labeled 13.7 fluid ounce rate, and we were looking at single applications at least timings here. So you can see V6, V8, et cetera, et cetera, but also compared that to two pass of V6 plus VT. At this point we were trying to validate our beta versions of Tarspotter, you'll see that these earlier versions weren't great, but we've got that kind of worked out now. But what I wanna show you here is, you know, so 2019 we had six locations in this data set, and you can kinda see the best timings are single applications between VT and R2, that was the window in 2019. Yeah, we had the two paths looked okay in there, but you can see the single V6 application, that's not the application that's carrying the load here, it was that tassel timing given two pass. So, we've been getting a lot of questions about, should I be spraying twice? And, you know, maybe 2021, maybe two passes might have been okay in 2021, I'd argue that 2019 and 2020 definitely were, in 2019 it was somewhere in the VT to R2, and then in 2020 it was somewhere between VT and R3. And I think that's probably where you should be looking, you know, if you know you need to probably put an application on, you're gonna have some tar spot, your window is likely VT to R3. Can you refine that? Yes, you could use a tool like Tarspotter or something like that to try to drill in and really get that timing optimized, you could also use those tools to ask the question, do I need to put a second application on? If I went, you know, I let's say, like a V8 or something like that (clears throat), but I'd really be focusing if my goal is tar spot, I'd be focusing VT to R3. And for us here in Wisconsin, I think the same for Michigan, we got ear rots, gibberella ear rot, and environment toxin that we have to consider in our corn grain and silage as well. And I don't wanna see folks giving up on those really well timed silking applications, just to go with a two-pass tar spot program. So keep those other diseases in mind and try to balance that across that window. I don't Marty if you had any other comments on timing there. - Hey, preaching to the choir there Damon. (laughing) That's right on notes, so you're all good. - All right, sounds good. And then yeah, I really like the slide, I think Marty likes it too. This is our colleague Darcy, she's been doing these trials for a couple years, we're gonna bring this back home again and just talk about the importance of the hybrids. And you can see pretty clearly when you choose that moderate resistance to hybrid, it almost negates the need for fungicides in some years, you know? And so, that's something to keep in mind. Yeah, again the yield potential, you can make a little argument there on some of those resistant hybrids, but remember you probably gotta put some added inputs to really achieve that high yield potential and some of those things. So just spend some time with the agronomic in making those decisions, and hunt around for those really good hybrids. And again, I think keeping optimal relative maturity in mind too, and resists that temptation to push super hard on that front, I think will help as well. - Yeah, and I guess I just add in too, like this is not unique to tar spot management in corn. We see this with head scab management in wheat, and white mold as well, when you can find that better resistance. Variety of selection is just so, so important. So, I don't think we're terribly surprised by this data, this slide really helps sort of just demonstrate that message, right? Remember that element of hybrid resistance is very, very important here. - It's foundation of all the management programs, at least that's what I teach my students. - Yeah (laughs). And I like this as well. So, I don't think you need to have a whole, you know, whole half an acre or whatever, or sorry, a whole half a mile or however long this is, just big enough check strips to, you know, just pick that up on the yield monitor, see how things were paying out. And honestly, I would do this, if you were the applicator, the co-op selling a product personally, I think I would have my guys doing check strips to prove to the farmer when things do look really, really bad, how would they have been if we didn't put a fungicide down at all? And if there's those check areas, then we can all go back and there's something to talk about, otherwise there's just pointing fingers and no one's getting anywhere. - Yeah, this is key, I mean, we learned this with white mold years ago Marty, remember, you know, when Endura came out, you know, a good day with Endura and white mold was like a 20% gain in yield over the non-treated. So, fungicide just make a bad situation less bad, right? So it's hard to tell unless you got a check strip, you know what the benefits were, because these fungicides they're really just sort of bandaids, unfortunately. And so it's hard to tell some years, and 2021 was one of those years, if you didn't have a check script, it was hard to see the benefits of a fungicide sometimes. - Absolutely. - Pressure was that bad. - Yeah, and I think, you know, guys tend to convince themselves of, "Oh, look it well worked or it didn't work," and I'm thinking about the like instances of white mold, and it ends up being the environment that was really the driver of a bad situation or a not bad situation. And again, the fungicides can certainly assist, but they're not silver bullets like Damon is saying. And this is a pretty obviously example here where that fungicide is being very helpful, but they're not gonna eliminate disease. And we have plenty of data too showing the length of time that they will sort of provide that activity, and then disease starts to march