Review of Herbicide Resistant Weeds in Michigan and Surrounding States, Submitting Good Samples to the Diagnostic Clinic at MSU & Nematode Management Update

February 16, 2021

Video Transcript

Continuing on our track and weed control and problem weeds. And Erin Hill will be our next speaker. And Erin is our weed diagnostician at the MSU plant diagnostics lab and part of the weeds crew in general, she's an important part of that and she's going to talk to us a little bit today about some of the problem weeds in other states that have become herbicide resistant. And I've asked her to kinda look into some of those things because we know that we some of those farm back, cross back and forth across the border in a lot of us will buy equipment from there. So it's always kind of nice to know what, what issues that those folks are having. Some of the other states surrounding us. Also in this thing likes to go very, very quickly. So I'm going to back it up a step and there I'd like to thank our sponsors for today's session. Nutrien Ag Solutions, Crystal Flash, let's see, Greenmark Equipment, Michigan Pork Producers, Michigan Hort Society, as well as a host of others. They've helped us bring this program to you today. And the major thing, because we are doing a program that does have a tremendous amount of costs as physical program would have on there is that we've developed a scholarship opportunity that will support those folks, seniors or high school seniors or college students that are currently in the field of agriculture. So we appreciate very much their support to help us work through providing scholarships for students that are interested in agriculture, and that's a very cool thing. So again, thank our sponsors for that. We also are very proud to be able to provide RUP and CCA credits for this session. So now we'll go back up a lead in there. So it's very important at the end of this session that you stay on at to the conclusion and you fill out the evaluation so that we will be able to provide RUP credits for you. And you need to be in session for the whole time. So that's that's how we monitor and verify that for MDARD partners, our partners at the State of Michigan. And so with that, again, we'll we'll start out with Erin and then following that, Marisol Quintanilla, who is our nematologist for MSU, will talk about field crops nematology soybean cyst nematodes, and maybe just a little bit on some corn in terms of whether or not we think there's what the potential is for that causing some unevenness in stands, so I'm going to stop sharing. Bruce, did you want to do the video now? Oh, I'm sorry. Yes. We do want to do the video that we have part of a program that is looking at a farm stress. And so I'll let Eric do cue up a video from Eric Karbowski. Thank you. Hi, my name's Eric Karbowski. I'm going behavioral health educator with MSU Extension that focuses on farms stress with a farm stress tip. We know that farming is a physically demanding occupation. And oftentimes in rural communities, health care is not always readily available. I'm going to introduce a term that might be new to you, which is psychosomatic pain. The term psychosomatic refers to physical symptoms that arise from or influenced by the mind and emotions rather than a specific organic cause in the body, such as an injury or an infection. Is psychosomatic illness originates from or is aggravated by emotional stress and manifests in the body as physical pain or other symptoms. Depression can also contribute to psychosomatic illness, especially when the body's immune system has been weekends as a result of chronic stress. A common misconception is that psychosomatic conditions are imaginary or are all in your head. In reality, physical symptoms of psychosomatic conditions are real and require treatment just like any other illness would. There are also social stigmas attached to psychosomatic illnesses which might prevent farmers or the farming community from seeking treatment. Now that you have a better understanding of psychosomatic illness, I think it's important to note that this is not intended to suggest that your pain is not real or that you shouldn't access proper treatment. However, if you are experiencing some of these symptoms and concerns, it might be a good opportunity for you to do some self-reflection and see if stress is playing a role with some of your concerns. I'd also encourage you to access the MSU Extension farm stress resource or website for additional resources and supports that might be available to help you. And know that there are a number of people that are working very hard behind the scenes to support you as you support us. Thank you and have a great day. Well, thank you. Well, let's let's learn a little bit more about some of the troublesome weeds that we're seeing, Michigan in adjacent states, the herbicide resistant. So Erin and I'll let you take it away if you will, Thanks Bruce and Eric. So I hope many of you were able to catch a Erin Burns talk earlier because she touched on a lot of great things. But what we're going to really talk about is the nitty-gritty of the herbicide resistant weeds that we have in Michigan and what's located in the surrounding states that we need to keep an eye out for. Before I get into that too much. As Bruce said, I work in the Diagnostic Clinic which has somewhat recently been renamed the plant and pest diagnostics. And if you're not familiar with us, we have a whole suite of people who specialize in plant injury from various angles. And we also work with all the specialists on campus. So before I start talking about herbicide resistance, I just like to review what that is. I do this every time I give a resistance talk, to make sure we're using the