Season 7, Episode 9 - Post Freeze Crop Load Decisions

Kari and Shan highlight the important things to consider over the next few days as the crop load for this year stabilizes. We discuss potential thinning decisions as well as disease management. 

Host: Don Seifrit
Speakers: Kari Peter, Shan Kumar

Photo Credit: Lindsay Brown, PSU

Music Credit: “The Raven and the Swan” by Josh Woodward is licensed under a Attribution 3.0 United States License. Courtesy of FreeMusicArchive.org

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Flight Seasonalities of Main Fruit Pests During the Growing Season

Transcript

Welcome And Orchard Snapshot

SPEAKER_01 0:07

Alright, welcome back once again, everybody. I'm Don Seafert. It's the Dr. Tree Fruit and Dawn Podcast. It is Tuesday, May 12th, 2026. I'm here with Dr. Carrie Peter. Say hi, Carrie.

SPEAKER_02 0:16

Hey Dan.

SPEAKER_01 0:17

And Dr. Sean Kumar. Say hi, Sean.

SPEAKER_02 0:20

Hello, everyone.

SPEAKER_01 0:21

Dr. Krawchek is uh doing some family stuff this week, so he will not be with us. Uh, so it should be pretty short in the grand scheme of things with just Carrie and Sean. Uh, Sean, if you want to take us away, go for it, man.

