This post a is text digest of the new Scaffolds Podcast. To listen to the original, visit the following link: Scaffolds Podcast
Monique Rivera Interviews Mike Basedow
Monique Rivera: Okay, so today I’m here with Mike Basedow. He is an extension associate and a tree fruit specialist up in the North Country in the Champlain Valley. So. Hey, Mike.
Michael Basedow: Hey, Monique. Thanks for having me on today.
Monique Rivera: Of course. So just want to jump right in with what is happening in the North Country? Is there anything that is novel or new this year that you think is different from previous years or some hot topics?
Michael Basedow: Yeah, so I’d say we’re pretty similar to the rest of the state at this point, just a week or so behind everywhere else. Obviously the big one this year has been the frost, so it’s been pretty variable for us. Some blocks have been more heavily hit than others, depending a lot on topography and whatnot. So that’s been a big one. Otherwise, we’re starting to see a little bit of fire blight popping up in some areas too. I think we have a pretty good handle on how to control it, thanks to Kerik and Srdjan Acimovic’s recommendations. I would say one of the things that are probably a little bit more out there for us is the apple leafcurling midge. That’s been a newer pest for us, and we’re starting to see it more and more creeping in each year. So we’re doing a couple of different things to try to manage that. But I would say that really seems to be a Champlain Valley specific pest right now. I heard it’s popping up in some western New York blocks here and there, but I think we really started noticing it up here probably three years it. Just started on some trees here and there, and now you can find it in quite a number of blocks up here.
Monique Rivera: So when you say leaf curling midge, they’re just curling the leaves and they’re not actually feeding on them, or how are they actually feeding on the plant?
Michael Basedow: I’m not an entomologist, I’ll preface with that, but my understanding is that the adult females are laying their eggs onto the leaves, and then once they do that, they must be secreting something that forces the leaves to actually curl up to protect the eggs and then the subsequent larvae. So as you look at the leaves, they’re actually really tightly rolled to where they’re pointed at the end. So more so than you would see with like a leafroller type of pest. I think that’s what made it so apparent to us. You’re going down the orchard row and you’re just seeing these leaves that have just been curled to a point. So it’s pretty striking. And there’s been a couple of conversations whether or not it’s been economically damaging. Initially I thought it wasn’t, but talking with a few other specialists out there, particularly Kristy Grigg-McGuffin out in Ontario, they’ve been finding that they also have this pest and at the level where they’re starting to see that it is probably having some impact on yield in some of their high density blocks. So it is certainly a concern for us.
Monique Rivera: So what are you guys thinking for treatment options? Have you guys thought through that? I don’t think there’s anything that I know of that’s labeled for this.
Michael Basedow: Yeah, so of the couple of recommendations that I’ve seen, Movento has been a recommended material and it is labeled for this pest. Similarly, like Woolly Apple Aphid, it needs to go on before you really start seeing the problem with it being more of a systemic material. So I think we’re kind of past the point of really using that for this pest. Another one that I’ve seen, is Exirel, and that one has a 2EE in NY for this pest. So that’s been two options we’ve been recommending. I think we’re also getting to the point where we’re probably a little bit behind on being able to use Exirel effectively, but it’s still an option and it’s another good material for LEP, so can do double duty. If you’ve got codling moth out right now, we’re recommending Exirel as an option for CM and it will also probably be giving you some protection against the midge. So, I also heard from Kristy in Ontario that they’ve also had some efficacy with Delegate. So it looks like that and some of the other group 5 insecticides might also have some efficacy on this pest as well. Delegate is not labeled for midge, but my sense is that if you’re treating for Codling moth at this time anyway, it might help pick up some of midge as well.
Monique Rivera: Yeah, I’m still trying to figure out how they are exactly feeding there. So, they only feed along the margins of the developing leaves. And so basically what I’m reading here is it seems like they’re developing some sort of gall like thickening and that’s causing the curling. That’s a weird pest. But yeah, I think Exirel is the only thing that’s in the Cornell guidelines for this. Based on my experience with Movento this season. Yeah, I didn’t realize how far ahead you would probably have to be to get Movento to properly target like, an incoming pest like this where it’s going to get bad and it’s going to escalate quickly. But yeah, it’s like you almost have to time it before you’re even seeing it in the field, like you’re expecting it to come. So that’s a little scary. So the other pest you guys have there that is not super common across the state is obliquebanded leaf roller. So I guess that’s the region for rolling of leaves or something? I don’t know. Well, why do you think you have OBLR so much compared to the other regions?