same language. Here I have an example of a grass that got sprayed with 2-4-D. So maybe in your lawn and the grass survives that application. So we would call that plant tolerant because that herbicide is ineffective and it always has been. If you were to take that same 2-4-D in your lawn and treat a dandelion. What you would expect is that it would die, meaning that the dandelion is susceptible. But if you have dandelions that survive, which we don't have this currently, but this is an example you would call that resistant because it is a plant that previously was controlled by this herbicide and no longer is. So those are kind of three definitions I like to cover tolerance, susceptible and resistant. And we're talking about resistant weeds today. So herbicide resistance in the United States and in the world, we have a great database that has a lot of information. The international herbicide resistance weed database. They provide maps and charts and tables that will tell you everything we know about herbicide resistant weeds worldwide. And they're collecting all that data from the scientific literature. And they're also collecting it from people who submit it directly to their database. So that website is And you can go in there and look at the resistant weeds around the world. You can see from this map that we have a high concentration of herbicide resistant weeds in the United States. And that makes sense with the history of agriculture in our country. You can also get down and look into our country as a whole and look at the individual states and see how many unique cases of herbicide resistant weeds have been reported. So that doesn't mean necessarily that there are 25 different weed species in Michigan. It means that there are 25 combinations of a herbicide and a weed species in Michigan. So you could see we're kind of in the middle of the road here. State like California has even more cases that have been reported over time. And you could see we're going to focus on Wisconsin, Illinois, Indiana, and Ohio. We're not that far off from those states as far as the number of unique cases that had been reported to the database thus far. Now the tricky thing about the database, like I said, is that they're pulling information from the scientific literature and people who are reporting to them like myself. And so it's not always what you read in the paper or heard about a line or a blog or whatever. Because sometimes you're going to hear about the newest cases there first, before they have been repeatedly tested in the greenhouse and then filed into this sort of repository. So it's a little bit tricky to get all the most current information. In Michigan. We have been testing weeds for herbicide resistance starting in the 1980s. But we've really, for over the last decade, been making a concerted effort with funding from the Michigan Soybean Promotion Committee to test any weeds in question. They get submitted to us every year. And that's something that makes us really unique from probably any other state in the country and from the states that are surrounding us too. So sometimes you're going to see that we have a high number of weeds reported and that's because we're doing a lot of thorough testing that isn't happening in other states, but that's good because then we know what's going on. So for our state of Michigan in particular, you can go to the diagnostic website and you can look at a map that breaks it down by county. So any sample that has been submitted and has tested as resistant, we have a record of that in this list. You can go click on your county and find out what herbicide resistant weeds that we have. And we're continuing this effort right now. That's what I'm working on in the greenhouse is screening weeds for resistance using our bioassays. So now because Bruce asked to talk about sort of Michigan and the region, we're going to cover a few key site of action groups and look at how much resistance we've seen in the course of history and maybe what to expect. Before we get into that though, I think it's important that you know your site of action groups or you try to start remembering them more. And there's lot of great resources that we've pointed out to you before, like the herbicides classification chart here. They also have an app that's available on your smartphone so that you can start to really learn those or continue to learn them if you already know them. And you can get a lot of that information at So we're going to start out with ALS resistance. This is the most widely spread incidents of resistance in weeds. And you can see, I guess my colors are a little bit off here, but we have 11 species that are showing ALS resistance in the State of Michigan, and that's similar to Illinois. Ohio has a couple more and then few less in Indiana and Wisconsin. So what do we already have in Michigan? We have ALS resistant horse weed or marestail, waterhemp, Palmer amaranth, powell amaranth, red root pigweed, smooth pigweed, common ragweed, common lambs quarters, giant fox tail, Eastern black night shade, and we also have kochia. So we have a lot of weeds that are showing ALS resistance and I think many of us are already familiar with that. That's nothing new. What do we need to watch out for that's coming from these other four surrounding states? Well, they have got ALS resistant giant ragweed, cocklebur, Johnson grass like Erin Burns just talked about, and also common lambs quarters. So you'll notice on these slides that I have the group number here and the top right. And then I also have some of the common herbicide trade names that have just a single active ingredient in them if you're not sure which herbicides I'm talking about in particular. Next we're going to