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

 Entomology Update with Monique Rivera 

So let’s jump right in to thinking about some considerations for treatments at Petal Fall.. So let’s focus on what we might be seeing coming in very quickly. A couple of those things are plum curculio and tarnished plant bug. Plum curculio I think could be easily managed with an application of Minecto Pro. The reason why I like Minecto Pro is because this also has high activity against the LEP pests, which are also worth considering at this time point. So right now we’re targeting the plum curculio that would be moving into the orchard and ovipositing. This is a critical timing to get this application on if you know you have a population of plum curculio locally because they will just generate more of themselves in your orchards. So the other treatment options, if you’re not into the Minecto Pro suggestion would be Imidan, Actara, Avaunt, and Verdepryn.  

Tarnished plant bugs are a complex pest because where they are happening, they are happening quite bad. And they feed on buds and flower parts in the spring, which can cause aborted fruit. So this is definitely a thing to consider if you’ve had this in the past. Unfortunately, pyrethroids are the main group of insecticides that are suggested. It is early in the season to be using this because you are going to also knock back your beneficial populations, which could flare European red mite. So I’d be very careful about that. So recently I’ve been focusing more on recommending trying to control the broadleaf weeds in the row middle as an approach to indirectly managing them.  

So lastly, woolly apple aphid. We have not seen any of this in any of the blocks that I’ve been scouting in western New York. It’s just too chilly. But I do anticipate over the next two weeks that things are going to escalate quite quickly. What we’re recommending is Movento at Petal Fall or the first cover spray. But you probably could get away with delaying this a couple of weeks if you’re already at Petal Fall.  

The other pest that I have been hearing has been outbreaking in certain locations is the apple leaf curling midge. And the current recommendation there is Exeril. There’s nothing else recommended at this time, and I have not played around with this pest, so I don’t have any other good additional suggestions. My guess is that this is the only product labeled. 

 So also keep on the lookout for rosy apple aphid is moving in around this time, along with San Jose Scale. So with San Jose scale, now is a good time to start monitoring with black tape, and your soft insecticide application of Movento targeting woolly apple aphid will also take care of San Jose scale if you have a history of this in your orchard.  

 Next week I will be having Dr. Jason Londo on and we will be discussing the freeze. So we had this late season cold period and many pocketed areas have had very bad effects and lots of loss of crop. So I’ll be talking to Jason about that and we will talk more about these cold snaps and what the effect on the fruit is horticulturally. So looking forward to that next week.  

 

Pathology Update with Kerik Cox and Liga Astra Kalnina 

So today, I think, is going to be the third part of my three part series on fire blight guidelines for this 2023 season in New York. Luckily, we have a cool wet season and it’s really hard for those populations to build on those flowers. I’ve been taking flower counts, and they’ve been sort of seesawing even on completely untreated trees from like a bunch to nothing to nothing and then a little bit with every little blurp of the weather. But it’s not staying hot enough for long enough to really let those populations really begin to grow on the flowers, if any are left. We’re after petal fall. We’ve done the western New York petal fall meetings. Things are looking pretty good.  

 And now I’m going to begin part three of my fire blight series, the quick guidelines for on-farm nursery production. If you want to do it, be very careful because this is a great way to spread fire blight to yourself or wherever you take the trees after you make the budwood.  

 The first one, always collect budwood from orchards where you’ve never really seen fire blight or from any other neighboring block or farm that’s never had fire blight. Don’t collect any from anything that’s ever had fire blight that you can see, if you can help it, just because these things like to hide out inside bud tissue.  

 Second, try to keep that streptomycin down to about two to three applications per season and rotate in the kasugamycin from time to time, swap back and forth, because the last thing you want is any resistant fire blight bacteria inside the budwood that you’re going to propagate and the nursery plants that you’re making. Also, when you do make them, use one of the disease forecasting tools. If you don’t like it, just use a CCE alert. The people will be making the forecasts for you. Or even listen to this podcast about the forecast. And, you know, when fire blight is high and the shoots are actively growing after bloom. And make sure to apply one of those coppers at that sort of lowest rate and keep making sure that the tissue was covered throughout the rest of the growing season while they’re moving and with one of those low rate post bloom type coppers.  

 Okay, before you do anything in a nursery block, especially if you’re going to work on plants, plant things, cut stuff, anything with a potential damage, it’s probably good to make sure the trees are protected with copper at the lowest rate. If you do any pinching or twisting, try to do it on dry, sunny days. Shoot for most cool, dry, sunny days as possible. We’ve had a bunch of these already. You can tell when you drive your vehicle down the road at your farm and it kicks up all the dust. You’re like, oh, it’s dry, it’s cool. This is a good time for one of these types of things. And make sure that after you’ve done pinching, twisting, or any of these other things, put on the application of one of those post blooms, low coppers, especially after the REI is over.  