on again and starts to increase. They don't eliminate it from the field, it's not one and done, it's one and suppressed for a period of time, and it stops picking up again, right? - Yeah, yeah, yeah, yeah. And this is key when you're thinking about these diseases that have many cycles through the season. White mold from some respects, I'll probably get shot for the statement, but it's one of the easier diseases to manage, because the window of opportunity for the plug is so much narrower, but. So the disease like tar spot, you know, it's all through these cycles over, and over, and over basically until the crop either succumbs, or we get a frost, or whatever. And so you gotta keep that in mind that eventually everything's gonna break when it comes to tar spot, it's just how soon will it break. And our whole management strategy here is to try to keep things in that lag, part of that disease progress curve as long as we can. - Yeah, absolutely. I guess if you wanna go to the next one, this is sort of our wrap up slide, but we did get a question in. The question was, once we get tar spot in a field, will that field always be susceptible every year? - Yeah, I think, you know, is it like white mold in terms of, you know, are we stuck with it now for eons? I don't know if that's necessarily the case, again, the structures that this fungus makes are very, very different in terms of their longevity of survival. I would say that it's a safe bet for within the next two to three years, I would estimate that that field, you know, you have inoculum density likely in that field that can help contribute to a next epidemic. And so, unfortunately again, I think, if you just look at this great lakes region, there's plenty of inoculum here. You know, so even if a field hadn't seen it before, there's enough of inoculum nearby, and the inoculum can apparently move a good enough distance, at least that's what we're learning out of our trapping work, and some of our observational work that... I think when we're talking about our geography, let's just assume that the inoculum is there in that locale, and it's gonna potentially be there now for a couple of seasons in those fields. So, assume, I think it's a safe assumption Marty, and you can correct me if I'm off base, but I would say, I would assume the inoculums there in that field if that- - Yeah, I completely agree. I guess what I'll do is just throw out a couple of quick anecdotes, right? I thought this was kind of interesting. I have had folk tell me, you know, they got smoke with tar spot one year, so like 2018, they went back corn into that field, and they didn't really have a problem the next year. Well again, you know, what hybrid did they plant? Maybe it was something that was more resistant, I'll probably put some money down on that if I was a betting man. And then the other thing, 2019 was after we got through the mess of planting, it was relatively dry during the season. So, environment is key. Yeah, if definitely if we get another wet season, year after year, yeah, we're gonna have more issue without a doubt, but I completely understand. - I think that environmental component of the triangle is the one you gotta pay attention to. I think it's safe here at the great lakes region to assume that we've got the host component, the pathogen component, so it's gonna be the environment that's gonna be driving everything. Can we manipulate that host component a little bit? Yeah, I mean, we can grow some resistant hybrids and bring that risk down, and some years we're gonna escape completely in those fields, just 'cause of the environmental component wasn't that, we're gonna have dry years and we're gonna have fluctuations and pressure in tar spot. And then guys like Marty and I are gonna be putting trial out for tar spot, which usually makes diseases go away when we put a trial. (laughing) - Trial is gonna work out, that's all. - Yeah so, you know, it'll probably not be around this year, we'll see, I hope that's the case for everybody trying to deal with this. - That's right. - Since we currently don't have any more, I'm gonna ask one. So I was at some conferences, and seeing some of these warm technology, and as you talked about the several applications that we can have in a given season to control all the issues we have going on, do you see that using some type of UAV tool to apply being a really good solution for that? Has it been working, have you been seen it happen? - Oh, that's a hot place right now. I mean, I see there's a lot of interest there. I think, you know, I don't know in a lot of our acreage here in Wisconsin, we have real small, tight fields against trees, and so, the whole drone thing is becoming a really hot issue in those fields, 'cause we can't get helicopters in. We actually had a couple helicopters go down last year with loads of fungicide on them, so there's some thought that there's gonna a be less aerial application this year. So yeah, I think that's what folks are looking at. I think there's more work that needs to be done on that, and obviously there's lots of logistical things like the load that they can carry, and there's talk about using even lower carrier rates, you know, that we are even in aerial applications to try to stretch that out, which, you know, that's a whole another debate that we could have in terms of coverage and those sorts of things. So, I do see it as another tool, especially in some of these problematic fields. Is it gonna be the end of the eerie? I don't think so. I think we were still gonna have to really look hard at the resistant hybrids here, especially in those situations where we just can't get aerial application in some