move on to photosystem 2 inhibitor resistance. So this is things like Atrazine, Metribuzin, Basagran. You can see that Michigan has 13 species that had been documented to show this type of resistance where the surrounding states have only a fraction of that. And the reason for that in part is, like I said, we're doing more testing. But a lot of these are not associated with field crops. So there have been several incidents that we've seen in blueberry and other horticultural crops that are added to our lists. So it's not just corn, soybeans, and wheat that we're looking at. It's the state as a whole. And we should be concerned about those two because they could move from those systems into our field crop systems. But as far as this type of resistance, again, horse weed is at the top of the list. Most of our amaranth a species are included in this common ragweed, common lambs quarters, Eastern black nightshade, common purslane, velvet leaf lady, some common ground swell and spear scale, which is a relative of common lambs quarters. But what we need to be on the lookout for that we haven't seen yet is waterhemp with, with this type of resistance, smooth pigweed, kochia and gypsum. And so in those four surrounding states, even though they have less documented cases, they still have some species that we are not dealing with. yet. And I think you'll see waterhemp continues to appear on this list. Glyphosate resistance is something we've been probably the most interested in during this testing period at the diagnostic clinic and when it was previously in Dr. Christy Sprague's lab, Mostly we have the same five species in all of these states. I'm guessing Illinois has a few more species than they have documented on here yet, but horse weed or marestail, palmer amaranth, waterhemp, common ragweed, giant ragweed. And this is the most common question, or at least it has been historically is, you know, are these resistant to glyphosate because we're using that so much in our Roundup Ready systems. As we're starting to transition to more technologies, we're going to see this question change to do I have 2-4-D resistance? Do I have Di camba resistance? Or maybe HPPD at resistance. So right now in this area though there's no other species that are showing glyphosate resistance. I like to point out that people are always very convinced about common lambs quarters having glyphosate resistance every year I get samples of that. And that's not to say that we shouldn't be checking for it. But. it's usually has to do with the lamps quarter being too big for glyphosate to control it. So after it gets four inches tall or bigger, you're really not seeing that control. So at that, those larger stages, we would say that common lambs quarter is somewhat tolerant of glyphosate. PPO resistance, So our group 14, like Flexstar, Sharpen, Spartan, those kinds of things. We do have a few species, but you can see we're moving down sort of the chain from our really high number with ALS, glyphosate and now PPO. We do have PPO resistant waterhemp that was just recently identified in 2019 by a sample that was actually sent to Illinois for molecular testing. And then for our bioassays we've identified Palmer amaranth, and common ragweed that are PPO resistant. And right now, in those surrounding states, we don't have other weeds that are PPO resistant to be on the lookout for. 2-4-D resistance, originally I had this slide as 2-4-D and dicamba resistance. What do we have in the area? But there really is no Dicamba resistance in this region so far. We do have a little bit of dicamba resistance in kochia, in the Great Plains and a few other states. And over in Wisconsin, they do have Dicamba resistance and prickly lettuce. But what we do have is we have a little bit of 2-4-D resistance that's been here for awhile in wild carrot in Michigan. And then in our other states, we've also seen it in waterhemp and then a sort of newer one in Indiana is Buck horn plantain. They found 2-4-D resistance in turf. That's an area not related to field crops. But I expect that we're going to see more testing that they want to get done is because I don't I don't think there's been a lot of testing done on turf weeds and I would suspect we'd see more resistance to these group four herbicides because they are so reliant on them. And we should be concerned about that in case they move over into field crops as well. HPPD resistance is the last one that I wanted to talk about thus far, we have not had any cases that are positive in the state of Michigan, but in Wisconsin and Illinois they have had water hemp and Palmer amaranth that is showing HPP resistance. So that's things like Callisto, Lautis, Bicycopyrone, things that we do need to be on the lookout for. Especially like Bruce said, if you are moving equipment from one state to another. So I could have shown this slide first, but I decided to show it last in that sort of line up. This is worldwide the number of species with resistance to those particular site of action herbicide groups. So you can see this red line here is the ALS inhibitors. So just like we saw in Michigan and in our surrounding states, we have the most number of species worldwide with ALS resistance. Then we have those photosystem two inhibitors. Down here further we have glyphosate and then we have our PPO inhibitors and HPPD inhibitors are, are not showing many species thus far, but we are seeing a little bit of an increase over time. The last thing I wanted to touch on, and this is a little bit tricky to show, is multiple resistance. So multiple resistances, of course, when you have resistance to different mode of action groups are different site of action groups. Here I'm showing how many species we have that are glyphosate