Orchard People

[00:00:00] Introduction to Sudden Apple Decline
Hi everyone. It is so sad when a beautiful fruit tree dies. But it's even sadder when a tree dies and you just don't know why. that's been happening in apple orchards in various parts of North America, including Ontario, New York State, Pennsylvania, and Washington State.
It goes like this. One day you're walking through your apple orchard and everything looks just fine. Your trees have a nice heavy crop of fruit on them and all is well. The next week though, You start to notice the tree's leaves are going just a little bit yellow, and within two weeks, those trees are dead, many with an almost ripe harvest on their lifeless branches.
Some growers are losing 10, 20, or 30 percent of their orchard trees in this way, and researchers don't yet know why it's happening. They call it rapid apple decline or sudden apple decline, and we're going to learn all about it in today's show.
[00:01:06] Guest Introduction: Dr. Kari Peter
My guest today is Kari Peter, PhD. She's an assistant research professor of tree fruit pathology at the Penn State Fruit Research and Extension Center, and she's experienced this problem firsthand in her test orchard.
So let's learn more about the very scary sudden Apple decline. Kari Peter is on the line right now. Kari, thank you so much for coming on the show today. Oh, thank you for having me.
[00:01:34] First Encounter with Sudden Apple Decline
So Kari, tell us a little bit about the dramatic story.
How did you first encounter sudden Apple decline? I started at Penn State in March of 2013. It was, I had been here a few months when it was brought to my attention one of my new apple orchards that had been, I inherited that had been planted the year before, was suddenly losing a lot of trees.
And as the new pathologist at the station, it was my duty to figure out the problem in my own orchard. we had decided to try various treatments on the trees, fungicides, soil treatments, to combat any issues that could be affecting the roots. we, tried to rule out stuff. And the more we applied products, the more the trees could continue to die.
So it seemed that We couldn't get ahead of it, and the trees just continued to collapse despite our efforts, our valiant efforts in trying to save them.
[00:02:37] Symptoms and Initial Observations
So what were the first symptoms that you noticed? there were a lot of, first it was there were a lot of dead trees. It was just a lot of trees that were in the process of decline.
just looking at them first, first glance, it was like The, leaves were yellowing, or they were completely brown because they had already died. And then as the season had progressed in 2013, I had noticed that trees that seemed healthy at the start of the season, meaning they had some fruit on them, were starting to collapse as well.
So that, that was very startling to see what appeared to be, trees that had, a decent crop on them collapse. so that was, that was definitely of concern for us. So you saw yellowing leaves, but was there anything else that, that could distinguish it from any other possible disease or insect problem, or?
[00:03:31] Investigating the Graft Union
we took a very close look at the entire tree, and when we looked closely, it was mainly at the graft union. That's where we noticed where the problem was at, it was at the graft union. And then we would dig up the tree and we noticed that the roots were perfectly healthy, and in all cases, the roots were wonderfully healthy.
The tree was trying to survive because, the, particular rootstock that these trees were on, rootstock denotes the size of the tree, was called M9, and they were pushing up a lot of rootstock suckers. So when you see that, you know that it's a healthy root system. But the problem area was at the graft union.
And so when we would scrape away the bark, we realized it was at this critical junction of where rootstock meets the scion wood that was collapsing, and death was going up the tree. So it was expanding up the tree, but really the, ground zero for the collapse was right at the graft region.
[00:04:26] Understanding Rootstock and Scionwood
for those listeners that don't, know, the idea of a fruit tree, the reason we get these wonderful cultivars and varieties is that you, they're actually frankentrees, aren't they? They're made out of two separate trees. Can you just summarize that for us? what is the difference between rootstock and scionwood?
Sure. So, yes, apple trees aren't grown from a seed. They're clonally propagated, meaning that you have the top part of the tree is called the scion. So that would be your variety or your cultivar. So that's your Honeycrisp, your Gala, your Fuji. And you would graft that scion wood to a rootstock, and the rootstock is, what controls the size of the tree.
