Key Insect Pests and Diseases of Tree Fruits
March 22, 2022
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Video Transcript
Today we're gonna be talking about tree fruit insects and tree fruit diseases and we're going to be talking about, key pests and diseases of tree fruit. And to kick this all off, we have the lovely Amy Irish Brown back again to teach us all about tree fruit. So we will let Amy take it away. Okay. Thank you, Cheyenne. So it's a challenge to teach you all the different tree fruit pest insect problems. In the 20 or so minutes that I am given because I have to share my time with Bill to do equally a difficult job, talk about all the diseases. but I'm going to give it my best. So here we go. Maybe there. Okay. So I'm going to divide up the talk into what I see is the two major ways that different insect pest attack or have impact on our fruit trees. So apples, cherries, peaches, plums, apricots, nectarines. Those that feed directly on our pests, are on our fruit. Because then they're competing with us, right, for the fruit that we're trying to grow. And then the pests that feed on foliage and wood or indirect pests. So maybe they're not quite as devastating. However, they still need to be managed. And then there's some of them of course, that feed on both our our direct feeding and indirect feeding. So I'm going to take it away that way. So let's talk about the major things that are our insect problems. And I have this little chart. Let me get this out of the way here. I have the chat in my way I can't see my own screen. This is actually from a master gardener curriculum that we teach, but it's here in a table. I don't think you can find it anywhere. It doesn't. I suppose we could share it with people afterwards if they want it, but it just shows you that there are, first of all, it shows you there are a lot of pests. This is just all the pests, common pests of apples. So there's what, 12, 15 of them listed here in this table or this column it shows us if they're direct or indirect. And as I mentioned, some of them are both. Aphids can feed on foliage or cause damage to foliage. I mean, yea to foliage and wood and they can also cause damage to fruit, same with Oriental Fruit Moth. So I'm going to go through those. Here. I have two screens, sorry, I'm confusing myself. Okay. So direct fruit pest are those of course that feed right on our fruit and nobody wants to eat cherries that have this going on. A lot of times some of these insects aren't problems. They can be in the orchard, but they're not a problem until the fruits developed or close to harvest. of course They want that nice sweet goodness as well. But it can be very hard, of course, to ignore any damage directly to, to fruit, but you still need to make sure you're instilling all those things. Hopefully, you were on yesterday and heard Mike and I talking about how proper id's important to make sure that you're calling it the right pest so that if you get to the situation for future years, you can instill the proper type of control so to avoid it in the future. So some of those direct fruit pests are listed here. I'm going to go through each one of them individually quickly. These are the big highlights. The plum curculio, there's plant bugs, there's codling moth and Oriental Fruit Moth, which are moth Lepidoptera pests, various types of fruit flies that can attack various routes. And then there's some leaf rollers as well. So lots of different pests from lots of different families of insects to deal with as well. And then our indirect pests are aphids and pear psylla, San jose scale that can also get on the fruit as well. Leaf rollers, Japanese beetle can also feed on fruit and leaves and the boar type of pass. So I'll start with Aphids. There are tiny insects and aphids are interesting group of insects they have, there's a lot of different aphids. A lot of them feed very specifically on certain plants. So woolly apple aphid that's on Apple, really doesn't feed on too many other things it might go into some forest trees, but is pretty specific to apples. Whereas there's other aphids that might feed on other plants in your yard and garden. And they're not necessarily going to move to your apples or peaches. So they do have some specificity. With their host plant as well. So that's okay. They suck the sap out of plants so you can see them all over the back side of this leaf. They oftentime around the backside of the leaves. And some of the aphids have alternate hosts which is kind of important for you to understand that maybe if you eliminate that alternate host, they perhaps can't totally complete their life cycle and that will make them less likely to be on your fruit plant. Although that's not an absolute way to manage them, but it's something to consider. This is taken from an apple tree a few years ago. So you see all these little aphids feeding on. They like to tuck in you know next to the midrib because they're feeding on the cambium tissue of the, the leaves. And what are these guys? These are surfeit fly larvae. So hover flies are the adults they are those little tiny black and yellow stripe bodied flies, they usually have kind of golden color wings. These are the immatures of the larvae and they love to eat aphids. So when we monitor for aphids, we also monitor for the potential for beneficials. This is a pretty good population of aphids however, though, so I don't know that these beneficials could eat them all in order to clean them up, but they certainly are trying their best. I think. The next one is apple maggot, and is pretty specific to apples. There are other different maggot flies for cherries and I'm sure the small fruit people who will talk about blueberry maggot tomorrow. But it makes the affected apples look kind of lumpy and it is a fly. I have a picture next of the adult, but this is the immature. So it looks like any, the imagery looks like any other fly maggot. You might get an unfiltered garbage or something like that too. They all kind of look the same nondescript little pieces of rice with some mouthparts on one end. So they're extremely difficult to identify. But if you pull them out of an apple, it's pretty likely they are apple maggot. So they come in early in or in the summertime. They're one of the later pest, they emerge after typically after a rain in July and August. They fly around for a couple of weeks and then they lay eggs, and the eggs hatch under the skin and immediately start boaring in and around the flesh. They do what we call railroading. Where they'll feed all around through