Adams County Thinning Window

Managing Mixed Fruitlet Sizes

Central And Northern PA Timing

SPEAKER_02 0:34

Sure, Don. Thanks. Uh yeah, I just want to talk a little bit about this week and then talk about where we are, sort of in the rest of the state. And so in Adams County, things are picking up, especially this week. Uh, fruitlets are sizing up in blocks where you do have a crop. We are seeing fruitlets growing rapidly, uh, anywhere from 7 to 8 millimeter to 15 to 18 millimeters, depending on how much you lost from the freeze event of April 20th, 21st. Depending on, you know, if you just lost your kings or first laterals, your sizes might be a little bit bigger. If you lost a lot of the primary set and the secondary set, secondary or lateral blooms are the ones that set, then you will have uh smaller sizes. In any case, uh, this weekend is looking like the best uh chance for you to thin your crop. I think on uh Saturday we have uh warm temperatures, early uh low 80s, and uh it that's gonna stay that way for Sunday and Monday as well. And so most likely your crops are gonna be in the 15 to 20 millimeter range, so larger fruit uh for you to thin off, especially since you've been waiting uh since two weeks, three weeks to sort of see what apples will stick, what apples are gonna fall off, and and so uh for in in blocks where you do have a crop, uh this weekend is most likely going to be your last effective thinning window in Adams County. And so if your thinning sprays from last week, if any of you any of you had tried thinning sprays last week, last Monday, Tuesday, uh, and uh I've heard some reports that it worked a little bit or it didn't work, and so again, this weekend will be your option to thin your blocks. If uh and probably one of the last windows to thin your blocks because of the sizes of the fruitlets that are currently uh currently there, they're growing rapidly and they will uh continue to grow rapidly, especially this week. And uh so uh with the temperatures forecasted as high as they are at 80 Fahrenheit, 6 BA products can be unlocked like Maxel or 6 barrel. They have peak efficacy between 8 to 15 millimeters, but and they can be tank mixed with carburetor. Uh, if additional thinning pressure is needed, also I know some folks use oil as well. Uh, and so if as fruitlets are approaching 15 to 16 millimeters, if they're closer to the 15 to 16 millimeter range, then 6BA with carburetor is a great option to use. Uh, however, for fruitlets closer to 20 millimeters, when you get to spray them this Saturday, uh, if they're closer to 20 than to 15 millimeters, then 6BA usually tends to be not as efficacious because it's slightly outside that uh thinning window for them to be the most efficacious to remove fruitlets. So for those fruitlets that you have a higher fruitlet size closer to 20 millimeters, you want to think about maybe tank mixing with a seed. Uh, a seed is product of AC uh is uh with an active active ingredient ACC, which is a precursor of ethylene, and it can help it is labeled for later season thinning, 15 to 20 millimeters. So, especially with hard to thin varieties where you're using 6BA products, it's good to tank mix with the seed. And if you want a lighter thinning uh in the 15 to 20 meter 20 millimeter size range, then you can some with the forecasted high temperatures, you could also use a seed alone, uh, which could uh result in a decent drop, and it's worth considering as a standalone option as well. Uh so for very hard to thin, I would suggest still mixing uh both these chemistries to make sure that you're getting a strong thinning response, and uh for varieties in which you think that you just want a little bit of thinning, uh, then a seed alone could also help do the job. Now there's also the other product, the newer product that's been registered since late last year, which is Metametron or Brevis. And it is also labeled up to 20 millimeters size for thinning, and it does remain an option. Although for Metametron to be very effective, uh you want uh nice cloudy days following the application because that reduces photosynthesis, and as a result of reducing photosynthesis, that creates additional stress combined with the Metametron application that results in thinning. But this week we have forecasted bright, sunny conditions, bright, sunny, warm conditions, so it might not be as efficacious. Nonetheless, if this is a new tool in your toolbox and if you haven't tried it yet, I would still suggest to uh try this in a certain section of your blog to see how it works and get your hands wet with some of these newer products that we have on the market. So uh that's that's the spiel for thinning. I know uh there's uh ethafon is also available, but with the temperatures that's been forecasted 80 plus, uh with ethafon you can really uh you can really remove all your fruitlets if not used carefully. Uh, ethifon is probably the best thinner when you when your fruit grow grow past 20 millimeters. Uh ethafon does a really good job, but you have to be very careful about the rates, with especially this high of a uh high temperatures that we are seeing. And you probably want to reduce the rates a little bit, uh accounting for that high temperatures. But ethafon will work if your fruitlets have passed the 20 millimeter size by the time you reached Saturday, then you can uh think about using Ethifon as well, uh deepening and vary the rates based on the variety and your prior experience. Uh, but we've seen that it does a great job with thinning, even when your fruitlets are past the optimal 20 millimeter size. So, one of the more common things that uh we are seeing because of the freeze event is we are seeing two distinct sizes of fruitlets in your blocks. Uh so uh and then this this question arises of what we can do if we do see two distinct sizes of fruitlets. So one I'm assuming one from the primary set, uh, where you have a few laterals left if you lost the king and first lateral, for example. And then you also have your uh those were mainly set on the spurs, and then you also have your uh fruit fruitlets that have been set on your one on the one-year-old wood. And then you're then basically what you have is two different sizes of fruitlets in the same block, and that's when you need to do some block-to-block level checking to try to see what sort of set you have in your primary set as well in your as well as in your secondary or lateral set in your one-year-old wood. So, in blocks where a lot of the spur flower flowers or fruits were killed by the freeze event, uh the bloom on