Michael Basedow: I guess we just must have tasty leaves or something. I don’t know. It seems to me there must be some type of geographic correlation where they must have grown in their abundance up here. I’ve talked to a couple of my colleagues in Vermont and in Quebec, and similarly, obliquebanded leafroller really seems to be really high up on our radar as far as the major lep pests go. So it seems to me like just the Champlain Valley in particular, spanning that sort of state and international line, we must just have a higher endemic population of them would be my guess. We do tend to see more damage from it, to the point where a few growers do come in earlier on at bloom or prebloom with some Dipel just to clean up that overwintering larval generation as a first step, and then really being on top of that first summer generation. We’re pretty much right about the time for treatment in the Champlain Valley for that first summer generation. I checked the degree day model earlier this week, and we’re pretty much right at that 350 degree day mark where we want to be treating against them. So I think growers will be making those applications later this week or early next.
Monique Rivera: And you guys are continuing with that little mini mating disruption trial?
Michael Basedow: Yeah, so we are doing a little mini project for mating disruption here in the Champlain Valley. So we set up last year, we started with some of the combo CM/OBLR Meso Lures. We put those out in one of a grower’s blocks, and we had a control block, and we saw fairly similar levels of both pests through the first generations. But then as we got into the second summer generations, we saw the coding moth trap captures really dropped off. The obliques dropped off a little bit, but not to the same extent as codling moth. And from what I’ve heard, that’s fairly common where obliques tend to be a little bit more difficult to control with mating disruption. So then this year, we’re continuing that trial. Now we’re into the second year when it’s under mating disruption. And to this date, we still haven’t caught either of those pests on our traps in those blocks. We are using the standard lure still, so I think maybe we’re not having the most sensitive captures with it, but we still haven’t caught anything.
Monique Rivera: Wow, that’s pretty promising. So it’s in the second year in the same blocks, correct? Right?
Michael Basedow: Yes.
Monique Rivera: Okay, so full shutdown. That’s pretty interesting. I mean, we’re trying out mating disruption here, but codling moth and OFM. Yeah, it’s pretty variable. We’re also comparing the puffers to the mesos. But yeah, we don’t really know anything yet. I’m hoping for that second generation shutdown, which we’re just going to start asking people now to start their limited spray program. So the last question I have for you is about weed management. So this is a big black box for me, so I’m coming to you as the expert. So what are you thinking about weed management in apple orchards this year? Specifically your opinion on using weed management to mitigate pests like tarnished plantbug?
Michael Basedow: Yeah, so that’s a great question. So as far as weed management right now, hopefully people were able to get their pre-emergents on either last fall or in the spring and were able to get a burn down or some other post emergent material on in the spring as well. So at this time of the year, I think what we’re really looking at is using some post-emergent materials so we can burn back the existing vegetation that we currently have. And I also think this is generally the time of year where we’re looking to focus more on using some of our post-emergent materials to help out with our perennial weed species. So, whether it be using contact materials or a really well-timed systemic material, they’re really going to be our main tools for dealing with these more problematic perennials. As far as can we use good weed management to target insect management, I totally think we can. And we’re trying that out this year based on some evidence that it’s been working very well for some growers out in western New York. I talked to a few growers that have been cleaning up their broadleaf weeds in their row middles as a method for reducing their tarnished plant bug damage. And so they’ve been using this in their peach orchards for a number of years. They’ve said they’ve really cut down their amount of tarnished plant bug damage just from cleaning up the broadleaves that are in their rows. And the way they’re doing that is from using fall applications of a 2,4-D product called Unison, and also using Stinger. So those are two systemic materials that are broadleaf specific. And so by having those materials, they’re going out and applying that to the entire orchard floor, they say, from tree to tree. So the row middles of the sod and also under the tree. And so by doing that, they’re really decreasing the amount of broadleaves that they have. And so when you don’t have those broadleaves in the rows, you’re really getting rid of a lot of that habitat for the tarnished plant bug and in effect, they’re seeing a lot less damage. So we want to test that strategy a little bit more in apple orchards in eastern and western New York. So Janet van Zoeren and I are working on an ARDP funded project right now to investigate that, along with some other perennial weed management strategies. Really looking at how can we best time some of the different systemic materials that are out there right now outside of glyphosate to really help us control the problematic perennials that we have. Like bindweeds, Canada thistle, perennial grasses. So those are the big three that we’re targeting with this study.