the flesh as opposed to some of the other moth pests that will go right for the seeds. So if you see Apple's near harvest that looked lumpy like this, it could be other things, but the first thing you want to do is cut it open and look for this railroading. So since the adults lay eggs and the eggs are underneath the surface of the skin of the apple. Once they're inside like that, it's very difficult, almost impossible to manage them. So you're looking for the adult fly. There's a lot of different regality flies. And they all have different cool patterns on their wings. So apple maggot has what looks like on its wings that we will also look for this white spot, the striped abdomen and other features to identify it on say a trap if you're using a sticky trap to to monitor for this pest. So here's a better picture of what that railroading looks like. I'll eat just about anything but I'm not going to eat that after, oh that looks disgusting. So it's oftentimes a problem at backyard trees where there's very little spray management going on and this insect can do quite a bit of damage, is probably just one or two maggots in each, in this fruit doing all that damage. They have one flight per year. I like this old graphic from it's from an old resource we have but doesn't change really. One big major flight per year might come in a couple, like a little BP care, but so the management period is about a month long to make sure you stay ahead of this pest. And I mentioned the red sticky spheres. Those are used for many of the maggots that, or a yellow to keyboard. And they have this little attractant lurers on them. There are apple essence. There's lots of different kinds of lurers that you can add to these traps. But basically you're using what the insect uses. Identifying yellow is commonly used in traps because insects are attracted to sick plants are plants that are off color. And so yellow is something that attracts them. Usually you'll catch the first flies on the yellow traps, on the red spheres. It looks like an apple, a ripe apple which they would want to lay eggs in. And usually you catch those more adult, more mature adults on those red spheres. And lots of things will stick to those. It's not just specific to apple maggots, so you really have to dig through the goo and make sure you can figure out exactly what's going on and identify them correctly because you will Collect a lot of things, bees and and lots of nats and other flying things, leaves, anything that blows in the wind will get stuck on the sticky traps. So they're not just only going to catch the insect you're looking for, but they do help you tell when it's flying and then you would instill your spray program after you start catching them. Because why would you want to spray before that if they're not out in the active yet. So that's using the IPM techniques that we talked about yesterday. There are, as I mentioned, some fruit flies, other species that will get in cherry, there's two species, Eastern and black cherry fruit fly. Again, the immature is a maggot, kind of nondescript. Much easier to identify. The adults with their wing patterns. You can see these are a little bit different than each other and different than the apple maggot as well. Pretty much same general life cycle. They emerge typically after rain and this with these could come out a little bit earlier, maybe late June, early July. And typically when the food start to color as cherries do in July is when their time very nicely to emerge and start laying eggs in them. Same management practices to target the adults. Codling moth is the proverbial worm in the apple that gets depicted in cartoons and whatnot. And this is the adult down here in the bottom right. Fairly descriptive. If you hang a trap out and put a pheromone in, you will attract this moth but you might actually get a few others and then miscellaneous things. that just start flying around. But it has this pretty copper band at the end of its wings. So pretty descriptive to be able to distinguish from anything else that might be stuck in a trap as well. This insect lays its eggs on the surface of the fruit, the eggs hatch and the little tiny larvae start to bore in within a few days. And then they feed around inside the fruit and different from the apple maggot, they go straight for the seeds. The seeds are protein source that they're seeking out. Whereas remember that apple maggot kinda went all around throughout the flesh of the fruit, seeking a different fruit source. Food source. So we'll see these holes or you might see this off what we call frass, which is just insect droppings pushing out of the hole. Pretty good sign that if you cut that open carefully, you'll be able to find perhaps some of these codling moth larvae. This one's really dark red. They are typically more of a cream color with a dark brown head capsule. That's that frass that pushes out the side of the apple. It could also be Oriental Fruit Moth It could also be less of apple worm a few things, but often times it's probably moth There are two flights, generations and two flights for codling moth. there's always a possibility of a third-generation. Don't often see that here in Michigan actually over 30 years. I've been working here. I've only seen it a couple of times. So pretty much two flights and they both need to be managed. Ideally, you would manage the first-generation really well so that there would be less eggs in the or I'm sorry, less larvae that develop into laws for the second-generation. Japanese beetle is a late season pest for us, but usually comes out, rain usually triggers it they overwinter in the soil as grubs. Then they emerge as adults, usually in late July and August, and they feed on foliage indirectly, but they also can feed on fruit. In some cases, particularly summer fruits and not so much apples. So you can trap for them to tell you when they're there. Although some of the Japanese beetle traps that we use have aggregation pheromones in them so they actually attract beetles from everywhere else. So you might actually bring more beetles to your backyard or your situation than if you hadn't put any trap up. So keep that in mind. Maybe hang the trap far away from where your trees are, that you attract them almost away from your susceptible host. There are a whole host of leaf rollers. The most common one is oblique candidly for I have a picture of that coming up next, but different kinds and they do just what they say they do. They feed the web and they roll up leaves together. If they are near a fruit, apples, peaches, they