The Mechanisms and Best Usage Practices for Most Used Fungicides

February 18, 2021

Video Transcript

- [Instructor] Number of presenters which have been very generous for us for getting this unique conference going as a result of having to combine Southwest Short Days, Ag Action day, Farmers day, a couple of others. So we wanna thank all the sponsors. The other thing that the sponsors have been able to do is provide a scholarship opportunity for high school and college students through the funds that they've been able to provide. This is a very nice opportunity. So if you know anyone or are interested in learning more about these scholarships the link is there and I'm sure we have it also available on the Michigan Ag Ideas to Grow with website. The other one is for those requesting RUP credits we do ask that you participate in the full session. We do have an evaluation link that we will post in the chat. A lot of you should probably also be able to receive it when the session closes it should automatically direct you if I can speak. The other one is my attendance will be monitored and verified. We're doing this a little bit differently than a lot of conferences you've been doing lately. What we do is we shut down Zoom after every presentation that builds us a report. So we get to see who showed up. So we validate that with the people that are requesting RUP credit. So what that means is when Tim is done talking and we go through the Q and A after that we will close things up. In this case we'll be closing up for lunch but we close the session and then we will open it right back up in this case, we won't because we're doing it for lunch. But if you're here for the afternoon, you'll recognize that. And then you can use the exact same link all day and just log right back in. So, one last thing I wanna mention or wanna point you to is a short video that we're doing this would be for each presentation during the conference just as an awareness of different farm stress issues. So I'll show you this quick video and if you wanna know more about farm stress after this video, there is a track tomorrow. I think it starts at 11 if wanna hear more. - Hi, my name's Eric Harboughski. I'm a behavioral health educator with MSU Extension that focuses on farm stress with your farm stress tip. What is farm stress and how can you help? Recognizing the high levels of stress affecting America's farmers and ranchers the USDA's cooperative extension system Farm Credit, American Farm Bureau Federation and National Farmers Union have partnered in an online course for individuals to understand sources of stress, learn the warning signs of stress and suicide, identify effective communication strategies, reduce stigma related to mental health and connect people with resources. Through this free course brings together knowledge of agricultural conditions and evidence-based approaches and behavioral health to help people recognize the signs of stress and better equip farmers and the agricultural community with tools and resources to help in the time of need. This course has been designed to provide an opportunity to interactively learn about farm stress and how to help others manage stress. Through this partnership Michigan State University Extension and the University of Illinois extension focused on creating engaging content through self paced activities voiceover slide presentations and downloadable resources. For more information about the rural resilience training you can access the MSU Extension Farm Stress website under rural resilience training. There they will give you the information to sign up and begin your journey on learning these invaluable tools and resources. Thank 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, have a great day. - So with that, I will pass the duties off to Bill to do our formal introduction of our next speaker. - [Bill] Yes. Well, this is Bill Shane Crew specialist with Michigan State University. If you want to ask questions or comments if you mouse down to the bottom of the screen you will be able to see a chat and question answer. And you can click on that and put your question into there. And Tim will gather these up and at the end we'll let you answer those. In some cases, they may be a pretty broad question too broad for us to handle. But with that, I'd like to introduce our next speaker, Dr. Kim miles, plantologist at Michigan State University. And he'll be speaking on the mechanisms and best usage practices for most commonly used fungicides, Tim, take it away. - Thanks so much Bill Well, hi everybody. Thanks for the invites. And I'm kind of sad. I can't be down in Southwest Short Days in person but I'm hoping that I'm reaching a few other people today. So as Bill said, that's my title. And I'm a somewhat new professor at Michigan State University doing small fruits disease research. And a lot of my program is focused on fungicide resistance. So this feels like a talk that I could deliver. So, yeah, so I would admit that some of this talk has a fair bit of great examples. It's a big part of my program. I've tried to be a little general as possible so it's a blueberry field but it might have a little bit more of a small fruit spin on it but try to be gentle as much as I can. So really the talk is gonna focus on and this might