Pruning grapevines

By Terence Bradshaw

Winter is definitely here and so is the time to start pruning grapevines. I like to wait as late as possible to prune grapes, but be careful to give yourself enough time to get the job done before bud break. Consider that an acre of mature grapes may take 40 hours or more to prune, so plan accordingly. Also, when pruning, keep an eye out for diseased wood in the canopy that should be removed from the vineyard. At the UVM vineyard, we throw wood into the row middle and clean up with a York rake at the end of the season. In an organic vineyard, sanitation is even more important so the few bits of wood left over from raking may be undesirable, you may want to lay a tarp down to put the wood on and drag it along as you prune, then scoop up when full and transport to the burn pile.

It’s also not necessarily a bad idea to under prune the vineyard now while it’s still cold out. That would mean doing a pass through to get the big stuff- the main cane wood from last year that needs to get out of the way before you can see what you’re doing to make the fine cuts, then come back and trim spurs (if spur pruning) down to the desired number of buds to make your final cane selections if cane pruning. That way, if we get a really cold snap, you will have left more buds that can be used to compensate for primary bud loss.

Here are some good videos to watch on a cold day to remind yourselves of pruning techniques.

· Finger Lakes Grape Program (FLGP): How to Prune Grapevines

o Top wire cordon

o VSP trellis

· Michigan State University Pruning and Training Top Wire Cordon Vines

Stay warm,

Terry

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

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The UVM Tree Fruit and Viticulture Program is supported by the

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USDA Value Added Producer Grants Information Sessions

By Terence Bradshaw

Hello:

The USDA Value Added Producers Grants Program is now open for FY2020. This is a great program available to growers and businesses aimed at helping to scale up or investigate entering the value-added food, fiber, and wood products industries. I have reviewed these grants in the past, and this is an excellent way to help fund the next stage of your farm business. Please see the information below i=on information sessions tio gain more information. –TB

From: Massey, Elijah – RD, Montpelier, VT
Sent: Monday, December 16, 2019 2:42 PM
Subject: VAPG Information Sessions

Good afternoon,

I am writing to follow-up on last week’s notification that USDA Rural Development’s Value Added Producer Grant (VAPG) program is currently open for FY2020. As indicated, there will be information sessions held in New Hampshire and Vermont to provide folks an overview of the VAPG program, recent adjustments from the current Federal Register Notice, and to address questions about the application process. The dates, times, and locations of these sessions are:

For interested parties located in New Hampshire –

Tuesday, January 28th, 2020.

10:00 am to Noon

Concord Center Building

10 Ferry St., Room 211

Concord, NH 03301

For interested parties located in Vermont –

Wednesday, January 29th, 2020.

10:00 to Noon

Lrg. Conference Room

Green Mountain Power Building

7 Green Mountain Dr.

Montpelier, VT 05602

(please park beyond the fence as the front lot is for State employees)

Please let me know if you have any questions regarding either of these meetings or the program more generally. As a reminder, VAPG program information is available on Rural Development’s website for both Vermont and New Hampshire. Hope to see you at a session!

My best,

Elijah

Elijah Massey

Business Programs Specialist

Vermont Beginning Farmer and Rancher Coordinator

Rural Development

United States Department of Agriculture

Office: 802-828-6081 | Fax: 855-794-3680

87 State Street, Suite 324

P. O. Box 249

Montpelier, VT 05601

www.rd.usda.gov/nh | www.rd.usda.gov/vt

Sign up for Vermont and New Hampshire email updates.

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Always read the label before using any pesticide.

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The UVM Tree Fruit and Viticulture Program is supported by the

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Grape maturity testing, week of 9/13/2019

By Terence Bradshaw

Grapes continue to be slow to ripen. Warm days later this week should move early cultivars (Brianna, St Croix) along a bit, but most grapes need quite a bit more heat accumulation before harvest.

9/13/2019

Cultivar

Brix pH %TA (g/100ml)
Brianna 16.1 2.85 0.71
Verona 16.5 2.75 1.40
St. Croix 17.2 2.93 1.28
Louise Swenson 18.8 2.97 0.89
St. Pepin 19 2.94 1.46
Crimson Pearl 19.8 2.86 1.17
Petite Pearl 20.6 2.9 1.11
Itasca 21.8 2.95 1.19
Data collected 9/13/2019 at UVM Horticulture Research & Education Center Vineyard, South Burlington, VT.