So you can have dwarfing rootstocks, which makes the tree small. And these are desirable because you can pack a lot of trees in a small space, like in one acre. Or you have semi dwarf rootstocks, where they're a bit bigger, they can typically stand on their own, and they need more space, so you would have fewer trees per acre.
The dwarfing rootstocks require support. And more and more growers are going towards this system because they can recoup their costs in a shorter period of time, so in a semi dwarf system, you may not get a sellable crop for five or six years in the case of a dwarfing root stock system, you would get a sellable crop in three years.
So you're paying off your debt much faster. So the investment is paying itself off.
[00:05:51] Field Observations and Grower Reports
Okay, so now what we're seeing, so you're out there in the field, oh my gosh, these trees are dying, but whoops, The roots are alive. Even when the tree is totally dead on the upper part, you can see that the roots are surviving?
Yes. Yes, we can. we can, we dig them up, we can, move away the soil, we can scrape away a bit of the material off the roots and they're perfectly white and healthy. There's no decay. There's no sign of decay. We've, looked for nematodes in a sense of nematodes are small, tiny worms that can exist in the soil, which can decrease root mass or the number of roots that you have there.
And, the root mass is just fine. there's plenty of roots, lots of feeder roots. So there was lots of material there to be able to get nutrition and what the tree needed from the soil.
[00:06:43] Listener Questions and Expert Insights: Potential causes and cures
We just got an email from Patty from Omaha, Nebraska. Patty says, Hi Susan and Dr. Peter, a great informational show today.
My question for Dr. Peter is, there a cure for this disease? Not yet. There isn't a cure because we don't know what the causal agent is. we've been in the process of trying to eliminate issues. And the first is biotic issues. The biotic issues meaning, fungal pathogens, nematodes, viruses, such as that.
And then, there's a biotic causes like drought stress or winter stress, and those can factor into weakening the tree. so right now what we know is that tree stress, some kind of tree stress factors into these trees becoming susceptible to opportunistic pathogens. However, we don't know what that ultimate initial tree stress is to prevent it.
So we're, that's why we're stuck in trying to find a fix for it. so Kari, you're in the middle of this. This is what, 2013 maybe? You're in the middle of this. you're looking out at this orchard and you're thinking, oh, I'm supposed to be the expert and I have no idea what's going on. How did you then realize the problem was bigger than just your little Orchard.
I had received phone calls from other growers in the state, and one particular grower had much greater loss than I did, and he, his symptoms were very similar to what my orchard was experiencing, where he had just planted this orchard, it was a couple years old, and the trees were just collapsing for a number, a mysterious reason, and He was working with an extension agent in his region, and they put it through all the tests.
they sent samples to the Penn State Plant Disease Clinic. they had nematode, soil samples to test for nematodes. They sent that to another state to, to check on. And what was ultimately found was that the nematode population wasn't, an issue. And the pathogens that the, clinic that we're, The clinic was isolating were opportunistic fungal pathogens, so they don't cause the disease, they take advantage of a weakened situation, so when they enlisted my help, I realized, oh, this is, much bigger than me, and I need to bring in extra help, so I enlisted the help of the Pennsylvania Department of Agriculture, who, they have a plant pathology clinic themselves, and they deal with sort of mysterious Problems all the time.
So and there have been a history of Penn State working with them, particularly with issues in the past. And so I helped. They helped me as far as trying to look at the problem a little more closely beyond what I was capable of doing. Oh, my gosh. So So there you are, here's your situation. Okay, Pennsylvania has a problem.
I always wonder if something new has been introduced, how do people from different states and different parts of the world even get in touch and say, Hey, I have this problem too.
[00:09:54] Regional Meetings and Broader Impact
They typically occur at regional meetings. sometimes it's just by happenstance. And that's what happened to me is that it was actually 2016.