sound a bit simplistic, but what is a fungicide? And then what's fungicide resistance. How do we use fungicides and manage resistances? And then a little bit some specific examples in grapes at the very end, which I think will illustrate some of the principles we talk about in the beginning. So I was cold when I wrote this talk and I used to be in California doing a post-doc and this is not Michigan at all. This is the Slams Valley. And this is something you're up against that. So I was just called thinking about sunny days. Oh, it looks a little hazy, but this is a vineyard in Galton California. But so first I wanna talk about what's a fungicide but I think it's important to acknowledge that fungicides do play a critical role in managing diseases. There's a lot of diseases that we wanna grow a specific cultivar. We can't rely on posters resistance and because of the way we're growing the plants, whether it's higher yields or tighter clusters for grapes or closer together, that there's really just no other way to avoid using fungicides just because it's being conducive to diseases. So fungicides do play a critical role in diseases. - So where first I said we talked about what's a fungicide, it's in the name, but it's a bio societal chemical or biological organisms but it kills fungi and inhibits their spores. Fungicides science can be a barrier to protect the plants and they can eradicate existing infections. That's sort of their main function. They occasionally can cure a little bit but in general they're not very good with back action and actually doing any kind of curative properties. So for the most part better if they're always applied for preventing. So fungi are an important group and I'm not trying to make everybody on my college list here but you know fungi it's a large group of organisms that we're talking about. And by and large most of the pathogens that we are are inhibiting and are in this group culprit the city of mycetes and the ascomycetes. So that does include things like mushrooms and other sorts of things. But many of the pathogens exist in this group. Most of the ones that are affected are cultural crops. So when you apply fungicides that's the group you really trying to eradicate. And that's the reason the fungicides don't work in plants because they're really distantly related from fungi. So that's sort of the the reason they work is they're specific to fungi. When you work on fungicides and fungi they can get a little complicated. And again, not trying to make everyone my buddy in my college here, but essentially fungi have a lot of names and that taxonomy is somewhat of a mess. So if you start to wanna do a little bit of your own research or whatever to sort of see things that have been done in the past just know that fungi have often two different things. And this has to do with the way they reproduce. They'll sometimes reproduce asexually by producing spores, chlamydia, and many pathogens do this especially they do it oftentimes if they have multiple life cycles in the season. So like powdery mildew will produce many many forms of itself during the season but it will do its sexual reproduction once a year, usually. So because of that and because of the way we kind of understand fungi they started off having two different names but now because of molecular biology we've kind of been able to figure out these are the same organism just at different states in their life cycle. So that's what we're in here, this growth germination things. So when you use fungicides and how do they help? So diseases it's kind of important to think about plant diseases a little bit. So I think about a lot and diseases are really not a very common thing. Organisms are crawling all over your skin they're on every plant surface but really you don't get disease very often. It's not a common thing. And it sort of, in some ways the stars have to align up for it to happen but if the environments right pathogens there and the host susceptible at that time disease can happen. So this is the disease triangle we use it a lot and find pathology. But what fungicides do is they disrupt this environment whether directly eradicating or killing the pathogen removing it from it or by making the environment really inhospitable. So really your tugged in that environment or the pathogen part of this triangle and kind of making disease collapse not actually happen. So that's really the part when you think about fungicides you're thinking about this part 'cause you can't really change the host. It's not moving. This is the part that you're really focused on. So historically down the history road a bit for fungicides. Fungicides have been around for a while now they kind of started off as a cereal seed treatment at first, small fruit crops particularly grapes, I'll have slide about it. The second kind of brought about some of the sulfur dust or dome mixtures in the 1800, 19th century. And there was a phase where there were pretty caustic chemicals being used with things that contain mercury for awhile. And then by and large some newer fungicides about 1940, came in 1930 and we still use some of those today. And we have a host of new chemicals as well. I got another slide. It's a bit more modern but in general the Bordeaux mixture is a fun story for grapes but