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

2019 grape maturity testing

By Terence Bradshaw

September is here, and grape harvest will soon be ‘on’ in Vermont vineyards. While the spring was generally wet overall, diligent management should have left you with relatively disease-free grapes and vines. The dry, hot/warm weather since July has been great for grape maturity, but these recent cool nights are likely to slow development.

This year, we will once again be posting fruit / juice maturity values on the UVM Fruit Program website. Watch for that link in the next couple of days, as I just switched computers so still have to load my web editing software. Until then, I am posting a snapshot of the data below. We don’t have all of our cultivars here yet, but you’ll notice some new ones from our new NE-1720 cultivar evaluation trial. We may pick Brianna next week, but the rest have some time to go.

9/9/2019 Brix pH %TA (g/100ml)
Briana 16.2 2.92 0.83
Louise Swenson 17.7 2.97 1.07
Crimson Pearl 19.0 3.02 1.36
Itasca 23.0 3.11 1.19
Petite Pearl 17.7 2.99 1.15
St. Peppin 18.3 2.98 1.50
Verona 15.9 2.78 1.63
Data collected at UVM Horticulture Research & Education Center Vineyard, South Burlington, VT. Accumulated degree days (base 50°F, BE model) since April 1 = 2118.

How do you assess grape maturity using juice data? Please see our relatively new fact sheet, Pre-Harvest Winegrape Juice Testing. That sheet also contains some target values for when to harvest each of the winegrape cultivars in our vineyard.

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

Vineyard management at veraison

By Terence Bradshaw

First things first: I’m going off-line later today for a rare, two-week, no-work vacation. Please note that I won’t be responding to emails that come in during that time.

Veraison is on or near in Vermont vineyards, which signals the start of the ripening period. That means a few things:

1. Get your pest management in order. Diseases should be kept down to a dull roar by now, and grape berry moth or Japanese beetle treated. Your window to apply fungicides that may affect fermentation, especially captan or sulfur compounds, is closing. It’s been dry, so there shouldn’t be too much in the way of late-season diseases if you managed them well so far.

2. Finish your canopy management. Grapes need to see the sun from now through harvest, so make your final passes through to comb shoots and pull leaves where necessary.

3. Get rid of green fruit. At veraison, you can see where certain clusters from secondary buds r less vigorous shoots are behind the others. Drop those now, they will only drag down the ripeness of the others.

4. Get your nets, squawkers, scarecrows, and other bird measures ready, but wait as late as possible.

5. Collect petioles and send in for analysis to assess vine nutrient status. See this post for more details.

6. A couple of weeks before expected harvest, start assessing grapes for ripeness. Sampling should be methodical and regular (at least weekly, or more often as harvest approaches). Generally a 100 berry sample is sufficient to ascertain general ripeness.

Sugar level and pH are easily evaluated with simple tools (a refractometer and pH meter, respectively) available from most winemaking supply outlets. We recently published a fact sheet on Preharvest Winegrape Juice Testing.
Remember that for most popular cold climate grapes, TA is a primary determinant for ripeness; for reds (Frontenac, Marquette), a target TA of 1.5% or lower is preferred; for whites, 1.2% should be considered the upper end, although La Crescent may frequently have higher values. Ideally, all grapes for winemaking should have TA below 1%, but that is not always possible for the cultivars that we grow. Work with any wineries you plan to sell grapes to to determine their preferred juice chemistry levels before harvest.

Enjoy the end of summer, and good luck as you plan for what looks to be a great vintage.

Best,

Terry

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

Midsummer vineyard management; veraison management workshop August 6

By Terence Bradshaw

We will host a veraison / preharvest vineyard management workshop at the UVM Horticulture Research & Education Center on August 6th, 3:00 – 4:30. This is folded into a larger Research Open House, I sent a flyer in a previous email (also available at: http://go.uvm.edu/hrecresearchday). We will cover out latest research on cold-climate grape cultivars, management decisions to be made as veraison approaches, and preharvest juice sampling to time harvest. There is no charge for this event, just show up. The rain date will be August 9, watch this email list for word if we do move it.

Most spraying in Vermont vineyards should be wrapping up as the vines and especially fruit are becoming resistant to most diseases. However, if you have downy and powdery mildew in the vineyard, it would be wise to maintain protection against them through veraison. Vines which have not reached bunch closure may also be protected against botrytis for one last time before veraison and harvest.

Japanese beetles are probably in every vineyard in the state. Their damage can generally be tolerated on established vines, but vines under 3-4 years old should be protected. Grape berry moth are mostly in pupal stages in Champlain Valley vineyards, although in some inland/cooler areas larvae may still be feeding. Careful and thorough scouting for webbing between berries will determine the presence of the pest. The threshold for treatment against the current generation is 6% of clusters with signs of damage.

