 All right, so I'm Amanda Scheer. I'm an assistant professor and extension plenipatologist with Alabama Cooperative Extension. I have a wide range of crop responsibilities, but I'm mainly gonna focus on turf grass diseases today, but I'm also your point of contact for ornamentals and some row crops as well. So the main thing I wanted to talk about was fungicide application considerations to manage turf grass diseases. As things are starting to green up, we're getting a lot more phone calls in the landscape about managing for turf grass diseases, starting to get some phone calls about patch diseases in turf as well as dollar spot. And of course on golf courses, they're always continuously, intensively managing for a lot of these diseases as well. So why do we even need to talk about fungicides? Well, if you look at our commercial turf grass IPM guide for diseases in turf, you'll see that this thing is a huge document with several fungicides listed. And so it can be quite daunting when you're trying to think about what type of fungicide you need for what type of disease. And really with fungicides, they account for a good input of your production budget, especially on golf course maintenance. It's about 13% in total maintenance costs. And so it's important when you're thinking about fungicides is what are they used for? They're primarily used to control diseases either by suppressing or slowing growth of that fungal pathogen itself or preventing the fungus from reproducing on your turf grass. It's important to note that they're not gonna promote turf grass growth as a whole. So you really have to in intensively manage turf or really damage turf, you need to look at the system as a whole. Nitrogen fertilization rates are really important, especially during the spring, when you start getting green up, a lot of people wanna put a lot of fertilizer out on their lawns, some herbicides as well. And so you need to do other things to kind of promote the growth of that turf. Fungicides are only active against a limited group of fungi. So it's important in turf grass selection, especially with narrow spectrum fungicides to know what diseases you have and then choose the right fungicide accordingly. So instead of focusing on the turf grass diseases, I've done webinars on those before. So feel free to check those out for more information. I believe they're all kind of posted up on our website or Facebook in our archives as well as YouTube. But I mainly wanted to go over the fungicide basics and what the categories of fungicides are, different considerations when selecting fungicides to manage diseases as a whole. And so it's important to know that there's kind of two main types, four fungicides in turf grass management. You have contacts which are considered protectants. So based on this figure, you can see those contacts don't move through the plant tissue. They just are on the surface of the plant versus systemics which are going to move through the plant tissue. And there's different categories of systemics. Some may just locally penetrate on the leaf blades. Some actually may flow through the vascular tissue. So it's important to note when to use a protectant versus a penetrant. So for your contacts, that's just provides just a general barrier that's applied to the leaf and stem surfaces of turf grass. It's most likely gonna be used for foliar disease control. It's not really gonna have much efficacy against a soil-borne pathogen like take all root rot. And essentially it just prevents one or more steps on that host surface. So the fungus can't enter or infect the plant. A lot of these are gonna be more broad spectrum, something like chlorothalinol is gonna be more broad spectrum and works more best as kind of a protectant or applied preventatively. And it's important to note with these that they're only active as long as they remain on the plant surface. And they have to remain on that plant surface at a sufficient concentration to inhibit that fungal growth. So that new growth is not gonna be protected. So a lot of times you have to do repeated applications at a regular schedule interval and you need to get thorough coverage. So you wanna make sure you're applying that according to the label to make sure that everything in the area that you're trying to protect is actually getting that adequate coverage. So any new fungus that enters the plant after that residual activity is kind of gone and if you don't do that repeated application, that fungus is not gonna be affected by that fungicide. So systemic fungicides, a lot of the turf grass fungicides are kind of moving more towards this. They typically have a more specific mode of action. They're more narrow spectrum. And since they're more narrow spectrum, it's a little bit easier to get those through the EPA process and labeled for use not only on turf, but other crops as well. These chemicals will penetrate the plant surfaces and they're moved within, typically within the vascular tissue. They can be used against foliar and root pathogens. They generally have a combination of kind of curative and protective properties with that extended residual activity. So versus protectants, with a curative, you may not have to apply it as often versus the preventative fungicides as long as you follow the label directions. So they can control fungi that have already entered the plant and initiated an infection and give you a little bit of curative action there. They can also inhibit fungi that are coming into the plant that are new, right? From initiating disease. So that's the preventative action there as well. So there's other, in addition to that, there's additional types of fungicides. There's a couple that are considered local penetrants. And these just kind of penetrate the plant surface just maybe in short distances right at that leaf tissue. But a majority of that fungicide is still going to remain on or near the plant surface. They're best considered as preventative fungicides, which include hyperbodion or vinsiclozin. So 26 GT is probably your best example for that. There is a new group of fungicides that includes triloxosterobin, which is compass, which is a mesosystemic, which it just really has a strong adherence to that plant surface. And then it is absorbed by the waxi layers, but