of those fields. So, we'll see. I think the other hot area too that we're seeing is short hybrids, because people wanna use ground rigs again, so that's the other ways where I think there's gonna be a lot of innovation, and marketing, and efforts. Don't you thank Marty over the next couple of seasons it'll be these short stature hybrids probably? And we'll see some broad application probably coming back in vogue. - Absolutely. I'm kind of excited to see what might get pushed away in terms of trials, and how they behave with disease as well. You know, being closer to the ground, will there be any different dynamics there? Yeah, I mean there's a lot of questions, so, I'm excited to see some of those innovations coming through. Okay, so we've got another sort of application related question here. So with drop muzzles with 25 gallons per acre be better than just over the top application or something like a 360 system, right? Where we're trying to get more application within the canopy. I've got some thoughts on that. I mean, do you wanna go Damon? Fine, you are nearly started. - Well yeah, I mean, I think the thing here is you gotta think about the target, right? So if I was gonna go after ear molds, absolutely, and I think there's a couple of data sets out there to show that our good colleague Albert Tenuta from Canada has generated some of that data, you know, drop nozzles with his colleagues, and shown 20% and 30% boost in efficacy if you get a good application pointed to that year. The thing to ask yourself though, is where is my target for tar spots? So if we're talking about the full year disease application, I don't know, in corn as if, you know, I need that kinda precise application because, most of the photo synthetic activity that's filling the year out is in that upper third of the can, right? We don't need those lower leaves, they're not doing anything other than they got the plant on the ground, and they got the thing to the point where it could start to make grain, but that upper canopy is taken over, and so if we can just simply get some coverage in that upper third, you know, then we're in pretty good shape. So I don't know if we need to go to all that trouble, and whether you're gonna see the gains with a foliar disease like this. It's very different to think about that something like white mold where yeah, we've gotta try to get it down, can it be because the biology there, the biology of that particular fungus does necessitate the need of trying to cover the center part of the plant. And again, the same thing when we're talking about ears and corn, it's the midsection of the plant that's the main target, so that makes sense to try to move the application strategy to where the target is. But I don't know if we need to be that fancy, I dunno Marty, what do you think? - I agree with you. It's that photosynthetic area at the top which is gonna get covered with a regular application over the top, I don't think anything fancy is needed there, yeah, I completely agree. Yeah, and I mean, I guess that can be extended to somewhat it to aircraft versus ground rig in fumigation. The application type I don't think really matters, as long as the correct nozzle and application volume is being used for that type of application method, then I think aircraft is very comparable to ground rig. And we've got a little bit of sort of demonstration data with fumigation too showing that that can work as well, as long as things are being done how they should be done. So, I don't think we need to get extra fancy with this. Yeah, do we have another question that popped in? - It's a past comment. He was just saying he was curious because they're set up to spray for years for sweet corn. - Oh, that's cool. So if you're talking about managing it for sweet corn though, and marketability of those ears that have been pulled, yeah, that's gonna be important, right? 'Cause I'd imagine get task spot on those ears, you're probably gonna have to end up like pulling, you know, consumers aren't gonna want black spots all over their sweet core, right? So yeah, that's a different situation. - Yeah, and if you're running that rig already, like it's probably just fine, I don't think it's gonna take anything away. I don't think you need to go after an application like that for this particular disease, or add that cost if you're not already doing that, but if you're already doing it, yeah, I mean, it should be okay. - That's right, I agree with you. I guess one other thing we haven't really talked about is lodging potential Damon. Sometimes I throw in like a particular trial that we had where we had amazing like 70% lodging potential like when we go through and do push test, right? 70% of stalks snapping, when we put a fungicide on, we're able to reduce that somewhere down to 50 or 20% snapping. And just a quick note here, you know, we have had some great yielding fields, but they ended up on the ground. So, just being aware of that lodging potential, that stock degradation. - That's key. And be aware that, you know, the other thing I'll say along those lines too is that, tar spot doesn't lead to crown and stock rot those are independent pathogens, and in some of those they're not linked mutually together, however, they can happen in the field at the same time. And we had a lot of that at least here in Wisconsin, so I've been in a lot of questions there. But tar spot is able to shut that plant down early enough, in some cases that the plant's gonna still wanna fill the ear out, and so it's gotta rob carbohydrates from somewhere so it goes, the plant is gonna naturally just go after the stock to try to grab some more carbohydrates to fill the