could be problems in many of our tree fruits. They, they attach that leaf right to the side of the fruit and they'll make a nice little home and they're just feet away on the fruit. And once they are stuck under there. They're really hard to manage because they're covered up and protected from any predators or any spray materials you might be applying. So they have two kinds, two broken up generations. So they'll come out as small larvae that spring. They'll mature into adults, fly, lay eggs and then have another set of larvae in the fall, which becomes this spring larvae for next year. But this is a good close-up of what An oblique banded leafroller it looks like there are tree fruit leaf rollers, variegated leaf rollers and red banded the rollers. Lots of different kinds of this one seems to be the most prevalent. Of all of them. There's Oriental Fruit Moth is most of the time a peach pest, but it can also take Apple's, particularly things that Apple's that aren't really highly managed in a spray program. So oriental fruit moth comes out very early and it attacks the early growing shoots, which can be a problem. in peaches, because peaches, your future crops are based on the shoots that grow. So this year's shoots will become next year's fruits. So if something's attacking this year shoots In the logic, you would have less fruits for next year. So first generation will attack the little growing shoots, the later generations. And there can be several generations of this pests and they kinda come out through the season and they start to overlap by the time we get later in the season. They can attack the peaches and causes very similar pushing out frass like in the codling moth picture that I showed earlier. But anytime you hurt peaches, they get this nice little gummy sap. So you'll see this done most as well. But in Apple's, occasionally they can be a problem. So this is Oriental Fruit Moth and apples. It can be very difficult to distinguish between the two. So you probably, when I asked an extension educator and entomologists for help and that very specific identification to make sure that you're having the right control program for the right pest. Oh, I didn't realize I had this in here. So this is that very specific reason. This is the backend business of our Oriental Fruit Moth. And it has what we call an anal comb. It uses it to flick feces off the back and keep itself clean. And so it can be, we use that feature to identify the difference between codling moth and OFM. That's way more science than I planned on sharing today. So in peaches, as I mentioned, it can attack the shoots and it bores down inside the shoot. So when you see this, you could use and really carefully with a sharp knife and cut it away. And you might see the little larvae feeding in there. And then it's, like I said, gets in the fruits as well, making them unmarketable. There are different types of Borers pests, so there's two different types of peach tree boars that it can attack all the stone fruits. And they attack not the fruits. They attack the tree itself and can weaken the tree, make it more susceptibility to winter injury and other diseases and conquers. There's another borer called a plump American plum borer as well. That can be a problem in all the different stone fruits. And then there's some Plum Curculio this is a beetle. Then it winter, stays here in the winter as an adult. And it attacks almost all of the tree fruits that we grow here in Michigan. So the adults come out and they lay their eggs on the tiny developing fruits soon after bloom or even, even during bloom, just depending on the growing season. And with the stone fruits, you know, after bloom and when the shock around the flower breaks open and susceptible to plum curculio And its larval form is a little grub that can develop inside the fruit and then they dropped down and then the whole thing starts over for next year. In apples they make this little crescent shaped scar. They basically, the female cuts a little flap, will their ovipositor so that she can lay an egg underneath that. And then as the fruit develops, that little flap kind of stretches out and you get these kind of half-moon shape scars on Apple's. It is very common to find these in orchards that are not managed well. There. They pretty much go hand in hand with apples and they particularly are worse along edges like wood lots. They like to go into the woodlot and hang out there for the winter and leaf litter and whatnot. And so when they start moving back into your, your crops, they, they tend to do that, of course, along the edges of a field rather than internal. There are some different types of scale insects. The most common one in our tree fruits here in Michigan at San Jose scale. So all these little dots, on here, are scale insects. And there they are permanent. They can attach themselves to the limbs or even on the fruit. And they suck on SAP from underneath that little shell. And they're really protected by that shell too, from pesticides that you might apply. So it's very specific management that needs to be done. It really should start with dormant oil sprays. Pretty soon here in Michigan we'll be doing those to help suffocate those scales and reduce their number before the season even starts. So if you get them on your fruit, there can be two generations of San Jose scale in a season. So the late season ones are actually, we think maybe there might even be a third generation now with longer hotter summers that we're having. And so you can see all these little white spots. They turn kind of dark gray as they solidify and, and build. They start out as little crawlers, little tiny, tiny insects, and then develop a permanent spot on the fruit. So that would be unmarketable for fresh. Obviously, the Apple responds by turning and a red color around the little scale as it starts to form. If you see this on your fruit, that means you really need to have some kind of management program moving forward for the next year. Or it's just going to continue to get worse. This, the scale that as it feeds on the stems of the plant, it reduces carbohydrates in the trees and can make them more susceptible to winter injury, particularly stone fruits. It can hurt them enough that they'll actually get some winter kill. If, if these populations aren't managed. We have a couple of different kinds of mites in our tree. Fruit crops, european red mite, it's red the eggs are red as well. And then we have a spider mite two spotted spider mite, and their eggs are more clear, light green