I was at a regional meeting in the Northeast in Vermont, and there were individuals there from New York State at Cornell, and they were mentioning they had recognized some unusual tree decline issue, and there are individuals there from Canada, and they had said, we have been witnessing this, too. And so then it was just a snowball effect where we all were witnessing and observing this very unusual massive decline of young trees that were on these dwarfing rootstocks with no unknown cause. And everyone felt, everyone had their own theory as to what may be causing it, but no one could come up with an ultimate cause. So we knew that there was something much bigger going on here than at the individual state level or even at the individual orchard level.
We have an email here from Ron and, all these emails, they speak to my heart because I feel the same way. He writes, Oh my gosh, can this disease wipe out an entire orchard? We have a small orchard in Greenville, South Carolina. Scary stuff. So the quick answer is no. I don't believe it is because we haven't identified, some causal factor yet.
And most likely what it is that there's multiple factors at play. and you also have to realize is that, the system of which these trees are being planted in, it is a very, it's, a very unique system in, in a commercial orchard. We're only witnessing this in commercial orchards that are planted in a high density system.
And what that translates into 1200 trees to an acre, your average homeowner or even small orchard may not be that dense. And, the other thing is that, in that type of system, there's a lot more competition for nutrients and stuff going on in the soil. And, the fact that we haven't seen a massive die off of trees across the board, it's very unique to a particular rootstock.
And there seems to be, There's nothing virulent, so to speak, that we have identified, so I don't, I think it sounds scary, but for, folks that may have smaller operations, I don't believe this is something that we need to be, it's not the apocalypse of Apple, so to speak. But it would be, M9 is a popular rootstock that many of us are getting from our fruit tree nurseries for dwarfing trees.
it sounds to me like what you're saying is it's a mixture of having this rootstock, have growing apples, and planting those apple trees really close together like they do now, in the modern way, in new orchards, basically. Also, you mentioned that this is happening to younger trees.
Yes. So tell me about that. So it seems that it's Primarily we see in trees anywhere from 2 to 3 years old to 8 years old. If you have trees that are 15 years old or older and they're dying, that's something else. And they've been healthy up until that point. What's so startling about this is they're newly planted.
trees that are just about coming into their prime. And so that's what makes this so startling. And it's the, occasionally you will get some tree die off for one reason or another, groundhogs, rodents chewing at the roots or even at the the trunk of the tree. But what's startling about this is that there's no rhyme or reason to the tree decline within a particular orchard.
And, we can't pinpointed to any particular event.
[00:13:45] Potential Causes and Research Directions
in the case in New York, they feel that their drought in 2016, I believe, was a tipping point as far as a stressor for them, and with these smaller root, these dwarfing root stocks, they require a lot of water. So if you aren't providing some kind of water through irrigation, that's a stressor.
that's a stressor you have to take into consideration. the, weird temperature swings that we've had during winter, that can be a stressor. there's not much you, there's, some things that you can do within your power to limit the effect of that fluctuation, such as, painting the trunks white.
That will help reflect the sunlight, so you wouldn't have that rapid freeze thaw that could happen during, the, winter season. but. As far as, the other thing is that, on semi dwarf rootstocks, we aren't seeing this issue. It's on young trees that are on dwarfing rootstocks, and particularly it seems to be M9.
and M9 has its own quirks that we know that has to be taking that into account when you have M9 trees and when you plant them too. we, got an email from Norm and Norm from Ontario asks, is there any cultivar rootstock combination that's more resistant to this?
That's a good question. We haven't seen drastic issues with Bud 9. it, doesn't seem to be the combination. per se, but it's the rootstock itself. Bud 9 is another dwarfing rootstock that seems to, we haven't had many reports of that. there are, the listeners are aware of Geneva rootstocks.
