 Today, we're going to be discussing Bermuda grass hayfield end of season management and the timing of the last hay cutting during the production season. To get us started, I wanted to first review overall goals of Bermuda grass hay production systems in the southeastern U.S. Bermuda grass is a warm season perennial grass that is often used in hay production systems because of its yield and quality aspects that it brings to the table. If you look at the figure on the right, you can see that overall quality aspects of Bermuda grass can be quite good depending on the harvest management of the forage in the system. So ideally, we typically take those cuttings around four to five weeks whenever we can optimize both the energy value as well as the protein value of that forage during the growing season. In terms of its efficiency, Bermuda grass is considered to be a very efficient crop per unit land area because of its high yield aspects and it supplies a quality product to livestock producers and it's often used as hay, as part of hay and supplementation systems in cow calf operations in the southeast during the winter months. One of the things we wanted to focus on today is how to maintain stand health of Bermuda grass over time. So as a perennial forage, we want to make sure that we're managing that system in a way that we have forage that comes back year after year, that is productive, competitive against weeds in the system and providing us with that quality product that ultimately goes to livestock producers. So in terms of Bermuda grass management for hay production systems, whenever we think about optimizing that production, this is where the concept of small things become large things. There are a lot of collective management strategies that we use in our Bermuda grass hay systems and whenever we begin to perhaps tweak some of those different aspects or change some of those management aspects over time, they can add up over a period of time to negatively impact the health of our Bermuda grass stands. So the photo shown here is a picture of what we call Bermuda grass decline. If you talk to extension specialists and agents around the southeastern US, I'm sure many of them have received calls just like we have about seeing my stand health decline over time or really just observing overall thinning of the stand over a period of a number of years. And so this picture demonstrates that concept. You can see that this is a stand that's coming out of dormancy in the spring of the year. The green area represents the Bermuda grass that's coming out and kind of the brown or patchy area is area that's now a gap in the Bermuda grass system. So very visible thinning of the stand in this situation. We see weed encroachment that's happened and in some cases we can see some thatch accumulation in places in the stand as well. So all of this are a function of the collective management of that stand from the previous season and perhaps even years before that have ultimately led to the decline or the thinning of this stand over time. So there's many things that can influence our overall stand persistence. The one that we wanted to really focus on today is how we manage our Bermuda grass stand at the end of the growing season. And what does that do to the root reserves that are used then to promote this regrowth during the spring of the following management season. So in order to manage our stands for persistence and help, when we think about just that aspect of taking the last hay cutting, we want to first think about the timing of the last harvest relative to the time of anticipated killing frost. So for Alabama, the dates of the first frost differ for different parts of the state. In the more northern part of the state we're looking at an early November window, whereas as we move into the more southern part of the state or the coastal plain region, we're looking at a later date in November typically for when that first killing frost occurs. So certainly there can be some fluctuation around this window but on average this would be kind of the timeframe we generally have in mind for when that first killing frost is going to occur. So that will influence when we should take the last hay cutting or essentially when we will have the final end of the growing season for our warm season forages occur. Is that killing frost will put everything into a dormant state until the following spring. So the question becomes relative to this first frost date, when should I take my last hay cutting and my bermuda grass system? And I would say that depends on a couple of things but one way we can look at this is first of all relative to this frost date presented here, is there measurable yield there in the first place? So if I were in North Alabama and I were to walk out into my field on November 8th, and the weather forecast tells me we're supposed to have a killing frost that night, if I only have two to three inches of regrowth since the last cutting then certainly there's nothing there that would provide measurable yield for us to cut off in the first place. So really the minimum amount of growth that we would want to see out there to justify final hay cutting that close to harvest or to a killing frost would be a minimum of eight inches of growth. And we'll talk a little bit more about why would we need to have this much growth in just a little bit in subsequent slides. The second situation is considering if it's an emergency situation. So maybe I don't have eight inches of growth out there in my field at that time, but I know that I'm gonna be short on hay and I'm not able to get anymore at that time. So I have maybe six inches of growth that I could go out and take a harvest off of that at that time and get some forage that I could use for later in the winter months. So this isn't something that we would want to do year after year, but in an emergency situation certainly it's something that people often consider if they're gonna be short on hay for the subsequent winter feeding season. So really then when should I take the last hay cutting? It depends on several things. And a lot of that is related to the biology of how Bermuda grass grows. So we said earlier that Bermuda grass is a warm season perennial forage, which means that it grows actively during the warmer months of the year. So the summer into the early fall, and then at that point, it really begins to slow its growth. The slowed growth that we observe in the fall months is in response to decreasing day length as well as decreasing temperature. So that's essentially nature's way of telling the Bermuda grass to slow down, that we're getting close to the time of that killing frost and to start preparing to hold on to some reserves so that that forage has something to pull from in the following spring to be able to generate new growth. So this environmental conditions that we see during the fall months essentially tell our Bermuda grass plants to shift plant carbon to the root system rather than solely essentially to the above ground yield aspects. So changing day length conditions encourage that plant then to begin to store carbon in the root system, which allows that forage to have a reserve for regrowth in the following spring. So in terms of timing of the last hay cutting then, essentially we should follow an all or nothing approach where we want to make sure from a Bermuda grass health standpoint and persistent standpoint that we're allowing that forage to have time to build up its root system to have that reserve for the following spring. So we can do that in two ways. We can either have adequate growth that's allowed to accumulate out there before the first killing frost or we can