basically it was meant to deter pilfers and people from stealing grapes. And they found out that by spraying the lime sulfur mix they actually would have less mildew. So it ended up being one of the most important fungicides in France. It's a long story with grapes that I don't have time to go into but it's a fascinating story, but okay. So in general this is a modern timeline of fungicide development. Kind of started off here with the Bordeaux mixture but products like products like captan and chlorothalonil which are still around today kind of were developed in 1940 to 1960. Then we started to have more specific chemicals, 1970, 1980 the DMIs or frank three came around this time. So do the phosphonates salts as well then 1990 to 2010 you had development of strobilurins and succinate dehydrogenase and resistance FRAC 11 and FRAC seven. And we have some new chemicals coming out today. So things that are specific powdery mildew, new FRAC codes, things like Quintec, lavando, Terino certain crops again sorry to be more specific but there are newer chemicals being launched today. So in general, fungicides have come a long way and as they've developed and they've gotten essentially more specific that's probably the important part of the timeline. So, back in 1940, 1960 these captans and clarifying those, they're pretty broad spectrum. They work on a lot of things but they're more content products but as you know, 1970 and going forward, we got more specific products that work in really fundamental modes of action of different fungi. And I'll get into that more in detail but that's kind of a trend of resistance development is to get more and more targeted to really specific organisms. So if you kind of wanna look at fungicides, fungicides are a little confusing. I can see why folks don't always necessarily know the difference between certain products because they have a lot of names and that gets a little bit complicated. So if you think about a product just as an example, many might know bravo or echo, chlorothalonil but that's the commercial trade name there is bravo. Now I've been finding it more as echo but a common names of that would be chlorothalonil this is a product that's developed in the 40s and 50s. It's an older product but it would have a trade name. It might be called funginil. It might be called daconil. For example, that'd be sold to the home market community. And then there's an IUPAC name which chemists would use and that's 2,4,5,6-tetrachloroiso, screw that up. So essentially they had a lot of different names and that can make them somewhat confusing. And then on top of that you'll see a lot of mixtures in commercial trading with multiple different active ingredients right here. And that even makes it more confusing. So anyway, it's important to note that they have a lot of names. So fungicides are pretty well regulated by the Fungicide Insecticide or the Insecticide Fungicide Rodenticide Act or FIFRA, FIFRA looks at any other unreasonable risks to the environment. It looks at economic and social things and then looks at human residue risks with pesticides. So the short story here is there's a lot of people that look at pesticides when they get registered and how those products actually come to market is a long process. I think I've heard that most site-specific products take at least 10 years to go through the whole system to develop a real fungicide and it's millions of dollars to do it. So yeah, so essentially there's a lot of regulations that go along with these products. Okay. So I kind of wanna talk a bit about how we classify fungi, fungicides. I apologize. We would look at how fungicides move often. So some fungicides are more able to move in a plant than others. Many are considered just contact fungicides sides, contact fungicides kill where they're at generally like products like captan, bravo or chlorothalonil, all of your coppers, your sulfurs, mans aides things like that are more content from site. So for those coverage is really important because they're not gonna move anywhere from where they actually are at. So those are called contacts. Many of the newer products are formulated such that they're systemic so that a lot of the site-specific products tend to be absorbed. There's sometimes even being trans located, be locally systemic, move from one leaf surface to the other, in many of those new products are able to move more within a plant. Some products like rhythm mill to be used for Downy mildew and certain crops that's highly systemic, but some of the site specific ones are a little less so. So the other way to classify them is their role in protection. So some are preventative. These are products that you need to be there before any infection event. You might have some products that have some curative activity, some of the FRAC threes, the DMIs the A's alls, whatever you'd like to call them have a little bit of backend. It kind of depends on the disease not a lot but they have some curative properties in some cases. There's ones that we'll call it eradicant. This is kind of similar to a curative idea but the idea is it will destroy an inoculum and we'll kind of clean up the plant surface a product like captans, a good example of that. So it's something that if you kind of run into a situation where you've lost