When you’re working in the nursery field, everyone should wear clean clothing. Everyone should wash their hands. This is where GAPS practices will also keep you from getting fire blight. If you’re working with a lot of different tools, it doesn’t hurt to sanitize them with 70% alcohol, Lysol or a Clorox sanitation wipe. You can sometimes keep the sanitation wipes on your belt. You can keep a little mist bottle of alcohol on your belt as well. Clean and wipe.  

If you ever do get fire blight in the nursery, remove the infected trees, including the root systems, and place them in a trash bag between rows. Subsequently, get these trees out and discard them. If they’re still actively growing or they’re still alive before they die and dry up in your rows, they can end up spreading things, particularly if you have a pop up thunderstorm. And whatever you do, don’t leave unbagged infected trees in the rows when they’re wet. You could get all kinds of spread throughout the rest of your nursery block.  

Always look out for the potato leaf hopper. Make sure they’re down because those things might be in your nursery blocks and causing trouble. Also, keep weeds down. Why weeds? Well, a lot of times weeds will keep humidity in the area and sometimes it takes just a little bit of humidity to cause a fire blight infection. And there are some residual herbicides registered for nurseries.  

Once you have your trees at a desired height, don’t let them keep growing. You can even put on Apogee at 1 to 2oz per 100 to sort of slow down any overly vigorous nursery blocks. And also, as usual, just manage your nitrogen levels to balance tree growth. Try to keep that excessive vigor under control and avoid any rapid elongation. You just want the plants to be alive and established. You don’t need them to be taking off and hitting that top wire in a nursery block.  

And those are my thoughts for the nursery. The last things I wanted to add is some cautionary words. We’re going into thinning times and a lot of the thinning recommendations are going to be coming out next week. I want to go ahead and caution against Captan. Depending on where you were, Terence may or may not have recommended putting in some Regulaid. If you get these complicated tank mixes, just leave the Captan out for the thinning period. If you’re going to be managing some diseases, the best recommendation is to include some of the single site fungicides belonging in the SDHIs, the DMIs and those premixes of QOI/SDHI such as the Merivon and the Luna Sensation Group, the Aprovia group, and Miravis and many others. The Fontelis for some of the SDHIs and the Cevya, Inspire Super for DMIs. You can put these on. Don’t put Captan with them because the tank mixes are getting complex. If you use some of the materials that have two fungicides in it, you’re going to get some built in fungicide resistance anyway. Now if you’re really worried about Captan in this part as well, you can add in a little bit of Double Nickel or Howler. They are some of these other types of biologicals for a little bit of resistance management if you’re worried about it.  

We’re going into the summer disease period. I’ll talk about that a little bit next week. Captan at these points can still cause a little bit of injury. You might have frost damage, and the last thing you want is a bunch of Captan. Under this weather, if it is cool and kind of wet outside like it is outside my office today on Wednesday the 24th, this would be a great type of weather to ruin your young fruitlets with a captan application. So let’s don’t do it. Just sort of leave them out there. I think Ziram is gone. Just stick to the single sites until you get through the thinning period. And if you feel like you need extra resistance management, put one of the biologicals in. They’ll do the job for you. That’s all I’ve got this week. Have a fantastic day and good luck with the crop. 

State of the State with Anna Wallis 

This is your weekly roundup of degree day accumulations and phenology from the major fruit production regions of the state. As usual, information has been aggregated from regional specialists, NEWA, and my own observations. After the cold early morning temperatures last Thursday, May 18, frost damage continues to be at the forefront of everyone’s minds. The reports that we are getting from across New York as well as surrounding states indicate that damage in tree fruit was widespread but extremely variable. NEWA weather stations indicate that low temperatures ranged from 32 down to the mid 20s across the state. Some blocks experience significant losses, while others appear to be completely unscathed. Within blocks, damage varies depending on the microclimate of specific locations in the block.  

So we are recommending that you cut fruitlets to look for damage in each block and even within blocks to get an accurate idea of how much your farm was affected. Damage has been observed in a few different forms. Smaller fruitlets have already been dropped. In many cases, severely damaged fruit will have brown or black dark internal tissues. We’ve also observed some damage to the calyx end of fruit in the form of darkened or water soaked tissue.  

Pay attention to position on slopes or the side of a hill, surrounding vegetation or habitat that may have disrupted airflow and different varieties. This was a strong radiation freeze type of event, meaning conditions were very calm and clear, allowing cool air to sink and form an inversion layer. Therefore, fruit lower in the canopy and closer to the ground were at higher risk, and there tends to be more fruit unharmed in the top of the canopy. There’s more information about radiation freezes in the link in the Show Notes if you’d like to learn more.   

Temperatures this week have remained relatively cool, so fruit growth has been pretty slow, perhaps a quarter of a millimeter a day, but things are expected to heat up next week, with temperatures in the 80s expected in many places. This will accelerate growth potentially to 1 mm or more per day. The thinning window is opening up in many places over the weekend and into the early part of next week.  

This week in the Hudson Valley, fruit continue to size and are currently in the range of ten to 18 mm. In the Lake Ontario region, apples are at petal fall, or just beyond, and fruit is just beginning to size in Geneva this week, a little further inland and a little bit more advanced than Lake Ontario sites. McIntosh and Gala king fruitlets were at about eight to 10 mm. In the Capital Region, fruit is nearing the 10-12 millimeter window, and in the Champlain Valley, fruitlets are between 5 and 7 mm.  