A lot of, nurseries are carrying Geneva rootstocks. we've had minimal, issues with Geneva rootstocks to date. but, With that said, M9 is one of the most popular rootstocks out there. So most likely why we're seeing what we're seeing is because of just the sheer volume of it. We've got an email from Steve from Detroit, Michigan.
Is there any known prevention for this yet?
[00:15:54] Preventative Measures and Grower Advice
the one thing that how we advise growers is when you are establishing an orchard, you need to make sure that you are putting its best foot forward as it's going into the ground. So number one, and even this can be for a homeowner too, is that check the nutrients in the soil.
Make sure things are balanced in the soil. make sure you have a water supply, that the trees aren't stressed in any way once it's planted. eliminating any kind of stressors whether it's disease or insects during the season. Tree stress seems to play some kind of role, even though we don't know what tree stress it is.
But there is a lot within, a growers power to minimize tree stress. So that is, water, painting the trunks to help reflect the sunlight during the winter. So you would eliminate tree stress. winter, limit winter injury, making sure you have balanced nutrients and you can test that in the soil.
You can also have leaf analysis done in the middle of the season, just a general overall health for disease and insect control too. We have one more idea here from Charlie. So Charlie says, what about completely sealing over the graft union?
Yeah, so the graft union is, there is, it's like a natural as far as how the plant heals over by itself. that's an interesting idea, but I'm not sure if it could potentially be coming from the outside, but we would have to test that experiment.
That's actually a really interesting idea. But here's the question that the one question that we still wrestle with is it is the tree already coming with it before once you buy that tree and you put it in your ground, is it already compromised? we don't know where this tree where we don't know where the issue begins.
Is it at the nursery, or does it start at the the grower, in a person's orchard once they plant it? but that's an interesting idea. I like that. I'll have to put that on my, thought list. That sounds fantastic. Yeah. It's interesting. I heard from, Kristy, from the Ontario Ministry of Food and Rural Affairs, and I said, okay, have you seen this?
so she wrote back, yes, we've been tracking R-A-D-S-A-D, so a rapid apple decline, sudden apple decline in Ontario orchards since 2016. She says mainly Gala M nine combination. So Gala apples on M9 root stock. But others too, she says, we have a national team of researchers looking at the fruit decline problem.
As we are also seeing this in stone fruit, stay tuned. Have you heard anything about that? About, with regards To the possibility that it's happening in peaches and apricots that could be something else. That's a whole other, that could easily be something else. But, I will say that in Pennsylvania back in the eighties, I think it was there was an unusual decline of stone fruit trees occurring in Pennsylvania, and they had a team of researchers they assembled and they determined that it wasn't any one causal factor, but that it was a multiple It was multiple factors that was causing the premature decline of trees. I hear reports here and there, as far as some declining stone fruit, and we have identified fungal organisms that were really specifically linked to that decline.
And one of the diseases is called Cytospora canker, that's Cytospora with a C, and that's, and that seems to have been prevalent in the area, especially after stressful years, stressful seasons. Okay, let's do one more email here from Stephen. let's see.
He's an orchard owner. Good afternoon. Is SAD, sudden apple decline, evident in many dwarfing rootstocks or a particular dwarfing rootstock like M9? Oops. I believe that's just been answered. Smiley. Okay. He continues to say also, is there any evidence of certain apple varieties?
being more susceptible to sudden apple decline. I wonder if the more vigorous apple varieties are more prone to SAD, perhaps due to the rootstock being unable to supply adequate nutrients to an apple variety that has a propensity to be vigorous. Perhaps this increases tree stress. And he says, thanks.
Yeah, that's an interesting idea. so I predominantly have seen it, I've seen it on a ton of different varieties, as far as Gala, Golden Delicious, Fuji, Crimson Crisp.
I don't know how familiar folks are with Crimson Crisp , Honeycrisp, there, there've been very few varieties that I have not observed it on, but that's actually a really interesting, observation. And I'd have to go back through the data that I've collected over the years to see if we, have seen any trends.