control of the disease and you still have time before harvest and everything a product like captan can be good for another reason too, that it's a multi-site. So it won't really drive resistance when you do that. But that's a separate reason. So it's confusing though because sometimes products can be all three. A product like captan can sort of hit all three of these bolts depending on how you're doing it. It's just sort of, it's important to think about what you're trying to do with these fungicides. So that's the general reason. So when you think about activity I touched on this a little bit. So we have single sites fungicides which I'll have some examples of later, these ones will target various specific enzymatic processes in fungi. So really fundamental pathways things that fungi need to germinates things like that. Really specific enzymes multi-site products are active at multiple points a product like copper would be good multi-site products. We really don't exactly know how it works because it affects many things inside of a pathogen. So that'd be a multi-site product. Then you also have a different way to think about activities, narrow spectrum. So these are things fungicides that are really specific again, using my brief example of Fonda or Terino would be very narrow spectrum. They would work on powdery mildew and they would do a great job at powdery mildew but not necessarily other pathogens that are on different labels. A product line that's considered broad spectrum could be something like some of the FRAC threes or the FRAC elevens would be probably considered broad spectrum or a product like man's aides or captan could be probably fall in the broad spectrum category. Things that would be active on many things. I put this little cartoon because a narrow spectrum may only get one of these mushrooms that have sunglasses but a broad spectrum would just gonna kill all these little ones. So in general, okay. I haven't got to punch a center resistant spot yet but if you are kind of a geek about fungicides and wanna learn more about the fungicide resistance action committee which is an international coalition have organized how these fungicides work and they've assigned codes. So when I talk about FRAC 11, FRAC three, FRAC seven those all come from the FRAC list and this is a charts that they could produce. You can buy it if you love this sort of thing. And they'll group these fungicides by how they work. But on top of it, there's a longer word file or PDF file. It's about 60, 70 pages where they basically grouped by mode of action. They've grouped the specific thing that it's targeting if there's resistance and then what FRAC code they've assigned. So certain like FRAC seven and FRAC 11 are quite large and have a lot of diverse chemicals but they all go after the same enzyme. So they're a part of the same code. So that's sort of how those FRAC codes have generally assigned. And this is constantly evaluated every year to update FRAC codes. So sometimes they won't have an assigned FRAC code for a certain species until a little bit later and then they will assign it as they go. Again I just wanted to show this. I'm not gonna bore everybody but I'll just do a first couple of ones but you can see that like these FRAC codes with its groups and how they work. They might group things by respiration inhibitors. So I just use 7 and 11 as an example but you can see all both seven and 11 FRAC codes will stop fungi ability to make energy which is respiration. So that's how both of these two different FRAC codes work. Some stop cellular communication. This is a Quintec right here as FRAC 15. So that means fungi is one cell of a fungus can communicate with another cell and it dies. And then I have some that would be like the multi-site group. So like things like captan would be down in this multi-site or siren these would not have a numbered FRAC code attached to them. And it's important to note some we don't actually know how these fungicide work so they would give them some a U code like a U six or U eight for example. I'm not gonna go into this too much but we have a variety of products. This is just grapes as an example just to show you some of these products and what FRAC codes we have available in grapes. And I'm probably missing a few but I'll try my best here. But you can see by FRAC code we have a lot of products that are probably the biggest differences between some of these are the ones that go after Downy mildew and the ones that go after most of the rest of fungicides or fungi. Sorry, some products are very specific like FRAC 17 for elevates really good on petritis for example some are more broad spectrum like the FRAC threes. So and this doesn't include any of the mixed products 'cause there's quite a few of those as well. Okay. So that's all I wanna talk about fungicides like what fungicide is. So let's talk about what's fungicide resistance. So this is an example. So what fungicide resistance is, is a change over time that leads to reduce sensitivity of a fungicide. It's usually a stable traits that occurs and builds up over time, oftentimes as a single gene but sometimes as many genes. And this is just an example in using this leaf. So you see that there's one resistant isolate here of the things you apply to fungicide most died except