color. This might be an actual red mite I'm not sure. But two spotted, pretty easy to say, to identify has two spots. And they cause bronzing as they, as they feed on the sap, they take the chlorophyll out, they feed on that. They kind of make the leaves turn off color bronzing as well. So this is a healthy leaf and shoot here. And then these, this is one that's infested with red mites. I like to call this one the 55 mile an hour insect to identify. In a commercial orchard, you can usually tell when it gets this bad. You can tell this by driving by, that there's a red mite problem there. the two spider mites don't usually cause the bronzing, but they still can make the leaves look kind of dull We have tarnished plant bug. This pest is that feeds on a lot of different plants, tree fruits and vegetables, flowers. When it's in our tree fruits. This is an example of Apple's. When they're really tiny and small like right at petal fall, the fruits just starting to develop, they might come along and sting it with its mouth parts. It injects attacks and back in and kills the immediate cells and tissue right there so that it dies. And then as the apple grows, it creates this kind of funnel around it. So the dead tissues way down there inside, but the Apple continues to expand around it. Sometimes a fruit will abort and fall off. Sometimes it stays on. And this happens in peaches. Similar damage it causes sometimes what we call cat facing. Same in strawberries. I'm sure they'll talk about that tomorrow. in small fruits as well. This is the adult tarnished plant bug. They feed on a lot of different things, weeds, they, they have a huge host range. which can make them. They're kinda ubiquitous in the landscape. They're everywhere and they build up in numbers and start attacking your fruit. They probably need to be managed. And then new insect to deal with this brown marmorated stink bug. This picture look huge. In our apples. They will sting fruit. And oftentimes you get a nice line of damage like this where you can just imagine that bug was walking and it stuck its beak in here and moved a little further and stuck it's beak in and you can just see that one bug probably did all that damage, or it can be more random like this apple. It's a really large insect. As a lot of the stink bugs are. Unfortunately that means it requires sometimes some big guns when it comes to pesticide management. Just because of its sheer size, it is a little bit harder to control. There are some neat new things with them. Some natural enemies that are being introduced and found in populations that maybe will help keep this one and check that. Often happens when something is an invasive species, it's not native here. So just the bug comes, but none of its normal natural enemies come with it. And eventually Mother Nature catches up to things, but sometimes that takes time and that the meantime, you get damage like this in this case was quite severe. So I might have mentioned beneficial insects off and on as we've been going here. And they're certainly not to be excluded. They're very important. Of course, bees are very important for our fruit crops, fruit vegetables because we need them to pollinate our crop. So anytime you're doing any kind of management of your pest, you do need to be considerate of when bees are there and what activity are they doing. So there are beneficial in that way. And then there's beneficials that are predators that feed on other insects. And we're always trying to manage our pest, our pest while also conserving beneficial. So it becomes a balancing game, which I think we talked more about yesterday. When we discussed IPM. Just quickly. Lady bugs, you guys know what those are. If you need some, I have hundreds of them on my Windows at home must have been a good year for ladybugs to come in the house last year. But they're very easily recognized There are mites, there are Cretaceous mites that feed on those, like the red mites and the two spotted spider mites. They require a hand lens or, you know, this is all happening in a very tiny level. But in good IPM programs and tree fruit, we do monitor for Cretaceous mites and if they're present, we maybe we'll hold off on, miticide application to see if those predator mites can catch up with the population and manage it on their own and we avoid a pest, a pesticide application. I've seen that happen many times. I've also seen when a pesticide application is disruptive to the pernicious mites and then the, the destructive mites kind of explode and that, that does happen as well, that rebound effect. This is the surf fly larvae, a different species than the one I showed earlier that was in the aphids. So they just look like a little slugged their hymenoptera larvae, so kind of like omega, but they are a little bit different with a little more features. And if you ever get to see one in some aphids, just unless you're a nerd like me, maybe spend some time watching them. They will actually play with their food. They like to throw the aphids around. They are kind of cool. So just to end things here because I ran out of time, there are lots of different pests. So we have to have some type of a management program to be thinking ahead of how we're going to deal with these. So here we are dormant. So maybe your horticultural oils, they're good for scales and mites and parasola and pear, leaf blister mites. We didn't talk about those, but and then bill's going to talk about the diseases and how much preventative applications I think we probably need to do for that. But you can see there's a routiness to. This is POME fruits, so this is mainly for apples and pears. We talk about the stages. Half-inch green pre pink, pink bloom petal fall first cover. And that's what the pictures here depict. So dormant's where we are right now. Silver tip. When we start seeing a little bit of silver, the bud scale start to pull open a little bit and you see a little silver tip. We don't have to make it hard to come up with these names. Green tip is when the green tissue starts showing and that's when the game really starts, right? Because if there's green tissue, they're insects can feed on it. Diseases can land on it. Half-inch green, tight cluster, pink, bloom. We don't spray any insecticides during bloom. And then petal fall is a key timing. You'll see in a lot of spray programs because that's just before the little fruit starts to develop. And this is what we're protecting, right Once a little fruits are there, all those direct feeding pests will start going for it. So you need to stay on top