the one-year-old wood becomes the primary crop. And so you should base your thinning actions on the size of the fruitlets in the on the one-year-old wood, if that's all you have, or that is most of what you have in that block. And so, for protecting this set, you need to wait until the king fruitlets in the secondary set or on the one-year-old wood is at least 12 millimeters, because uh usually they can get very easily thinned off when you apply thinning materials before they reach that size 10 to 12 millimeters. Uh, by which point, if you think about it, the spur fruitlets are already uh sizing up to 16-17 millimeters, so there's like a good three to four millimeter size gap and much much higher in some locations, depending on the amount of damage that you had from the freeze event. And so uh the suggestion for those blocks is to wait. If your secondary set or lateral set hasn't the king of the lateral set hasn't reached 12 millimeters, then don't thin. Wait for them to reach 12 millimeters and then apply your thinning chemicals, and that will be useful. Uh, I mean that will be helpful to manage crop load. And I I do think that with Adams County, with both the primary and the secondary set, you will be at your prime thinning time this weekend. Even the secondary set is also sizing up, and by this Saturday, I think you will be at a place where you you are able to thin. Uh, but please check your blocks to decide uh on the sizes, look at the sizes because you based on the fruit size, you will have to decide on the thinning chemistry that you want to use. Now, uh, if you had used promolin or perlan, uh, one of these uh gerbilin and cytokinine products for improving fruit set after the freeze event, uh, sometimes and you still have damage in those fruitlets when you those fruitlets could still be growing, but when you cut them open longitudinally, you can kind of see that seed cavity sort of decaying. So these fruits are most likely going to drop, or uh uh sometimes uh these fruitlets can have other sort of damage, for example, some frostering or some russeting or misshapen development. And so both of these types of fruitlets are uh sort of hard to remove by chemical thinning, and you'd have to do some hand thinning later on after chemical thinning, sometime late this month or early next month. Uh, you'll probably need some hand thinning to remove these sort of fruitlets uh if they have if they've been damaged, because they're sort of hard to remove with uh chemical thinning. And so this is where we are at in most of Adams County and southern Pennsylvania. If you have blocks that are closer to uh uh the sizes that I've mentioned, then this weekend is probably your uh last bet. The temperatures are uh warm, they are gonna be warm for three consecutive days at least. That's what the forecast says for Friday to sorry, uh Friday moving into Saturday, Saturday to Monday. That's what the forecast says, it's gonna be 80 plus. So uh usually with those temperatures you will be able to see something in action. Now moving on to more central northern Pennsylvania. Uh we actually uh took some measurements from some orchards to try to understand where the primary kings and primarily primary laterals are and where the secondary kings and secondary laterals are. So when I say primary, I'm thinking I'm talking about the spur, uh king, spur laterals or the terminal, king, terminal laterals, and then I'm when I'm talking about the secondary, I'm talking about the fruitlets on the one-year-old wood that I've set. So uh we did some measurements in a couple of varieties, and so for this uh in an in an orchard in Ellisburg, and so for honey crisp, we saw that they didn't have any primary kings remaining, but the primary laterals were about eight millimeters in size. This was these were measurements taken yesterday by my student Michael. And if you look at the secondary king, it is around two millimeters less at about six millimeters, and the secondary laterals are way smaller than the secondary kings, which they are only at three millimeters, and so uh and similarly we have uh gala slightly larger, with a they do have some of the kings remaining, which are 10 millimeters, or and the laterals, primary laterals that following closely behind, but when you look at the gala secondary uh set, they're they're at least six to seven millimeters smaller in size than the primary set. Uh they're only still at three millimeters, both the secondary kings and the secondary laterals. And so this just goes to show that each block there's something slightly different happening, and so this year you might need to pay a little bit closer attention to what sizes your fruitlets are developing at in order to think about your thinnings when to apply your thinning sprays. I mean, first, even if you want to apply a thinning spray, and then if you do want to apply a thinning spray, when to apply it uh because uh uh these seem to be quite variable across blocks, even in blocks that are located right next to each other. And so, uh, for example, in this particular uh block that we looked at of the gala, there is a six or seven millimeter difference between uh the primary and secondary set, whereas for Honeycrisp, it seemed like they were much closer uh in sizes, the secondary and the primary set. And so uh when uh in most of these blocks you have to wait for the secondary set because that is going to be that that is gonna be the provide you that is gonna be the major crop provider this season because of the amount of loss we had in the primary set, and so you will have to wait until the secondary kinks reach at least 12 millimeter, 12 mm in size before you apply your thinning spray. So for central and northern Pennsylvania, it could be that this weekend is not uh the right time to thin, depending on where the sizes of your fruitlets are. It could be because for some varieties, like for example, in this honeycrust block, the fruitlets are going to grow, and by the time they reach uh this Saturday, we are most likely going to be the kings, secondary kings at 10 to 12 millimeters, in which case you can thin that block. Uh, but for other varieties, for example, this gala, which is at 3 millimeters, it's unlikely that it will reach uh 12 millimeters by this Saturday. So you might have to wait a little bit more to sort of get to thinning them maybe sometime mid next week to later next week. So that is why it's important to sort of look at the sizes of uh where some of these blocks are to assess what you want to do, uh what you want to do with these blocks.