the resistant one. And then you kept applying the same fungicide and the red ones kept reproducing. So that's kinda how it works. And it's important to think about it as a shift in the population. This is just an example of a Powdery mildew fungus in grape that's able to germinate in a hundred parts per million of flint on mildew sole germination. And this is nearly a hundred times the field rate. So the fact of becoming resistant 'cause this fungus to be able to germinate much, much higher rates than would have. With same field rate for flint would be about one part. So that is a really resistant fungus at this point because of this single shift that's occurred. The conditions that you need for resistance, you need to have some very ability in the population. So that usually means the population of after needs to be big. So there needs to be a lot. So it's more likely that this great cluster is heavily infected with powdery mildew in this case. It's more likely that there's gonna be some resistant individuals here because there's so many, it's so many individuals there. The worse the disease the more likely there's gonna be enough variability for those little red dots start to build up. And then you also need continual selection so that the products that are driving the resistance need to be continuing to apply. So those are the two components that need to happen. This is the two forms that are kind of common for resistance development. The top one's FRAC 11. And this is FRAC 11, which is the spore. I just showed you generally in a couple of slides ago. That's represented here by a little black circles. And you can see there was a few members of this population that resistant but over time the black ones predominate after multiple applications this is sort of a light switch thing. It's a yes, no. So these are sensitive, these are resistant. For FRAC three it's more complicated, essentially. It's kind of a spectrum of resistance. So the light gray and the dark gray, the darker the color of the circle here the more resistant it is, but this means that most of them were sensitive here. There's a few that were kind of resistant but then over time there was a little bit more resistance and over time it becomes dark and dark. It's the same effect you have a little bit more variability in the resistance. It's more of an academic thing but these are kind of the two fundamental types of resistance that happen. And this is one, you see it with FRAC 11. This is the one we see with FRAC three. Okay. There's also a few other types of resistances. There's cross resistance that can occur. And this happens when one fungicide is similar enough to another one that actually causes resistance in that new fungicide. So I'll give you an example. Boscolo is a component of a product like pristine and Boscolo resistance was detected a while ago but some of the new products that have come out there's been cross resistance to sort of if the isolate was resistant to Boscolo and ended up being resistant to some of the newer FRAC sevens. This is would be considered cross-resistance and it doesn't even require exposure of the new fungicide just because it already had their resistance from Boscolo resistance. So that can occur. You can have multiple resistance. So this is an example of this in petritis where you're resistant to multiple modes of action and negative cross resistance. But this is a pretty rare occurrence in fungicide resistance. An example of cross-resistance could look like this. Sometimes there's these both inhibit sterols and if an isolate resistant to FRAC three it can be resistant to FRAC 17 because ultimately the function is to inhibit the sterile biosynthesis or the ability of the fungus to make cell walls. And essentially this resistance can cause this resistance to happen. With multiple resistance this would mean that they were both resistant for example, oh, I apologize. I misspoke here, with the FRAC these are all cross resistant to each other within FRAC three. I apologize. And this one because it's so different is not cross resistance. I misspoke that's the cross resist. With multiple resistance this is when you have resistance that occurs is resistant to FRAC 17 and resistance to FRAC three. I apologize for that. So moving a little bit forward some examples of fungicides and the risk of resistance. So essentially, I showed this a bit, but we really with fungicides we really target very specific parts of the fungal's ability to reproduce. So things like the cell wall, the ability of the fungus to make energy, ability to make these microtubule structures which allow them to divide making nucleic acids. So that's a lot of these will target very fundamental processes within a fungus. I showed this a bit but site-specific fungicides like the FRAC 11s for example act on a specific site in the fungus. They usually penetrate fungicides, they're at really moderate to high-risk resistance develops. So that's sort of the main issue with site-specific products. Here's an example in grapes. I'm not trying to turn everybody into a biochemist but a lot of these are site-specific products here like over FRAC 11s, the FRAC sevens, the FRAC three they inhibit really specific processes but there's the multi-site products that don't exactly. So I'll show one