Scaffolds 2024 Digest: Week 3
This post is a text digest of the Scaffolds Podcast. To listen to the original episode, visit the following link: Scaffolds Podcast on Spotify
Welcome to season two of Scaffolds. This is Monique Rivera, your host and assistant professor of entomology at Cornell AgriTech. Co-hosting with me is my pathology counterpart, Kerik Cox, who’s an associate professor of plant pathology. This year, we will also be joined by Kelsey Tobin, a postdoctoral researcher in my lab, and occasionally also by Anna Wallis, our New York State Fruit IPM coordinator. On this week’s episode, I talked to Savannah Shelnutt about climate resiliency programs; Kerik forecasts diseases; and Kelsey and Anna give us our state of the state degree day accumulations and phenology updates.
Dr. Monique Rivera Interviews Savannah Shelnutt
Monique Rivera: Okay, so we are having some weird weather, so I thought this was an ideal time to bring in a climate specialist. So today I’m talking with Savannah Shellnut, Ag Climate Resiliency Specialist with Harvest New York. Hey, Savannah.
Savanna Shelnutt: Hey, Monique. How’s it going?
Monique Rivera: Good. I was hoping that you could tell us a little bit about your job.
Savanna Shelnutt: Absolutely. So, my name is Savannah. I work in the Hudson Valley. My position is called an ag climate resiliency specialist, and what that means is that we work with farmers and other landowners to help connect them with resources like federal money from soil and water conservation districts that’s being dispersed through Soil and Water, from the USDA or NRCS to help you build your climate resiliency. That could look like helping you install drain tile or water management systems or finding money to help you begin a new practice, like cover cropping between rows. And another important thing that we do is, if you’re interested, we help folks account for their greenhouse gas emissions and figure out how to mitigate that, if that’s something you’re interested in.
Monique Rivera: Wow, that sounds really cool. So, can you describe some of the programs you oversee and how in particular people could access them?
Savanna Shelnutt: Absolutely. So, some of the programs we oversee are, for example, this summer we’re going to host a biochar field day in the Hudson Valley. And what that’s going to look like is that we’re installing a plot of biochar on a diversified vegetable and fruit farm, and we’re going to host folks. You can come on out to see it for yourself, or you can keep your eyes peeled for some research bulletins that we’re going to put out as the trial progresses over three or four years. In addition to that, we have Facebook, Instagram, Twitter, where we try to disperse a lot of information on funding that’s available. And you can find us on all those platforms @ResilientAg_NYS. And in addition to this, we’re going to host a series of webinars over the summer. So, we’re going to cover topics from installing rice for the Hudson Valley, all the way down to how do you access money, or how do you build yourself a climate resiliency plan, which is another service that we offer. I work exclusively in the Hudson Valley, but my counterpart, Kitty O’Neill, works across the state. So if you’re someone that’s not located central to me, if you’re somebody in western New York, we have a person that can help you out.
Monique Rivera: Yeah and we’ll include their information in the show notes. So, so far, in your position, what have you seen as the most common problems people are bringing up?
Savanna Shelnutt: That’s a great question. So, for me, in the Hudson Valley, especially with the weather we had last year, folks are having a lot of issues with water management. We’re seeing an excess of flooding in our area, and so folks are really trying to access resources to help prevent that. And that looks like either going out and figuring out which areas of your field you might want to look at putting drain tiles in, or where you might want to install ponds to help capture water as it runs off, or looking at your roads that are on your farm to make sure that you have plenty of drainage around them so they’re not being washed out, making sure that you have adequate resources to help handle that water as it comes off the field. So that would be our number one thing that we hear here recently. But, you know, in addition to that, folks are experiencing more and more freeze and frost damage. The weather is funky, as you’ve mentioned, so as we deal with these warm winters and trees and other perennial plants are coming out of their endodormancy earlier on, are entering into eco-dormancy. We’re seeing a lot of issues there.