SPEAKER_01 14:58

Okay. Thanks, Sean. That was really comprehensive. Uh yeah, I think I sent you some stuff this morning about how we are looking like we're between like 10 to 12 millimeters, but uh yeah, that's it's still pretty few and far between when it comes to actual actual fruitlets.

Hidden Freeze Damage And Storage Risk

SPEAKER_02 15:16

So yeah, thanks, Don. I just wanted to mention one more thing. Uh uh because uh in some orchards we are seeing growing fruitlets, uh, but when you cut open the fruitlets, we are seeing the damage, the central cavity and the seed cavity, and these fruits, depending on the amount of damage, they're most likely going to drop. But some fruitlets, especially ones that have been sprayed with perlan or promolin, uh, there is a chance, and which fruitlets have minimal damage, they do have damage, but not as much. And they have been sprayed with promolin or perlan. There is a chance that these fruitlets could likely also last and keep growing, but they will still have that uh uh decayed seed cavity, even if the fruit is growing, and so you just be aware of that. Uh, if you if you are planning to take these fruits to harvest, then uh accordingly you will have to deal with the fruit because they're most likely not going to store well. Uh, first of all, a lot of these fruit is gonna fall off. If they don't fall off, then uh you must be aware of this when uh when you're looking at fruitlets and we when you're thinking of uh uh what to do with these fruit because some of these fruit, because of the way how they're growing, I feel like some of these damaged fruits could could actually keep continue growing uh as long as they have even a small connection, vasculature connection with the with the tissue, these fruits could grow still, and so you should be aware of uh aware that even though it has a damage in in the center in the seed cavity, it could still grow, but it will still have that decayed seed cavity even as it grows, it's not going to go away. And so it might be that those damaged fruit could be could go for juicing or something that could be sold immediately. That's just something to keep in mind uh as you're evaluating your blocks uh for damage. And we saw this damage in quite a few places around this date. And as of late last week, some of these damaged fruitlets are still growing, uh, they're still on the tree, they're still growing, and it could take anywhere uh still. Uh hopefully, this warm weather will help in this weekend to sort of uh uh fasten the drop from these damaged fruitlets so that we're not confused by what's gonna stick, what's not gonna stick. But it could still take another week, another two weeks for all of those damaged fruitlets to drop off, especially during uh the June drop, which in southern Pennsylvania we seem to have the June drop mostly in mid to late May. And so uh or late May at least. So uh we'll have to wait until then to sort of uh understand uh if these if these fruitlets are gonna drop or uh or they're gonna stay on.

Scab Ending And Marssonina Pressure

SPEAKER_01 18:00

Carrie.