thing about multi-sites and emits things like sulfur some of the biologicals would fall underneath being multi-site products and contact materials and oils as well. So with multi-site products, they act on multiple sites generally are the contact products and there's multiple genes that are affected. So usually this is considered a low risk of resistance developed. And what we really want to happen, I don't have time to go into it too much but we really want it to happen. So we want this population to go from being so in this case, I'm sorry, different colors. In this case you have resistant individuals that are this lighter color and then the sensitive individuals that are darker. So what you want is you want in this case you want the sensitive individuals the dark ones to predominate because you want your fungicides to still work. And one principal component of that is over time if you stop applying a fungicide you want this population to go back. But the main thing to think about as wide is to go back and the reason we really don't have it there the reason really is that there's fitness costs attached to it. It's expensive you can think about it for this fungus this dark blue one to stay resistant because it's not a natural version of that fungus but it needs this. It needs to be resistant in order to survive a fungicide application. So over time, if you wait enough time you want the sensitive individuals to come back into the population of these dark and you want these resistant ones to go away. And that happens because of fitness costs. So that's what we want to happen but it doesn't always happen as clear as we'd like. So another way to look at that is, essentially this is fitness. So like the more resistant and isolate is so the bottom axis here, this is a sensitive individual. This is a resistant individual. And essentially if you stop, this is an absence of this fungicide and this individual right here loss of fitness but this individual here maintain fitness. So it's kind of a complicated thing to think about but essentially it's very dependent on various specific products and how expensive it is for resistance to occur. I'll have an example at the very end about FRAC 12. So I'll talk about. So anyway resistance can be occurring and you might've got a report or a slab sample that said you had resistance in your field but really how does it impact management? And I think that's important. So, you know, cultural practices have a big effect on how chemical management practices work. Things like pruning practices, plant spacing, nutrient management your issue management are all really important. If the disease isn't really conducive the resistance might not be as important. I feel like sometimes folks blame funder centers systems and that might not be the actual case of what caused a control fee. It's important to think about spray practices. When you think about managing a disease and then thinking about your disease management program. So I'll just give you a couple examples. So I don't take forever. It isn't always resistance. And sometimes you just miss the target when you spray. So thinking about coverage issues that might've happened, how much liquid gallons per acre was used, driving too fast when you go through and make an application nozzles, droplets change depending on certain conditions and then pH on captans got a real, you have to be very careful with water and pH for counting because if its too alkaline captan loses its activity, for example. So it's things like that can really cause a control failure. With spray practices, nozzles and equipment and 'cause doing maintenance and calibration on those is really important and can help with coverage. I think seeing sometimes is believing with this but those cards, those water sensitive papers to see what kind of deposition you're getting going through a field can be really important. Wind can have a big effect on spraying and how windy it is. You kind of don't want it to be no wind like zero miles per hour but about one defines good conditions for spraying in the morning and humidity can have a big effect in droplet size. So this is if you have high relative humidity and lower temperatures droplets tend to stay large but with low rail and with the wind and then with low relative humidity and high temperature droplets tend to get smaller really fast. There's a lot of things that can affect how sprays work. Okay. I'll ask a little bit and then I'll get into my grape fungicide resistance examples. So intervals may differ and it really kind of depends on what disease you're going after. So like a disease, like the mildews the powder in the downy for grape, those are diseases that are season-long diseases. The pressure is constantly there. So really calender spray intervals work pretty well for them just to keeping kind of consistent coverage for those crops. Sometimes though, like bloom, for example, in blueberries and apples fire, blood's really important but in blueberries it's really important time to think about the phonology because bloom tends to be when they're the most susceptible to those diseases. So a phonology based spray can work really well in that case. I think it's really important when you make a disease management program to just plan ahead and designing a goods