Monique Rivera: So, one of the things that I think is a barrier for people wanting to access these programs is definitely the bureaucracy, filling out forms, you know, all of the paperwork. Some programs are not very easy to access. Could you maybe talk a little bit more about how your program supports making that easier?
Savanna Shelnutt: That’s a great question. Definitely, when you hear free money immediately, your first thought’s probably going to be that you’re going to spend hours and hours doing all this paperwork. It might not be worth it. So, Kitty and I, our job is to meet with you, learn about your operation, and help target which programs are most applicable to you. And something that a lot of folks might not know is that several organizations like Soil and Water, they really don’t require you to do much physical paperwork yourself. It’s more of a conversation where you sit down with your soil and water agent, and they learn about your operation conversationally, they help you fill out one form about your farm operations, and then they apply for money on your behalf. It’s not like this with all organizations. But that’s something that a lot of folks might not know that you don’t always have to be the applicant for these monies. And Kitty and I are always happy to help folks who are interested in applying for money but might not have the time to parse through the information. We’re happy to give you a primer on what exactly you do or do not need to do to access money.
Monique Rivera: Have you seen any of these issues that come up be more specific to apple?
Savanna Shelnutt: That’s a good question. I haven’t so far seen any specific apple issues, although I know that in grapes last year, there was a huge issue with that late May frost. I’m not so sure about apple folks, but, yeah, I’m sure that apple growers deal with a lot of the issues that all crop growers do, which are flooding, excess wetness, drought, if it may come up. So, we’re really here to help anybody out as they need it.
Monique Rivera: All right, that’s awesome. Thanks for sharing with us today, Savannah.
Savanna Shelnutt: Definitely, anytime.
Pathology Updates with Dr. Kerik Cox
Okay, well, let’s see what we have going on for this week in the apple scab forecasting system. Everyone should be well into green tip at this point, all varieties, almost everywhere should be in green tip; maybe as you move north, there’s still a couple that haven’t quite hit it yet, but it’s going to be warming up enough that I think it would be worthwhile to, even if you’re not at green tip, double check and maybe set your model back and see how the predictions go this week.
The first place we have up is Riverhead, Long Island, and we believe in this particular instance, the models may have accumulated heat units a little too quickly since January, taking in those heat units in February, but the trees weren’t really using them to the same extent. And right now it’s predicting a green tip date of March 7, what was probably actually more like March 21. Now, all that being said, if you change this green tip date, you’re going to see that if you change it, leave it at March 7, it’s going to say it’s 22% discharge coming up this week on April 11. But if you move it back to maybe more your actual green tip date, it’s going to be closer to 14 and will not indicate that much of a threat from apple scab. So that’s one thing to consider going forward. It looks like you haven’t come off of a big infection period, so I think you’re fairly safe to stick with your protectant mixture of Captan, Mancozeb in that particular instance, or you could go in with a little bit of a stronger hitting material, it’s going to be a little warmer, maybe this is your chance with the big infection event to use a Syllit (dodine) or a Scala or Vangard with your Mancozeb and go in with a little bit more punch against any potential apple scab that would be coming up.
As we’re moving back up a little bit into the Hudson Valley, we are looking at an instance where they’ve just come off of a fairly heavy wetting period and are going into a brief extent of dry weather that’s going to pick back up again on the 10th with a pretty decent sized infection event. Now that infection event will change depending on how you move the green tip date. If you’re thinking, “Oh yeah, green tip, really? on the 24th?” You’re going to see that infection daily discharge drop from about 14 or 15 to about 7, meaning it’s not so scary. So, depending on where you are, these things could have accumulated more or less ascospore potential. And in this instance, I might recommend doing a little bit of that reaching back and protecting forward by going with some Mancozeb and Scala or Vangard since it was really cold right after this infection period. And who knows, maybe it picks up something and then it will protect you forward for the big event coming up on April 11.