resistant plus also resistant to some other herbicides site of action. A lot of times it's ALS, it could also be PPO. In Michigan, we have multiple resistance with glyphosate and water hemp, Palmer amaranth, we actually have one population that has three modes of action that it is resistant to. Horseweed or marestail and common ragweed. But what we really need to look out for is this sort of evil water hemp in Illinois, they have one that is resistant to up to six different modes of action and also giant ragweed like Erin was talking about. But this water hemp is really a concern. So far, in all of the US we've seen populations that have resistance to up to seven different modes of action separately, not necessarily together. But this population in Illinois has resistance all in one populations had six different modes of action. So you really start to run out of options. And that's what we need to start talking about alternatives or, or before we even get to that point, we need to be proactive in using these alternatives. So resistance identification and management is getting trickier. The one thing that Erin already touched on was resistant weeds aren't aren't necessarily always behaving the same as we've seen them in the past. So I have this giant ragweed here, that's the abbreviation am AMBTR, showing rapid necrosis response to glyphosate in the greenhouse. I have seen this a couple times with our samples. And so this ragweed plant here was treated with glyphosate just one day before. And so you see a lot of necrosis here on the older leaf tissue. And that's not generally how we think about glyphosate working, but reiterates the importance of going back after your applications, you know, a couple of weeks later to make sure are they regrowing from those growing points like she talked about. The other thing that we haven't seen here yet in Michigan, but they have seen in Illinois and some of the other states in the nation is we're starting to see resistance to our pre-emergent herbicides are those that have residual activity. And this is really concerning because that's one of the tools that we talk about relying on as we diversify our chemical programs. But they have seen, for example, resistance to water hemp, to esmacolatore dual magnum when it's used as a as a pre and so that's, that's really concerning, that we're losing that tool in that population. The last thing I wanted to talk about as far as resistance getting trickier. And this is kind of a complicated topic, but I try to make it as simple as I could, is historically, when we're looking at resistance, we're thinking about what's called target site resistance. So usually that's a single mutation in the plant, or sometimes increase expression. But that's kind of been, what we're expecting is this, this target site. There's one like a switch in the plant that makes it resistant. But what we're starting to see more of and we're starting to be able to define, though we don't completely understand, is resistance that is not target site related. It's related to metabolism or the ability of the plant to break down the herbicide or, or the herbicide doesn't move into the plant like it should or it gets isolated once it's into the plant. And this is really tricky and we're still working on understanding this. But what's tricky about the non-target site resistance or the metabolism based resistance also is that it's not as easy to predict. There doesn't have to have been a history of use of that chemical in the field for the plant to have this type of resistance. In target site it's selection pressure that is constantly being put on. So you're using glyphosate every year in the field. And then we see resistance. That's not what's happening with its metabolism base. So it's harder to predict. With target site, you're more likely to see cross-resistance. So within that same site of action, let's say atrazine resistance, you're expecting to see resistance to those other photosystem two inhibitors like maybe metribuzin or something. That's not the case in metabolism based, But there, what's more concerning is it's more likely to confer resistance to other sites of action or other modes of action that multiple resistance. So it's getting trickier. We're still trying to wrap our heads around it and figure out how to identify these populations. But it's not, you know, we're still, we're still learning all the time about this. The last thing I wanted to touch on is a couple new cases we're seeing in Michigan. They're coming from vegetable systems. We're getting more things submitted that way. But here we have large crab grass that is showing resistance to clethodim or select max. So those group one, graminicide products. And so that is concerning where we're doing our dose responses and confirmation of this, but quite certain that we do have this type of resistance in Michigan in vegetables. The other one that we have been looking at as we have unfortunately a new species of pigweed that we identified last year called Purple amaranth, or sometimes it's called livid amaranth. And this again was in a vegetable population. But this weed is now here and already has resistance to those photosystem two herbicides. So we are getting new things to look at every year. I'm never bored in the Diagnostic Clinic working with new weeds and new types of herbicide resistance. The testing for herbicide resistance and weeds is going to continue in our lab. This year we're going to be sort of testing out molecular testing, working with Eric Patterson. We have received funding from the North Central IPM Center to work on that. So we'll be, we'll be out collecting on our own and with the help of some agro businesses samples to screen the tissue for