program that is sort of the worst case scenario. And then you can lighten up if it ends up being a drier year, it's like that, not making a program that's overly complicated. And I think I've hopefully shown that these multi-site products and actually biologicals, I didn't talk about them much, really have a place in managing fungicide resistance because they are multi-site and low risk and there are different modes of action. I think programs should really start to consider. So I'm going to show a couple of grape example because I was trying to be general but just a little bit about grape. So do we have fungicide resistance in vineyards? Yes. And mostly powdery mildew resistance to FRAC 11 is pretty widespread. And then we have quite a bit of resistance in botrytis as well. So some of the stuff I've kind of pulled for this talk is actually from a group that I'm a part of, it's called Frame Networks. We have a workshop going on two weeks in Michigan and essentially you can get a lot of resources about fungicide resistance. It's a pretty specific thing for grapes but if you want to check sorta those resources out this is the website and it can again give a bit more of a background, different fungicide resistance practices. I think though, we did a survey as a part of that grant. And there's a lot of, I mean, a lot of people had a lot of knowledge about fungicides but what we found in the survey is that the smaller your operation was and the less years you've been in the industry the less knowledgeable you were about specific products. And that was a nationwide survey not specifically Michigan Growers, but I think we could probably improve our education on fungicide resistance as well. So and I think that because Michigan's a smaller industry with at least with grapes again this is grape growers it's important to think about that because some of our acres are less than 50 acres. And that's what we found is this, in some ways 38% of those growers weren't very confident about what different fungicide groups they were applying so with what FRAC. So the bit about powdery mildew with FRAC 11 because I know I'm running short on time FRAC 11 effects a variety of fungicides of FRAC 11 for grapes. So we've produced a dashboard as a part of this project. And I've kind of found over time about 85% of the isolates that we pull off grapes are resistance and listen to the FRAC 11, really this project came about because there were quite a few patrol failures in the Central Valley of California and Michigan also has quite a bit of resistance to using our service, but we have a little dashboard tool that you can click on if you go to that website and look. So in general we've been finding resistance 2018, 2019 and I have some 2020 data as well. We're looking at some of the other fungicides right now but it's a bit harder to look. So just because we're detecting resistance doesn't necessarily mean a control failure is imminence. We really need to understand how to modify management practices to preserve these chemistries. Because again they take 10 years and millions of dollars to develop. We don't wanna lose the tools. So part of this project we've actually developed a decision tree but this really relies on having a laboratory to be able to send samples to. So for grapes we actually have that infrastructure out West and growers actually can send samples and get testing to see if they have fungicide resistance for pattering molding. So botrytis effects a lot of root crops. So I feel a little bit, more general talking about botrytis, but we found it's controlled by a variety of site-specific products not as heavily well controlled by multi-sites. We did a survey in 2014 and in 2018 and found isolates were resistance often to five to six modes of action and resistance looked like it was increasing over the span of those four years of the study looked at so we had quite a bit of fungicide resistance in that case and it would affect several products. So this is FRAC 12, FRAC seven, 11, 17, two and nine. And if you're not familiar with some of those are not always the same in different fruit crops but you can see these are products that are used fairly regularly. And interestingly we didn't find resistance to FRAC 12 very much. And we actually think that's because of those fitness costs. There seems to be quite a bit of a fitness cost to become resistant to this practice. Well, but I don't really have time to get into that but yeah, we've found resistant to pretty much all of these and some isolates losses seven different chemistries. Again, same caveat here, just because we're finding resistance doesn't mean fungicides won't work but it probably makes me wanna be cautious and how to modify some management practices based on the fact that we know resistance is around. And again this is my push for the multi-sites. So I think that products that are multi-sites things like captan, manzate, sulfur really do have a place. And then also these newer biologicals have a place as well to help manage resistance. So with that I just want to say thanks, Tara for making it a little bit grape specific try to be as general as I could but there's been a lot of people who helped support my program since they started. And if I talk too fast maybe I can answer some things in the QA. So