Bitter Rot Alert And Spray Choices

Fire Blight Triage And Action Steps

Apogee And Thinning Interaction

SPEAKER_00 18:01

Okay, so uh interesting week, or I should say week to ten days ahead of us. So I'm gonna cover the next bit further this week and next week, um, because it sort of all blends together. So, first over the weekend, we did have another scab infection event, and this might have also been a Marcenina event as well, Marcenina leaf blotch. Uh, so just as a reminder for Marcenina, we are in peak time for Marcenina spores, and they are still a threat to your apple trees, regardless if you have fruit on them or not, because it goes to the leaves. So Marcenina infection favors 68 to 77 degrees Fahrenheit. You don't need very many leaf wetness hours, you only need a minimum of four. And right now, your broad spectrum fungicides like mangazeb, or if you're using Captan right now, that works. But your frac group three and frac group seven fungicides are your go-tos. Um, so this is your Sevian, and Spire Super, and uh Procure and Trionic and uh Lunaflex and Tesseris and Aprovia, that's just a snapshot of them. So these all work, especially when you're tank mixing with a rainfast manga zeb. Now, for those of you who um may not have a crop and don't want to pull out the big guns to add to your mangazeb, you can tank mix, you can do a few things. One, um, if you if you don't have a crop and you do want to use um another um another fungicide in addition to your broad spectrum, you can also use something like lunisensation and maravon. They have frac sevens in them, they will also help, but the frac 11s in them will not. So just as something just to make you aware of. Um, if you do have fruit, I would not use those products. I would save the frac 11s for the summer. Uh so that's your lunasensation, maravon, flin extra, and cabrio. Uh so and also the frac 11s don't touch Marcenino, which is another reason to kind of save them for later. But like I said, if you don't have fruit and this is in your shed, um, you can still use this on your leaves. Now you may want to be conservative, and maybe you're planning on already being conservative because you lost you have lost your crop. So one thing I would recommend um during this time is using a tank mix of mangazeb and captan. So maybe not using mancazeb alone and and maybe adding a little more oomph. So if you use a rainfast mancazeb and captain, the idea is you get the spreadability of captain and the stickability of mangazeb. They use this combination a lot in New York. It's called Captozeb. It does a really good job. But remember, it is only effective as far as how you use it. So some things to keep in mind, some very important points when you're using just broad spectrums right now to keep your trees protected. Because I've heard some folks say, oh, I when there was a year I didn't have fruit, I used this and it failed miserably. Uh well, it's probably how you used it. So remember, these broad spectrums are surface only, and for them to work effectively, they need to be on the surface of the plant tissue prior to that infection event. There is going to be no reach back activity, like your single modes of actions from your frac threes and sevens and nines, etc. So another thing is that when you put those broad spectrums on uh and you're using alternate row middle, remember that the other side is naked. And you also have to remember it may be naked through a wedding event. Um, so be mindful of how long your interval is in between those half sprays. That's very, very important. Also be mindful of at the time of the rainfall or infection event, how recent was that broad spectrum application? Was it old? Was it sprayed just yesterday? It's the how when it was applied is going to determine its efficacy. If it's two weeks old, it may not be as potent as when it was just a few days old on the on. The um as far as on the on the tree. Um, also be mindful the trees are growing right now, so they're pushing out a lot of new tissue. So if you're putting on a spray and significant time has passed, you may have new growth, so that new growth may be unprotected. So these are things to really keep in mind when you're just using the broad spectrum fungicides due to a low or no crop, that there are limits to them. But you can use them smartly and get away with not having to pull out the big guns and adding them to your broad spectrum. So just a lot of things to keep in mind, especially if you're using alternate row middle sprays, which again I don't advocate, but I know the reality out there. So just be very mindful of that. Uh also um for when we're talking about leaves, don't forget your tart cherry trees. Uh, we're an active cherry leaf spot. You're going to have to still uh be um spraying through the post-harvest period. I use that in quotes, even if you may not have sour cherries, because it's still attacking the leaves and can cause severe defoliation. Um, so as far as the leaves goes, we are at the end of apple scab. This is probably the last week, the last push. We're at the end of rust. The rust skulls are still active, they'll probably dry up come next week. And Marcenina, we're like right in the middle of it. So you're still gonna have to be vigilant for Marcenina probably for another month, I would say. Now, um moving on to bitter rot. So, bitter rot, if you have fruit, we will most likely have our first major infection event this week. Remember, bitter rot likes it warm. It also has a quiescent period when it causes its initial infection. So it's very important to have those fungicides on the tree prior to the infection event. Uh, so things to be thinking about what to apply right now. Aprovia would be a great option to tank mix with your rain fast mega zib. Uh aprovia is great, it's a frac 7, it's great against bitter rot, and it's also great against Marcenina. Um, you could also use Omega, um, and that's uh that's Fluazinam. So frac group 29, that's also Orbis. It's that's also another name for the product. And there may be other names out there for Fluazinam. Uh so this uh has both Aprovia and Omega have like a 28-day to 30-day PHI. So this is the time you want to be using it. Uh I would probably hold off on your Frac 11s, the Flynextra, the Luna Sensation, Marivon, Cabrio, just because we're in the middle of Marcenina. So I would use something different. Um, so you could kind of really uh beef up your broad spectrums with the Mangazeb Captan, that would probably work as well. Um, and as far as um Topson is another one or Fontelis, they are a bit weaker, but they will do the job, especially when they're tank mixed with a broad spectrum. So I always mention about Frac 11s being great for rots, but just because we're in the Marcenina period, I would still wait on them and push them to a little bit later. As far as organic options, they are limited. Um, we've got Howler out there, Serenade ASO, Opti, Double Nickel, Oso. So these products alone are fairly weak, unfortunately. So if you need a good organic control for your Omri certified site, you probably want to stick to sulfur for a while for with regards to uh with regards to bitter