Because when we've looked at it, it just seems to be, it's, a ton of different varieties. Wow.
Before we dive into some, different research that's being done right now, I've got an email from Tommy. Tommy says, Hi, new listener from Youngstown, Alberta.
This is a very scary situation. Is there a reporting website or a telephone number to report on this if discovered in our orchards? I'm not aware of anything. I would recommend that whoever you work with, either if there is a consultant that you work with, that you let them know or keep them in the loop, and then in Canada, there are folks that are working on this in Canada, so it's a matter of basically getting in touch with them, I would say.
Yeah, definitely. In the United States, it's different. in the United States, what I would recommend, for people, if they, if there are, Folks that are in tree fruit growing regions, they would contact their local extension agent in their area who they interact with, or the university.
Find someone at the university that is working specifically on tree fruit diseases to put this on their radar. Yeah, I would think, I think it's a really good question because I would think it's important and especially We don't know if it's happening in backyard trees too, because most backyard growers don't have a relationship with somebody who is an expert that they can consult with, and they may have a tree that's dead, and they don't know why.
yeah, and so in the case of the backyard grower in the United States, you'd want to contact your master gardeners. that is, those are the extension volunteers that are trained to work with homeowners. so you would just contact your county, extension office and ask for the master gardeners.
And then hopefully they would be able to steer you in the right direction or at least find someone to help with you. And in the case of the backyard grower, what's so striking with this is that, you're dealing with, on a commercial level, so many trees in such a short period of time.
Where this may not show up in a backyard homeowner because. There you are controlling for so many more variables that you just are able to control than a commercial grower is in what sense, in the sense of, being able to keep your tree watered, making sure that you're, keeping the weeds around the soil free.
So you have limited competition for nutrients, most likely, hopefully, keeping an eye on for diseases and insect control and such. so I feel that like on a smaller scale, you'd be able to limit the tree stress much, I guess maybe the right word be more efficiently than when it's on a mass production scale when there could be variables that just are just beyond, may just be on the commercial growers' reach.
Yeah. It's really hard to inspect 10,000 trees Compared to three. it's not until you see like a swath Yes. Of declining trees that it catches your attention. That it catches your attention. Yeah. We've got an email from Getty who wonders, does warmer climate make things worse versus colder climates?
That's a good question, and I'm not sure if it, matters like warm or versus cold, but it would mean, I would think it'd be during the winter when you have the drastic swings. when we've had the quote unquote polar vortexes, for vortices, that have occurred the last several winters, where you could have 60 degree fluctuations in a 24 hour period.
Trees in general are very sensitive to that, and especially fruit trees. they can be very sensitive to that drastic swing. they like it when it gradually gets cold, it gets cold, it stays cold. It doesn't like those warm up temperatures. I would think that would be factoring in, as a potential stressor than whether it is a, I wanted to ask, and I know that you mentioned to me that there are people, researchers across North America, exploring different aspects of the disease.
Tell me a little bit about that. Are you guys on the phone to each other and saying, Okay, you do this, I'll do that? Like, how does that work? That's a, that's an excellent question. How we've landed on our own personal projects is based on what we have found at our location. So for instance, in Pennsylvania, we've discovered a new apple virus.
We have no idea what role, if any, this virus plays In the decline. And the reason we were able to find it is because of the technology that is available today. It's just there's very sophisticated tools that allow researchers to basically find a needle in a haystack and that weren't available 20, 25 years ago.
and so we've been working on a particular virus, trying to understand its role, surveying our orchards and surveying nurseries out in Washington state. They have found the Completely different new viruses and they are doing the same thing in North Carolina. They've noticed there's an insect, a wood boring insect that seems to be prevalent in these declining orchards and these wood boring insects.
They can bore tunnels in the tree and they carry fungi with them, and those fungi can clog up the tree, thereby choking it off and causing it to die. so they're, investigating the role of the fungi and also the role of the insects. But a caveat with that is that those insects are only attracted to stressed trees.