of it. I'm going to skip ahead to the end because the other one was just a stone fruit table t'is basically the same thing. So went a little long, sorry. That's okay. We learned so much, lots of awesome information. I think that a couple of questions that we might be able to talk about, we'll wait to the end. Okay Because and then worst-case scenario, you don't get to the shorter ones. We'll talk about them on Friday. And with that, Bill, are you ready? Yes, indeed. So now we are going to have Bill Shane talk, He's based at swim rock and he is the Tree Fruit Specialist for South west Michigan. As your position. Excellent, he's great take it away Bill well Amy did an excellent job and so she's a hard act to follow. a really deep level of understanding. I'm going to take a slightly different attack for talking about the key, key diseases. I'm going to integrate the discussion of what disease is like with the control as we go along. And because quite often when I talk to folks about this very flip side of the very next breath, It's okay, what do I do about it? So I'm going to use that approach a little bit different, but hopefully that will be okay. Maybe see if I can get this going. Okay. And I want to move the screen out of the way. With diseases, as many of you know that had been dealing with them. There's a lot of factors that affect whether a disease is a problem under crop. Things like the variety that we know that varieties have different disease susceptibility. The site and surrounding make a big difference. Soil, if the soil borne pathogen. The woods can be an important source of diseases. If you have wild whole set harbor similar type of diseases, they can really make a difference. We see this with virus diseases, some of the, the rod organisms and also that that's surrounding the woods can make a difference on how accessible the orchard is to wind and wind blown sand, can change humidity. We often find that, say, powdery mildew is more of a problem close to woods. And we also know that weather can make a big difference as far as the pathogen is concerned. So it's with insects. if it's warm enough and you have a host, there, we figured then we have to protect against insect. But with diseases it gets a little bit more complicated. Okay, So I'm going to use a strange analogy for those you that may remember stadium checkers game that was popular quite few years ago. And hanging in with the stadium checkers was a game that you had colored marbles. Say that you were the blue marbles and that is, this game. Board is shaped like a bowl. And so the marbles would move to the middle if there was a slot that allowed them to move. And so your strategy and your turn was to move one of the rings. And that would allow if you chose it right, your marble to move to the next level. And this, to me is this disease is sort of like stadium checkers. And with a pathogen you have to have a pathogen that is virulent. A tough pathogen, need to have a plant that is susceptible, need to have the environment, the weather has to be there, the humidity and the moisture. And there has to be sufficient time for all the marbles to move to the center and get that disease situation. So it's, it's one of those things that I use that concept to. It's all got to work in order for have you have disease. And disease is more the exception than the rule, meaning that there are a lot of things that keep disease from being a problem. And when you have disease then it's because things happen to line up. And I, my approach for reason for mentioning that is that when we start looking at the diseases, we, we kinda sort through our minds trying to figure out, well okay what diseases are there and what can we do about it? And so I have listed quite a few apples diseases here. And the way that I like to think about it is, first of all, is a particular disease a serious problem for Apple's? Apple scab definitely can be a serious problem. However, may not be a problem if you have resistant variety. So if you haven't planted your trees, then you could say, well if this, I don't want to spray much, so I can use resistant right as long as I'm happy of eating that variety. But if you say okay, you know what, I have a susceptible variety out there, then the next question is, well, is there anything that you can do about practical chemical controls? And you'd say, Oh yes. And then the next question is, okay, how much do I need to scrape? So then you might be daunted, particularly if your backyard situation say, I'm not willing to put in 10 sprays here. So then you start dialing down the numbers to what you're comfortable with or maybe wouldn't sprayed at all. So you have that same type of mentality for the other diseases. Is it a problem with the varieties I have And if it is not a problem, you're up, okay But if it is a problem in your varieties and either chemical controls and then number of sprays. So that's kind of a strategy mentally that you breakthrough and it takes experience over time for you to know what disease to worry about on a particular host that you have in your situation. And with apples of some kind of the big four here that we will see Apple scab again is probably the biggest issue. Powdery mildew is another one, sooty blotch and flyspeck and rust And all these differ depending on your situation with Apple scab. It's what I consider a serious disease. Not only does it hit the leaves, but it also hits the fruit, it is powdery mildew will hit leaves, but the damage that it does to fruit is much less, is more of a netting effect. The effect of it on the leaves can suppress the tree growth if it's really significant, particularly on a young tree, it can inhibit the development of that tree from getting the full size if it keeps on going year to year. Sodium Blache advice back showing the little dots here, this fly spec, this city blotch and scab, similar to what you saw up above. That's more of an action organism that lives on the wax of fruit. So if you put a croquet ball covered with a wax in your orchard, it can get sooty blotchy and flyspeck And what it does is it reduces the the moisture barrier that the wax provides. And so if you put this food into storage, the fruit will shrivel faster and it's something that commercial growers don't like. Rust is a disease is somewhat spectacular. It has a kind of an orange color to it. And it really takes a lot of spots per lead for it to have an impact. My rough rule of thumb is that you have to have at least 30 percent of the leaf area covered by spots before you will see a significant