This post is a text digest of the new Scaffolds Podcast. To listen to the original, visit the following link: Scaffolds Podcast

Kerik Cox Interviews Monique Rivera on The Current and Future State of Insect Management in New York

Kerik Cox: This week, we’re going to turn the tables and I’m going to interview Monique Rivera about insects in New York for Scaffolds episode twelve, right? Yeah. So I’m Kerik, tree fruit pathologist.

Monique Rivera: And this is Monique Rivera, tree fruit entomologist.

Kerik Cox: Oh, goodness. So what do you think the state of insect problems in New York is?

Monique Rivera: So I’m going to be honest, I’m new to apples, and I feel like I’ve graduated to apples because there’s always an insect issue happening at any time. And I think that our biggest questions to answer right now are optimizing control with newer technologies, and then secondarily, understanding how climate change is going to impact the amount of insect pressure that we have in the future.

Kerik Cox: What’s insect number one? What’s the big problem? What’s the biggest of them in your mind?.

Monique Rivera: At least for me in my lab right now, acutely, woolly apple aphid. So we have a spray trial and a Federal Capacity Funds funded project focusing on efficacy of control of woolly apple aphid. I think that always, in apple, because we have primary lepidopteran pests, meaning that they feed directly on the fruit, that’s always a huge concern. So I’m hoping my lab will eventually get permitted by USDA to have a codling moth colony. We’re getting inspected next week, so fingers crossed, but I would say those are the top couple. Then we have our rotating assortment of invasives that’s constantly knocking on our door.

Kerik Cox: So I’ve seen a couple of people today texted me, PC – not the thing sitting on our desk – for plum curculio and apple leaf curling midge. Are those just minor things? And are they just showing up because that’s all I ever get as a pathologist?

Monique Rivera: No, I think leaf curling midge is a concern this year, and I’ve heard lots of commentary about it, and there’s not a lot of work that’s been done on it, so there’s not a ton of recommendations. Plum curculio is an interesting pest because it’s native and it’s very voracious on apples in terms of damage, and it’s very hard to get under control. So in that first cover spray, you’re supposed to be targeting their oviposition, but if you don’t catch them at the right time, which I think is the key to most apple pests, then you’re going to have a build up in your field and you’re going to see a bunch of damage at the end of the year, which is not ideal for marketing. I just think it’s a very persistent pest that’s hard to control, and I am excited that I’m testing a new product from Syngenta that if it works the way they say, has a lot of promise for the management of plum curculio and brown marmorated stinkbug, both of which I think have similar attributes in that they are ambiently in an orchard and causing very significant damage. And the key to this new product is that it allegedly has a very long residual activity. So hopefully it would deter feeding by both of these pests, which are persistent and hard to control. That could reduce damage, but we’ll see at the end of this year.

Kerik Cox: So once you already see damage from these, is this just throw you up your hands and come back next year or is there anything you can do now?

Monique Rivera: I think you’ve got to optimize your spray timing. For bmsb, we don’t have as much pressure as they have in the Hudson Valley in western New York, but when they do aggregate and feed, they can cause a lot of damage. We’re still trying to figure out exactly what that damage looks like and making sure it’s not mistaken for bitter pit. But I think that at this part of the season, the growing apples are very delicate and the damage that happens now, you’re going to see it at harvest. So making sure to get that cover spray on at the proper timing is really critical to limiting this early season damage and then just tracking your degree days to know when that second cycle is coming through. But I do think that we need to refine the degree days based on newer developments. Like, for example, degree days starting January 1 seems irrelevant when what happens in late November and December is really critical for how those generations will come out in the spring.

Kerik Cox: Now, speaking of that, what about how does climate change is that going to interplay into these starting the degree day accumulations at all? Because sometimes it seemed like in November and January I had 70 degree weather both months.

Monique Rivera: Yes. So I don’t think we know a lot about how that affects insect development and that’s work that needs to get done so that we can refine the predictive models. I also think that another big threat is the limitation of products that had very solid placement in the IPM program. So lorsban was very solidly used for a bunch of different pests and it was very efficacious. And so with that loss, I think we’re kind of scrambling to figure out what happens now. I think one of the big issues with Woolies is that when you would put on your lorsban for the borers you were capturing the woolly apple aphids as well. So now we’re seeing this resurgence and trying to figure out how do we deal with this. Not by recommending, for example, diazinon. We want to be having solid recommendations for the newer products that are softer chemistries.