They're attracted to ethanol that's emitted to stressed trees. So then we go back to the question of What ultimately is stressing these trees out? so in New York, they're looking at the soil at that soil composition is the microbial community different in the soil, based on a healthy orchard versus, declining orchard.
And they have found that the soil community is virtually, I think, identical or near identical. And so they have felt that up there that it was mainly the drought in 2016. The stressful winters that we've had, but at the same time, they also realize that wasn't the complete story, that there are other factors that they wanted to explore.
Another area that no one's exploring yet, but that we want to look at is the role of herbicides. Unfortunately, herbicides are a necessary evil in the orchard. You don't want the trees competing with weeds underneath the trees for water and nutrients. And so herbicides are used in order to give the tree that leg up to make sure it's absorbing everything it possibly can in its space that it's, living in.
However, herbicides today are formulated such that they can be taken up by plants, weeds, very, well. And so there's, we do know that some herbicides can, when inadvertently taken up by, an apple tree can mess with their immune system. And make them susceptible to pathogens that normally aren't an issue when a tree is stressed.
there are a ton of different areas that are ripe for the picking with trying to investigate this problem.
[00:28:32] Concluding Thoughts and Resources
We have an email from Alice from Philadelphia. And Alice says, Hi Susan, wow, very important issue. Does your guest have any other information published online?
Thanks. I have several articles on the Penn State Extension website. So if you just Google Penn State Extension tree fruit rapid apple decline, I think my first article will pop up on the, internet search. so I've written extensively about that. And then, there are, a couple journal articles that are written about the new virus that we found and then the research that came out of Cornell.
But as far as a broad overview of this issue, the Penn State Extension article I think is the best bet because it gives a nice overview of what we've done, what we've explored, and other possibilities. And it's also good, isn't it, to look for pictures online. I think in my Facebook post I've put a bunch of your pictures so that we can recognize it when we see it and we know what it, if we have something else we can say no, that doesn't look the same, whatever problem I have in my tree doesn't look like this, right? And the important thing to note is that this does sound really scary. However, if you have a tree that's declining, we need to rule out, I always rule out a lot of things first before jumping in this area. And if homeowners have young trees, that they just planted and after a couple of years, they start to decline, you need to start asking questions like, was there any kind of damage, like physical damage by rabbits or moles or voles or any kind of rodent or you have to have a groundhog, in the yard?
the other thing is, was the tree stressed at any time with regards to water or nutrients or anything? Yeah. Yeah. in some cases, some, folks like to crop their trees sooner than they should, and that can stress out a tree, trees tend to put out blossoms early, but you don't want to crop them too soon because you can, that's a tree stressor.
So I think as well, I totally, that it all makes so much sense. I think for me. Familiarity with what the diseases that are out there is so important, especially for home growers. In my online course, I teach people to recognize the five or six or seven common diseases that you're going to get in fruit trees so that when they see them, they know exactly what it is and how to solve the problem. I think there's so much fear around my tree is sick. Oh my gosh, what is it? When you know what to expect and you know your tree is going to get sick at some point, just like your kid is going to get sick at some point and okay, it's the flu. This is how I deal with it. It's a cold.
This is how I deal with it. So I think as well, like just to be familiar with the problems that are out there. Once you know what's out there, you can deal with those little problems. Then when something big like this comes along, you say, whoa, okay, it's not that, it's not that, it's not that. Time to contact my local extension service to say, help.
What is this? Yeah. Yeah. And, it's because, in this case, when a tree declines, it's all, you automatically look at the root system or just at the crown of the tree. when a tree's declining, it has nothing to do with the top part of the tree. It's all either in the soil or at the crown.
And that's often like a misperception, like my tree is sick, but it's, the leaves are just the symptoms of what's going on down below. Down below, exactly. and it could be a soil borne pathogen, it could be, there's so many, there's so many options, let's put it that way, that could lead to a tree looking like that.