herbicide resistance because this is a service that we will be offering in the future. So this is kind of our soft opening this year on that. And then of course I'll be continuing to do the bioassay screens where you need to submit your seeds to me by mid November. And that's what I work on in the wintertime. We do have a sheet to help people understand where the weed seeds are, how to collect them, where to submit them that's available on our website And then is Erin had mentioned and I have mentioned there are a lot of resources out there for battling herbicide resistant weeds, both through our weed science website with the field guide and with some of their other extension publications. And then also I really like that Iwilltakeaction website. The work in a diagnostic clinic is supported by our industry through Project Green, the Soybean Promotion Committee, and now the Michigan Vegetable Council is helping with some of those screens. And then we do have funding from the North Central IPM Center. And with that, that's all that I have. I know that Marisol has presentation to do as well. Well fantastic, Thanks Erin and I really appreciate the update on what's going on around the region. And as well as in Michigan itself in terms of herbicide resistant weeds. We will ask if those folks that have questions for Erin or have any questions about how to submit samples to the lab to answer to put those questions in the Q&A chat or the probably the Q and A portion in the bottom there. And if Erin, if you'd be willing to kinda take a look at what comes in and we'd be greatly appreciative. No problem. Thanks again. And Marisol, I see that you're here. Let's see if we can get your, get your presentation up. What are we gonna learn today, Marisol? Hello, how are you? So I need to share my screen. Thank you for inviting me, Eric and Bruce. So I need to figure out the screen-sharing. Okay. Is there's a little green button at the bottom there? Yeah. Now, I just need to turn it on and you should be able to see my presentation. I'm putting on presentation mode. Yeah, there you go. It looks like it's coming up. Okay, fantastic. Thank you. So hello everybody. I suppose many of you are soybean growers. And today we'll be talking about soybean cyst nematode. Soybean cyst nematode is the number one yield robbing pathogen in North America. So it is an important problem. So here you can see a picture of my team. I have some new members now, but here you can see us in a soybean field. So, so here you can see a picture of soybean cyst nematode. You can see it's like this skinny worm right here coming out of the egg. So you see that round thing. Can you see Bruce when I move my mouse, you know, can you see that arrow? I guess Bruce doesn't hear me. So there's an egg there and the nematode is coming out of the egg. We can see your arrow. You can see the arrow? Good. That way I can point well, so you can also see in the roots and the root of this, of this soybean. Those little white balls that almost look like grains of sand. Those are soybean cyst nematode females. So a soybean cyst nematode, juvenile starts looking like this, like the picture you see here. Just a humble little worm. But Marisol? Yes? Sorry for interrupting. We had one person that said, it can be just a little bit louder. So if you could maybe get a little bit closer to your microphone that would be great. So you do not hear me very well? Yep. That was better. Okay. So I guess I need to get closer. You'll get to get a close-up of my face by the camera them. So if you see there, those round things are soybean cyst nematode. They They enter and they start out like a worm, like you see here. And when they entered the root, they, they secrete certain chemicals that make the plant make it a, make it a home and to, and to start super feeding that nematode. In other words, get food straight to the nematodes so it doesn't need to move anymore. And this nematode becomes, especially the female actually becomes enlarged and obese and sedentary is stays own, it stays all her life in one spot. The plant is feeding her. So in other words, she's getting VIP room service, getting food straight to her room, you know, doesn't need to go anywhere. And she becomes enlarge an obese and those white brown things, those are actually the females to enlarge females that are full of eggs. So she will be full of eggs. Of course, a male, will mate with her and then there will be full of eggs. So it, soybean cyst nematode has a big impact on soybean yield. So today we'll be talking about the different trials that we have done for managing soybean cyst nematode and also best management practices. How can you best manage it. The order of the presentation is not in the order of the most important to least important. But I will mention to you which ones are the strategies that are most important or not. I'll mention you right away. The number one strategy that's most important to manage them. Soybean cyst nematode is not getting an a in the first place. That's obvious, of course, if you don't have the problem, does the best thing. In order not to have the problem try to make sure to wash equipment when you go from one field to another or field that you know has a problem. Or if you're sharing equipment with other growers, also wash, remove the soil. If you have removed the soil, you have removed the vast majority of nematodes. Well, once you have it, the number, the other number 1 strategy the most important strategy once you have it, is to rotate with non host. In other words, plants that soybean cyst nematode cannot feed on. And that is really a lot of things. It can feed on a lot of things including corn and wheat, and just about any crop, except things like dry beans. It