S5:E2 Everything You Need to Know About Alfalfa Diseases

Feb 22, 2023

Show Notes

There has been a shift in the last few years towards round up ready and low lignin alfalfa. Traited alfalfa is becoming a key factor in growing high quality, high yielding alfalfa. Leta Larsen, Forage Specialist with CROPLAN discusses not only how these traits impact yield and quality but also how the underlying genetics that can play a big role in disease prevention and stand persistence. 

First, let's talk alfalfa traits. There are 2 traits offered through Croplan Alfalfa, first is Round Up Ready and the second is HarvXtra. The HarvXtra is always stacked with the Round Up Ready trait in the CROPLAN varieties.  

“HarvXtra is a trait, not a variety,” started Leta. “[HarvXtra] is a trait that allows for lower lignin alfalfa. Since it has lower lignin, it is going to start at higher quality… So if you were to harvest every 28 days you would see around 20% higher quality- particularly better digestibility, higher NDFD and higher RFQ.”  

In addition to choosing the best trait package to increase your alfalfa quality, the genetics you choose can give you protection from diseases. AA Alfalfa Genetics gives you protection from Aphanomyces and Anthracnose. 

and  and Anthactnose stem and crown disease later on in the alfalfa plants life.  

Aphanomyces is a severe root rot disease that you can see in seedlings and mature stands. Typically, you’ll see Aphanomyces in May and June but you could also see an impact on mature stands in wet fall conditions. Aphanomyces stunts growth. It could appear with symptoms representative of nutrient deficiencies or it might look like herbicide carry over.  The growth is stunted and roots will appear gray and water soaked. Eventually the roots turn brown, collapse and die. The roots that do survive, will never have the vigor and potential of a plant that was not infected.  

“With the AA genetics we have high resistance + to Aphanomyces- all races,” shared Leta. “This is the gold standard for disease resistance in alfalfa.”  

Anthractnose typically infects in mature alfalfa stands and can show up as a foliar disease as well as severe crown rot. Wet conditions in the late summer causes diamond shaped lesions that can escalate to a girdle causing Shepards Hook. This results in leaf and stem loss that can equate to a yield loss of 25-30%. AA genetics include resistance against all races of Anthractnose, including race 5. This disease resistance rating is only provided through genetics coming from Forage Genetics International (FGI). 

There are a few other diseases that alfalfa growers should have on their radar. The first is Phytothera root rot which AA genetics provide excellent resistance. Phytothera was one of the first diseases identified in alfalfa so across the market there is fairly good control today. The second is Pithium that causes seed rot in the soil or dampening off where if it does germinate but later dies. A fungicide seed coating with Apron XL can help provide control for Pithium with it’s Grozone 34% coating.  

When protecting yourself against these diseases, the best course of action is variety selection.  

Aphanomyces, Pithium and Phytothera are hard to control with crop rotation because they can last in the soil 10-30 years even without the presence of a host crop. By choosing a host with resistance you eliminate that portion of the disease triangle, giving your crop its best chance for successful stand persistence. 

To learn more about these diseases, and the available traits and genetics available today in our alfalfa line up, tune into the full podcast episode with Leta. In our next episode we will be focusing on alfalfa management in season, and how precision ag affects agronomics of alfalfa.  