Elton writes, are there any nutrients that can be amended to reduce the stress on orchards? Any research on this? I love that question because, you go to different events to learn about all the miracle, put seaweed or fish essence or this or that and they'll make your tree stronger. So is there any, studies on what can actually build up their defenses against problems like this?
That's an excellent question. And since this, since this issue has come to light, nationally, internationally, I'm actually going to be doing some studies this summer on just that, of people, different products, synthetic, products, and also, biologically based products, that are made up of microbes, as far as maximizing what is in the soil, there is for the tree as far as, that's out of my wheelhouse.
I have to admit as far as knowing that information, but I do know that, there are people out there that are looking at what can we do to make the tree healthier and, making sure that nutrients are optimized. I don't have a quick answer right now, but I do know, I have a small portion that's working on it, and then I know, there's folks out there who probably can answer that better than I can.
once you do your research, we're going to get you back on the show to tell us what you find. We all want to know. Okay, can I talk about the elephant in the room right now? Do you see that elephant? I think so. Okay, there's a big elephant in this room right now, everybody. And the elephant is I want to put it out there.
I love orchards of all types. I love orchards with freestanding trees. I love these beautiful, new, high density orchards where trees are planted really close together, almost like grapevines. They're, It's supported by trellises, they're lower, so it's easy to harvest, to care for the trees, and one of my online courses, I teach people even how to prune and create a high density orchard.
I think it's a beautiful idea, but perhaps It is not good for trees because, on the one hand, we teach, make sure that your tree has enough room for its root systems to expand. don't plant it too close to your strawberry plants or whatever else you're going to put there. Give it space to grow.
And on the other hand, we're saying, and if you want a really big harvest, plant them three feet apart and let the roots fight it out. And that will prevent the tree from getting too tall and, it'll give you a great fruiting wall of delicious fruit on fabulous trees. Is the problem here that we are taking a square peg and putting it in a round hole, that we're taking trees that need lots of space and we're squishing them together and telling them to fight it out.
That is something that we have talked as like in the university community among horticulturists, pathologists, and entomologists. We've talked about that a lot as far as that, How we grow trees could be having an impact. However, with that said, we also feel something may have changed in the last 15 years where it seems that rootstocks may be more susceptible to not being able to weather those stressors.
because it just seems like, when I've talked to folks that have been in the industry forever, they've never seen anything like this. yes, in the sense of that we definitely are stressing, that is a man made stress of expecting the tree to do a lot in a small area. But at the same time is that has something changed in our production system, i. e. at the nursery, and growing trees, has something changed there? that is Basically setting things up for downfall in the orchard. We don't know. We really don't know. Wow.
Oh my gosh, so Kari, Sudden Apple Decline, you said it's not an apple apocalypse. I don't believe it is. You don't believe it is, but you can see how, it's scary. And I'm just curious, what kind of damage, what kind of expense is this causing some orchardists?
the grower who I first experienced this with several years ago, who I realized this looks a lot like mine, he's lost more than 200, 000 U. S. dollars as a result of this, and that is the removal, the replacement, the labor all involved with regards to, I think it's about 15 or 20 acres that he had that's also not taking into consideration of the revenue loss that he has occurred because he missed those years of being able to get fruit from that acreage.
so for, some growers, it's been extraordinarily costly. and other growers, they end up, they cut their losses sooner rather than later. They'll, remove an apple block, sooner than they want to just because this isn't worth it. I've lost 20 percent of my trees, so I'm just going to start over.
it becomes a hardship for, some growers, unfortunately, many growers, they're diversified enough where they're able to absorb a hit. and now in the United States, the USDA has a tree assistant program for woody perennials like for grapes and apple fruit trees that are hit with either natural disaster or disease or, unknown.
And in the case, I have a grower in Adams County, Pennsylvania, who is able to, who took advantage of this tree assistant program. To get compensated for the 20 percent loss of trees that he experienced in his one orchard as a result of this. So there does seem to be a safety net in the United States for folks with this tree assistant program.