ear. So, this isn't uncommon actually with tar spot, we see this with severe epidemics, with gray leaf spot, and northern corn blight, and it's just something that the plant does to try to continue to fill that ear in spite of being consumed by a foliar disease. So, just keep that in mind, and make sure that you're getting things identified correctly, and don't just assume that you have crown and stock rot pathogens in the field because you saw logging in the same year that you had tar spots, so, just something to keep in mind. - That's a really good point. I guess the only thing I'd add to that, is we did in some fields some of the samples that were coming in, there appeared to be what, you know, some red root rot and some gibberella stock rot, and we haven't done that much work on those 'cause they are hard to work on. I guess the only thing I'd say is, I could see the potential where tar spot might bring some of those along. Yes they're caused by different things, and you've gotta have that other pathogen infecting. But yeah, I mean, tar spot like this photo here, we did not see any other stock rots in this field, this is all tar spot, tar spot is totally capable of doing it on its own. - Yeah, I didn't mean to suggest that when you have of stock rots and crown rots along with tar spot, it's not a train wreck because it is. - Right, absolutely (laughs). - You know, I've seen those fields, but I think the key piece is to do some homework and make sure you're digging in and you know that, you know, what's causing all the issues in the field, that's the key piece. So, that you can then make some decisions on how to manage because, what I don't wanna have happen is folks making the assumption that, "Well, I'm just gonna use a foliar or fungicide to control all my stock and crown rot issues." And I think there's still research that needs to be done there to show some of those things. So, just be aware and make sure you're doing your homework and getting diagnostic clinics involved when we get these problematic fields. - Absolutely. You can't manage what you don't know, so, it's worth taking that time to figure out what was going on. - Right, yeah. - Do you have any other questions? - I haven't had any, so, I think what we'll do is, we can move to the wrap up, and if some people have some - All right. - while we're getting through that, we can answer them at the end. - Absolutely. - And so, we will be pisting the Qualtric survey into the chat box here, and it will also come back to you though, by the way, at the end you get an email, and it will come to you that way as well, but that is your opportunity to request your pesticide certification credit. And so we have had a couple people we've been sending messages to, to please give us their full names, and haven't had responses. So just make sure to take a look, and please give us your last name so you can get those credits. We will put the link in there for you to get the CCA credits. And Marty also went ahead I think and re-pasted what I pasted earlier, and that is Thursday, this Thursday, our virtual breakfast series will be starting, and we just wanna make sure you have the opportunity to join us. I don't recall what the topic is, it's probably early planting, or early weeds, or something early, but I just wanna make sure that you can get on and get registered and join us again with our specialists. And Marty will be on later in the season when it's more around our fungicide applications for white mold or tar spots. So, I'll let some people continue to ask some questions here. - Sure. - And there's one- - And there's one, yep, you see it, okay. - Yeah, so this sort of comes back to that timing window, right? And I guess just to reiterate really quickly, and Damon said it already, I guess if I'm the farmer and I wanna schedule an aircraft, I'm concerned enough and I wanna spray something, and I'm gonna schedule an aircraft, I'm pretty much gonna schedule that somewhere between VT through to maybe R3, right? So, with that in mind Damon, how would you go about answering that particular question? And just maybe just read out the question in case people didn't get it. - The question is just about how delayed applications due to weather and lack of planes, and that penalty of that late application actually seemed worse than maybe making the application a little early. And I think where Marty's had it is, as long as we're in that VT to R3 window, I think we're all gonna agree that pushing it early is gonna be better than waiting with tar spot. Because again, that lag phase is super important here, being able to keep the crop in that lag phase of disease increases as long as we can is really important, and once we get start to even approach the exponential increase. So as that disease is really starting to ramp up, even at that point, the shoulder of that curve is actually too late. 