Morgan Seger (00:03):
Every day we rely on food, fuel, and fiber. But how much do you know about these industries we depend on? In this podcast, we dive deep into the production and processes of these everyday essentials. This is field points and original podcast production from Siri Solutions. Welcome back to Field Points. I'm your host, Morgan Seger. This is the second episode of our fifth series, and this series is focused on the agronomics behind dairy nutrition. In this episode, we will be continuing our conversation with my co-host, Allen Pung and our guest Leta Larsen from Croplan. As we work through this conversation today, Leta is going to break down for us the difference between traits and genetics and how those both play a significant role in high quality, high yielding. If you listen to our first episode that Leta's masters project focused on early seedling diseases in Alfalfa. So throughout this episode, we really get into her wheelhouse and she does a great job explaining not only what these seedling diseases are, but how you can combat and manage them and how genetics and traits play a role in that process. So let's dive right in.
Leta Larsen (01:13):
I would say that the switch to Roundup ready as well as HarvXtra is kind of happening right now. I would say that a lot of our conventional acreage has shifted to HarvXtra in the past two years, would you say Al, even this last year, a lot of the dairy farmers are focused on quality and they really understand that yes, we have to have high quality, high quality haage if we want to have a cow that's going to reach their full potential and milk well. And with soybean meal prices the way they are, canola prices the way they are, they want to have high quality haage, right? And if they can utilize the HarvXtra trait, harvest it at 28 days, see 20% higher quality, they're going to do it. And then obviously Harve extra's coupled with that Roundup ready trait, which makes weed control easier, we're not going to see a ding from that roundup ready trait like we would using conventional herbicides. I don't know if I could throw a percentage out there, but there's definitely been a shift in the last few years. Two HarvXtra round.
Allen Pung (02:12):
There's definitely differences in areas too. Yes, in some areas are high adoption of Roundup Ready, whereas some areas very little, almost all conventional alfalfa yet. I would say overall in our area, I would say 50%, maybe even as high as two-thirds now is Roundup Ready
Leta Larsen (02:28):
Alfalfa. And there's a common misconception still that I run into that Roundup Ready or Harve Extra is lower yielding and we really don't see that anymore. Early on, it definitely was right as you introduce a new trait, it's going to be a little lower yielding. But now with our megatron aa Harve Extra and our Roundup ready our Avetron AA product with the HarvXtra, I think our Megatron AA is generation four now. And so we really don't see that it's lower yielding. It actually is right with or beats our conventional products. And so I think that's a common misconception that I've run into quite a bit as guys think, oh, the traded alfalfa doesn't yield, it doesn't yield, it's not really the case. And if you can go in, you can clean weeds up early, get rid of that competition, then you have a stronger seedling right out of the gate, it's probably going to be higher yielding than something that wasn't strong from the get-go, right? So being able to control weeds early has will definitely give you a yield advantage. And then just that quality aspect of the Harve Extra, that's been a win-win for most growers that have been using the latest generations of our Harve extras.
Allen Pung (03:34):
I think Leta's comment about quality is quality is really driving it because there's two traits. You got the HarvXtra trait and then the Roundup Ready trait. Well, for a grower now looking at HarvXtra, which is driving that quality decision, there's not a lot of price difference anymore. It used to be, you know, had Roundup ready and then you had, because of the way the traits are stacked, HarvXtra was Roundup ready. It was a big jump for somebody pricing. If they were complaining conventional, well now there's not a lot of difference in pricing between Roundup Ready and to go all the way to Harve extra Roundup ready. So quality issues driving that Harve extra decision and it, it just happens to be Roundup ready too. So we can manage it a lot differently and it's just easier to keep it. And there again, you're driving the quality because it's so much easier to keep the alfalfa weed free. It's just pure alfalfa, very simple, but it works really well.
Leta Larsen (04:23):
And it's farmer word of mouth that has driven a lot of that too. There's a lot of growers that might've trialed it and started it and said, oh wow, my quality is a lot better when I cut it at every 28 days. Or if I'm delayed a week, I know I'm not going to take a ding on my quality. It's still going to be the exact same that a conventional would be at 28 days. Plus I get an advantage in yield because Alfalfa actually grows an inch a day that translates to 125 pounds of dry matter. So you get all that if you were to extend that harvest window. So they actually have to live it and see it, I think. And then as more growers communicate and talk to each other and talk about the benefits that they've seen, I'd say that that's really what's been driving it. Honestly, it depends on the operation on how they use Harve Extra, but a lot of the growers when they're transitioning from conventional to Harve Extra, they use it as an insurance policy. They'll cut those fields last or if they get rain, they know they're not completely out of luck if they're over that 28 days. So just depends on the operation. If they cut it every 28 days or if they're driving it for yield and they'll extend it to 35 or whatever they end up doing. So Maybe it'd be good to explain exactly what,
Yes, we should clarify because so HarvXtra is a trait, and so it's not a variety, it's a trait that's inserted into a variety. And so it would be like a smart stack is to corn, right? It's a trait that's actually inserted into an alfalfa variety. And so what HarvXtra is, it's a trait that allows for lower lignan alfalfa. So what that means is because that plant has lower going to start at higher quality, so we see that alfalfa that contains that harve extra trait has around 20% higher quality as compared to those that don't have the lower lignan trait. So if you were to harvest at every 28 days, you would see around 20% higher quality, particularly better digestibility, so higher N D F D and higher rfq, not necessarily higher rfv because the R F V doesn't take the N D F D portion into that equation.
And so we look at N D F D in RFQ when we're evaluating Harb extra quality. And so you start higher. So you automatically start at 20% to 25% higher quality with Harve extra. So if you harvest it every 28 days, you're aiming for higher quality alfalfa. If you were to stretch that out to seven to 10 days, we know that you're then going to see higher yield in that alfalfa, right? Because you're leaving it grow for another week. But then that quality is, it's going to go down, but it's going to be where a conventional would be at 28 days. And so you're not going to see basically a quality loss in that if you were to let that go an extra week to 10 days, it's just going to be wherever a conventional would be at 28. And so that really allows for a lot of flexibility, right?
Because you can continue to harvest every 28 days like you would a conventional alfalfa plant just to aim for higher quality hay, which a lot of dairy farmers are doing. That's probably the most popular, I would say among my farmers if they're 100% Harve extra. And then if you were to be transitioning to Harve Extra from conventional, so you've got fields that are both Harve extra and conventional you can just have higher quality hay if you're harvesting it every 28 days into that pile. There's just a better quality in that because you're harvesting that Harve extra at every 28 days still. And then the other option is just extending that yield potential. So because Harve Extra does start higher, it's going to be, if you were to extend that an extra seven to 10 days, it's going to be around 20 to 25% higher yielding than you would have cutting it every 28 days. And the same quality that you would have with a conventional cutting it every 28 days. So for those guys that want a little higher yield maybe willing to have the same quality that they would with a conventional at 28 days, it's there lots of flexibility and lots of options. And then of course, like we mentioned earlier, you have the Roundup ready trait in there as well. So all Harve Extra is also Roundup ready.
Morgan Seger (08:20):
The lower lignan content in the plant could make a difference in what you see out in the field. Litta walks us through what to expect.
Leta Larsen (08:28):
So the standability standability of the plant is not influenced. So yes, it sounds like it might be right. You're like lower. Oh no, it's all going to fall down. That's actually not the case. There's been a lot of studies with Forged Genetics International. So FGI is owned by land, so they are the alfalfa breeding company for cropland because crop land's also owned by land, right? So was the company that invented the Harve extra trait. And so they did and years of studies before they even released the trait onto the market, and it showed that standability was not at all influenced by the trait. However, as you leave that plant in the field, so if we're getting into 35, 36, 37 days cutting window instead of every 28, you do risk that plant getting taller. So you might get above 28 inches, above 29 inches, 30. Once we get above 28 to 30 inches, we do risk that plant going down and lodging from either rain or wind or whatever it might be. And so I think that was a common misconception early on that Harve extra varieties don't stand well, it's probably because they were into that 36, 37 day cutting window and those plants just got too tall. They might've had plenty of rain, what growing conditions might have been just perfect and they just got too tall and fell down. So it's important to remember that even if you want to extend your cutting window with HarvXtra, that you're still keeping track of the height of that and cutting inside of 30 inches
Morgan Seger (09:56):
With conventional. Would you see lodging at that height or no?
Leta Larsen (09:59):
Yes. Yep. You would see lodging in any type of alfalfa at around 30 inches or even 28 to 30 is typically the rule. So if you get above that, that's when things get scary. And that's so we can see some severe lodging
Morgan Seger (10:12):
Right now. I don't have much hands on experience with alfalfa, but I do remember being taught that you went to harvest when you start seeing blooms or that you at least didn't want the whole field to bloom because your quality would go down. Lida walks us through what this can look like with Harve Extra in regards to those extended harvest schedules that she was mentioning. So harve,
Leta Larsen (10:31):
Extra impact flowering at all. It would flower like a normal conventional wood. If you extend your harvest window, if you cut into 35 days, you might see those plants flowering, oh no, I'm too late, but my quality's going to go down. It's not the case with Harve extra. So it might flower and you might think that you're going to have a dinging quality there. Obviously that quality's going to go down some, but it's not going to be where a conventional would be at that same day, right? Because it starts higher and it ends higher. So if you're out to 35 days with Harve extra, your quality is still going to be at or above what a 28 day conventional would be at. So the harve extra and the Roundup ready, that's the trait. And so there's genetics that obviously have to go into that trait as well. So it's the genetics that would drive the yield potential the winter hardiness or the stand per persistence of that too.
Morgan Seger (11:23):
So now we're going to dive deep into the advanced genetics that Lida is talking about. We're specifically going to spend some time talking through AA alfalfa varieties.
So our AA genetics, so the AA stands for is awesome alfalfa. No, I'm kidding.
Speaker 4 (11:41):
That sounds about right. Joke. We joke that's what it means but it actually stands for two different diseases. So it stands for emisis and anthracnose. So a phantom ISIS is a severe root disease and it can infect seedlings as well as mature stands. And then anthracnose is a stem and crown disease that typically infects later on in an alfalfa plant's life. So a pto, my disease was actually the one of the main diseases that I focused on in my master's. And so I get you're really excited when I talk about it, so I'm probably going to say more than I even need to. But a phantom isis like I said, causes a severe root rot in seedlings as well as mature stands. And we typically see a phantom mys, in fact, as the soils start to warm in the spring. So think May and June is typically when a phantom ISIS would infect a lot of those seedlings.
And what it does is it actually stunts growth. And so your seedlings might come up, they might look great, they might be off to a great start, and then all of a sudden that growth is just stunted. The plants might exhibit symptoms of nitrogen deficiency. It might look like herbicide carry over. It might look like a fertilizer issue, but it could potentially be a phyto myosis. So we typically see a phantom myosis infecting really wet soil conditions. And so if you think back to the spring of 2019, it was a really wet year pretty much across the entire Midwest, even out east where I was in New York at the time. And we saw a lot of seedling failures due to a phantom myosis infection. And what it does is it basically just stunt alfalfa root and then eventually those roots are going to appear gray and water soaked and then eventually just turn brown and collapse and die.
In those plants that do survive, do fight off that pathogen, those roots really aren't going to be very healthy. And so when I explain a PTO myosis to a lot of my dairy producers, I compare the seedlings to a baby calf. Say a baby calf gets infected with salmonella or pneumonia gets sick right away as a calf, she's probably never going to milk is good as she could have had she had a healthy start. The same thing goes for alfalfa. So if that alfalfa is infected with a pto, ISIS early on in its life, probably never going to yield as high last as long as it could have had a healthy start. And so if pto, ISIS really infects early on, and then it can also infect in immature stands in wet fall conditions. And so that can obviously just chew away at those roots and make a plant that's a little slower to regrow.
So a little lower yielding and then obviously not healthy, so not able to uptake water and nutrients from the soil and survive year after year. So you might see a decrease in stand longevity and stand persistence because of that. With the AA varieties, now we actually have high resistance plus to a phantom isis, all races. This probably isn't well explained in our industry, but there is actually a variety review board out there that rates all varieties based on their level of resistance to various diseases. And so high resistance plus is basically the gold standard. That's as high as you can get in resistance to all these pathogens. And so there's a moving scale, so zero to 5% resistance is considered susceptible. And then from six all the way to 50, there's a moving scale of resistance from low resistance to moderate resistance, resistance and then high resistance.
So a plant that's highly to a certain disease is considered greater than 50% resistant to that. When I first learned that, I was like, well, what about the other 50? Right? <laugh> still a big swing from 50 to 100. This doesn't make sense. So there's a lot of varieties out there that can actually be highly resistant to a pathogen, but it might only be 51% resistant to a pathogen such as a phantom isis. But in our AA varieties, we actually see that they're 70, 75, almost 80% resistant to that particular pathogen. And so that gives them that HR plus. So when you're evaluating a lot of varieties on paper, they might look the same. They might both be HR to a PTO isis. Well, one might only be 51 and one might be 80% resistant. So it's really confusing to growers, and I wish there was another scale, and that's why we gave the AA varieties to HR plus rating because they're a lot higher than just that 50%.
So I always like to explain that. Like I said, I don't think it's well explained in the industry what the different disease skills are. Obviously I was exposed to a lot of that just in my research alone with the University of Minnesota. But then on the flip side of a phantom isis, like I said, we also have this disease called anthracnose. And so anthracnose typically infects immature stands. It can cause a foliar disease as well as a severe crown rot. And what anthracnose does is in wet conditions in the late summer, it will actually cause these diamond shaped lesions on the stems. And eventually, if that's severe enough, they can form a girdle on the stem. And basically we see this thing called shepherd's hook. And what happens is that that stem is basically dead, so we're going to lose leaves from that and we're going to lose stems from that.
And that can equate to a yield loss of around 25 to even 30%. So that's a pretty large yield loss in the AA varieties. We have resistance to all the races, including the newest race identified called race five and that was actually that's specific to just F G I varieties. And so there's no other varieties on the market besides those coming out of F G I that have that resistance to that race five. That's what the AA genetics entails. So there's other diseases in alfalfa that are pretty major. A couple are pythium and phytophthora that I had mentioned earlier that we typically see in the cold soils in the early spring. We had done a lot of work at the University of Minnesota with pythium and phytophthora, and with both of those in particular, we do rely on, well, for pythium, we rely on our apron cell fungicide seed treatment.
And so that would be in our grow zone, 34% coating on our seed. And the apron XL basically allows for control of that pythium early on because what pythium can cause is a seed rot in the soil, so that seed will actually not germinate and then also a damping off. So where that seed will germinate, but then eventually will to away and die, the seed doesn't germinate from the soil, or if it dies, we're obviously not going to have a stand that can last a long time. It didn't even live. So that's obviously going to result in a replant. And so a lot of that can be prevented by just planting a little bit later in the spring when the soils are warmer, but also a fungicide seed coat to protect. Now, we've also got high resistance to phytophthora in those AA varieties as well. So phytophthora root rot that that's a severe root rot that's been around, it was one of the first diseases identified in alfalfa. So across the market there is fairly good control of phytophthora in most varie varieties today. That's probably a lot on diseases I kind of geek out about.
Speaker 5 (18:12):
That's pissed off, but
Leta Larsen (18:14):
But it's a big deal, right? I don't think, like I said, I don't think the different disease ratings and all of those details have been communicated well enough in the industry. There's still farmers I go to and I'm teaching 'em about a PTO my season and threat, and they're slow down. I can't even say that. And it's like, well, you don't necessarily need to even remember all the details, just know that they're out there and know that they can cause a severe threat. And so really when we're controlling a lot of those diseases too, the number one method of control is variety selection. Because with a Phnom ISIS as well as pythium and phytophthora, those three are a type of pathogen that are really hard to control by use of crop rotation. So they're called emmic pathogens. And so they can last in the soil, they can last in the soil anywhere from 10 to 20, maybe even 30 years even without the presence of a host crop.
And then on the flip side of that, so if you have your disease triangle, all three corners of the triangle have to be met. So you have to have the pathogen. So like I said, they can last in the soil for a really long time. And on the other side of the triangle, that ideal environment, so in that case it'd be a wet soil is when those oo mye pathogens would. In fact. So if anto, isis, pythium, phytophthora, we can't control the weather. We can't always control how much rain we're going to get. Obviously we can try to not plant alfalfa in our really heavy fields. If you have that luxury, if you've got a lot of different types of soils that you farm, a lot of farmers. And then the other piece is if you plant a resistant or susceptible host, so that's the other piece of that triangle. So if you plant a susceptible host and all three of those factors are met, you then invite that pathogen into the alfalfa plant to infect it. But if you plan to resistant host, you eliminate that piece of the triangle. So then the dis disease can't infect. It really is the number one method of control with those three. It's just variety selection. It just comes down to the seed selection piece.
Morgan Seger (20:05):
Leta shared that many of the varieties coming from the crop land lineup will have this AA disease package moving forward because they have put such a strong focus on disease prevention in their alfalfa varieties. Next we're going to talk about cost breakdown of these traits and genetics. It's a little different mindset than the corn and soybean farmers where the crop is in and out in one year. I feel like depending on how you farm, you justify those input costs differently. Lida walks us through what this looks like with alfalfa.
Leta Larsen (20:37):
Well, so actually that's really funny that you mentioned that because I gave a presentation in Minnesota back in November on the AA varieties and all these diseases and all that and how variety selection is huge and what the AA varieties can do. And I presented all the yield data and we see a 20% increase with our AA varieties as compared to the checks and the other competitors. So I'm just really focused on all that, and I didn't get into pricing at all. And so someone came up to me after, and they're like, so these AA varieties, they sound great and it makes sense, yada yada. The roots look healthy. We've got these great disease resistance genetics, but it sounds super expensive, like how expensive is it? And I'm like, wow, that's a good point. We don't do a good enough job. And Al, you can probably add here because we price everything through series, but the cost is very comparative to other varieties on the market with the AA
Allen Pung (21:35):
Itself, right? I mean, yeah, it's very competitive compared to some other brands that are out there that are not bringing any of these technologies. I would say they're more competitive than what probably a lot of growers would think is realize price pricing, that technology is available to a lot of folks well within your reach.
Leta Larsen (21:54):
Yep. And then of course too, if you have a healthier route that's going to be able to uptake more water and nutrients from the soil, maybe get another year or two out of that stand, just a greater ROI overall, right? Because you get more yield out of that if it's healthier plus greater stand longevity in the long run.
Allen Pung (22:12):
And I think with the harve extra trade right now, everybody is like litta said, everybody, the consensus seems to be cut your normal schedule and just put up high quality great feed. I think it'll be interesting as we get some folks, because the other end of that is you may want to let it have somebody that goes for big yield, let it grow that extra week and the quality is still going to be equal to what you would've had conventional. Maybe you only cut those fields three times a year instead of four or five. And I think without pushing it so hard, I maybe we'll get another year out of that alfalfa too. I mean, I think they've done some research on that and it kind of looks like it's going to go that way. But so far right now, most of the growers I know that are planning it, they're going for what I'd call rocket fuel. They want the best quality feed they can put up because like Le said, feed prices are driving some of that feed costs are high right now, and I think the goal most dairymen is I want to grow it. Everything on my farm I possibly can. The more feed, the more forage I grew on my farm is the less stuff I have to buy. It saves money.
Morgan Seger (23:17):
As we wrap up this conversation, Lisa and Alan share some information about where they are getting their genetics from and the relationship that forage genetics and cropland alfalfa have with land and the cooperative systems. I
Allen Pung (23:30):
Don't think a lot of times we do a very good job when I say we, I mean as the cooperative system series, talking about what F G I exactly does for means. I, and I appreciate everything Leeta has done for us because I think that's one of the things that really has helped. I mean, obviously all the things she's doing directly, but I think indirectly it's given our salespeople a lot of confidence when they walk on the farm and talk cropland, alfalfa, they don't take a backseat to anybody. Fgi is the world's leader in breeding alfalfa. Nobody else does. Even compares to many what germplasm they have and what percent of the alfalfa we're selling today. And as a cooperative system, just like, I mean, you think about it, who can tie that all together better than us as being a cooperative? I mean, land fgi, obviously we're in the feed business and they got started by dairy farmers.
Leta Larsen (24:18):
Dairy farmers,
Allen Pung (24:19):
Yeah. It's like, and
Leta Larsen (24:20):
We're still owned by dairy, dairy
Allen Pung (24:21):
Farmers, so we need to do a better job of talking about that because you still walk on, I bet there's problems we walk on. Yet today when you talk about cropland alfalfa, they look at you like, who?
Leta Larsen (24:30):
Allen Pung (24:31):
Randy. They don't. Don't really, seriously. They don't. Yeah. And that's shame on us for not doing a better job of talking about it and promoting it, I guess.
Leta Larsen (24:37):
Yeah. Our national alfalfa agronomist, Randy Welch was up in Michigan last week and we were sitting down for dinner in, he leaned over and he's like, Hey, should I talk about more that cropland is owned by Land O'Lakes to producers in Michigan know that? And I'm like, no, they don't know. That's where I've started almost when I first get onto farms. I just like to talk about the history and the brand and who we're owned by and that yes, we are owned by dairy farmers and they respect that. They like that. They like that we don't just report to someone in some corporation. We report to a board of directors that also farm across the country. So it's really neat. It's what ultimately led me to land. I obviously, having the dairy background that I have and growing up on a farm, that was a huge deal for me, being a co-op still and being farmer owned.
Morgan Seger (25:28):
Thank you so much for tuning in to this episode of Field Points, and thank you again to my co-host Alan and our guest Litta for joining us and sharing so much valuable information about genetics traits and seed lean diseases. In our next episode, we are going to continue our conversation and we're going to look closely at managing alfalfa specifically in season, and we're also going to be including how Precision Egg plays a significant role in proper management of alfalfa.

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