Kerik Cox: So now I got to ask, the smoke, is it going to do anything to impact our pest situation other than make them… will it even make them hide?

Monique Rivera: I don’t think for insects, it seems like that big of a concern. I think they’re going to persist. We saw no difference with this in California. When it came to fire season, your insect pressure pretty much stayed the same. So they are passively breathing, but as long as there’s enough oxygen in the air, I think that in a way, they have an easier time dealing with this than we do. Our lung system is not quite as simple. So, yeah, I am not thinking that we’re going to have any effect of the smoke, but I’m more worried about the wine grapes. We’re going to have, like, smoked wine.

Kerik Cox: That’s true. Yeah. It’s not going to affect fire blight. It’ll still kill stuff. All right, well, what about the future? What’s our future entail?

Monique Rivera: Well, I think that we need to probably collaborate across disciplines more often, so getting horticulturalists more deeply entwined with entomologists and pathologists so that we can evaluate and think about from the horticultural side and the breeding side, how all these things interplay together. I think that insecticides will continue evolving, but there is that backdoor threat of regulation. So I think it’s just an ever changing landscape then, with all of our climate issues. I liked what California was doing in the sense that when they banned something, they threw millions of dollars of research money on replacements. So I think funding research is critical and timely funding of research, if it’s an acute issue, getting that money quickly is going to really help us develop localized recommendations, which I think for apple and many other cropping systems is really critical.

Kerik Cox: Yeah, well, I like that idea. With Captain and Ziram gone, we could sure do some good research. Well, any last parting things for the group this week?

Monique Rivera: What did we see? We caught an oblr in one of our traps. You found a woolly apple aphid, you sent me a picture. So I think it’s time to really be in your orchards and scouting, because this is a critical time for those growing apples to get to the late stage looking very presentable and with a clean finish. That’s all I can think of for this week.

Kerik Cox: All right, that sounds great. Well, catch us next week for something different.

 

Pathology Update with Kerik Cox and Līga Astra Kalniņa

Okay. Coming at you from AgriTech with a plant pathology update for the week. Notice we’re getting a lot of rain out right now throughout the area, and I’m also seeing a little bit of fire blight showing up here and there. If you’ve had a control failure even as far as say, Maryland, you might be starting to see some shoot blights showing up now. And if you do, don’t forget to check out our blog at blogs.cornell.edu/coxlab/ and there is a disease submission sample form tab and that’ll tell you everything you can do to send in a sample. If you’re seeing fire blight now, check it out, maybe send us a sample. We’ll look and see if you have strep resistance, that type of stuff.

But also with this rain got me thinking of some other stuff. We’re finished with scab but if you have a little bit of lesions even in the smallest form around the very early from the early season infections, just even one or two now this rain can splash it around and that’s sort of where we are now. We’re in that sort of uncomfortable like 3rd, 4th, maybe fifth cover depending on where you are in the state. And all it takes is a little escape lesion infection to blow some new conidia all around the orchard and cause some new infections and that type of stuff. So that’s what we’re thinking about now we’re deep into the covers and all this rain makes me think it might be a good week for you to consider a summer disease application if you haven’t done one in a while. Maybe it’s been 10 to 14 days, maybe it’s been 14 to 21 since the last time. What’s happening now? Right now our biggest threat (and we seem to have learned by watching these sort of epidemics pull up) if you’re further south, you might get glomerella leaf spot. But if you’re up in New York, you’re probably going to see apple blotch which is the formerly known as the Marssonina leaf blight type system. It’s gotten a new name. Now they’re naming it by the sexual stage diplocarpon. So if you see Marssonina, this is the thing we’re talking about. Frog eye leaf spots can show up now. Scab, secondary scab can show up now, even Alternaria.

How do you beat these things? You’re still going to use the same scab fungicides that you’ve used before. Now, where they become a big issue is this type of rain post petal fall. You skip making your apple scab applications and you’re going organic or you’re really heavily reliant on the multisite protectant fungicides. These things aren’t as strong against these very focused pathogens, if you will. Now what does do well, if you have any leftover, this is the time to consider making one of your strategic uses of one of the QoIs, or the SDHIs, or the DMI fungicides. It’s your 7,11, and 3 groups, if you will. These will provide high levels of control against all these diplocarpon apple blotch and the glomerella and those types of things. And one of the things that we noticed last year from watching apple blotch develop in our own orchards is that the treatments that just got the multisite protective program of a half rate a Captan 80 and Prophyt were the ones that were defoliating the hardest, and the ones that got an SDHI at around that first through fourth cover, that sort of early on inoculum, really had low damage and they weren’t defoliating at all from your marssonina (or the new name Apple Blotch) whatsoever.