problem. And, but it does affect the fruit, so it can be an issue there. And so you have to, when you're thinking over the plant disease, you have to think, well, is it enough damage for me to worry about spraying for commercial guys have to keep the fruit clean. But some of these other diseases, if you have a less lower standards than you might be able to live with it. Back to Apple scab as an example, a kind of a classic disease. It's, there are, as I mentioned, scab resistant varieties that you can use. The, the particular thing with Apple scab is that it overwinters on the leaves underneath the tree. And in the springtime, when you have enough heat units develop the, the little there's a little ejection structures in the leaves that under wet conditions will shoot the spores into the tree and starting the infection. This is the ascus spores. that can start it in the tree and then once it's established it gets the spots on the leaves or the fruit than they produce another batch of spores, the committee of the summer spore and they can keep the disease going. So the strategy is trying to keep the powdery mildew off of the the leaves and now blossoms to begin with. And so that's if you really do a thorough job that's starting at that half inch screen that Amy was talking about. You apply fungicides every 10 days until about three weeks after pedal pop, which is why those commercial guys put on so many sprays. And so what you're trying to do is, again, prevent that initial establishment on the leaves. If you're successful with doing that, then you don't have to worry about the summer spores all that much. So that's a classic disease. And what can you do besides spraying Partial helps is to attack the leaves underneath the tree so that they can't produce the spores in the springtime. This is hard to do and you really don't do a can't really do a thorough job of there's so many leads and so forth. Spraying a foliar urea, which is a nitrogen fertilizer to help the leaf decompose. There's some effect of shredding the leaves on the litter. But as you can imagine, with all the leaves, it's only a partial chop. The commercial organic guys will do it because it's sometimes the organic guys are looking for any help that they can get. Back to the apple susceptibility to scab. There's a huge range of susceptibility to it. And so, depending on the varieties that you grow, you can have an easier time or a harder time controlling it. You know, the Macintoshes are notorious for having a lot of scab, but a lot of commercial varieties are in the middle case that will require a fungicide sprays depending on how much disease carry over to be shared. There are a group of women that have less susceptibility, honey crisp. And surprisingly one that has pretty good scab resistance is not immune, but you can certainly get by with a lot less space if you grow that one If you want to go even more stringent scab resistance. There are these scab resistant varieties. Over time. Some of these may develop more and more scab. That sometimes suggested that putting one or two sprays of scab, fungicide for scab is a good idea. It helps slow down the development, natural development of strains of scab been more resistant. But again, there's some fairly nice quality apples that you may want to consider. And so. We'll have recordings of this talk later so you can go back and look at it and you can find this type of information online as well. So a little bit more on powdery mildew. I mentioned the damage on the fruit. It is a little bit different than scab and that it over winters in the buds. So when the buds open up in the spring time, it will have this kind of a powdered look to them where the name comes from and the spores move from that. The spores that you see here on the left to the foliage. And then from there, they will affect that the developing fruit. And so you do get secondary spread if it's not, you don't protect the leaves. Here. Another thing about powdery mildew, that's a little bit different than scab. It does have a higher optimum temperature is in the 60 to 80 degree range. Whereas scab can get going, it actually can develop when the temperatures are in the 30s up to about 70 degrees. And so that makes a difference. And when you control these types of diseases. Also similar to scab with apples, there is a range of susceptibility to powdery mildew. So it's sometimes hard to get the variety that has resistance to all the diseases you might control. Plus being good tasting. And, and sometimes that's the compromise that you have to work out for these scab resistant ones that I mentioned before. You can see that the ratings for our four different diseases are given. Here. You can see these are kind of uniformly resistance. There is some difference. There is, there's some like liberty has a little bit more, more than one source of resistance. But if you look across some of the other that seizes that one's indicated in yellow here that are kind of a, an Achilles heel for that, For example, crimson crisp which is really nice apple, but it does get powdery mildew and it's susceptible to a bacterial disease, fire blight and cedar Apple rust. So you need to do a little bit of work to find out what are the good and bad parts of all of these apples. Amy mentioned the growth stages in apples, which is a good way for us to, to keep track of where are the susceptibility of the tree is at any given time. This is because each year is different as far as how quick things warm up. And so you can't really control where the calendar spray you have to do it with growth stage. Otherwise you may be completely off as far as the timing. This is a diagram that we use sometimes to indicate looking over the season as a whole for when you might want to spray things, you can get these types of things in our online. We do have a fruit Management Guide E154 that has these type of diagrams. So this gives you information at a glance at when the control windows here indicated by the dark red here, are generally occur by month this April and May and more or less the growth stage, etc, associated with this. and if you wanted to figure it out in terms of heat units there are the degree days as well. So this shows you with Apple scab starts pretty early where it, just when you start having a look at green tissue, you could have potential for infection and it kind of teeters out here. Shortly after bloom. If you did a good job controlling it. Powdery mildew. Again, it's a warmer Disease you can Control that one started in around pink shortly before bloom. And