Monique Rivera: So I know how systemic insecticides work. What about in systemic weed management? Does that need to be watered in further? Are there any pro tips for using those products?
Michael Basedow: So I would say the big thing with the systemic materials and the same with the contact materials, really coverage is key. You’ll see on the label that they’ll tell you that the bigger the weeds get, the more gallons per acre you want to put out just so that you know you’re getting good coverage. Essentially, they need to get onto the foliage, and then once on the foliage, they’re going to be transported through the plant and ultimately getting down into the root of the plant. And I think that’s where we see the systemics really coming into play. When we’re dealing with perennials, a lot of the contact or burndown materials, just like the name implies, essentially what those are doing is they’re touching the foliage and they’re burning the foliage right there. So it’s kind of like chemical mowing the lawn to me when I think about doing it on the perennial grasses. So you feel pretty good about it because it burns it back down to the ground, but I have found you give it two weeks, that grass starts growing again. So with the systemics, the goal is that that material is going to be moving down into the roots and the rhizomes, all those perennial structures that these weeds have, and is going to do more of a slow burn where we’re reducing the growth of the weed species that we’re targeting.
Monique Rivera: So I have to ask this as a continuation from last week, but are they recommending adjuvants for herbicides?
Michael Basedow: Yeah, so some of the different products do come with adjuvant recommendations. So as an example, most glyphosate products are going to recommend that you use AMS, ammonium sulfate as an adjuvant. Certainly one part of that is it’s going to be a water conditioner, because glyphosate is really affected by hard water, because it can really get bound up if you have hard water. So the AMS kind of helps with that so that it keeps it really active. I think another part of it why they might recommend AMS, and I don’t know this for sure, but I think maybe that little bit of nitrogen boost might help the plants just grow a little bit more shortly after the application. Because with the systemic materials, the plants really need to be in really optimal growing condition to get the best results, because it needs to be transporting that active ingredient through the plant. So if they’re stressed from hot and dry weather, they aren’t growing much, and aren’t transporting that product where it needs to go in the plant. so I think if you had gone out and put a systemic on at that timing, you wouldn’t have really seen that much action because it just wasn’t transporting that material as well.
Monique Rivera: Wow, interesting. I would have assumed if they’re more stressed, they would be more likely to uptake the water, but yeah, I am not a weed scientist by any stretch of the imagination, so I’m just asking to continue our black box. Anything else you want to share with us today, Mike?
Michael Basedow: I guess just a follow up on that, too. The other one that I commonly see recommended usually is some type of penetrant, just to get it into the weed a little bit more.
Monique Rivera: So like an oil?
Michael Basedow: It depends. So, for our project, we have two different herbicides that we’re playing with, and I I’ve needed two different types of penetrant adjuvants.
Monique Rivera: Really? So you’re not sticking with the same one across the different treatments?
Michael Basedow: No, so we’re doing just what the label calls for. So we had two different herbicides. Each one called for a different penetrant, so one called for an NIS, and the other one called for MSO.
Monique Rivera: Wow. Okay. So, yeah, I have a lot to learn about all the different things going on in an apple orchard, but other than that, Mike, maybe I’ll have you on in another six weeks as we get closer to harvest, if I can beg of your time, but this has been great, and thanks so much for joining us.
Michael Basedow: Thanks for having me.
Pathology Update with Kerik Cox
Hello, It’s Kerik coming at you from Cornell Agritech. Just in the week before the Independence Day holiday, been out in our fields looking around at things. I’ve seen some shoot blight here and there, and our team has started to cut our shoot blight out of our own blocks. It’s not a bad time to do it. I mean, yes, it’s a little bit rainy. It has some really nice, cool weather, and we’re getting a couple of dry days interspersed amongst the wet ones. And so on some of these dry, cooler days, we’ve decided to cut our fire blight out. It looks like this year, fortunately, shoot blight is not migrating really quickly. Plants are growing, but the cold weather has really kept the shoot blight spread within trees and within blocks down to almost a negligible level, almost to the point where you think it could never happen again. That won’t be the case because next year, we’re going to have one of these really hot, explosive years where things get really dire for some places, but maybe not others.
But I thought I would talk briefly about shoot blight and systemic infections and the big question is, can we sort of get rid of systemic infections of fire blight by pruning things out? So what the bacterium does is it starts to get into the shoot tissues. It’s going to wiggle away in between the spaces between the cells and your shoot tissues, and it’s going to move very gently. But as it’s doing it, it will be infecting these parenchyma tissues with its type three secretion system, and it will move into the necrotic phase. That’s why it’s black. That burnt look is the necrotic phase. Now, the sad and scary part about this is that once the necrotic phase gets going, it triggers the fire blight bacteria populations to explode and move even faster. And then once that happens, the death enhances their ability to grow and multiply in the tissues. And then they’re hitting the vascular tissue. And once they get into that xylem for moving through those sort of parenchyma cells around the vascular bundle, that’s when they’re going to start going fast through the tissue.
So the question being, can we cut it out? We’ve done a lot of work. We did some work with Tiana Dupont and a couple of others in Oregon, Washington, Pennsylvania, looking at different pruning trials. And over the years, with about four years of study, with a couple of additional ones at Cornell, we all found very similar things. And one of the things that I noticed, because we did them both on very young, vigorous trees in really bad years, and on some four year old planting, high density, and we also did some on just classic vertical axis, about 18 to 15 year old plants. On these really rough years, we noticed, and I think others have noticed as well in Michigan, on these really young plants that you might not see the shoot blight after inoculation for a couple of days (on a really bad year it could show up in as quickly as five days) but we’ve realized that even when we didn’t see it on those bad years, it had already moved throughout the plant, and probably 24 to 35 hours moving very quickly when young plants are moving. Now, this is only in the really young blocks.
Now, in those older blocks, it wasn’t this way, it was slower and it just took more time to get throughout the plant. It’s a bigger woodier tissue, not too surprising. But, in that case, systemic infections and really small, young, high density plantings can move quickly in a bad fire blight year. Now, the other thing that happens, it looks like it was almost four days once we had those temperatures above 85, consistently with rainstorms.
We’ve had some pretty cool seasons. And so that doesn’t seem like it’s spreading as much this year, giving you the opportunity to cut it out. But what we’ve really wondered about is it even worth it, cutting it out in really young blocks? Because we tried and it had already moved very quickly even before we began to see it. And in this particular instance, we did notice that in general, it can help a little bit, but it may not stop the spread in really young trees. Now, on an older tree, like 10 to 15 years, you can probably do a pretty good bit of restricting the systemic movement throughout the entire plant. In an older tree, probably once you start to get into the more woody versions, about probably ten plus. Maybe seven, that’s going to be the zone we’ve never really tested before.
But what do we know about some of the different pruning practices? What are the best things you can do? As I was thinking about this and cutting myself just the other day when we had a cold, dry day, for the most part, you want to get on it fairly quickly. And always remember, if it is a high vigor, high growth year and you do prune, you’re going to stimulate growth. So you’re probably going to want to shut the tree back down from that stimulation with an application of Apogee. And it may take a second one, depending on how vigorous and how things are going. But in general, if you can get to it, you might be able to save the trees. Now, we’ve usually talked about this best management practice, which is basically going to be cutting into two year old plus wood. If you can go into three year old wood, you can really get rid of systemic infections and it’s going to be harder to get into three year old wood on a small plant, but that’s okay.
Now, if you can, in some studies we found that even going further into three and four year old wood or just going almost to the leader, and just leaving a tiny stub, has been pretty good in my work in New York, but not always been the case in Washington and other places. It’s generally not any better than just going into two year old wood. But the further away you can get from that infection and as soon as you can do it, the less likely these things are going to go systemic. And we’ve also found that across all the different studies that if you can leave a stub, even if it’s one on the main leader, leaving that five inch stub can preserve the structural wood. That way, if you were to cut it out, you don’t have to cut deep into the actual structure of the plant and that can sort of preserve the tree shape.
Now, there’s been a very exciting process about breaking off fire blight at whatever distance you like. Usually if it’s in the two year old wood, we found out that that ends up either leaving a lot of cankers or ends up actually reinvigorating and stimulating that sort of aggressive systemic movement. And we’ve seen a lot more shoots show up in trees that we practice the breaking.
And everyone’s wondering about sanitization. No matter all the different studies we’ve done in this last collection over the last five or six years, with all the different teams across the country or in ones previously, it doesn’t seem that there is a statistical benefit from sanitizing your tools. Now, it’s not going to hurt to do it, but it may not always be the saving grace. At the same time, if you have the stuff on hand to either use your ethanol or your Clorox wipes or your Lysol wipes (Clorox will rust your tools). If you’ve got a system, you’re definitely not hurting by doing it, and I don’t think you’re wasting a lot of time. Then I’ll talk about something next week, but this is it for pruning out fire blight. A good time to keep an eye on shoot blight development in your orchard as we all leave and want to do things for vacation.
State of the State with Anna Wallis
And now for the state of the state, your weekly roundup of Degree Day accumulations and phenology from the major fruit production regions of the state. As always, the information here has been aggregated from regional specialists, NEWA, and my own observations.
Fruit across the state is continuing to size and color, and over the past couple of weeks we’ve had some significant rainfall events interspersed with very dry weather. On Monday this week, we had over a half an inch in some places, much less in others, and unfortunately, there was hail reported in some locations associated with the storms in western New York. A good place for you to search severe weather updates and get hail reports or other significant weather events are the NOAA Storm Prediction Center and the associated websites, which we will link in the Show Notes.
https://www.spc.noaa.gov/exper/archive/event.php?date=20230626
With fruit continuing to size or continuing to see frost damage across the state, it’s easier to see now more of the fruit cracking, frost rings and other fruit marking, including calyx end of the fruit damage, some lopsided fruit, and general cracking.
We are continuing to track Degree Day base 43 as an indicator of insect activity and phenology. Both base 43 and 50 are summarized in the table in the Show Notes and have been used historically. You can also find an average of Degree Day accumulations for phenology and arthropod pest activity in the Cornell Tree Fruit Guidelines. That’s table 7.1.4. As we know, degree days since January 1 isn’t always the best predictor of apple pests, so we always encourage you to use the models in NEWA that correspond to each pest. Here are a few things that are active now.
OBLR or oblique banded leafroller is the focus of many of the pest management regimes that are going on throughout the state right now. For blocks with a history of this pest, an application targeting larvae should be timed at about 350 degree days base 43 after the first sustained trap catch and then again in about two weeks. In the Hudson Valley and the Capital Region, the second application should be going on about now and the first application should be going on soon in western New York and in the north country.
Codling moth: in western New York first flight is winding down and second generation will begin soon. In the Hudson Valley we’re nearing the end of the window for management for this pest.
Oriental fruit moth is between generations in most of western New York and northeastern New York and beginning a second generation soon in the Hudson Valley.
Mites are present in orchards now. You can find a sampling procedure in the Cornell Guidelines figure 7.1.4. We haven’t heard of major outbreaks or significant problems in orchards yet this year.
Rosy and green apple aphids continue to be very active throughout the state.
Woolly apple aphid has been reported in many locations throughout the state, starting particularly on pruning cuts inside the canopy and lower in the canopy. This week we’re starting to see it move to young tender shoots, but there hasn’t been much increase since last week, likely due to the rain that would suppress the populations.
San Jose scale is active. It has been for the past couple of weeks in the Hudson Valley and now in western New York. You can be monitoring for them by placing black electrical tape or double sided tape around branches just above active infestations. You can also be checking your fruit for the white marks of unlignified or unhardened adults.
Apple leaf curling midge has continued to pop up in some locations across the state. It’s a relatively new insect that has become significant in the Champlain Valley and in some locations in Ontario. So it’s important to pay attention to. Again, we’ll link to the YouTube webinar recording of Kristy Grigg-McGuffin from OMAFRA, who’s been doing a lot of work on this insect that was recorded by the Eastern New York Commercial Horticulture program previously.
In terms of diseases, this week we’ve continued to see more fire blight infections in places that had infections last year, so keep an eye out, especially following the severe storms that pass through much of the state this week. Also keep an eye out for secondary scab infections where it may have slipped through. We’re entering the infection periods for summer rots, so keep an eye out for that and pay attention to the models and stay covered. Powdery mildew has been less problematic with the wet weather that we’ve been having.
And finally, here’s a rundown of the degree day base 43 accumulations at NEWA weather stations throughout the state. As usual, they’re also in the show notes for you to reference later.