We’ve also noticed that some varieties seem to be a little worse than others, the goldens seem to defoliate a lot more quickly than our Empire and Mac type parents from the Apple Blotch type pathogen. And so as you’re going out and you think we might have skipped the Scab season, look around for lesions and seeing what’s out there. And if you still have one or two of the DMI’s, QoIs and SDHIs in your use allowances for the year, it doesn’t hurt to use a couple into the beginning of the summer cover period and then finish strong with the last remaining ones you have. And this rain and this weather seems like a good time to really consider putting one of those out there. They’re going to get the fruit rots too. A lot of these fruit rot things are latent. I’ll talk a little bit about fruit rots next week and the different factors that they can become a problem. But right now I’m a little worried about our leaves. And it seemed like last time targeting the rains around this period after that post petal fall  thinning weather and getting it right now was sort of key to ensuring that a tree had lots of leaves in October versus a tree that did not have any leaves in October. Good luck and talk to you next week.

 This is Liga colonya Kerrick’s, graduate student from Cornell AgriTech, back with another episode of Scaffolds. So this week I want to talk to you all about fly speck/ sooty blotch infections for this week, as well as application timings with the continuous rain that we’ve been experiencing this week. As well, a call for Apple Scab sample submissions.

So we’ll get into the fly speck/sooty blotch forecast first. As for Hudson Valley, there is a high risk of fly speck/sooty blotch infection this whole week. So if you have not made a cover application in the last few days, this week would be a good week to do so when you get a break in the rain. Some good options to consider for applications might be Flint Extra, Captan 80, or low rates of a phosphorus acid fungicide.

For the Finger Lakes, the situation is a little bit split. So if you’re more closer to the Ithaca side of the Finger Lakes, you should be making an application when you get a break in the rain as well, as currently, there is a high risk of infection. If you are closer to the Geneva side, the infection risk is currently moderate, but is expected to become high by end of the week. If you get two days of rain, which you most likely will, and if you have had more than three inches of rain since your last application, consider making an application this week when you get a break in the rain.

So there’s also a similar story for Champlain Valley, currently moderate but will become high infection risk by end of the week. So consider making an application if you have not made one in the last two weeks or have had more than three inches of rain.

As for the rest of the state, Long Island, Capitol District, Wayne County and Niagara County, currently the risk of infection is low, but is predicted to become moderate by end of the week. So if you have not made an application in the last 14 to 21 days, and if you had more than two days of rain, at the end of the week could be a good time to make a cover application. If you recently made an application and have not been getting any rain, you might be able to hold off for an application until a later time when conditions are more favorable. So as a reminder, if you are making an application, some good options to consider are Flint Extra, or Captan 80 of the low rate, mixed with a low rate of phosphorus acid fungicide.

Now I want to talk to you about a call for apple scab samples this year. So with all the rain this season, we have been noticing a lot of apple scab this year in our research blocks here in Geneva. There has been more apple scab in 2023 than in the last three years combined. This is the most scab we have seen in the last five or seven years. We have also gotten reports of apple scab across the state and some samples from growers. While it may be just a cool, wet year, we should be concerned about the selection for fungicide resistance. So we are looking to screen apple scab isolates for resistance to the newest SDHI and DMI fungicide chemistries. If you have samples and would like to send them to us, please do. We are especially looking for samples that are freshly sporulating.

So on our lab web page, which will also link to the show notes, it’s https://blogs.cornell.edu/coxlab/ there is a Disease Sample submission form page. Go to the apple scab submission form and it will give you directions to a Google form to fill out about your samples. It has instructions about how to label your samples, what information to provide, and where to mail it. So your sample should be mailed to Kerik Cox, Cornell AgriTech, 15 Castle Creek Drive, Geneva, New York. And all of this is also listed in the form for your reference. So if you have any questions, reach out to me at LK387@ cornell.edu or also Kerik. So that’s it for the week and we hope to get some of your scab samples.