cedar Apple rust is one that is kind of of Dust started about the same time as the powdery mildew. Fire blight is a bacterial disease that really zeros in on bloom on, on tree fruit. And so that's why the window for that is there and other diseases that I won't have time to discuss. If you look at later in the season, this is June, July, and August, you can see the window or things that you need to be concerned about changes. Apple scab is, again, hopefully to control it early, you don't have to worry about it in the summer months, powdery mildew, that this one slows down once the once the tree gets to the point where it's really stopped growing, It's terminal growth. And the Apple develops a little bit more resistance as Apple's get bigger and more mature. sooty blotch and flyspeck, that one I mentioned earlier, we start worrying about that one First of all, you need Fruit, be infected. So you have to be far enough out passed bloomed, to have fruit out there, but also there's a certain stage of the spores that develop on brambles and things like that. And it takes a while for them to kind of build up and be there and sufficient levels to cause problems on the fruit. So that's how the timing goes with these. So. So I wanted to spend a little bit of time talking about fungicides because you need to, I think, have a bit of a sense of how they can use what to expect out of them to be able to apply that to this, while you know, the control window. So what do you do Fungicides in general, you can think of those as providing seven to 10 days of good control. the day after that point, they start to weather away. It can get washed off. The duration that we have is less under rainy conditions it makes sense, that's being wash off the surface. And also if the tree is growing rapidly, the new tissue or may not be covered with the fungicide there is a little bit of redistribution, but that's not real great. There are two major classes of materials. The systemic materials that get into the tissue, they will persist longer than protective materials that stay on the outside of the plant surface. There are things that if you get more sophisticated, you can start to look at additives, stickers, things that stick the stuff on the surface. You'd want those for the protected materials on the outside. But one that might be most practical if you have your water pH is way off. Particularly if it's high above seven. This can reduce the lifetime of, particularly for insecticides. So you might watch on that. And there are some other things that you need to have a fair amount of trees to start worrying about things like penetrants And the other point I'd like to make about fungicides is that you have to be a little bit more careful with systemic materials from the standpoint that they are a little bit more prone to the development of pathogen resistance. So we liked to focus our program for managing them more on the protectant materials when we can but and, and save the systemic materials until they're really needed. So back to this overall scheme here on controlling Apple diseases. If you're being really thorough than the stars indicate when you put them with the materials down. And you might be able to modify this a little bit. Okay. If I did a good job, maybe I can drop off the last one, it's been dry a while and there's not a lot of growth than I might be able to stretch the interval little bit more if you're a backyard situation and you only want to get by with one or two sprays. You can choose maybe a little bit before bloom and another two or three weeks later. But obviously you're not going to do a bang up job with just two sprays, powdery mildew. Again, you're kind of aiming one or two sprays here, but you only need to do that if your growing a susceptible variety. So that's one of the tricky things that if your growing, a group of trees in different varieties is that it is hard to do a spray program that satisfies all situations. So you end up spraying for most susceptible things and a commercial orchard, they would spray everything. So you only get an advantage if you have a lot of you have a way of selectively spraying So little bit about fungicides for once it, if you look in loaves and places like that, It's the very common ones are Captan, sulfur, copper, mancozeb. Immunox is a material that you'll see the active ingredients myclobutanil And these first four are protected materials. The last one is systemic. And the downside of some of the, the protective materials is that some of them can cause browning of leaves and fruit under slow drying conditions. It's these conditions that allow the material to move into the tissue or put the tree under stress. For example, we know that sulfur, it can be a problem at high temperatures, particularly if you use it multiple times. There's other draw backs on, on these materials as well. Captan is objectional to some folks, it does cause a kind of a congestion. Sulfur. You can imagine that one is unpleasant to use. Copper is used a lot in organic and it is a heavy metal. And there's actually restrictions in some parts of the country, California in particular where you have low rainfall that to worry about heavy metal accumulating in the soil, it can cause negative effects on earthworms and things like that mancozeb is a little bit safer material as far as less is easier and foliage. There's certain things it'll control and not control. One thing it does have a long pre-harvest interval. So it's got limited use, immuneoxism is a material that has single site it is, is okay for scab control, mildew, it is prone to resistance. Now there are other things that commercial growers have access to, which actually anybody can buy the fungicides. They're not restricted materials. However, it's probably hard to find consumer insights packages for some of these things. If you fish online, sometimes you can find materials if you know what you're looking for. Again, looking over this overview of The scab season powdery mildew and receives. And here you can see I've laid out some possible materials focusing mainly on the protectant materials which we'd like to invoke a coppers use early to avoid the rusting effect on the trees, tough on the foliage, mancozeb has a broader range. Captan is a broader range I tend not to like to use it during bloom because it inhibits pollination practice. The, the viability of a pollen on the flower. And it, again, these, then you have to think about, well, this is scab. How about some of these diseases These materials here really don't do a good job on mildew. So