rock control. You could think about rotating these products like howler, double nickel, serenade, ASO, or Opti. Um they're a lot softer and they need a little bit of extra help when managing disease because they are they get overwhelmed by the disease pressure so easily. So you could think of a rotational program and maybe rotating sulfur in these products. That's also an option. Uh, I was just on a recent phone call with some Ohio growers, kind of giving them from some bitter rot advice. And one thing I forgot to mention that I'm glad a grower brought up was regalia. So many folks have seen the the sort of the utility of regalia, adding regalia, not using it by itself, but adding it to your spray mix. So, what does regalia do? What's so special about it? So, this is a plant extract, it thickens the plant cell walls, and so it's this mode of action that probably why we see an additive effect or maybe a synergistic effect with conventional fungicides, because it thickens the plant cell walls. And so if the plant cell walls are thicker, fungi can't penetrate it as easily. And so um that may be why it's working so well is is because of this this um mode of action. So that is another option as well. One to two quarts per acre, adding it to your mix, not using it in lieu of or by itself, because again, it will get overwhelmed, but using it as an additive. Uh, and you can use it in every single tank mix. So this is something else, is maybe um, I haven't tried this. We tried this many years ago and we we didn't see any statistical differences, but I think if we would do this again um during especially maybe a severe year, that we may see things um sort of uh settle out a bit differently. But this is something if it were my orchard, I would do because um of the way that regalia works. So this is this is also something to think about. And we will revisit it, but I just want to emphasize for folks this did go out in the disease update that was sent out uh this morning. And I just want to emphasize we are in the bitter rot zone for infection right now. The temperatures are warm, um, they're getting warmer, and rain is in the forecast. Uh, so we need to be on high alert for bitter rot infections. And I cannot emphasize that enough because last year people were caught off guard by these early infections and it kind of ruined the rest of the season because they saw infection later on. Once you see infection, that's it. There's there's no going back because there's most likely latent infections. And you need that fungicide on ahead of time because of the way this fungus causes infections. When it causes infections, it goes asleep, it goes latent. And when it's latent and asleep, fungicides can't attack it easily. And this is in contrast to other diseases or fungi, like the one that causes apple scat, venturia inequalis. That doesn't go asleep once it starts infection, it continues the process. So it's easy to use fungicides to kill it or use this reach back mechanism of fungicides. We can't really bank on that with regards to bitter rot. You're better off having it on ahead of time. Don't count on fungicides working 100% post the infection event. So I can't emphasize that enough. So people need to be on high alert really over the next 10 days. Um, the last thing I want to mention is fire blight. So I'm starting to hear, as I basically was setting my watch to it, of really a lot of high incidence out there that people are seeing of blossom blight. And I knew it was only a matter of time. The cool weather was holding things back. So, what can you do? So, some some tips. First, it's still not too late to use the prohexadione calcium, so apogee or kudos. Um, so especially for people who may have a low or no crop, just be mindful that this product will interfere with your thinning. So plan accordingly with it. And um, when I'm done with the fire blight, I'll let Sean comment about prohex and thinning chemicals because that's not my wheelhouse, and I don't want to say anything inappropriate. But the prohexyxidion calcium will harden off the shoots and that will limit shoot blight. So this is important. Uh, as far as other products you may be able to use to stop fire blight in its tracks. So, right now, preventative may be out the door. So you're now chasing the infections. So applying anything may be really difficult right now. But if you want to um use something that could help stop the fire blight that you see, I'm gonna mention a product. Now I am in the process of uh just disclosure, the little disclaimer statement I should say in the beginning is that I'm testing this product this year. So I do not have data in hand. So this is from more anecdotal evidence. So I've mentioned this earlier, the product fungiut, which is citric acid. Uh, it's one, it's 1.07% citric acid. And this product is considered a fungicide and bactericide. So, how would this work for fire blight and managing active fire blight? Erwinia amylavra, the causal agent, the causal bacteria fire blight, does not like acidic environments. It hates it when it's acidic. And I can say this firsthand because when our fire blight or Erwinia media has been off in the lab, it will not grow if that media is not at neutral. If it's at 5.5, it will not grow. So Irwinia really hates acidic, like acidity, acidic environments. So, how would this work? Is that you're spraying an acid, you know, on your trees. And this should not harm the fruit finish issues in theory or the leaves. Uh, it it's basically it's you it's no different than adding probably um an acidifier like LI700 to your spray tank. But I would, but you don't need to add any adjuvants. You could add a spreader sticker to this to sort of aid in the spreadability. It says this on the label. Um, but if you have an active infection, you could spray this and maybe, maybe it will burn things out and stop the spread of the Erwinia. I've heard this anecdotally from growers saying this does work. I cannot attest to it because I'm actively trying it right now. So we shall see. But I would say, in theory, this should work based on what we know of how what Erwinia does in acidic environments, it doesn't like it. And the fact that that's what this is doing. It's an acidifier. And so uh if you're desperate and you're like, I want to we'll try anything, this is something. The rate that you use is 1.4% volume to volume, and you would do this every two to three days. That's what the label says. I'm quoting the label. So this is something that's not not just one and done. You're going to really have to monitor, and you may have to go in multiple times. So use this at your own discretion because I don't have data to back it up just yet. Um, but again, in theory and thinking things out, this might be a worthy option. Um, again, if it were me and I would be in this position and knowing what I know, I would try it. Um, especially if it's if I have too much to prune out, this would be something that I definitely would want to look at. So just a word, just again, use it at your own discretion. Now, if you are going to plan on cutting out fireblight, uh, some a triage method, there's a triage method that you