 

State of the State with Anna Wallis

 And now for State of the state, your weekly roundup of Degree Day accumulations and phenology from the major fruit production regions of the state. As always, information has been aggregated from the regional specialists, NEWA, and my own observations.

So, after a couple of really hot, dry weeks, this week we saw some cooler weather, and we’re getting some much needed rainfall. In eastern New York, we’ve had at least a half an inch in most of the state as of the beginning of this week, and in western New York, some locations have had as much as two and a half inches. We’re expecting at least a half an inch more over the second half of the week. We continue to see frost damage, fruit cracking, frost rings, other fruit marking damage to the calyx under the fruit, and lopsided fruit. This damage is easier to see now that the fruitlets are getting a little bit of size.

We’re continuing to track degree days base 43 as an indicator of insect activity. Like I said in the past, degree day base 43 and 50 have been used to track phenology and insect activity in the past. We’re including a table in the show notes of each, and you can also find these average ranges of Degree day accumulations for phenology and arthropod pests in the Cornell Tree Fruit Guidelines table 7.11.4. As you know, degree days since January 1 isn’t the best predictor of all apple pests, so we encourage you to use the models in NEWA that correspond to each pest, and I’ll talk about that a little bit more.

So here are a few things that are active right now as Monique and Kerik talked a little bit about.

Plum curculio is active, but nearly finished the oviposition period in most of the state. Lake sites and farther north, where sites are a little bit behind, should still stay covered through the end of this week. But warmer sites like the Hudson Valley and Geneva are past this window. This insect continues to be active from petal fall until we accumulate about 308 degree days base 50. Using the NEWA model, you can enter your petal fall date and it will predict the degree day accumulation for the next five days. The model also generates a petal fall date based on Degree Day accumulation, and using that information, most sites in western New York and eastern New York will be beyond the 308 degree day threshold by the end of the week.

Oriental fruit moth flight is over in most of the state. The second flight is just beginning soon in the Hudson Valley.

Codling moth first generation flight continues. The second application should be going on this week, about 14 days after the first application in western New York for sites that have a history of that pest.

OBLR first trap capture was recorded in Geneva and in the Champlain Valley last week, and in western New York sites this week for the earlier locations. So hopefully you have traps out for tracking this pest emergence for blocks with history of this pest. An application targeting larvae should be timed at about 350 degree days, base 43 Fahrenheit after the first sustained trap catch, and then a subsequent application should be made about two weeks after that.

Mites are also present in orchards now, and there is a sampling procedure in the Cornell Guidelines figure 7.11.4 that can help you if you’re looking for those. You’ll sample about 20 leaves, four each from five different trees, and inspect the top and bottom with a hand lens to determine if there’s the presence or absence on each leaf, and then use the schematic to determine if you’re above or below a threshold to treat.

Rosy and green apple aphids have continued to be very active throughout the state.

As Kerik and Monique mentioned, we’re starting to find woolly apple aphid in hotspots this week. It’s been reported in many locations throughout the state, particularly look on pruning cuts or inside the canopy, and lower in the canopy where they’re usually present.

San Jose scale is another insect to be monitoring for now. Crawlers are typically active at about the beginning of June. We haven’t had any significant reports of this pest yet, but you can be monitoring for them by placing black electrical tape or double sided tape around branches just above active infestations that will catch the crawlers as they emerge.

We’ve found apple leaf curling midge in the Lake Ontario region, and it’s also been reported in other parts of the state, notably the Champlain Valley. This is a relatively new insect, as I’ve said before, that has become significant in the Champlain Valley and in Ontario, so it’s important to pay attention to. Kristy Grigg-McGuffin from OMAFRA in Canada has been doing some work on this insect, and there’s a great webinar recording that was hosted by the Eastern New York Commercial Horticulture Program if you’re interested in learning more. https://www.youtube.com/watch?v=bnSqoYIj7kk

In terms of diseases, we’re continuing to see quite a lot of powdery mildew this week. We’ve continued to see natural fire blight infections showing up in places that had infections last year, so keep an eye out for that.

Scab primary infections are present in places that were unmanaged or maybe slipped through.

We’re entering the infection periods for summer rots, so thanks to Kerik and Liga for their guidance on that.

And finally, here’s a rundown of the degree day Base 43 accumulations for NEWA weather stations throughout the state. As of the end of the day on 6/13, degree day accumulations were: