Scaffolds 2024 Digest: Week 9

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

 

Monique Reviews Plum Curculio, Aphids

On this week’s episode, I discuss insects to consider treatments for at petal fall. Kerik gives us the disease forecast, and Anna gives us our weekly update on tree phenology and degree day accumulation.

No guests this week, but I do have a couple things that I’d like to talk about. So let’s start out with plum curculio. Right now, they are really in their egg-laying-oviposition stage, and with this intense heat wave coming up over the next three days, that should be even more apparent. They only have the ability to lay so many eggs per season, so it’s important to catch them when they are active. And right now we’re in this post-petal fall timeline, and the warmer this post-petal fall period is, the quicker they actually finish ovipositing. So it’s really important to try to time this and catch them very soon. Also, the long-term forecast will be instrumental in trying to decide how many cover sprays might be needed after petal fall to adequately protect the orchard, even throughout oviposition. Most orchards will have probably received their petal fall spray last week or the week before or maybe this week. This has been a really long bloom period, so people making that call, you know, it will diverge across the region, and we have just started to see damage now. People are starting to say that they’re seeing the plum curculio damage in the field now.

The way to look at this in terms of trying to figure out where you are in their particular life stage would be using NEWA. So in NEWA, you put in your petal fall date, and it will tell you approximately at what stage the pest is at. So for Geneva, when you pop this into NEWA, it does show that they are in the oviposition stage. Additionally, if you have rosy apple aphid colonies active in your trees, now would be a good time for potentially an Actara application. This has a good activity on both species. Now, unfortunately, this is definitely going to batter your natural enemies. But plum curculio is very difficult to control, and it can do a lot of damage if left unchecked. So with that treatment, you’re really going to want to continue to watch out for woolies, because as you knock your natural enemies at this time, you could really see them explode further if you have some tame colonies going on right now.

The next pest of concern is San Jose scale, and this is about the timing when we would see the males emerge and the crawlers should be coming out any day now, at least in Geneva. So the females of this species produce live crawlers within four to six weeks of mating. And these are the insects in the life cycle that we want to target because they’re actually moving around. These crawlers will make their way to new sites and then insert their mouth parts into the tree, and then they secrete that white waxy covering that eventually darkens to black. San Jose scale infestations on the bark can contribute to the overall decline of a tree and reduce its growth and productivity. So this is a pretty dangerous pest if it is out of hand. Additionally, fruit feeding causes distinct red/purple spots that can decrease the cosmetic appeal of the fruit, and so we recommend insecticidal sprays to be most effective when directed against the first generation crawlers, and specifically timed for the first and peak crawler activity, which are usually about seven to ten days apart. In the Geneva area, where we are here at AgriTech, the first crawler emergence usually occurs sometime around mid-June, but I would say we’re moved up about two weeks in terms of the phenology and with a long bloom that’s also making this quite weird to make calls from other years.

So if you have this pest and you’re monitoring, you can monitor using black electrical tape where you’ve had previous infestations, or you see the scales, you can go ahead and put this black electrical tape nearby those areas, and that will trap the – of course, the black electrical tape needs to be sticky side up, and that’s how you’re going to catch these crawlers. They’re very tiny, and they, you know, any kind of tape will probably work, but the black electrical tape is more heavy duty than, say, Scotch tape.

So the idea is, is that if you have these and you’re finding the crawlers, it would be ideal to use Esteem against them. Esteem also, although it’s not labeled for this, may also have some activity against woolies. So thinking about those curculio sprays and this Esteem spray, maybe trying to follow up that Actara treatment for plum curculio and rosy apple aphid with an Esteem treatment to see if you can knock back two to three weeks after with that Esteem treatment to ensure that you’re also maybe targeting woolies at the same time. Again, that’s not on the label, but anecdotally heard people say that this can be useful.

Our trees are pretty much leafed out at this point. So I’m going to belabor again for these treatments, in particular, woolly treatment, 100 gallons per acre. I know it’s a pain, but I think we really need to get the coverage into the canopy for woolies so when you do that Esteem treatment, although, well, San Jose scale is also on the interior of the tree. So I really think that for that Esteem treatment in particular, making sure that’s 100 gallons per acre would be very helpful to getting the most out of that product.

So Esteem is another one of those products, which suggests that putting an oil in could improve penetration. I know the timing on this is horrible. Same thing if you’re doing a petal fall spray of Movento. So if you can dodge the captan interaction and use the oil as an adjuvant, that is very helpful.

So those are the insects that I think we should be thinking about right now. Next week I’ll have another guest on and we will have a conversation about internal leps.

 

Pathology Updates with Dr. Kerik Cox

Okay, let’s look at the weekly forecasts. This is tree fruit pathology. This is Kerik at Cornell AgriTech. And we’re going to give you the rundown. This is probably one of the last weeks I might even talk about things like apple scab. But I am going to show you for maybe a week or two longer some of the wetness and how it might influence the dregs of apple scab and some of the newer diseases that come out shortly after, including our apple blotch or Marssonina blotch as well.

Let’s take a look at Riverhead, Long Island. You should be long done with apple scab and look – easy week for fungal diseases. It is pretty fairly cool. Not like the rest of the state, very little leaf wetness, not a lot of rain. Should be easy going. I wouldn’t worry about fungal diseases this week.

I’m going to stick and go through everything with apple scab first because fire blight is a lot more interesting.

Let’s move up a little bit to the Hudson Valley, see how their fungal weather looks. Real easy, similarly easy as well. Not a lot of leaf wetness. The apple scab season is over with just some temperature, a little bit of wetness in the terms of leaflets, probably a little bit humid on the 20th and 21st, making things a little more scary for fire blight if there’s any flowers left. But apple scab and the fungal disease, this should be an easy win.

Moving into Voorheesville in the Capital District area, let’s take a look. Similar situations. If anything, the wettest of the days are presently and moving into the 20 and 21st. After that, things get really kind of dry. It might start becoming easier for us to manage our apple diseases. And I definitely don’t want you to focus on managing a lot of apple scab at this point in time. I think it’s a little bit more important that we focus on fire blight coming up.

Let’s look up into the Champlain Valley in Peru. They could still have some apple scab left. And yes, they’re still at the last little bit. In this particular case, it’s not really called for an infection, but you should get some ejection. The last little bits of it, maybe like 11% or so. If you were going to spray for fire blight and you hadn’t put anything on, I’d put it on before the 20th. Looks like there’s not a lot of leaf wetness predicted. The conditions are perfect for ejection, but there’s not a lot of wetness produced in the area. Probably not actually leading to an infection event. In this case, these spores will probably eject and dry out. Maybe you don’t need to worry about fungal diseases at all in this place as well.

Let’s take a look, moving into the middle of the state. Let’s go to internal again, Finger Lakes area. Looks like you’ve just come off an infection period. Yep, probably had a little bit of rain last Thursday, Friday, or Friday, Saturday, and combined infection period coming up. But going into another week of very low leaf wetness. Maybe a little blip on the 20th, but other than that, you’re excellent.

I suspect that when we head up to Williamsburg in the Sodus area, things are going to be looking as well. Coming in again off of another little wetting period. I don’t think you need to rush to get in there and cover those trees for apple scab. A little blips of some wetness, but really no ejection. All the ejections essentially over in that region as well.

And then we’re moving into Niagara. I think we’re really doing well, with Appleton was just coming off of an infection period. If you’re protected against it, you should be in great form. Coming into the week, just little blips of leaf wetness is probably due to dew. And relative humidity greater than 90%. Now, that’ll present a bigger problem for fire blight if you still have flowers on the trees.

So let’s get right into it. Let’s start back at the beginning and look at fire blight. This is the type of trend that I’m seeing now throughout the state. We’re finally coming out of a cold, cool bloom. Yeah, there’s been a couple high days here and there. But for the most part, looking at the season, I just picked Geneva, but a lot of the other places look fairly similar. Coming out of a really cold bloom without a lot of things. You see, I’ve sort of artificially cheated a little bit, put my first blossom open there, so it would show me the terror that is actually showing up tomorrow, if you will. And it shows things, it’s been sort of ups and downs a little bit. Highs there, but extremes. But look, once again, we’re going into Memorial Day weekend with a lot of hot weather coming later in the week, and I’m going to talk about that and see what it looks like in Riverhead. And right now, the model is going to tell you it’s done. You’re over. All the flowers are off the tree. But if you had very susceptible-looking, uh, maybe cider apples or other cultivars and a little bit of rat tail bloom, you can make the model show you what you want to see by moving it up forward. I’m just going to put it in May 1 for the first blossom open day. And Riverhead, kind of as it shown with apple scab, looks pretty cool. Great during the week. Low TRV values even on the 20th and 21st. And moving into the Memorial Day weekend, you will not have the Memorial Day heat streak that I showed earlier. You’re off the hook.

Now let’s move into the Hudson Valley area and see how they look if you have blossoms lingering on moving into that area. Yep, the terror is here, as you can see, as we’re going into the beginning of the week on Monday, we’re starting with TRV values at 500, greatly increasing right up to the 21st with EIP going over 100 and into 180 and almost 200, 200 to 300. These are the highest EIPs we’ve seen over the entire season. And if there’s anything left on the trees, things can get kind of pretty intense. And you can kind of see the water is coming on the 20^th and 21st. So sometime around there, if you had anything left on, very susceptible trees finish strong because we’re at that last crunch, and anything that happens here could lead to some trouble.

Let’s move up in to see how Voorheesville is doing in the Capital District. Same situation. Looks like they had a really hot and very strange day on the 18th. TRV is around 122, but we got an infection from the Maryblyt model right there. Must have had something to do. I don’t even know. I guess it was just a dip in some cool weather. That came with the storms, but the accumulated heat values in the Maryblyt seemed to pick it up and then clearly had some rain. But going into the week is the big one: the 20th and the 21st for this region, EIP in the 300 and TRV is getting as high as 1300. That’s the day I would do it, tomorrow [Monday May 20] or Tuesday. It looks like the event is just wetness. And remember, just with a heavy dew you can cause trouble. I think I would probably maybe try to put something out tomorrow if I still had susceptible flowers on trees and rattail bloom. If you’re not, it’s a complete petal fall.

Let’s take a look at Peru, which probably is not in the complete petal fall, and see how we’re doing in the Lake Champlain region. Same situation. It says today’s [Sunday May 19] the big day, worse with infection and the TRV just keeps climbing into some dangerously high values. If you sprayed for fire blight, as with Mike’s message on Friday, you were probably golden for this infection event and did quite nice because it doesn’t look like the rain is going to get you as badly into the next week.

Moving into the Finger Lakes region, it says we’re done, but I’ve seen enough flowers on my own trees to know we’re not done. And this is what it looks like once again moving into today. Um, that hot weather, a little bit of dew, but it looks like tomorrow will be the big one. My guess, yep, there’s a little blip of leaf wetness and we’re moving into those dangerous EIPs over 100, and TRV is getting into the week. Things are going to remain over 100 throughout Memorial Day. I think if you squash it now, you’re going to be fine.

Let’s take a look at the Sodus area, Williamson, all right, let’s see, bring an open date. Let’s move the model, says everything’s done, but you probably have a cultivar that’s not done. Let’s see what it looks like. Things look pretty good here up along the lake area. And yep, you’re getting into 100, but you’re not going to hit it just until the 22nd and things are going to cool down for the weekend, allowing you to enjoy Memorial Day. In this case, you have a little more time to be agile with that. Water must be predicted on the 23rd or so, right at the crux of weak temperatures. I think I would go out on the 21st if I wanted to finish strong fire blight this year.

Heading up into Appleton says you’re done. Are you done. Who knows? Um. Only you can tell. Once again, coming up 21st, 22nd. You got tomorrow to get it on, um and remember, if you want to go Kasumin, go tomorrow evening and don’t let that sun break down your antibiotic. And if you’re going Strep, you can go tomorrow morning. But it looks like the real crux of the meat and potatoes and that Niagara region is happening on the 21st. Just the littlest bit of leaf wetness.

 

State of the State with Dr. Anna Wallis

And now for the state of the state, your weekly roundup of phenology and degree day accumulations from major fruit production regions of the state. I’m Anna Wallis with the New York state IPM program at Cornell, and I’ll be sharing information as usual, aggregated from the regional specialists, including Mike Basedow, Janet van Zoeren, Mario Miranda Sazo, Craig Kahlke, and Dan Donahue. It also includes my own observations and information we’ve collected from NEWA. At this point, we’re a little bit more than halfway through the month of May and the average temperatures for the first half of the month were near or above normal for most of the northeast. Precipitation varied across the northeast, with very dry conditions in western parts of the state, including Niagara and Orleans County near Buffalo, and then slightly drier than average conditions in the Champlain Valley with a little bit wetter than average in the Hudson Valley and the Capital Region. We’re in a very warm trend right now and expected to continue that throughout the rest of the week. Highs in most parts of the state are in the eighties and upper eighties [°F]. Degree days in general are ahead of averages in western New York and Champlain Valley. They’re about average for the Hudson Valley and we’re rapidly accumulating more degree days across the state and that’s going to push us even more ahead of average this week. In the six-to-ten-day outlook, according to the Northeast Regional Climate center, much warmer than normal conditions are expected with highs in the upper eighties, and precipitation is also expected to be higher than average. The medium term eight-to-14-day outlook looks closer to normal temperatures with continued greater-than-average precipitation.

Thinning season is in full swing across the state. Farther south, fruit is beginning to size around 8 to 12mm beginning of this week, and petal fall in some of the later locations. We’ve had lots of great weather for pollination in most of the state. There were some rainy days, but at this point we think the probability of pollination was really excellent. We’ve seen a lot of great pollinator activity. There’s a large potential crop in many locations. In some places we’re still evaluating frost damage, so be sure to be doing that as you’re making thinning decisions, both in different parts of your canopy and in different parts of your block, it can be helpful to make maps so you can be thinning accordingly. You can be using the carbohydrate model to be adjusting your rates and timing, being careful with the extremely warm weather predicted in most of the state this week. Also, there are many thinning meetings that are being scheduled in regions locally, both in person and virtually, so hopefully you can attend some of those.

With regard to general insect and disease trends across the state despite the early spring, in many locations it’s been a relatively cool spring and so we’ve seen somewhat little insect activity and disease activity. But with the warm weather expected this week, we expect things to pick up considerably.

Looking at phenology across the state now in the Hudson Valley, degree day accumulations are just a little bit above the 15-to-30-year average, but advancing considerably this week with the heat. Apples are past petal fall; varieties like Honeycrisp, Gala, Fuji and McIntosh measured eight to 12 mm on Monday and Tuesday. Of course, spanning the north and south parts of the valley, pears are past petal fall and beginning to size. Peaches, cherries and plums are at shuck split and also sizing.

We’re seeing OFM peak flight in the valley. It’s variable at Highland at the Hudson Valley Research Lab compared to commercial sites, somewhat sporadic depending on where you are location-wise. Codling moth sustained capture was two weeks ago, the first moth, and so we’re watching that insect and predicting when larval emergence will happen. That’s typically 200-to-250 degree days base 50 after the biofix is set. Primary apple scab season is just about over, with potentially a few more ascospores hanging on that may be able to cause infections. We have a significant fire blight risk wherever blossoms are open, so keep watching the models and protect any open blossoms. Again, you can be using the new feature in the NEWA fire blight model, which allows you to enter your streptomycin application date up to five days in the future, and that can help you select the optimal timing for putting on those applications. We’re seeing a little bit of plum curculio activity this week and last despite the relatively cool nights ahead of that, but with the warm temperature, we expect lots of movement into orchards at this time.

In western New York, the Lake Ontario region, degree days continue to be well ahead of averages and so phenology is as well, pretty similar conditions to the Hudson Valley this year. Many varieties are past petal fall and beginning to see fruitlet sizing. Continue to assess your blossom damage as we move into thinning. It seems to be dependent very much so on location. OFM flight is also peaking and then soon will be tapering again. It’s also sporadic this year depending on location.

Codling moth sustained trap captures in Geneva were last week. This week in Geneva we also had the first dogwood borer and obliquebanded leafroller moth captures.

In the Capital Region, degree days are also above average. We’re past petal fall and the beginning of fruit sizing, potentially at 10 to 12 mm this week. There’s a little bit of damage to kings, but a strong bloom and potentially great set in most locations. Also nearing the end of primary scab and considerable fire blight risk this week are both things that you should really pay attention to.

In the Champlain Valley. We’re well ahead of degree day accumulations again this week with the warm trend again expecting us to accelerate forward. We’re at about petal fall with 4-to-5 mm fruitlets. We’re in the middle of primary scab with that season tapering off again. The hot weather puts everything that is open blossom wise at risk for significant fire blight risk.

And now for a few upcoming pest events. Again, our early season insects have been not very active to date. We’ve seen very little European apple saw fly, just a little bit of plum curculio so far, a little bit of aphids, rosy apple aphids, and green apple aphids. We’re seeing more and more woolly apple aphid activity. Mostly we’re seeing on old pruning cuts, significant wool covering aphid colonies inside the canopy that are somewhat covered by the canopy. Mites, we haven’t seen very much activity to this point, but with the heat this week, we expect to see much more activity. With regard to the lepidopteran complex, again, OFM biofix was set in both eastern and western New York at the research stations two weeks ago, and we’re seeing continued flight this week. Codling moth sustained trap capture was also recorded at both research stations in Highland and Geneva. So we’ll be watching the degree day model, knowing that about 200-to-250 degree days, base 50, from the biofix is when we expect to see larval emergence and insecticide should be timed. OBLR we’ve seen a significant amount of overwintering larvae and other lepidopterans that are similar active in fruit clusters in many places. We usually recommend to get your traps out around petal fall and we’ve already recorded one to two moths in a couple of locations throughout the state with known high populations, so make sure that you’re getting those traps placed as soon as possible if you are doing that this year. We’re continuing to see spongy moth in the Hudson Valley, although mostly it looks like it’s been controlled with petal fall applications, so keep your eye open for that insect. Dogwood borer is usually active after bloom and we have the first few insects captured this week in Geneva. Mites are typically becoming active around this time of year, especially with warm temperatures. So far we haven’t seen too much activity, but we’re looking for them this week. For plum curculio Monique gave a great overview this week, so I won’t belabor that, but make sure to be paying attention and looking for activity as insects move into the orchard after a few really warm days.

And with regard to diseases, again, we’re ending primary scab in most locations and we’re beginning to see the first signs of infections. They’re being reported on the 6th or 7th leaf, which points back to our April infections. So you can be looking around for infections at this time, either as black to brown or sometimes olive green fuzzy lesions on the leaf. And just to reiterate that there are high fire blight risks throughout the state wherever blossoms are open. So be paying attention to the models when looking at that disease.