Canopy management is critical at this time of the year- every fruit cluster should see at least some direct sun. However, if opening up congested vines at this time, be careful not to fully expose clusters that have been heavily shaded, as the risk for sunburn increases when a shaded cluster is exposed to full sunlight in midsummer.

Get your bird netting ready.

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

UVM Horticulture Research & Education Center Research Open House August 6, 2019.

By Terence Bradshaw

Since 1952, the UVM Horticulture Research & Education Center has hosted projects that have furthered production of apples, small fruit, vegetables, and ornamental specialty crops in Vermont and the surrounding region Join UVM faculty, staff, and student researchers on August 6 (rain date August 9) as we show off our current research projects at the UVM Hort Farm. The agenda will follow projects via a walking tour across the landscape of the 97-acre facility throughout the day from 9:00 am – 4:30 p. Attendees are encouraged to come and go to fit your interests. Pack a lunch and make a day of it, or attend just the sessions you’re most interested in. The tour is designed so that attendees can join and leave at any point to suit their interests.

A tour agenda is attached and can be found at: http://go.uvm.edu/hrecresearchday

A research synopsis can be found at: http://go.uvm.edu/catfarmresearch

No RSVP is needed, but if accommodations are required, please email Hort Farm Director Dr. Terence Bradshaw at: tbradsha.

Please distribute to your contacts as you feel appropriate.

See you on the 6th,

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

20190806_UVM_HREC_ResearchDay.pdf

Grape canopy management

By Terence Bradshaw

High Summer is here, and this period from after July 4 through early August is the perfect time to apply some canopy management to the vineyard. By thinning and positioning shoots; removing unwanted clusters; and cleaning up trunks, we can significantly increase penetration of sunlight into the canopy and especially into the fruiting zone. This will make for measurably better juice and wine quality, improved winter hardiness, and less disease pressure.

There are a number of practices that should be performed, but the most important is shoot positioning (also known as “combing”). This practice includes separating each shoot from its neighbor and directing the growth into the vertical plane: usually down, for high-wire cordon vines, or up for those on a low wire, vertical shoot positioning system. Once shoots are pointed in the right direction, it’s easy to see where runty secondary or tertiary shoots are in the canopy, and where smaller clusters that are behind in development compared to the main crop are- those can both be removed.

(Retired) Iowa State Extension Specialist Mike White presents a good overview of the concepts and practices behind canopy management in his February 8, 2012 newsletter found here.

There’s a video of some UVM staff doing some (silent) canopy management here.

Ohio State Extension has a nice video here.

While I have you, it’s worth mentioning that we’re not out of the woods as far as disease management is concerned. It has been a difficult year so far with all of the rain, and the frequency of it, to maintain fungicide coverage but I have been seeing mostly clean fruit and foliage in vineyards which have maintained an appropriate spray schedule of 4-5 well-selected and –timed fungicides since prebloom. At this point, phomopsis is pretty much done, and black rot will soon be winding down. Powdery and downy mildews (PM?DM) should be the main focus for disease management, as well as botrytis a few weeks down the road. If this wet weather continues, I would recommend a specific botrytis material such as Flint, Rovral, Vangard, Endura, or Pristine before bunch closure (the point where berries size up to the point where spray material cannot penetrate the cluster to protect fruit from infection). As always, check your Pest Management guide (New York & Pennsylvania or New England guides) and the label, rotate fungicide classes to reduce resistance likelihood, and follow all safety precautions when spraying. Organic disease management spray options include copper (DM, a little PM), sulfur (PM), stylet oil (PM, do not spray before or after a sulfur spray), and possibly some of the biologicals but I don’t know enough about them in regards to their performance against these late-season diseases.

Next week would be a good time to scout clusters for grape berry moth (GBM) webbing which could suggest a need to treat for that insect pest. The threshold for treating this generation is 6% of clusters showing damage, which appears as small bits of webbing in between berries up inside the cluster. GBM is the primary insect pest of established vineyards in Vermont, and if it is the only pest insect need to manage, then some very specific materials with low potential for non-target effects may be used, including lepidopteran-specific materials like Bt, Intrepid, Delegate, or Altacor (the latter has some activity against Japanese beetle). Bt (DiPel and others) and Entrust would be effective materials against GBM for organic growers- the former affects only lepidoptera, while the latter would have some activity against Japanese beetle and some other insects as well.

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

Vineyard management at bloom

By Terence Bradshaw

Many vineyards are in bloom across Vermont, and inflorescence looks good and bodes well for a promising year. As I’ve been saying all along, be sure to maintain spray coverage for the next couple of weeks; to remove any diseased tissue as you find it; and to do your best to maintain an open canopy (more on that in a minute). All of the main diseases, including downy mildew, should be active now, so fungicide choice should cover all of the bases. That likely means applying a mix of materials that have multiple modes of action, like mancozeb (watch the 66-day preharvest interval) or captan and a strobilurin (Flint, Abound) or DMI (Rally, Elite, etc.). There are some good premix materials available that cover two modes of action, like Inspire Super and Pristine, but even they could use some protectant activity from mancozeb or captan to improve efficacy and reduce resistance development. The New England Small Fruit Management Guide has a good table that outlines the efficacy of the main fungicide materials available to growers. For organic growers, a rotation of sulfur and copper is pretty common now, but be sure to watch for signs of phytotoxicity. Coverage maintained for the next few weeks will pay off by allowing you to relax a bit for the second half of the summer.

Wild grape bloom occurred on June 19 in South Burlington, which sets the clock for grape berry moth management. The first overwintering generation is rarely significant enough to warrant a management spray except in vineyards that have had extreme damage in previous years. Each generation requires about 820 degree days (base 47°F, or DDb47°F) to complete, and the first generation typically emerges around the time of wild grape bloom. So if we use June 9 as our ‘biofix’ and track DDb47°F, we can estimate the best time to treat for the more damaging later generations.

This is made easy by the Network for Environment and Weather Applications (NEWA) system, which I coordinate for Vermont. The network includes twelve on-site weather stations (all located at orchards) and six airports, and imports data in near real-time for use in pest models. It is free to use, and growers can locate the site nearest them and develop a best-guess of phomopsis, black rot, and downy mildew infection periods as well as a sense of the grape berry moth generational development.

Plant tissue sampling is one of the best ways to plan fertility management in your vineyard, and now is one of the important times for collecting samples. Petiole samples may be collected at bloom or veraison, and comparisons between years or blocks should be based on the same time of collection. The benefit of a bloom sampling is that it gives you time to make corrections, if needed, during the present growing season.

Samples should be collected separately for each cultivar or block. In each sample, a random collection of 75-100 petioles should be collected from throughout the planting. Petioles should be collected from the most recent fully expanded leaf on the shoot, not across from the fruit cluster as is collected for a bloom sample. Just remove the whole leaf and snip the petiole (the leaf ‘stem’ off with your pruners. Gently wash each sample in water with a drop of dish detergent, then rinse fully and place in an open-top paper bag to dry. The closest analytical lab for grape petiole analysis that also provides pretty comprehensive management recommendations is the . There is a great section in Appendix A of the Wine Grape Production Guide for Eastern North America (which every grower should have a copy of on the bookshelf, ready to grab with short reach) which helps to guide fertilizer application rates based on soil and petiole samples. If you have a copy of those to send to me, I’d be happy to help you with the numbers as well.

Finally, I have two events to mention. First is a reminder of the July 9 Canopy Management Workshop we will hold at Ellison Estate Vineyard in Grand Isle. Please preregister here to attend.

The second is a UVM Horticulture Research & Education Center Research Open House that we will hold at the farm in South Burlington on August 6. Researchers with projects across the farm and working in multiple disciplines will showcase our work. I will host a tour of the research vineyard, and will have a pre-harvest management workshop at which we will discuss bird protection, late-season canopy and crop management, and preharvest sampling procedures to optimized juice quality at harvest. Watch for details on that event in the next week or so, but plan on it happening in the later afternoon around 3:00.

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

July 9 UVM Grape Canopy Management Workshop

By Terence Bradshaw

Summer canopy management is one of the most important tasks for producing high-quality winegrapes, especially in cool/cold regions where ripening can be impacted by low heat unit accumulation. The tasks taken to open and manage canopies aren’t necessarily intuitive, and are often overlooked by beginning fruit growers.

Join the UVM Fruit Program on Tuesday, July 9, 2019 for a hands-on workshop on managing canopies in cold-climate hybrid grape vineyards. The workshop will run 9 AM – Noon at Ellison Estate Vineyard 69 East Shore North Grand Isle, VT 05458 United States. There is no fee for this workshop, but please pre-register by completing this very short survey.

https://survey.uvm.edu/index.php/187557?lang=en

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, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.