you need some other material added in there to control mildew. Sulfur does provide mildew control and scab control. It's not a real great materials kind of short-lived, but it doesn't have the rust activity. so then you zero in and okay, mancozeb is good at rust if you have a situation where rust is a problem, Ziram is another one. So you can start to see kind of dance that you need to do in order to manage some of these diseases. I'm going to continue on with a little bit on stone fruit diseases. The same type of thing. You figure for stone fruit, there's peach, plum and cherry, which are the important diseases, brown rot is a problem, particularly for whether it's favorable for it. We really have only so sole resistance against brown rots so this tends to be something that we use chemical control for it. It kind of two to four sprays, powdery, mildew are fairly selective. And so it depends on what variety you're, you're dealing with. With peaches. We don't really see them on plums. Sometimes a problem on tart cherries and other diseases. One that's pretty important, on tart cherries is Cherry leafspot. Another disease phytophthora is another one. And I'll give a little bit more details on some of these. So you have to go through the same thought process of is it a problem? And what is the what can you do? This shows you for tart cherries, cherry, leafspot and are the first two which are insects. You can see Cherry leafspot has a pretty long period of time that it can be a problem starting at about bloomed to even pass post-harvest because this one is very effective. It effectively use and, and I'm knocking leaves off the tree. This is shows you brown rot. We tend to focus trying to keep it out of the bloom. If the temperatures are favorable for brown rot Then we will maybe put one or two sprays on here and then start up again as we get to the pre-harvest time and powdery mildew, if it is more of a Northern Michigan problem, then down southern area where I am, but it's maybe a couple of sprays there. But generally, we don't focus as much on this disease on, on plums. Plums are similar to cherries and that brown rot is an issue. Another thing that we have on, on plums that less of a problem on cherries is black not and it's a fungal disease at, swells up the other limbs, it causes the limbs to dieback and can be very devastating if it's not controlled. Pruning is important for this, but you can, you need to team up with fungi. Program bravo is one. This is quite often used, but it has restrictions that you can't use it after shuck split when the shuck comes off the fruit and there's other options out there. I kept on itself as a halfway decent brown rock material, but it doesn't do a whole lot against the, the black outside of thing. So each of these has their issues as far as controlling the diseases. Little bit about phytophthora, this one that we see and sites that have heavy soils are usually a drainage problem. And it's out. The type of tree that we have, that type of rootstock makes a difference. A little bit about the symptoms, the canker, it's usually at the soil line. Sometimes it's hard to tell it from just waterlogged soils. But the issue is is that if you look under the bark, you can sometimes see a reddish color and it extends up from the soil line. And so, uh, we, quite often we'll have to send samples to the lab to do a positive ID. Now there's a couple of different fungal species that can cause it. A little bit about rootstock for those of you not familiar that are commercial fruit trees are our two part. There's the She puts a bud on a rootstock. And so the tree is a genetically different from the root down and the top. And the reason being is that the red stuck provides size control on the tree and they have disease resistance. And this is a very important point, especially for apples. This shows you a table of different rootstock that you can buy apple trees on, and the effect of the red stocks is get different sized tree. So you could have something on bud 9 rootstock which has a small tree, about 25 percent of up full size tree. Whereas you can get some of the older ones like M7, M, M 106 can be a much bigger tree. However, if you have a heavier soil, then you want to zero in on this collar rot phytophthora resistance. And there are selections like the M, M 106, the lower the number the more susceptible it is to the problem. So you can see that there are some stocks that are very susceptible, other ones that have quite a bit more resistance. And so some of the newer ones that are available have better rootstock. Characteristic disease resistance and this other characteristics that you'd worry about as well. Varietal resistances very evident in a disease like fire blight, bacterial diseases. Gaussian orchard where the golden delicious trees are pretty much unscathed and the galas are declined due to the disease. So it's if at all possible use a more resistant variety unless you're really set on a certain characteristic. And this shows you that the table that you can get it from various places braiding different varieties for their susceptibility to things like ginger, gold, pink lady. Very, very susceptible. Things like red delicious, much more resistant. So important to know, there's plenty of variety in that list. And so I advise you to find out the ones that are useful. Fire blight. You can do pruning, remove infected material that will help you. Some insect control isn't going to do a whole lot. Resistant cultivars. If you hold back a bit on the fertilizer, limiting the lush growth. But the commercial people and even backyard people sometimes resort to some of the chemicals on pairs. There is also a range of susceptibilities to harrow sweetest like a Bartlett with very good characteristics. So if you're planting parents, you might look into that. So I covered a lot of information and I appreciate your attention and if you want to ask ask me questions, you can always contact me afterwards. And Friday we'll have an opportunity as well. With that, I will turn it back to Cheyenne and you can take over and be glad to hang around and answer questions if anybody has them Awesome, Thank you so much Bill so just as a reminder. I've noted all of your guys questions and I'm going to send them out to our experts and we will try and hit the ones that you guys sent today on a Friday if you have any other questions, don't worry. You can also us reach out to your local extension office or visit ask.extension.org They can help you help you get in the right, in touch with the right people