As we move into Voorheesville and sort of the Albany area, it says, oh, you’re not a green tip yet, but let’s catastrophize a little bit and move our green tip date back a bit and you’ll see a similar picture. Just coming off of an infection event; had you had mature ascospores on this last Friday and moving into something coming up again on Thursday. I think in this particular instance, if you’re there, you can just do fine with protectants, your Captan, your Mancozeb combo, or your Omri-approved protectant materials, and you’ll be okay going into the end of the week. I mean, it is increasing and depending on when your green tip date is, it’s going to change these numbers and make that daily discharge amount a little higher towards the Thursday April 11. So watch that.
And then in Peru, looking at a very similar situation, you’re at green tip, but let’s just move it back anyway because we’re all terrified. I’m going to move back to March 27th. And you’ll see that a very similar situation. Capital cold, cold, cold. And not enough maturity has been present to make that big daily discharge a really high percentage, it’s a low percentage. So you could probably just keep getting by with managing and really no need for the single site materials at this point. Use your protectants, your Captan, Mancozeb, or your Captozeb mixture and just sort of, you know, protect yourself going forward. And I don’t think you need to have worried so much about the big event on Friday [April 5]. But if you sprayed something, with all the rain, it might be washed off. We believe an inch of rain or so may wash some of your protectants off. So you’ll probably want to put something or recover before that big event on the 11th.
Moving into the Finger Lakes – Similar situation we’re in green tip or have something coming. If we move the green tip date back, our ejection will go from 11% to more like 4 or 5 in that particular instance. We have a shorter period of time coming off this wet weather that’s presently on the ground today and before going into the Friday. So it gives you just a blip between the 7th and 9th to recover with some protectants to sort of manage this sort of issue. It’s approaching the period where you might want a single site. And if the rain becomes more intense, you might want to move up to sort of a Mancozeb – Syllit combo. You only get two applications before pink and it would be a good material going in strong against scab, or the Scala or Vangard if it’s cold. But looks like we’re going into the sixties, so, I might lean more towards the Syllit for the Finger Lakes.
Heading up around Sodus, similar situation, just coming off of one infection and going in to another. It’s going to be a little cooler. They probably wouldn’t need to worry so much about going in with a strong single site material on Friday. Lower maturity should be a little cooler up near the lake. If it’s warmer in your area and it’s saying a lot warmer temperatures and higher maturity than about 7%, then you could worry. But I think now you can just sort of coast through on protectants.
Niagara area, depending on where you are, it could show that you’re going into a very brief period on the 7th through the 9th to get in some coverage before it stops getting wet and just sort of maintain. It’s really predicting an 11% ascospore discharge and that’s assuming you hit green tip on March 12th, and like I said, you move these things forward and you’re really only going to have a 5% discharge, indicating you can probably just creep in, maintain coverage and you’ll be just fine.
Okay, well, we had a really cool period last week, and for this week on Scaffolds, we’ve had some hot weather finally, and I would say it’s almost time, or just about time, where every place at least has a few varieties finally at green tip. Now that they’re at that point, let’s talk a little bit about managing apple scab from green tip to bloom and what we might want to start to do in the early season. Now that we’re past green tip, it’s always good to get protectant fungicides on for apple scab. And even though they’re protectants, you get the best control and the most cost-effective management with these, if we time them according to the infection events predicted by the weather conditions. And it’s always advisable to use some forecasting system, such as the NEWA system at NEWA.cornell.edu. And this is going to help you identify predicted ascospore releases and potential infection events such as the one coming Thursday April 11, and it’s going to improve application timing, cost effectiveness of any fungicide investments.
And regardless of which disease simulation you use, whether it’s NEWA or another one, I think it’s best to put your best fungicide feet and your best materials forward, just prior to predicted large releases of ascospores, you know, greater than 15% discharge is a big event. And in this early season, depending on when these things had initially started flying and when green tip was, we could see a considerable difference in the amount predicted to discharge if green tip happened much later in the season than much earlier, as predicted by some of the standard pages of NEWA. So, even if there’s not a big discharge event coming, it’s always good to maintain a little protection, even for some of those lesser events that are lesser than 15%. Now, if it’s on one of these weeks where there isn’t a lot of discharge or any wetting periods, this is a good time to try one of those bio pesticides if you want, these are the types of events that you can use those very safely, the less than 15%. Now, if you’re having a different production paradigm, you may not have a choice and you may need to use these anyway.
All right, so one of the most popular programs for the early season management of apple scab consists of a tank mix of Captan with Mancozeb and at the half maximal rates for each product. That’s for Captan 80, about 2.5 pounds per acre, 100 gallons ,or Mancozeb 3 pounds per acres, of Mancozeb 75. We usually refer to this combination as Captozeb because of the excellent residual sticking power of the Mancozeb and the wonderful redistribution properties of Captan. You’re not going to get post-infection activity and you want to get it on before the rains. It can weather, but it should give you pretty good protection for about seven days or at least a good inch or so of rain.
Now, prior to bloom, I think it’s still best to stick to the protectants. Mancozeb, Captan, copper, and there’s a lot of single site fungicides that could be very effective at this time, but I think it’s best to start saving them for post bloom and then beyond petal fall when you’re starting to get disease pressure for powdery mildew, rusts, apple blotch, bitter rot, fly speck, sooty blotch, all of this increases. The protectant fungicides aren’t very effective against these diseases and I think when those come in, later towards the end of bloom, it’s best to save as many applications of single site fungicides that you can. Now all that being said, there are a few single site fungicides that are really only effective against apple scab and these would include stuff like Scala from Bayer, Vangard from Syngenta, and Syllit, which is dodine marketed by UPL and sold by them.
Now if we have several days of rain as you start to get close to bloom, it’s important to use one of these single side products as they’re going to have a little bit of post-infection activity. The Scala, the Vangard work really well in cold weather, and at that time they have a little bit of curative or kickback activity. Syllit it’s generally pretty good all around, it doesn’t necessarily need cold weather and it should provide reasonable kickback activity. The resistance that seems to be present seemed to have diluted out over the last 30 or 25 years and it actually works pretty well.
One of the things that we are a little concerned about is the use of fungicides in kickback or curative mode. It’s really no longer recommended to apply them for post infection activity intentionally. You don’t want to let a bunch of infection build up and then put them on. What you want to do is go in, protect against an infection event. And then if you have to use them, think about them instead, is making the applications between infection periods with a focus on protection against the next one. That being said, if something just happens, you can put one of these materials on just after the event and you can then sort of get a little bit of that curative post infection activity, but then also protect the entire rest of the week against the next infection period. So that sort of being the idea, if you have a little infection period you’ve just passed, but you’ve had protection materials on prior to that one, you’re concerned about it being washed off, maybe using one of these specific apple scab single site fungicides just right after the infection period, and then prepare yourself, such as the one we are having on Thursday. We’re coming in off a kind of cold, wet, rainy period. Perfect opportunity to start the week off. Now that you can finally get back into the orchards with the Scala or Vangard, really good at those cold temperatures. And if something slipped through and all that rain, even though it was very cold, it would sort of clean that up. But also, when put with Mancozeb, protect towards the big infection period that we have on Thursday as well.
And then the one thing about Syllit is it’s quite effective and has some of the strongest kickback activity or curative activity I’ve seen in recent years. Even in orchards that were formerly resistant, you can only use it twice before pink, so consider using those now. And there are other options as well, like the Cevya, Luna Tranquility, Luna Sensation, Flint Extra, Fontelis, Merivon, Rally, Rhyme, Inspire Super, Tesaris, Miravis. These all have great curative activity, but they’re still going to be good protectants because they’re generally a little less water soluble, allows them to persist a little bit better than their predecessors, maybe at the cost of a little bit of post infection activity. But that being said, they’re more recalcitrant to the fungus’s ability to develop resistance. And then, of course, with many of these, as I mentioned before, as we move into bloom, you’re going to want to save these other materials I just mentioned, the Cevya, the Lunas, the Merivon, the Rally, the Rhyme, Tesaris, and Aprovia, for those other diseases that are going to start coming in, especially apple powdery mildew, which will be coming in a little bit later. All right, that’s it for this extra little blurb, and I’ll see you next week.