'Cause unfortunately with these diseases that have many cycles, there's lots of continuous infections that are happening, and there's lots of infections that you can't see yet. So this is why the whole thing with weight fungicide applications and tar spot just doesn't seem to work, and I had lots of farmers, you know, once they realized that tar spot was increasing in mid August, I was getting lots of calls with folks just wanting me to tell them to go ahead and spray, and I was telling them not to spray. And I know there were fields that got out sprayed anyway, and they're just kicking themselves in the butt for doing it, 'cause it cost them a lot of money and they definitely didn't recoup costs at that point in the season. So, definitely this is a disease where you wanna be on the early side, but be patient, you know, let yourself get into that kind of VT window there before you really start to make that decision, because we can see that you can go really early. And we did spray in our epidemic in Arlington, we did spray some stuff at that B10 when we first saw tar spot, but remember that fungicide's gonna wear off, and so in those cases that second application was really critical when we went that early. So you just gotta keep that in mind as you're making those decisions. - Damon, just real quick, how did you say, where you did put two fungicide applications out in terms of yield compared to a single application, what were you generally seeing there? - Yeah, it sort of depended on the product a little bit. We actually did do a Veltyma back to back, and the single application of Veltyma actually was enough to hold through. But I think we're all seeing the residual and that product's is actually a little better than some of the other products, so that makes some sense to me, and that we did get a tremendous benefit there. But we did see some other products like Miravis Neo which probably has a little bit shorter residual there, we did see some of the two pass Miravis Neo applications actually given us some yield benefits. So, it is gonna depend a little bit on some of the products, although is a little bit unusual and the fact that it does have that residual that it does have. I think the rule of thumb is, and Marty can correct me if I'm wrong, but I think that three week rule of thumb is a safe rule of thumb, when you're trying to make that decision and that reapplication decision. We actually in tar spot, we actually use a 14 day window, so we actually air a little earlier on that window, but I think three weeks is probably about as much as we can expect out of most of our modern products there so. - Yeah, I agree with that. I just thought I'd ask you that question about that, especially around the Veltyma thing. We saw the same thing, right? The two applications were .9 of a bushel better than a single application at R2, so it's like, as you wanna pay that much money for that .9 of a bushel. - Yeah, and I think if you were gonna use something like Veltyma with that long residual, in my opinion, and we're gonna run lots of these trials this year, hopefully we get tar spot to look at with some of this. But I think I'd have that long residual product first, and then maybe keep a cheaper product that, you know, I can readily get a hold of, keep that in my arts snow, and maybe I'll need to use it for the second application, but maybe not. If the weather is dry and crops looking good, you may not need the second application, but you know, we've been getting a lot of those questions, which order would you spray some of those products? And that's kind of the way we're thinking about things. - Yeah, I'll be excited to see what we get out of the trials this coming season. We had a question here as well about, "Are there any resources for finding which hybrids are resistant?" (laughing) I mean, basically I point the fingers back at the seed dealers, right? It's challenging for various reasons to go ahead and do all of that screening. I mean, Damon works with companies as well, we work with companies to screen material, so I really just point the finger back at, you know, talk to your seed dealer, make sure that they are asking the questions, they're getting the best information they can from the company, that sort of my go to line there. - Yeah, we're starting to see a couple of the companies, there's a couple companies out of smaller companies outta Illinois that started putting ratings in. I think, you know, if I talk to my colleagues on the breeding side and in the seed companies, if you ask them and push them they'll tell you, they kind of know. They're hesitant to publish that data right now because they don't have a strong data set, they do try to make sure that they can get data points from multiple years and multiple locations, and one of the troubles with tar spot is, we can't inoculate this particular pathogen. And so, everybody is just sort of grabbing opportunistic data at the moment in terms of what resistance looks like on these hybrids, and so the companies just start. They're really hesitant to publish that, but if you ask them and push them, I mean, I know I've reached out to my colleagues this winter and asked those questions straight up, they're willing to tell you that information. So, I agree with Marty, just put it back on the seedsmen, push them a little bit, and make them tell you what they think and what they've seen, because they know, they know what's out there, they're just hesitant because they don't have that deep data set at this point. - Yeah, I agree with that. - We did have another one coming into, did you see that? Hybrids that are resistant, are there any resources for finding out which ones they are? - Yeah, that's what we just sort of dealt with then. - Oh, I'm so sorry, I was dealing - No, that's okay. - With a screaming child, (laughing) It's my child. - I know. - And I was distracted, I apologize. - That's okay. Damon and I have done well with the kids tonight, we haven't had any interruptions yet. - Yeah, no visitors yet, I'm surprised. The electronic baby sitter must be doing a good job. - Well with that then, I don't see any more questions, and so usually if there's none, I shut it down. So, thank you both for getting on, and we really appreciate your expertise. And again everyone, the link was in the chat box, but if you have any questions or concerns afterwards, you're welcome to reach out. So, thanks and have a good night.

You Might Also Be Interested In