can't feed on dry beans. And also a couple of weeds. Not all weeds, but a couple of weeds. Any grass weed, it can't feed, but there's a couple of weeks that it can. So controlling weeds in the winter and not in the winter, but Spring and for controlling weeds, it's good for many, many reasons. But one of them is that some of them are alternative host to SEM. And then after that is you see resistant varieties and this is very, very effective. {inaudible} is a very common source of resistance and it has worked out very well for 20 years. They are the resistances breaking by now after 20 years of using the same strategy. But it is still working pretty well. So using resistant varieties, it's important and rotating sources of resistance is also important. We'll also discuss things like seed treatments, manures, cover crop, trap crops. Those are things that we're evaluating. But none of those strategies can replace things like rotating sources of resistance using source of resistance and rotating with non host such as corn or wheat or just about any other crop. All right. So are we going to tell you about our greenhouse cover crop trials. In other words, we're trying to evaluate what are the best cover crops to manage soybean cyst nematode. Dr. George Bird came up with an idea of using a trap crop. And actually the trap crop is, it's a type of plant that the nematode sees as such a good host. So it hatches out of the cyst and goes, goes to feed on it, but it can't reproduce. So it's a trap, you know, he thinks is great, but it can't reproduce. So the population in the soil declines because soybean cyst nematode as I told you, is this cyst this female that die full of eggs, you know, 200 eggs, 150 eggs. And they will remain viable the soil for ten years, 20 years, bop a long time. So therefore, you want to bring the population down and this might be a good, a good way. So would the SCN trap crop is tested alone and then several cover crops with it, like red clover, Zero Rye None of those are trap crops. The {inaudible} trap crop is actually a legume that there's been evaluated. Okay. So the one who's doing this work is my post-doc Sita. And you can actually see that trial right here. You can see the parts, what soybeans and grasses, etc, those are the different kind of cover crops. And we check and the effect on soybean cyst nematode and other trials that we have tested is composted manures. We have tested this for SEN and for other nematodes. One of the trials that we did is putting nematodes straight on composted manures, different types. So you can actually see the compost and manure in the little containers there. And if the nematode is alive and healthy, they will, will go down to the water below those containers, and then we can count them. You can see this is not for soybean cyst nematode, this is for root lesion nematode. But you can see that poultry manure and layer ash killed all the nematodes when it was used. 100 percent concentrate. Obviously nobody's going to plant them a 100 percent compost. But we, we just did the initial try, the experiment just to set this compost kill nematodes. Compost someone was kill nematodes yes or no. And turns out that some do. The control was just plain sand. And you can see that the nematodes remain alive throughout the different days, right? So we also did different dilutions. In other words, this would be pure compost and the lightest one would be like 0.1% compost, I mean very little. So it went with the several trials. One is like 100 percent and then 95% or not 95 percent but 5% compost and 95 percent sand. But anyway, the different concentrations below we'll see the results. So we can see here from a 100 to zero that's a 100 percent compost all the way to 0, in other words, species about 5%. And you can see that these black lines would square. That is the, that is the poultry manure. This black line in the bottom. And this is the layer ash plants. So you can see that the poultry manure and the layer ash {inaudible} and the low even under low concentrations lead to control of root lesion nematode. All right, so this is our even under low concentrations and we can see similar, similar result in which at 5%, even at, even at 1%, you can see that things like the layer ash {inaudible} and the poultry manure, we're having some control. All right, so this is actually on soybean cyst nematode. So we tested, we put on chicken manure, on corn, on the ear of corn and soybean cyst nematode. And we saw a decrease. This decrease was not significantly different at 95%, but it was significantly different at 90 percent. In other words, we can tell you with 90 percent confidence that the manure actually had an effect. And this, what happened is that it seems like the manure is even affecting the nematodes when there's no soybean there. So we repeated this trial in 2019. The one before is 2018. We repeated this and we can see that. Also the poultry compost had the lowest number. And it was, yeah, it was significantly low. But you can, what's important to note is that the decrease is not as important, and we'll see late,r what happens when you rotate good sources of resistance. That is a much bigger deal. So compost, especially in the ear of corn, corn can benefit from manures, like poultry manure, but soybean doesn't. So applying in an ear of corn can give you an extra help in managing soybean cyst nematode and some fertility for your soybeans. All right? So I'm not going to go into all the details here. What {inaudible} rotations of SCN resistant varieties. You can see in 2017, we started this trial rotating with different sources of resistance. PI stands for {inaudible}, which is the most common source of resistance. Like 95% of the soybeans grown