State of the State with Anna Wallis
And now for the state of the state, your weekly roundup of phenology and degree day accumulations from the major fruit production regions of the state. I’m Anna Wallis and I’m sharing information that we’ve aggregated from regional specialists including Mike Basedow, Janet van Zoeren, Mario Miranda Sazo, Craig Kahlke, and Dan Donahue. It also includes our own observations, and information collected from NEWA.
For the most part, the past week has been pretty uneventful. We had cool temperatures across the state, which kept trees at about the same phenological stage, and we’ve only accumulated a handful of degree days. It’s good news, since temperatures in the month of March were about three to five degrees warmer than average across the state, so this cooling trend has been welcomed. It was also among the 20 warmest Marches on record, according to the Northeast Regional Climate Center monthly regional analysis. There are some really excellent maps on the Northeast Regional Climate Center website showing monthly precipitation and temperatures, including monthly averages and departures from normal. Link here https://www.nrcc.cornell.edu/.
The precipitation map from the NRCC website showed huge disparities across the state. It was “sopping wet” for some from their regional report, including up to eight inches in some parts of the Hudson Valley, while western New York was below average with rainfall accumulation with only two to four inches in most places. This past week, we had ample rain across the state with over an inch from Tuesday to Wednesday and more coming this week. While I’m talking about precipitation, I want to give a quick public service announcement about rainfall gauges and weather stations. If you own a NEWA weather station or any other weather station, don’t forget to keep the stations clean and calibrated. The rain gauge should be really easy to clear of debris and it can have an enormous impact on accuracy of your precipitation data. Remember, this is essential for predicting infection events such as scab and other diseases.
Back to cold temperatures – we did experience a couple of cold nights, including Friday and Sunday evenings this past week. In some locations, NEWA stations recorded temperatures in the upper twenties, but we shouldn’t be too worried, at half inch green, we should need to see temperatures in the low twenties to have any significant damage, for apples. And similarly, peaches, cherries, pears, which are at bud burst or early swelling buds, would need to experience temperatures in the low twenties to sustain damage. Dan Donahue has been checking this in the Hudson Valley in a couple of places and he’s seen insignificant damage at this time. Even apricots appear to be strong this year. You can find a link to the Utah State Critical Temperatures for frost damage here [https://extension.usu.edu/productionhort/files/CriticalTemperaturesFrostDamageFruitTrees.pdf].
Our cool streak is about to change though. This week we’re seeing warming temperatures and additional rain which will definitely move things along. I really enjoy the Climate Smart Farming tool that shows a degree day accumulation graph for the location and base temperature selected by the user compared to the 15 year average and the 30 year normal. It’s showing mostly a flat line for the past week for degree day base 43, and then the forecast spikes up indicating the warming trend in the forecast.
This week for phenology across the state right now, in the Hudson Valley, apples are at about quarter inch green. Quarter inch green 50% for McIntosh was about this Monday, April 8, we’re seeing half inch green in some varieties that are a little farther along. Early varieties such as Pink lady in the lower Hudson Valley are approaching tight cluster. Pears are about bud burst. Peaches, cherries are at bud swell and apricots are in bloom.
In Western New York, in the Lake Ontario region, most apples are about quarter inch to maybe approaching half inch green in some places. In some locations it’s further along. This seems to be a little bit site dependent. In general, there are similar degree day accumulations and phenology in western New York compared to the Hudson Valley.
This year in the Capital Region, McIntosh is about at green tip. Some earlier varieties like Zestar are closer to quarter inch green.
