VT Apple IPM – More codling moth materials

A good question came up today regarding my recent recommendation on codling moth management: “Saw your note on Codling Moth and was wondering if Assail or Leverage or Belay would work as well as what you listed (Intrepid, Altacor, Belt, Rimon)?”

It’s helpful to have someone read your words back to you. The materials I mentioned are all pretty targeted, if not specific to, lepidopteran pests, and are all effective against codling moth. My unspoken statement was that if you are only targeting CM and want to use a ‘softer’ material, these fit the bill. But certainly, if you still have fresh curculio activity, or just have another material ready to go in the shed, a more broad-spectrum pesticide is fine to use. Assail, Delegate, Imidan, Voliam Flexi, and Danitol are other materials rated at high efficacy against CM in the New England Tree Fruit Management Guide. By all means, use them. Managing CM in high-pressure orchards is pretty critical now.

Take care. I’ll be out tomorrow morning with a tank of Intrepid and Calcium at the crack of dawn tomorrow morning. Were I in the commercial business, I might consider one last fungicide before calling it good for apple scab, but it’s important to get the fire blight I’ve seen out of the orchard and the 4-hour REI on Intrepid is pretty key to getting that done.

Where trade names or commercial products are used for identification, no discrimination is intended and no endorsement is implied. Always read the label before using any pesticide. The label is the legal document for the product use. Disregard any information in this message if it is in conflict with the label.

The UVM Tree Fruit and Viticulture Program is supported by the University of Vermont Agriculture Experiment Station, UVM Extension, USDA NIFA E-IPM Program, and USDA Risk Management Agency.

UVM Extension helps individuals and communities put research-based knowledge to work. University of Vermont Extension, and U.S. Department of Agriculture, cooperating, offer education and employment to everyone without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or familial status.

VT Grape IPM – Peak disease management

I apologize for this overdue communication. Some grapes at the UVM Vineyard in South Burlington were starting bloom yesterday, and we are in peak disease management season. I’ll keep this brief:

  1. Pretty much every major disease is likely active now, including black rot, Phomopsis, powdery and downy mildew, and anthracnose. Vines should be protected with the best materials in your toolbox. For non-organic growers, that means mancozeb or captan plus a DMI (FRAC code 3, e.g., Rally, Vintage, Inspire super) or strobilurin (FRAC code 11, e.g., Flint, Sovran, etc) material. Rotate those FRAC codes and do not use materials with the same code more than twice in a row.
  2. For organic growers, this is the window to be using whatever copper material you choose.
  3. Keep fungicide coverage on at 7-14 day intervals, shorter as there is more rain.
  4. Keep an eye out for grape tumid gallmaker to be popping up. If these have been a problem in your vineyard, Movento or Assail are your best materials. I don’t know any organic option, so you’ll need to remove them by hand.
  5. Shoot thinning is still critical now, the sooner it’s done, the more resources you will leave for the remaining shoots. Shoots have not lignified enough to do any combing.
  6. If you suspect any nutrient deficiencies, this is a good time to collect petiole samples for analysis. I prefer the veraison timing, but bloom sampling allows for correction this season if somethings comes up particularly low. Details on petiole sampling can be found here.

Where trade names or commercial products are used for identification, no discrimination is intended and no endorsement is implied. Always read the label before using any pesticide. The label is the legal document for the product use. Disregard any information in this message if it is in conflict with the label.

The UVM Tree Fruit and Viticulture Program is supported by the University of Vermont Agriculture Experiment Station, UVM Extension, USDA NIFA E-IPM Program, and USDA Risk Management Agency.

UVM Extension helps individuals and communities put research-based knowledge to work. University of Vermont Extension, and U.S. Department of Agriculture, cooperating, offer education and employment to everyone without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or familial status.

VT Apple IPM – ‘Cover’ spray time

Category [tree fruit; IPM]

June 8, 2021

Sorry- I’m late on getting anything out, so I’ll cover the high points that are important for managing Vermont orchards in the next few days / week:

  1. It’s time to get a codling moth spray on for many orchards. CM is best managed by using the NEWA degree-day model. For your site, enter the first pheromone trap capture (Biofix) or, with less certainty, let the model predict emergence (that’s the default). Most materials should be applied between 100 and 200 degree days (base 50°F) from that date. For most orchards, that is now. A lepidopteran-specific material like Intrepid, Altacor, Belt, or Rimon (latter two should have been on a few days ago) is best against this pest.
  2. Plum curculio still has some activity left in it for this season in most orchards. If you covered the orchard with a relatively broad-spectrum insecticide at petal fall, border sprays will suffice to keep late-season damage down.
  3. Apple scab primary season is done pretty much everywhere. Scout the orchard meticulously for signs of scab, if you have it, keep up a Captan program until things are burned out. Otherwise, fungal diseases are probably good for a little bit.
  4. Fire blight- Streptomycin works!! We have tow partial rows at the UVM orchard with many dead trees that I plan to rip out (that’s another story), so I haven’t bothered spraying them this year. They are right in our Fire Blight-riddled cider block, which is 95-98% clean right now, but those Spitzenburgs are toast. Scout your orchard carefully for signs of the disease and plan to prune out ASAP, on a dry day. Except in the case of hail, do not apply streptomycin to an orchard that shows symptoms of the disease.
  5. Fertility- If you’re applying nitrogen, start making plans to back off and shut it down soon. This is a great time to apply magnesium, potassium, and other cations if our soil or foliar analyses calls for them.
  6. Every spray this time of year should include some calcium. On Honeycrisp, calcium should go on even if another spray material isn’t needed.
  7. Keep an eye on thinning. This has been one of the most inconsistent years I have seen in my time with this crop (25 years) and I’m seeing and hearing of fruit densities all over the place. It’s getting late to apply thinners, so while scouting for Fire Blight, keep an eye out for trees that need a little hand thinning.
  8. Water, if you can. Many areas of the sate are running dry, and we’re still in the window of maximum cell division that determines fruit size and quality.

All for now,

Terry

VT Grape IPM: Things are taking off

Vine growth is really ramping up in Vermont vineyards, which means that the next two months are critical to set the stage for a quality vintage for 2021. I often say that, once established, grapes are weeds, and I’ll stick to that assertion. However, there’s a difference between a plant that can grow profusely and managing it to provide optimal crop quality. It’s our jobs as farmers to manage the vines for our needs- that what makes us different from foragers of the wild grapes that indeed do grow like weeds all around us.

Top of mind right now should be two practices: shoot thinning and disease management. Shoot thinning is critical to channel the vine’s energy into an appropriate number of shoots to maintain vine balance, and to high quality shoots to ensure consistency of ripening. We typically target 4-6 shoots per foot of canopy. So, vines on six-foot spacing should have about 24-36 well-spaced shoots on them, assuming they have filled their space. Adjust that as needed- vigorous vines get more shoots, less vigorous ones fewer. Now, since they haven’t lignified, you can just pop them off with your fingers. Be sure to select the most consistent and healthy shoots to leave behind. On many cultivars, the secondary shoots, which will be behind in development and thus smaller than the primary shoots, may emerge from the same bud at the base of a more desirable shoot- break those off. Remember thought that breaking off shoots is likely to remove the basal buds that could form next year’s shoots, so you only want to break these off that are in a position where you do not want a renewal spur for next year. This is a great time to strip shoots off the trunk from the fruiting zone down to the trunk base, but leave a sucker or two at the bottom as a renewal option in case the trunk freezes out or is otherwise damaged. I explain this process in a video here (15 minutes, pardon the wind noise); my colleague at Cornell, Dr. Justine Vanden Heuvel, describes in more succinctly using Vinifera cultivars in slightly different training system here.

This is a typical time to start thinking about a spray program to manage disease. The primary disease of concern at this point is phomopsis, as rachis infection at this point in the season is may cause significant fruit loss at harvest. Anthracnose may also be active at this point , given the warm/hot weather are expecting later this week. Vineyards that have had recent problems with those diseases or organic growers using copper or other less-effective materials may consider treating this week; if you haven’t had major problems with those diseases, treatment can wait until the 5-8” growth stage as long as you are using a highly effective contact fungicide like mancozeb or captan.

As a reminder, a refreshed version of the Initial IPM Strategy for New Cold Climate Winegrape Growers is available at: https://www.uvm.edu/~orchard/fruit/pubs/Factsheets/UVMFRT004_initialIPMStrategy.pdf

Organic growers are in for a bit more work. The standard fungicides, copper and sulfur, have only fair efficacy against this disease at best, and in a couple of weeks when black rot becomes the next disease of concern, those materials will have even less efficacy against that disease. The first line of defense in an organic vineyard is a strict sanitation program. This includes removing all mummies still in the canopy (not dropping on the ground, but actually removing them from the vineyard) as well as any obviously diseased wood. Phomopsis and anthracnose both overwinter largely on infected wood in the canopy, and removing this wood during dormant pruning or now is essential to reducing disease pressure. Stubs left at the ends of spurs should now be removed since you can see where this year’s shoot growth will resume (at the developing shoot)- these stubs will die and may become infected with phomopsis this season (or were last season) .

Removing stubs at end of retained spurs.

It is worth noting that both copper and sulfur (including lime sulfur) can cause phytotoxicity on certain cultivars. Dr. Patty McManus summarized her research on copper and sulfur sensitivity in cold-hardy grapes in the 2/8/16 Northern Grapes newsletter, and I’ll summarize it to say that Brianna should receive no copper; and Frontenac (all types), La Crescent, Leon Millot, Marechal Foch, Marquette, and St. Croix should receive no more than 2-3 copper sprays per season. Save those for later when black rot and downy mildew become bigger concerns. Sulfur sensitivity was observed on several cultivars, and its use (including lime sulfur) is discouraged on Foch, Millot, Brianna, and Louise Swenson; with limited (2-3) applications suggested on LaCrescent and St. Croix.

Despite the rain we just received, most sites in Vermont are still running very dry. Established vines on most soils should be okay, but consider watering young vines. I’ll discuss soil fertility later this week.

Where trade names or commercial products are used for identification, no discrimination is intended and no endorsement is implied. Always read the label before using any pesticide. The label is the legal document for the product use. Disregard any information in this message if it is in conflict with the label.

The UVM Tree Fruit and Viticulture Program is supported by the University of Vermont Agriculture Experiment Station, UVM Extension, USDA NIFA E-IPM Program, and USDA Risk Management Agency.

UVM Extension helps individuals and communities put research-based knowledge to work. University of Vermont Extension, and U.S. Department of Agriculture, cooperating, offer education and employment to everyone without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or familial status.

Honeycrisp Virtual Meetups

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Virtual Honeycrisp Meetup – A three-part series of conversations about Honeycrisp

Researchers, extension specialists and grower panelists;
New York grower Rod Farrow; Michigan grower Chris Kropf and Washington grower Bruce Allen

Join us and bring your experience and questions!
Register to each date in the links below.

JUNE 3rd
CROP LOAD MANAGEMENT
Register

JUNE 17TH
ROOTSTOCKS
Register

JULY 1ST
NUTRIENT MANAGEMENT
Register

Facilitated by B. Sallato WSU Extension, M. Miranda Sazo Cornell Cooperative Extension, and A. Wallis MSU Extension. Supported by IFTA, USDA-SCRI Root2Fruit project and Good Fruit Grower.
For more information visit http://treefruit.wsu.edu/event/virtual-honeycrisp-meetup/2021-06-03/

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VT Apple IPM: Petal fall thinning meeting TODAY, 1PM

I want to get this one out quick:

(Cornell) Champlain Valley Virtual 10-12mm Thinning Meeting Today at 1PM
The Champlain Valley 10-12mm meeting will be held today from 1-2PM. At this meeting, Dr. Terence Robinson will discuss his thinning recommendations for the 10-12mm timing. To join, simply click on the link at 1PM.

Join Zoom Meeting

https://cornell.zoom.us/j/99544274591?pwd=NHZkZU1HK2ZmTDkvc2hCeHhCdW96QT09

Meeting ID: 995 4427 4591

Passcode: 288556

One tap mobile

+16468769923,,99544274591# US (New York)

+16465189805,,99544274591# US (New York)

On that note, here’s my quick rundown of things to in the orchard:

  1. Manage plum curculio. This should be pest # 1 right now, and with hot, humid weather, its activity should be pretty high. PC is active from petal fall but especially at 8-12 mm fruit size, until 308 degree days (base 50°F) after petal fall. There is a model in NEWA, use it.
  2. Codling moth is pest #2. If you monitored CM in pheromone traps and recorded first date of capture, use that in the NEWA model, or hand calculate degree days (also base 50°F). Sprays should be timed at 150 DD for ovicidal materials (Rimon, Intrepid, Esteem) or 250-360 DD for most other materials. As usual, use the New England Tree Fruit Management Guide to help guide selection.
  3. Start adding calcium to sprays any time now, especially on Honeycrisp.
  4. While we’re talking nutrients, trees are in their main flush of growth, so any nitrogen fertilizers you’ll be applying should be going on now.
  5. Water! Things are really, really dry out there, and that’s not looking to change any time soon.
  6. Because of that, apple scab is on the back burner, mostly. When we get rain, scab will be an issue. When you next spray, make sure you’re staying covered.
  7. There are a lot of reports about powdery mildew showing in area, which does not require leaf wetness, only high humidity. For orchards with a history of PM and with susceptible cultivars (Cortland, Gala, Ginger Gold, Idared, Jonathan, Mutsu (Crispin), and Paulared), you may want to include a material with some efficacy against the disease. From the NETFMG: “The most common multi-site fungicides, captan and mancozeb, are ineffective against powdery mildew. DMI fungicides vary in effectiveness. Unfortunately, the DMIs most effective against powdery mildew, Rhyme, Rally, Rubigan and Procure, are least effective against scab, and vice-versa. QoI fungicides, Flint, Flint Extra and Sovran (and pre-mixes with Group 11 ingredients) have good efficacy against powdery mildew. SDHI fungicides, Aprovia, Fontelis and Sercadis (and pre-mixes with Group 7 ingredients) are somewhat less effective, but still provide good control. Low rates of sulfur are effective in low disease pressure environments, such as New England, but the risk of sulfur injury increases as temperatures go over 85°F. In organic production systems, sulfur applied at weekly intervals, and bicarbonate and peroxide-based fungicides applied on 3-5 days intervals are the best options. (TB note: in my 12+ years of growing apples organically using sulfur to manage scab, I never saw PM in orchards managed using that system.)
  8. Keep an eye out for fire blight infections. If you find any, cut them out as soon as you do. But, please send me an email, as my colleague Dr. Kerik Cox at Cornell is tracking Erwinia amlovera (the causal bacteria of the disease) strains in the northeast and testing for streptomycin resistance.

Okay, that’s all for now. Who knows a good rain dance??

VT Apple IPM: Thinning, fire blight, scab

May 20, 2021

It’s looking pretty hot out there in more ways than one. Many orchards are at or near petal fall, but those with bloom should be keeping the streptomycin sprays on, with all this heat we’re having. Fire blight remains a concern statewide, and I would expect some infection in any orchard that has sufficient inoculum. That last part is important, and yet hard to quantify. Certainly if you’ve has the disease in the past, especially in the last two years, it’s likely that it will show up. The next disease concern is apple scab. Any promised rains keep getting pushed back in the forecast, now Saturday-Sunday looks like the most likely chance for any substantial rainfall. Whenever it comes, we should be prepared with a good coating of protective fungicide. Most growers are switching over to captan now which is fine, but be careful not to mix with Regulaid if you’re using that wetting agent to improve strep penetration into blossoms, as the combination of that, captan, and heat will likely cause leaf burn. If you’re looking at a second application of strep after one that already had a wetting agent included, you can leave it out this time. It’s also nota bad idea to put something in that would provide broader disease control, like an SDHI, SI, or DMI fungicide (take your pick from materials with FRAC codes 3, 7, 11 here, and always rotate FRAC codes after two successive applications of the same one).

Growers at 100% petal fall may want to consider adding in an insecticide against European apple sawfly, plum curculio, and early codling moth. However, if you have any blooms remaining, including in the groundcover vegetation, I recommend holding off on applying any materials harmful to bees and other pollinators. I typically include some Dipel or other Bt product in this ‘almost petal fall’ spray to help keep lepidopteran pests like green fruit worm and obliquebanded leafroller at bay while I wait until the following week to apply something more broad spectrum like Avaunt, Actara, or even Imidan if you’re still using organophosphates. Sevin applied in a thinning spray will have some efficacy as an insecticide, but not a lot.

As for thinning, it’s time to get on it. Blooms are heavy this year, and the sooner you remove resource competition and gibberellin formation from excess developing seeds, the more likely you will get reasonable return bloom next year. If you still have any bloom, or just want to stay away from it, please leave the Sevin / carbaryl on the shelf. With the hot weather, trees are going to respond well to thinner applications anyway, so an NAA or 6 BA spray should suffice. Pick one- the former is typically good on McIntosh and most large-fruited cultivars, the latter on varieties that tend to produce smaller fruit (Empire, Gala, Fuji, Macoun). See specific recommendations here.

For cider apple growers, I don’t have a great recommendation for managing biennialism on European cultivars. The need to thin for fruit size is less of a concern than for dessert cultivars, but you don’t want to overstress the tree and have no crop this year. I would plan on multiple applications of NAA, say bloom, petal fall, and at 8-10 mm fruit size, to encourage return bloom.

For what it’s worth, here’s the tank mix I plan to apply tonight or tomorrow morning: Captan (5 lbs/ac), Merivon (5oz), Dipel DF (1 lb), Refine (8 oz), Harbour (24 oz). This is to a very mixed orchard of ~50 varieties in all stages of bloom to petal fall.

Announcing June 8 Eastern Viticulture and Enology Forum “Town Hall: Questions from the Field and Cellar”

Sharing this from our colleagues across the lake. This looks like a great opportunity for learning. -TB

In collaboration with viticulture and enology extension programs at: Ohio State University, University of Maryland, Rutgers University, North Carolina State University, University of Tennessee, Texas Tech, Texas A&M, Iowa State University, Purdue University, University of Minnesota, Michigan State University, and the University of Wisconsin

VT Grape IPM: Early season disease and vine management

As she had last year, Dr. Katie Gold, plant pathologist at Cornell, has posted a summary of grape disease issues and recommendations. Here it is as a web page and as a PDF.

Growth in the UVM vineyard ranges from bud burst to 2-3 shoots emerged; a few shoots are nearing three inches in length. It’s time to really be thinking about protecting vines from early season disease infections. Most cold-climate cultivars will not need disease protection until 5-8” of shoot growth, but any vineyards with heavy disease pressure last year and organic vineyards may wish to begin earlier, especially if inoculum reduction through thorough removal of diseased wood and mummy berries and/or dormant application of lime sulfur was not performed. I still recommend our fact sheet, An Initial Integrated Pest Management (IPM) Strategy for New Cold Climate Winegrape Growers as the best resource to boil the decisions down to a simple ‘prescription’, with the caveat that since it was written some new pest management materials have been released and inoculum may have increased in your vineyards which could lead to increased disease pressure. Growers should have an up-to-date copy of the New England Small Fruit Management Guide (on-line and hard copy versions) and/or New York and Pennsylvania Pest Management Guidelines for Grapes as a reference for specific materials, their efficacy, and use considerations. Remember however that the guidelines are written largely for vinifera and less disease-resistant hybrids, so the specific spray programs recommended may be overkill in Vermont vineyards.

I’d say any time now is good to get your shoots thinned down to 3-5 shoots per foot of canopy. Keep more on more vigorous vines, less on weaker ones.

Where trade names or commercial products are used for identification, no discrimination is intended and no endorsement is implied. Always read the label before using any pesticide. The label is the legal document for the product use. Disregard any information in this message if it is in conflict with the label.

The UVM Tree Fruit and Viticulture Program is supported by the University of Vermont Agriculture Experiment Station, UVM Extension, USDA NIFA E-IPM Program, and USDA Risk Management Agency.

UVM Extension helps individuals and communities put research-based knowledge to work. University of Vermont Extension, and U.S. Department of Agriculture, cooperating, offer education and employment to everyone without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or familial status.

VT Apple IPM: Petal fall thinning meeting, fire blight clarification

From our colleagues across the lake at Cornell University. This should be a very informative meeting. -TB

The virtual Champlain Valley Petal Fall Thinning Meeting will be held on Tuesday, May 18, from 4-5pm. At this meeting we will hear from Dr. Robinson on his thoughts for thinning at the petal fall timing. To join, simply click on the zoom link on Tuesday at 4pm.

Join Zoom Meeting

https://cornell.zoom.us/j/99544274591?pwd=NHZkZU1HK2ZmTDkvc2hCeHhCdW96QT09

Meeting ID: 995 4427 4591

Passcode: 288556

One tap mobile

+16468769923,,99544274591# US (New York)

+16465189805,,99544274591# US (New York)

Clarification on Fire Blight notice:

A couple of people have asked if it is safe to apply streptomycin when bees are in the orchard. To my knowledge, there are no indications that strep is harmful to bees. In fact, its labeling to be applied during bloom indicates that it has passed the EPA standards for pollinator safety. The outlook for fire blight has only gotten more favorable for this week, given the warm weather expected at the end of the week. If you have open blossoms Tues-Fri, I’d plan to treat sometime during that window.

Where trade names or commercial products are used for identification, no discrimination is intended and no endorsement is implied. Always read the label before using any pesticide. The label is the legal document for the product use. Disregard any information in this message if it is in conflict with the label.

The UVM Tree Fruit and Viticulture Program is supported by the University of Vermont Agriculture Experiment Station, UVM Extension, USDA NIFA E-IPM Program, and USDA Risk Management Agency.

UVM Extension helps individuals and communities put research-based knowledge to work. University of Vermont Extension, and U.S. Department of Agriculture, cooperating, offer education and employment to everyone without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or familial status.