it's not a true penetrant in that sense. And so that's still gonna work best as a preventative. So you may be wondering why I went through and gave you a lesson on different fungicide types. It really comes in terms of recovery process of turf. So one is gonna be, you know, once you see a disease, that recovery process is gonna be governed by the type of fungicide that you're applying. Also, of course, the environment, fertility and cultivation, we have to continue to manage the turf, try to keep it, you know, from getting stressed and more prone to infection. And sometimes excessive nitrogen levels can increase your risk for disease or too little nitrogen or some of your other micronutrients as well. And also, you know, cultural practices. But if you're looking just strictly at a fungicide point of view, this was a study that was done at NC State where they wanted to see the curative suppression of dollar spot with fungicides. And so you have five different fungicides. You have secure, which is in the blue bar, daconil, which is green, chipco, which is that kind of local penetrant in red. And you have nextema and posterity. And one of the things that you'll notice is that depending on the type of fungicide like daconil, that's gonna be work best and secure, but probably more preventatively. They aren't systemic, so you're not really gonna get that curative action like you're gonna see with maxteema, chipco and posterity. And so these were all applied at the same time on May 13th and they followed this through through two weeks. So they did not do a repeated application. You can see within that first week, all the fungicides are doing very well compared to that non-treated control. But then your protection kind of start to fall off towards the tail end of there where you still get some more bang for your buck, with those more curative type fungicides. And so the main takeaway from these is that you have to be patient also with recovery. It's not gonna be immediate. It's gonna take a couple of weeks at least and maybe some repeated applications. And those contact fungicides are not gonna give you those curative actions as we saw from that graph. And daconil and secure are gonna work best when applied preventatively. So you can do that maybe when you're most at risk for disease. And then if you do see that disease to start to develop a little bit more then go in with a more different mode of action or a more of a penetrant fungicide to give you that extra control there to gain that recovery of that turf. So in terms of fungicide basics, most of our fungicide failures are really either due to misidentification of the problem. So a lot of times, and this is more true for some homeowners where they see damage in a turf, they get really nervous about it and they throw everything in their arsenal. You know, a lot of fertility issues can be a confused sometimes with plant diseases. So if it is a fertility issue or maybe you just have poorly drained soil, a fungicide application isn't gonna help with that. So you're not gonna see that recovery. Also sometimes misapplying a fungicide, whether it's a coverage issue, not watering it in or not selecting the right fungicide for the proper disease can also be an issue. In terms of failures, I wanted to highlight that a lot of these chemicals, sometimes people wanna add additives to kind of improve the adherence or coverage of a fungicide. Don't add these additives like a surfactant to these fungicides unless the label says so because you're not gonna see a benefit from that. Sometimes it can have an adverse effect where you get an increase in phytotoxicity. Fertilizer solutions should typically be applied separately and shouldn't be mixed or tank mixed with those fungicides. This is especially true for any fungicides like Mancasette, Foscielle, or Chlorothalonil that has zinc, they contain metals. And so a lot of times, if you don't determine compatibility first, you can actually get some adverse reactions to that turf and make the problem worse. So sticking on the topic of fungicide failures and properly identifying the problem. This graph is just to represent that different fungicides with different mode of actions are going to have different activities on different plant diseases. So a lot of your OMI seeds like Pythium Blight or Yellow Tuff, you have very specific fungicides that have activity against those. A lot of your SDHIs, DMIs or QOIs are not gonna have activity against those OMI seeds. And you'll see that, you know, DMIs have pretty good broad spectrum activity against several plant diseases. Some of your SDHIs are gonna be a little bit more specific to something like Dollar Spot or Gray Leaf Spot and some of your patch diseases as well. The other reason why I wanted to bring up different types of fungicides and I specifically mentioned your DMIs and QOIs, these are single site fungicides. As I mentioned, a lot of these systemics have very narrow spectrum in terms of activity. And that, while it's good for, you know, the fact of the environment where you have less environmental toxicity issues, you know, less potential for it to be a human carcinogen or, you know, activity against aquatic organisms, it makes them more at risk for fungicide resistance development. And that's because they target one specific pathway or target site in that fungus. And so all it takes is a few genetic mutations for it to overcome that. And so it's important when you're applying fungicides is to rotate with multiple modes of action or incorporate a broad spectrum like chlorothalanil into a spray program if you have to do repeated applications. So there is fungicide resistance known in the turfgrass pathogens, Dollar Spot, Gray Leaf Spot, and then Brachnos and Pythium Blight all have known resistance to different fungicides, you know, DMIs and QOIs are going to be most at risk. So that includes your benzobenzene dial, Propoconazole, Stroboyurins, also theophonic methyl, as well as minifaxum. And so all of these, we do know that there is resistance to them. And so typically on those labels, it will tell you, you know, you're only limited to maybe one or two applications before you need to rotate to a different fungicide with a different mode of action. So it's important not to rely solely on fungicides