time our last harvest to really be exactly at the time of the last killing frost. So by doing this, what we're doing is we're allowing that forage to build its carbon pool up in the root system. And we're using the leaves as the solar panel to be able to capture sunlight and shift those nutrients into the root reserves. So in terms of thinking about the overall harvest management in the fall months, if we think about kind of in the early fall time frame, if we were to go in and clip that stand very short, what we would be doing is encouraging the Bermuda grass to focus all of its efforts essentially on regrowth. Okay, so we don't have a lot of above ground leaf material remaining, just basically stem material. And that plant is going to pull from its energy reserves in the fall months to try to generate some above ground growth rather than shifting it down into the root system to have something to use later on in the following spring. So ideally, in order to get a window on when we should collect the last hay cutting is not only a combination of the regrowth window, but also the overall harvest height that we would use at that time. So when we're thinking about overall timing of the last harvest, we're using our anticipated frost date as a time where we're going to kind of build back from to identify the appropriate time to take the last hay cutting. So what we want to do relative to that time of first killing frost is either allow the forage to have adequate regrowth before that frost event occurs. So generally that's going to be about four to five weeks of growth to try to get to about that eight inch target height that we mentioned before. Or we want to time the cutting according to frost. Okay, so that would be where if we were to go out in late October or early November at the time of the first killing frost and we had adequate growth, eight to 10 inches of growth in the field, we would ideally take that cutting and then the frost event would occur really within the next 24 hours so that that plant does not have time to try to regrow. So by doing that, we're able to take a cutting time at relative to frost where we're not in kind of that in between phase where the forage is just trying to get some regrowth on it when the first killing frost event comes and hits it. So the impact of this in terms of the root systems, when we think about the forage harvest height, we mentioned that it's not only a combination of the length of time that we need to allow that forage to grow to get it to a certain target height, but also whenever we take the last height cutting, we want to make sure that we're leaving adequate amount of stubble out there in the field to encourage regrowth. So this is specifically applicable if we are looking at that early fall time period for taking our last cutting, we want to make sure that we're getting a minimum cutting height of four inches and then allowing that four to five week window before the time of frost for regrowth. So by having a greater amount of residual stubble that's out there remaining after that cutting in the early fall, what we're doing is we're encouraging that plant to regrow a bit faster and by doing so then it's able to shift some of those nutrients back into the root system and better prepare for that time of upcoming frost. A study out of Florida showed that whenever you're looking at taking the last height cutting out of the season that with more residual forage that's remaining post harvest. So looking at either a four, seven or 10 inch residual stubble height remaining post harvest that they observe greater root reserves associated with increasing amounts of residue that were left. And so what this tells us then is that whenever we have a greater amount of forage growth that's remaining in the field before that first frost event occurs we have a better chance to accumulate nutrients in the root system of that forage which then helps favor persistence and gives that plant the energy that it needs to come out of dormancy in the spring strong aggressively and help fill in some of those gaps like we saw in the photo earlier in the presentation. So additional considerations as we think about end of season management. During the winter months we talked about how small things ultimately become large things. So certainly the end of season management is going to be important for helping encourage better growth aspects of that forage the following spring or the next management season. But there are other things that we can do in the winter as well that can help us make sure that that plant is best prepared to meet the needs or the challenges that we put on it the following year as well. So one thing to think about is obviously check fertility during the winter months making sure that our sole pH as well as our potassium levels are where they need to be. So these are factors that can also influence the persistence of that forage over time and are a really good time to make sure that we're preparing to make those adjustments while we have time before the forage becomes actively growing again. Also weed management is important so making sure that we don't have too much cool season weed competition that occurs during the winter months that could perhaps delay Bermuda grass from coming out in the spring or begin to compete with that Bermuda grass in the spring as it comes out of dormancy. Finally we also want to think about thatch management. So if we were to have quite a bit of regrowth still out there in our Bermuda grass field after the time of frost we would want to think about trying to remove that so that we don't have just a large amount of thatch or dead material that's out there all winter long and can ultimately hinder again the emergence of that crop again in the spring. There are a couple of different ways we can think about managing thatch in the system. One is after the killing frost to cut and remove that material. Two is to think about using fire. So this is a great way to help control thatch that's out in our Bermuda grass systems to get rid of that residue over time. And then finally perhaps another thing that's not often thought about would be grazing of fields where applicable. So if you have a water source near the Bermuda grass a field that you're working with you could essentially graze off that material as kind of accumulated forage as a way to help remove some of that thatch during that time as well. So all of these are things that in addition to our end of season management in terms of harvest management can help make sure that stand is better prepared for the following spring and we are managing the stand and the residue in a way that allows that Bermuda grass to stay persistent and healthy over time. If you have additional questions about Bermuda grass management in general this is a new extension publication that we recently released that has information on hay production as well as grazing management of Bermuda grass systems in Alabama. It also goes a bit more in detail related to fertility, weed control, insect management as well as some of the harvest management things that we discussed in today's webinar. So I would encourage you to visit our website at aces.edu and if you put Bermuda grass in Alabama in the search feature it should bring up this publication for you to download and print at home. With that I'd be glad to take any questions if you would like to reach out to me by email I have that listed here and I would also encourage you to visit some of our Alabama extension resources AlabamaBeefSystems.com as well as regional resources SoutheastCatalystAdvisor.com to learn more about Bermuda grass management in the southeastern U.S. Thank you.