pretty much in the Michigan or wide area. You know, all the Midwest are from a {inaudible} source of resistance. Picking is the second most common source of SCN resistance. That's I abbreviate as PE and this the other ones are yeah. You understand? So we can see that {inaudible} and picking when we started the strong 2017, there was no significant difference in the yield that pretty much {inaudible{} and picking yielded the same. Things started changing in the year after 2018. We can see that rotating with {inaudible} and picking this rotation trial. In other words, we'll have one year, one year picking Another year of {inaudible} a year picking another year {inaudible}. This is, This is the first part here. The second bar is PID 7, 8, eight back-to-back. In other words, 2017 we group {inaudible}, 2018 We group (inaudible} The third bar It's picking back to back. And and S stands for Susceptible. In other words, we planted a susceptible soybean. Very clear things here you can start seeing. First of all, anywhere we planted susceptible with an S, You have a significant reduction in yield. So that's very low yield. Anything that has an S, despite any seed treatment, we have a big decrease in yield. But also it's interesting that we plant the peaking back to back two years. We're starting to see a decrease in yield. So and at the highest yields are with the {inaudible} and picking back to back, in other words, we see a big improvement in yield when you plant picking after {inaudible} which is what Greg Tilka found in large trials all over Iowa is that when you plant picking, after many years of planting {inaudible} See an important yield bump. Now that yield bumps does not last forever because after we planted picking back to, back two times, we are seeing an important decrease. In other words, picking is an important strategy that you can use. But it's not a good long-term tool that we're going to use it every year you're going to get yield decreases. You need to rotate with {inaudible} Of course, don't even think about using susceptibles if you have soybean cyst nematode. But I think most people don't. If you look here at can you still hear me well, Bruce? Yeah. Yeah, we hear you fine. That's good. You're doing great. Kiddo. Had thank you Bruce. So you can see here in these bars right here, these are actually the SCN numbers, the nematode numbers. And they are totally inversely related to the yield numbers. In other words, the higher the yield, the lower the nematodes look, you can see, the higher the highest yield was with with {inaudible} and picking rotated. And this matches with the lowest nematode numbers. In other words, what's driving the yield difference here is soybean cyst nematode. Soybean cyst nematode is a big problem. It eats up your yields. I mean, that's no question. It takes away money. If it eats your money, for sure, this is no question. So the lower the number the nematodes, the higher the yield. You can see BIT 78 with picking rotated, we had the lowest number SCN, PIT 78 back to back. In other words, when we're rotating them back to back, we have the second highest, picking the third highest. And obviously the susceptibles are the highest with very high numbers, you know, six thousand, eight thousand per eggs per a 100 CCs of soil. So insane, all right, So next one, 2019 which is the third year of our trial. In the third year of our trial, you can see a couple of things start popping up. Again. We're seeing the same trend when you rotate {inaudible} with picking, in other words, rotating source of resistance, we have the highest yield. So now we are getting a clear picture. We are recommending people to rotate sources of resistance. {inaudible}, back to back three years in a row, has the second highest yield and picking back to back has the third lowest. I mean, it has the lowest yield is lower than the ones that have a susceptible. So don't switch to be picking in the sense that you want to just lock picking and only plant picking every time you planted. No. you have to rotate {inaudible} Source of resistance with picking. And if companies come with a new source of resistance, you can include them in the rotation. I have not tested three sources of resistance. But my guess is that the more the merrier and the better we're going to manage to soybean cyst nematode. If the sources of resistance are different, you know, different mode of action and Erin probably understands this. You know, you want to use herbicides, a different mode of actions. You also want to use sources of resistance to SCN with different mode of action. So if you don't want to have resistance, so that principle applies to just about everything. Okay,. So generally you can see the picking with {inaudible} back to back in. I want the rotation that had the highest yield has the lowest number of nematodes, and the Picking back to back has the highest number of cysts. So yeah, Same story. Nematodes, SCN is driving yield, okay? And if the lower, the lower the nematodes go, the higher your yields go. In other words, SCN is your yield robber. He is pocketing up your money. Alright? 