for disease control, do those other things that, you know, like Dave Hahn and Scott McRoy, you know, promote in terms of promoting overall turfgrass health, you know, avoid using highly susceptible turfgrass varieties, you know, and there's some diseases like Tachol and St. Augustine. Sometimes you have to completely renovate those lawns, go away from St. Augustine when you go back into that. Limit the number of fungicide applications of those at-risk fungicides and alternate with those different frat groups. More recently to kind of help combat some of this fungicide resistance, we've moved to from just single active ingredients to fungicide products that contain multiple, you know, active ingredients with different modes of action. And so that's really kind of changed over the last decade. And more than two dozen combination products are currently on the market. These are gonna broaden your spectrum of activity, increase your efficacy, and help with that resistant management. And I don't expect you to memorize this table, but it's just to show you that, you know, we have, you know, something like Xteris that has a QOI and SDHI. So those frat groups 11 and seven. And so as long as you see those different numbers there, that means that they're a different mode of action. And so it makes it really easy. When you're looking at a label, it's one of the things that's always at the top or kind of right hand corner of those labels. So going back to when to use a fungicide. So keeping all of that in mind now that you know how to kind of alternate with different frat groups, when to use a preventative versus a curative. Preventative applications are perfectly fine to do as long as you know what type of diseases are likely to occur at that particular time. You know, with turfgrass diseases, they typically happen at the same time every year. And I have a slide on that, a couple of slides from now that'll kind of show when you're gonna see the damage. And it's just important to remember that if you don't have or haven't seen issues in that lawn in the past or on your golf course, you may not need to do a preventative application. It just all depends if what kind of variety you have, if it's zoysia or bentgrass for certain diseases. They should only be used when absolutely necessary. You know, lawn disease in one location does not mean it'll occur on adjacent landscape. So cultivar and environment are gonna be your primary factors in disease development. And that all goes back to that plant disease triangle where we have to have the pathogen present at the right time of year with that favorable environment and that susceptible host has to be there. So environmental conditions are gonna strongly influence your turfgrass disease development. You know, brown patch requires wet human conditions during warm to hot weather. You know, dollar spot likes a little bit more overcast kind of just for long periods of leaf wetness. And also micro environments can affect disease development. You know, one side of the building may have its own micro environment that's influenced by trees or other buildings that are around that or bodies of water and soil types. So sometimes it's perfectly acceptable to do spot treatments. It just depends on that particular situation. So here's just kind of a summary slide of when we're most likely gonna see some of these diseases. You'll notice that brown patch, dollar spot and spring dead spot we see in the spring and fall, gray leaf spot we start to see in the summer and fall as well, whereas take all root rot we see kind of in spring and summer. So if you just kind of remember what time of year you typically see these diseases that can kind of help govern if you feel like you need to do a preventative application before this kind of starts to develop. So it's also important to note a couple other things that I just wanna cover before ending my talk. Think about when you're gonna apply fungicides. So you don't wanna apply fungicides when it's too cold or too hot. Sometimes that can influence adverse reactions for those fungicides. So typically, you know, temperatures between 60 degrees and 85 degrees Fahrenheit kind of give you the best results with the lowest risk for phytotoxicity development. You also don't wanna apply fungicides to turf that's stressed either by drought or temperature before or at the time of application. If the turf is stressed it may kind of adversely react to those fungicides. Probably the biggest takeaway and I wanted to really end with this is coverage. Coverage is gonna govern your efficacy. You wanna make sure you're looking at those labels, select the proper nozzle sprayer and pressure to ensure those adequate coverage. You know, definitely keep track of the weather. You know, we're entering in a time where we kind of have a lot of afternoon showers. So when you apply a fungicide you wanna make sure it's at least allowed to dry on that surface for at least six hours to make sure it doesn't get washed off for that product to properly adhere. And some of your fungicides need to also be watered in especially if you're trying to get good efficacy against more of a soil-borne pathogen. Usually one gallon of water per thousand square feet should give you adequate coverage in addition to that. And I hope everyone knows this. Do not apply fungicides. When conditions are windy, you will get drift. And so that fungicide is not gonna go where you want it. It may end up on other parts of the landscape where that fungicide is not really adequate for those particular plants in that landscape. And I know that was a lot to cover in a short period of time. I do wanna say if you're not sure what plant disease you have feel free to contact me if it's turf grass related. The Plant Diagnostic Lab is also an excellent resource. When you're looking at fungicides for selection our commercial turf and lawns disease and nematode control recommendations is a great resource. I update this yearly. If you also wanna look for efficacy data there is a publication put out by the University of Kentucky and in addition to the University of Wisconsin and Rutgers where they list the different fungicide active ingredients and in terms of efficacy. So it's a great resource to make sure you're selecting the proper fungicide there.