We’re continuing to track degree day base 43 as an indicator of insect activity and phenology. Both 43 and 50 have been used as base temperatures historically, and there is a table in the Show Notes summarizing each, but for clarity in an audio format, I’m continuing to only record base 43 here. The average range of Degree Day accumulations for phenology and arthropod pests can be found in the Cornell Tree Fruit Guidelines in table 7.1.4. We’re also including the most relevant events in the table in the Show Notes. Here are a few things that are active now or to be on the lookout for: 

OFM flight in Geneva and western New York is beginning to decline this week, with trap captures still evident.  

CODLING moth first trap capture was recorded last week in Geneva and western New York and numbers continue to increase. This week first trap capture is typically around 475 degree days, base 43.  

OBLR overwintering larvae continue to be active in some places that haven’t been treated. Shortly after petal fall or by the beginning of June is the best time to be hanging traps to monitor for first flight of this pest.   

Rosy and green apple aphids also continue to be active throughout the state. We also found cherry aphid in multiple locations this week.  

Plum curculio is active now. We found a few scarred fruitlets in Geneva and other locations in western New York in both apple and cherries this week. They typically move into orchards around petal Fall. After a few warm nights and a lot of moisture in the soil, typically around 550 degree days. They’ll continue to be active for at least a couple more weeks. Start to monitor Degree day. Base 50 on this insect. Once we accumulate 300, the activity typically decreases and protection is no longer needed.   

European apple softly scars on small fruitlets have also been observed in the Hudson Valley.  

San Jose scale is another insect to be monitoring for now. Adults are typically active around this time about 500 degree days. Apple leaf curling midge has been reported in the Lake Ontario region in isolated locations. This is a relatively new insect that’s become significant in the Champlain Valley and Ontario, so it’s important for us to be looking out for it.  

Lesser peach tree borer first catch was reported on Friday last week in Geneva, typically at about 570 degree days.  

Dogwood bora larvae continue to be active in many locations. They’re typically found in rootstocks that produce burr knots. We’ve also seen some disease signs and symptoms showing up primarily in untreated locations.  

Early apple scab lesions are apparent, so you can start looking for them now to assess your primary scab control. Look for olive green to brown lesions on the tops and bottoms of leaves.  

Powdery mildew is also present. Look for twisted terminals covered in white sporulation. This disease prefers a warm humid condition but no free water, so the weather this season has potentially been a little bit more conducive to infections.  

Now I’ll give you a rundown of the Degree day based 43 accumulations at NEWA weather stations throughout the state every week. We’re including a table in the show notes for your reference for later. At the end of the day Thursday 5/25, degree day accumulations were: 

 

Phenology & DDs for NY NEWA Stations from 1/1 – 5/25
Station	Stage	DD 43F	DD 50F
Geneva	8-10mm	619	344
Highland (HVRL)	10-18mm	889	487
Clifton Park	10-12mm	713	392
Peru (Forrence)	Petal Fall	567	307
Medina – Inland	Petal Fall / Fruit sizing	581	307
Appleton North – Lake	Petal Fall / Fruit sizing	521	262
Fairville (The Apple Shed) – Inland	Petal Fall / Fruit sizing	595	326
Williamson (DeMarree) – Lake	Petal Fall / Fruit sizing	562	293
*all DDs Baskerville-Emin, B.E

 

 

Upcoming Pest Events: Ranges (DD avg ± std):
Event	DD50F	DD43F	DD50F
Lesser appleworm – 1st catch	217 (± 88)	420 (± 144)	217 (± 88)
Lesser appleworm – first peak flight	313 (± 130)	569 (± 205)	313 (± 130)
American plum borer – 1st adult catch	240 (± 45)	457 (± 64)	240 (± 45)
OFM – 1st flight peak (DD45)	223 (± 57)	369 (± 91)	223 (± 57)
Codling moth – 1st adult catch	249 (± 55)	475 (± 85)	249 (± 55)
San Jose scale – 1st adult catch	284 (± 61)	533 (± 88)	284 (± 61)
Spotted tentiform leaf miner – 1st mines	241 (± 76)	472 (± 129)	241 (± 76)
Plum curculio – 1st oviposition scars	286 (± 37)	555 (± 77)	286 (± 37)
Pear psylla – hardshell stage	312 (± 51)	569 (± 87)	312 (± 51)
Lesser peach tree borer – 1st adult catch	308 (± 59)	570 (± 94)	308 (± 59)
San Jose scale – 1st flight peak	355 (± 58)	644 (± 89)	355 (± 58)
European red mite – sample (2.5 mite/leaf)	June 1	June 1	June 1
Obliquebanded Leafroller – set traps	June 1	June 1	June 1
Black stem borer – 1st flight peak	383 (±122)	681 (± 170)	383 (±122)
*all DDs Baskerville-Emin, B.E