want to follow. So, first, the highest priority orchards are those that are young. So, three to eight orchards with a few strikes. So, few strikes means single digits. So, like one to three, four. Um, anything if you're getting close to ten, that's too many. Um, and so that would be the next level of younger orchards with a lot of strikes, older orchards with a few strikes, and the walk-away orchards are those that have so many strikes that basically you're gonna be cutting out the majority of the tree or stumping it if they're young trees. Just walk away. I know that might be hard, but the reason why you want to walk away from these orchards is that too much of a good thing could really negatively impact you as far as pruning. So the more you prune, the more you're gonna tell that tree, I need to put out new shoots, um, because you're removing the apical dominance of all those branches. So it's gonna want to produce more and more shoots. And that's just gonna create the problem to be worse and worse and worse because you're giving it more young tissue to grow and to become infected because that fire blight now is actively in the trees. So you're going to want that walk away from those orchards that may have a lot of fire blight. Now, if you are going to cut out fire blight, some things you want to keep in mind. Uh, don't cut out infections in wet weather. So be mindful of how wet it is. And that includes dewy mornings. Um, you want it dry because the wetter it is, the more you're going to spread that bacteria around. You want to cut active, um, you want to cut active infections out as early as possible. So once it gets real crunchy, that's usually a little too late as far as to limit the spread. Uh pruning's most effective when the incidence is low. You want to salvage tree structure, especially in young high-density plantings. And be mindful that bacteria can invade the tissue up to three feet or more. So sterilizing your tools might be a moot point. Um, but if you see active oozing, uh, this may be warrant some, you know, this may warrant some sterilization or at least some um cleaning up of the tools in between cuts. Uh, so you may be reluctant to use bleach because that's hard against um steel and metals. So if you use something like um peroxide or pine salt or something that's a little gentler on tools, that's something to consider. But again, the bacteria is moving ahead of the infection. So sterilization, it's a it's a hot topic and can be controversial. Personally, I don't during the season, but that's just me. Um, some people feel a lot better sterilizing. You do you. I'm not gonna discourage you. Um, practice the ugly stub method. So you want to aim for six to twelve inches beyond the site of infection, leave a stub because it's the stub is where the bacteria is going to collect, and you can come out in the winter and prune it. And then um ideally you want to remove the tissue from the orchard, but I know that can be challenging, um, especially with labor and maybe reduced cruise. So, what can you do alternatively to limit spread? Well, throw it in the tree row middles, let it dry out, and then mow over it and crunch it up and chop everything up into little pieces. That's what we do at Freck, especially for little stuff. Um, for big, big branches, no, you can't do that. You would want to remove those big things from the orchard. But for little things, just throw it in the row middle, let it dry up, and then just mow over it to crunch it up. The last thing um I will mention about management is the actigard paint method, and I'm using paint as a verb, not as like um mixing something with latex. Um, you're using it as basically um a spray. It's a concentrated spray for the tree of Actigard. Uh, so it is a um you are mixing a one ounce of Actigard in one quart of a 1% penetrant. So that can be Pentrabark, that can be Li 700. Um, but what you're gonna do is if you have limited strikes on your trees, you make up uh like you make up a bunch of this. Uh and so like one quart will treat approximately five cuts. I usually make it up into uh like a one-gallon, I use a handheld one gallon sprayer for ease. Um you're gonna cut the basically make the pruning cut, and I spray the cut and then also the trunk right below that. And so what this research has shown, this came out of Oregon State, is that this should limit canker production and also limit spread of the bacteria further into the tree. So it is a little laborious, so I'd recommend doing it in teams if you do do it, but it does work. I've used this in the past when I've had really tough situations. Um, so I do advocate it, but it is a little bit of extra work. So you want to kind of do it in a tag team, maybe someone who's cutting and then someone's coming in in spring. Um, so it's just an idea. And then the last thing that I will mention, and I'm gonna try to get this article re-published week, is for folks who really are hit hard to not forget about the farm service tap program, the tree assistant program. And so this program um will aid growers who've been hit by some natural disaster in their perennial crop. So whether it's grape vines or trees, um, you can contact a farm service agency and make a claim. But there is a period of time that you have a window. Um so if you have a really overwhelming situation that the only way to fix this is to remove a huge chunk of your orchard, contact FSA. You will get compensated for a portion of what you lost as far as the trees replace and the labor that it takes that's necessary. Um, something's better than nothing, especially if you're faced with fire blight and having the need to replace it and also stopping it in its tracks. This has been successful for several growers I've worked with. Sometimes you need like someone to have be an expert and provide a letter saying this is what happened, these were the conditions. The growers did everything they could humanly possibly do. Uh, and this is it still happened. And this was a year where tap should be taken advantage of if people really were hit hard, because we had the absolute worst week for conditions for Fireblight, and it was unreal. So this would warrant um making a claim for tap. Uh, so I would encourage growers to do that. And I'm gonna try to get this. We published this article, Jay Harper and I, many years ago, but that article is no longer on the extension website. So I'm gonna try to, I'm gonna update it and republish it later this week for any growers out there because I have a feeling some people may need that this year. So with that, I thought this was gonna be short, but uh um that is those are the very long uh broad brushstrokes for what people need to be thinking about over the next 10 days. And I say the next 10 days because I'm gonna be at a conference next week. So I want to make sure that people have their information of what's gonna cover this week and next week. So before we finally wrap up, I just want to have an addendum and have Sean address the use of the prohexadion calcium that I mentioned to be used for fire blight and how that may or may not interact with thinning. So I'm gonna have Sean describe that.