That is a part of the USDA farm bill, which is very fortunate. And I've worked hard with the farm service agency to make sure that this mystery issue gets recognized, and I'm happy to say that they do recognize it. Oh, that's excellent. We have an email from Brad. Brad says, great show, listening from Honolulu, Hawaii, hoping this does not cross contaminate our pineapple crop.
So let's hope not. Oh my goodness. I hope not, no. I think this does seem to be something weird exclusive with apples right now, but, pineapple can get their own issues too, plant diseases and plant issues are, there are no boundaries with them, Yeah, they don't behave, that's for sure, sometimes they don't behave. Now, if a grower has lost a block of trees, they've, dug them out, whatever, got rid of them, should they replant in the same place? Could the disease or whatever it is still be in the soil or would that be not recommended?
first the grower would have to determine if the trees were declining to a non soil borne issue. If it's, so that should be confirmed right up front. If the trees are declining by, if it's a soil borne issue, meaning if the roots are dying. if the roots aren't dying in this case, if it's one of these mysterious decline issues, they could replant.
typically what I recommend growers is for good management practices, plant in your grassy middles, the row, the grassy row middles. so just as, just as, that's just part of good management practices. We don't believe it's anything with this decline issue, and if a grower would experience this, and it's their graft units collapsing, their roots are healthy, we don't believe there's anything in the soil that would limit the production of the next tree that's to be planted.
That's good to know. Now, also other recommendations. How can growers protect themselves from this disease? Now, we know it affects M9, which is a rootstock that's a dwarfing rootstock developed in England, is it not? Yeah, it's a very old rootstock. it's been around for over 100 years, and it's a very popular rootstock, too.
So it's been around for 100 years. This is a new problem. Should we be avoiding M9? I hate to say it, but it may be a good idea for now to limit acreage, new acreage with M9 just because we just don't know and I'm nervous to recommend anything other than that just because, there's so much we don't know.
If growers do have, say they have an order of M9, a bunch of trees, on order and they're coming. I have M9 trees, I'm still planting M9. but the big thing is that when they go into the ground, it's a really good idea to make sure you limit the stress. and M9 are, they're really prone to winter injury because the graft union seems to be, Late in going in hardening off and going into dormancy. So when a tree goes into dormancy, it hardens itself off to whether the winter coming and the graft gene area is the last place to harden itself off and M9 seems to be slow. So one thing is, just keeping an eye on. And, doing those preventative practices of painting the trunks white or having white guards that reflect, reflect the sunlight so you would limit that damage that could occur during in the middle of the winter.
making sure that you have, if you don't have irrigation and you do have issues with drought, invest in irrigation, doing soil tests to make sure that your nutrients are correct. the Northeast has experienced a tremendous amount of rain. over the last year. And I know other parts of the country has this year.
You can get soil leaching or nutrient leaching as a result of all that rain. So it really behooves people to make sure they know where their soil nutrients stand. again, controlling for diseases and insects, not letting anything go, not stretching spray intervals. so a lot of there's a lot of within the grower or the backyard homeowners within their power to limit stress.
Exactly, yeah, that sounds, like good advice.
[00:42:44] Final Remarks and Show Wrap-Up
And I want to thank you, Kari, so much for spending this time with me on the show today.
Thank you so much for having me. I really appreciate being able to shed some light on this issue. Oh, that's wonderful. goodbye for now. We'll talk to you again. Okay, goodbye. You take care. Bye. That was Kari Peter, PhD, Assistant Research Professor of Tree Fruit Pathology at the Penn State Fruit Research and Extension Center.
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This is Reality Radio 101, and I'm Susan Poizner from the fruit tree care training website, orchardpeople. com. Thank you so much for tuning in, and I look forward to digging into a new fruit tree care topic with you next month.
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