A few reminders about resources that are available as you’re navigating NEWA models and doing your pest scouting. First, the NEWA help desk frequently-asked-questions and table of contents – This is a new landing page on the New York State IPM help desk for NEWA, and it includes a list of frequently asked questions, including the model tutorials, which are 3 to 10 minute videos organized by crops, and so you can quickly find answers to how to use the models on that page and search through that table of contents. We’ve also created a NEWA quick guide for apple insect pests. And so in addition to those video tutorials, we created this quick guide with the purpose of providing a quick overview for using new models pertaining to a few key insect pests, including plum curculio, codling moth, OFM, and obliquebanded leafroller. A new resource that we’ve started this year is the statewide orchard monitoring network. This is a collection of trap capture information from industry members across the state, including extension specialists, consultants and growers that are contributing to a virtual resource. It includes a dynamic map that you can filter to a specific region, location, timeframe and species, and it produces a table map and graph that you can use to track trends across the state.

And now here are the current degree days in major fruit producing regions across the state. As usual throughout the season, we’re aligning this information with previous work that was done by Art Agnello related to McIntosh phenology and degree days. These degree days are in base 43 Fahrenheit, and as a point of reference, full bloom for McIntosh is around 378 and petal fall is 479. Phenology across the state, and newest stations include Geneva, 712; Highland, 764; Clifton Park, 650; Peru, 541; Medina, an inland site 714; Appleton North, a lake site, 597; Fairville, an inland site 661; and Williamson, a lake site, 650. That’s all for this week.

Hope you have a great Memorial Day and stay safe out there.

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 & DDs for NY NEWA Stations from 1/1 – 5/20
Station	DD Accumulation	Stage
Geneva	712	Fruit Set
Highland (HVRL)	764	Fruit Set
Clifton Park	650	Fruit Set
Peru (Forrence)	541	Petal Fall
Medina – Inland	714	Fruit Set
Appleton North – Lakeside	597	Late Petal Fall
Fairville (The Apple Shed) – Inland	661	Fruit Set
Williamson (DeMarree) – Lakeside	650	Fruit Set

 

Upcoming Pest Events

Pest/Phenology Event || DD Base 43˚F || Approx. Date

Full bloom (McIntosh) || 378 ± 35 || 10-May ± 6 days

OBLR Overwintered Gen. Sample || Bloom

Codling Moth Traps set out || Bloom

Lesser appleworm – 1st catch || 420 ± 144 || 13-May ± 12 days

American plum borer – 1st catch || 457 ± 64 || 16-May ± 7 days

OFM – 1st flight peak || 369* ± 91* || 15-May ± 11 days

Codling moth – 1st adult catch || 475 ± 85 || 18-May ± 7 days

San Jose scale – 1st adult catch || 533 ± 88 || 21-May ± 8 days

Cherry fruit fly traps set out || 20-May

STLM – 1st sap-feeding mines observed || 472 ± 129 || 18-May ± 13 days

Petal fall (McIntosh) || 479 ± 42 || 18-May ± 6 days

Lesser appleworm – 1st flight peak || 569 ± 205 || 22-May ± 13 days

Plum curculio – 1st oviposition scars observed || 555 ± 77 || 25-May ± 9 days

Pear psylla – hardshell stage observed || 569 ± 87 || 22-May ± 9 days

Lesser peachtree borer – 1st adult catch || 570 ± 94 || 24-May ± 8 days

San Jose scale – 1st flight peak || 644 ± 89 || 29-May ± 8 days

ERM Sample – 2.5 mites/leaf || 1-Jun

OBLR traps set out || 1-Jun

Black stem borer – 1st flight peak || 681 ± 170 || 1-Jun ± 9 days

RBLR – 1st flight ending || 753 ± 140 || 2-Jun ± 8 days

American plum borer – 1st flight peak || 784 ± 183 || 3-Jun ± 9 days

Codling moth – 1st flight peak || 768 ± 206 || 3-Jun ± 12 days

 

*Base temperature for OFM 45F