In the Champlain Valley in Peru, Mike Basedow’s telling us that there’s a little green tissue that he’s observing in early varieties like Pink ladies and Zestar. Varieties like Honeycrisp and Gala are still at silver tip.
A few upcoming pest events to keep your eye on. We’re continuing to see red banded leaf roller and speckled green fruit worm flight in the Hudson Valley and western New York. Pear psyllid eggs have been observed in both locations. Now’s a good time to be scouting for black knot on all stone fruit. You should also be scouting for scale in all tree fruit. Looking on the limbs, this can pop out and be very red for San Jose scale when the trunk is wet. When it’s dry, it can look more like a dark sheen, especially if you have a really large infestation. Also be on the lookout for trunk borers, which could start to become active around this time. It’s a little bit early, but on warm, dry days you can start to scout for ooze in places where you had fire blight last year, and also be on the lookout for powdery mildew in opening buds. You can see that as twisted or distorting tissue as the buds start to emerge. That’s all for now, and good luck until next week.
Degree Days with Kelsey Tobin
Kelsey Tobin: Hey everyone, it’s Kelsey Tobin here to give you the current degree days in the major fruit producing regions of the state, as well as the projections through the end of the week. As you know, by now we’re correlating the phenological information with some previous work done by Art Agnello relating to historical McIntosh phenological averages and degree days.
Things are starting to warm up and we’re seeing different phenological stages throughout the state. So historically for McIntosh, at 43 Fahrenheit base temperature, silver tip is between 58 and 106 degree days. Green tip is 99 to 144 days. Half inch green is 150 to 201 degree days. Tight cluster is 206 to 257 degree days and pink is 267 to 316 degree days. That covers where we are throughout most of the state right now. Going forward, we’re going to start reporting degree days as Baskerville Emin corrected, which is just a different way to calculate these degree days when the minimum daily temperature is below the base temperature for development, it provides a more accurate measurement, especially in the spring when we have low evening temperatures that are below 43 Fahrenheit. These numbers are going to sound pretty different from our reports last week, but it’s a better representation of what we’re actually seeing in the field.
So for the degree days from January 1 to now, Geneva is at 142 degree days, projected 212 by the end of the week. Highland is at 164 degree days, projected 238. Clifton Park is at 98, projected 159. Peru is at 57, projected 97. Medina Inland is at 156, projected 222. Appleton North Lakeside is at 123, projected 168. Williamson Mason Inland is at 126, projected 184, and Williamson DeMarree Lakeside is at 142, projected 186 by the end of the week. We are starting to have some steady, warmer temperatures this week throughout the state and so we’ll be accumulating quite a few degree days and phenology will be moving right along. Hopefully spring is here for good. Until next week.
| McIntosh Phenology and DDs (43F BE) (avg +/- std) | |
| Phenological Stage | DD Accumulation |
| Silver tip | 58-106 |
| Green tip | 99-144 |
| Half-Inch Green | 150-201 |
| Tight Cluster | 206-257 |
| Pink | 267-316 |
| Bloom | 344-415 |
| Petal Fall | 439-523 |
| Phenology and DDs (43F BE) for NY NEWA Stations from 1/1-4/8 | |||
| Station | DD Progress | End of Week DD Projections | Phenological Stage |
| Geneva | 142 | 212 | Green Tip |
| Highland HVRL | 164 | 238 | 1/4 ” Green |
| Clifton Park | 98 | 159 | Nearing Green Tip |
| Peru (Forrence) | 57 | 97 | Dormant |
| Medina – Inland | 156 | 222 | 1/4 ” Green |
| Appleton North – Lake | 123 | 168 | Green tip |
| Williamson (Mason) – Inland | 126 | 184 | 1/4 ” Green |
| Williamson (DeMarree) – Lake | 142 | 186 | 1/4 ” Green |
Monique Rivera: That concludes this week’s update. Thanks for listening.
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