SPEAKER_02 40:36

Thanks, Terry. So when I look at the literature, uh it's has it's it's a little bit mixed on this, where some folks have observed that it is slightly harder to thin. And anecdotally, I've heard from multiple growers that when they've applied really high rates of apogee uh or kudos, which is the 10 to 12 ounces rate, uh, that sometimes it's a little bit harder to thin uh because you don't have as much uh vegetative growth happening, and uh so it's not like the tree's resources are being directed towards uh vegetative growth, and so there is availability of resources, there's carbohydrates, and so when you have that, it uh it makes it harder to have a carbohydrate deficit, which makes it uh slightly harder thin, especially when the shoots are hardened off. Uh but uh there's evidence, uh there's not clear evidence either way, and I think that there's needs to be more work to sort of like clearly say one way one way or the other, but it's just something to be mindful of when using high rates of apogee and uh and with with with thinning chemicals, and especially for Adams County, I think we'll get past most of those concerns by the end of this week because this week will be the main thinning window this Saturday.

SPEAKER_00 41:53

Awesome, thanks for clarifying that.

Irrigation With Low Or No Crop

SPEAKER_02 41:55

Yeah, thanks. Uh I also just wanted to quickly mention that I got some questions from growers about irrigation and what to do with irrigation with low or no crop, especially in your high density blocks. And so I just wanted to address that, I just remembered, is that uh so when you have uh rainfall occurring like every week, and when you have enough soil moisture, enough moisture in the soil for sustenance of the crop, then when you don't have a crop and when you have a vigorous high-density planting, I would highly suggest you regulate your irrigation that you have. It is not necessary to irrigate if you have a low to a no crop. The only exception to that is when you have really hot weather and you want to mitigate the stress of that heat, then yes, it will be good to irrigate if you have irrigation and drip irrigation, but uh especially during the times when you have flowering initiation, initiation of flowering that happens for uh for the crop of the next year. So the flower initiation inside, I mean we don't see it, but it happens uh within 45 days after full bloom for honeycrist, within uh between 45 to 60 days of full bloom for Fuji and about 90 to 100 days after full bloom for gala. And so uh during these times it's important that the tree doesn't face additional stress. And so if you do have if you do have irrigated blocks, it's important to provide irrigation during those times and during times when it's very hot outside uh because it does lead to cooling. But other than that, if you have a vigorous block and you want to limit its growth, then I think it it's it's important to sort of limit the irrigation that you provide. Maybe uh you could reduce it by 50, 30 to uh 50 to 70 percent, and just have a sort of like maintenance irrigation schedule, meaning that you provide water when uh if you have sensors to help you with it, either evapotranspiration or soil moisture sensor to kind of guide your application. You can reduce your irrigation by about 50 to 70%, except for these two exceptions that I talked about, so that you're not uh growing your shoes too long so that it exceeds such that it exceeds the space that it has in the high density block. And uh irrigation can do that. So you might want to uh change that if you have irrigation settings set up as compared to like a normal year. So that's something I want to say.

Planning Session Invite And Sign Off

SPEAKER_01 44:26

Thanks. Well, thank you guys both so much for jumping on here today and doing this. Uh and we will return next week, I guess, um barring any major catastrophes. So um I uh nope, I still have one more week before I need to encourage folks to come to the Mid-Atlantic fruit and vegetable uh planning session that we have down at Frec, uh, which is on the 27th, uh, just as a heads up for folks. Um so that said, if you're in the local region and you want to come to that and have input on what the educational program looks like for mid-Atlantic, uh feel free to swing by. Let me know.

SPEAKER_00 45:07

Yeah, and growers are encouraged. 100%. Yeah, it's just not the extension folks that are um you know invited. It's it's we want to hear from the growers. You know, we we develop the program based on what your interests and needs are, so absolutely.

SPEAKER_01 45:22

Uh all right. So with that, um say goodbye.

SPEAKER_00 45:26

Goodbye, everybody.

SPEAKER_01 45:27

Goodbye, everyone.