2020. We can see that Picking back to back has very low yields. And when we are rotating picking with {inaudible}, back-to-back would already getting a yield decreases. Not significantly different, but we're already getting a yield difference. So my guess is that we're planting picking to often. So a{inaudible} seems to be a more robust source of resistance. So planting it probably better to plant two years of {inaudible} picking two years of {inaudible} one picking. And that is considering that you are planting corn. Because if you're planting corn, all of these things are happening just in a longer amount of time because instead of having them in three years, maybe they happen in six years. But all this is happening. All this is happening when you're planting corn because corn SCN does not go away. It just has one year of, of population decline. But whatever you planted the year before that's the source. But thats plus the population of nematodes you're going to get. And whatever source of resistance you plant, the {inaudible} is going to benefit those nematodes that can feed on{inaudible}. Okay, So, um, and you can see that susceptible is the lowest of course. All right? So summary for this trials rotate sources of resistance. The more sources of resistance, the better you picking But use it wisely. Use it after {inaudible} and maybe use two years of P edit 78 and then picking, you'll get a yield bump when you plant the backing. But don't think, okay, I got a yield bump therefore, from, from now on, I'm only going to use picking. Because that's not going to work very good for you. All right? So we have several trials, over, all over. Michigan. And I'm not going to read you all the trials, but we have tested several seed treatments and them, alright. And some seed treatments have lead to numerical differences, but not really big significant difference in now, it's difficult. Managing SCN is not easy. Okay. All right. So we have several trials continued planted to trap for trap crops. What I mentioned about is that SCN source of resistance as a trap crop and then different cover crops, composted manures, and to do an SCN survey. All right, and and to keep on testing different sources of resistance. For our long-term goal, as a lab, is to test different rotations of SCN resistant varieties. Test the use of different cover crops and trap crops and evaluate compost use. So this slide here will tell you what is the best management practices. Some of the best management practices collect samples from the field and know your numbers. You can submit soil samples to the MSU diagnostic lab. This is covered by your checkoff dollars. So you're not going to have to pay out of pocket. That will let you know, do you have SCN do you not have a SCN? And they can even tell you your SCN type. In other words, can your SCN reproduce on the different sources of resistance that we have, which mainly commercially we have pickiness, {inaudible}. In other words, it can help you make wiser management options. Grow non-host, corn, wheat, grains, and a few others in-between soybean. Grow resistant varieties, like I mentioned, and rotate them and cover crops. We're evaluating that. Seed treatments. We're also evaluating that so far they're not a big game changer, but they can help a little bit. All right. So all right. So I think that's it. And I want to thank all the people and all the commodity groups and all the sources of funding such as number 1, the Michigan Soybean Promotion Committee. They are wonderful. They have provided funding for most of this research. North Central IPM. North Central IPM has also promoted, provided funding for some of this research. Michigan Wheat, Michigan Sugar, Corn Marketing, Project Green, Ag-bio Research the wonderful diagnostic lab, with Fred Warner and {inaudible } the nematologist at MSU. The SCN Coalition, Dr. George Bird, and USDA MIFFA So that's a picture of my team. You can see there my team and any questions? So there are a couple of, well, there's at least one question in there about manure compost on the on the Q and A. And maybe because of the time here for an order to get people kinda onto their next session here, maybe we'll, we'll let you answer that if you're willing to. Marisol, just on the Q and A, but. I'll do that. Do that directly on that.. And then other than that, we'd like to thank Marisol for the update. I I learned something there. I had not seen that. I had not seen your research on the importance of that rotation between the source resistance and that's very interesting. That's, you've, you've have that much of an interaction between the two. So I know we have we have some challenges on the horizon and I think keeping a very close eye on how you, which source resistance you're actually raising and mixing that through as well as putting that into longer rotation seems like a really good thing to be able to do for controlling soybean cyst nematode is down here, so. It is very key. It's very important. So thank you so much Bruce and Eric, for inviting me. You're very welcome. All right, so the next time we got Eric just put into the chat, the survey link. Remember, make sure that you fill out your survey for this talk. It also has our RUP place to put your or your certification number and that thing, and so fill that survey out. And again, thanks to Erin and Marisol to for this presentation and we'll be looking forward to you perhaps returning in the afternoon. Our new session is just about to get underway, so we'll let you go. And Eric, if there's anything else, you can share it. If not, we'll close this session out and we'll record it and we'll see you back here after lunch. Do you talk with Dr. Chilvers about corn tar spot? So just a reminder for those of you who if you're looking at the schedule, if you do want to attend the noon hour, that's a different track. And so it'll be a different look that that's a home horticulture track. So yeah, if that's what you are wanting to attend over the noon hour, make sure to click on that separate link. It'll add a lot of the same passcode, but it'll be a different link. So in about 10 seconds, I am going to close this session out. So go ahead and click on the survey link here if you're wanting to give us some feedback on the session and apply for those credits.

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