thank you. Appreciate it. - [Bill] Thank you, Tim. We have time for a few questions. I can read them for you. How do you time applications of fungicides? Is it relative humidity, temperature based? - Sure. I'm reading it right now. So the first part of it. So first part of the question was how do you time applications? And I think that, early morning is always a good time before you get like convective currents going on in the field. But I was actually reading a little bit about this last night. It's not always great if it's, the wind is completely still but one to five miles per hour is what most people recommend from making an application. In terms of relative humidity I don't know that you can totally work around that. But I think that I showed that slide just to say that if it's really humid or really dropping droplet sizes are gonna be a little bit different. So it's kind of important how you do your application at that point. Are there tables at the onset of leaf spot that's bacteria, which is trouble for us? How do we know when to apply? When do we stop applying and how do we best rotate agents to avoid resistance? So I'm not a tree fruit pathologist here, but I will say that I've listened to a couple of talks about things. And I think incorporating a multi-site for rotating would be helpful. I don't know that I want to comment. I wanted to stop applying for that specific disease but appreciate the question. Let's see. How do we impact soil micro rising and looking at fungicides for sustainable? Well, the thing with a lot of these fungicides are more specific. So a lot of the site specific products tend to be very specific to certain organisms. So in general, I think a lot of the products that have been developed from the 70s going forward are probably a bit better for soil communities than some of the older products because those older products tend to be like captan things tend to be a bit more broad spectrum and like coppers and things like that. Newer products are a bit more specific to target organisms. So that's one thing to think about. Yeah. And there's not a lot of specific research on that though the question you asked. Melanie also asks is Neem truly a fungicide? Are there studies of efficacy with fruit grounding intent? In some trials that our lab has done in small fruits crops. So we've actually found Neem to be a moderate fungicide. That's not usually labeled as such. It's more of a labeled as an insecticide but we have got from societal a good decent efficacy data for that, but yeah. Okay. Elizabeth, you said, should we wait for heavy due to drain off especially on grapes? And I would say yes, you should. Because essentially if you apply it when you have a heavy due all of it will basically will volatilize when the due dries off. And then Chad, the more biologicals the better I think I am playing with bio science. I think we've had some good results with biologicals recently. What I've noticed is that they seem to be very crop and pathogen specific. So I think it's entropy but that was catered in the chat. Sorry Bill, I didn't mean to take over if you want to. - [Bill] That's fine. Let's see. I would like to mention that in the chat we have posted the link to the survey that you need to go into to get recertification credits. And for us get feedback on the section, Tim thanks so much for your excellent information. We could spend several days just going over the materials. So great there again if you need more help with these areas that extension is always available. You can go online Michigan State University and put in the area that you're interested in. There's also an ask extension if you're more of a backyard situation you can get a lot of great information that way that personalized information. So with that, let's see any, I think that's all we have, this is worth one credit for recertification credits for one C, for core, for private. There are no CCA credits available for this and we are taking a break for lunch here and then we'll start up again. I believe it is one o'clock. - Well, I just wanna say thanks everybody for inviting me. And yeah if I was doing a more specific talk I can probably get more into the details, but yeah, it's a broad topics. Thanks for the invitation. - [Mike] Yes. Thanks Tim for coming. Appreciate it. I think those of us that regularly attend meetings like this we hear some of these specific talks and so it's really nice to take a step back and listen to the broader perspective. And so when we do hear those more specific talks so we'll have a little more background so thank you much for that. Appreciate it. And like Bill said, we're gonna close up here in a minute or so. Let you hit that link if you want. And we'll close up for the lunch hour and we'll start back up right about one o'clock. Thanks for attending today. And we'll see you guys again soon, hopefully in an hour. And just for reference the first talk after lunch will be Mark Langstroth coming back. He just recently put in for his retirement. So we're lucky to have him back right now. So he'll be talking about cold damage and how that impacts your crop. So come back after lunch for that one. So thank you all much. I'll go ahead and end the session and we'll see you guys soon.

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