Vineyard Management at Bloom

June 17, 2020

I’ve visited some vineyards from the higher-elevation interior of the state to the Champlain Valley in the past week. Champlain Valley grapes are entering or even well-into bloom, upland and inland are around 5” shoot growth stage. Bothe are at key management points, so it’s best to spend some time in the field in the coming week. If it hasn’t been done, now is the time to thin your shoots out to 3-5 per foot of canopy length. That’s a pretty gross rule of thumb, it might be better to adjust down to a per acre target and go from there, especially if your vines aren’t completely linear. I’ve seen a couple of instances where established VSP / mid-wire cordon vines are being shifted to a top wire cordon training system. Those vines have plenty of vigor to hold a decent crop, but the canopy is in a middle-stage and shoots originate from all over the place. In that case, consider a target harvest per acre and count back from there. Day you want 3.5 tons, or 17,000 lbs per acre. You have 800 vines per acre on a 6 x 10 foot spacing. (Calculating vines per acre = 43,560 square feet/acre / (in-row spacing (ft) * between row spacing (ft) or 43,560/(6*10) = 796). That means you’ll want 21.25 clusters per vine. If your clusters average about 1/3 lb each, that’s 60 clusters to keep per vine. Then, you’d thin out shoots to select the most uniform and appropriately-spaced ones to get to that number. In many cases where vines give you two clusters per shoot, that would leave five shoots per foot of canopy (or 30 shoots on our six-foot vine).

Just as important as getting your shoots and cluster numbers in order is disease management. We’re blessed to be in such a dry spell during this critical period for disease, and I’ve seen remarkably little disease even on minimally-sprayed vines. But we’re in the prebloom and soon, postbloom window where all of the major grape diseases are primed to infect. Chances of rain are increasing as we move into the weekend and beyond, so it’s important to get things covered this week. Be careful spraying in hot weather, for two reasons. First, a properly-protected spray applicator (Tyvek suit, gloves, goggles, etc) is at risk for developing heat-related health problems, so spraying at dawn or even at night can help. Second, some of the more phytotoxic materials like captan, sulfur, and copper can cause more plant damage when applied just before a heat wave. Spray material choice is dependent on your management system, I recommend our Initial IPM Strategy for Grape Growers fact sheet in general, and specifically for non-organic growers. Regardless of system (organic or non-organic), this is the time to use your best tools available. For non-organic growers, that would be a protectat and single-site fungicide combination, like mancozeb or captan plus a strobilurin (e.g., Flint) or DMI (e.g., Rally) or SDHI (e.g., Aprovia). Note for that last part of the mix, there are also some good pre-mix combinations like Luna Experience (SDHI + DMI) and Pristine (Strobilurin + DMI) that can cover a lot of bases while reducing resistance development in the target pathogen.

For organic growers, I’d also consider a two-part mix. Regalia has been getting a lot of interest lately and it does appear to have good efficacy against downy and powdery mildews. It needs to be applied 1-2 days before infection, and requires sunlight to activate resistance in the plant- spraying the night before a wetting event won’t do it. Regalia can be mixed with sulfur or copper (more on those two later). Serenade is another biological product which is approved for organic production. Its mode of action is as a microbial antagonist to the pathogen, so it must get established and colonize susceptible tissue before wetting and infection events. Because of this, Serende is not compatible in a tank mix with sulfur or copper, but it could be rotated with them in separate sprays. Serenade has most efficacy (good but not excellent) against powdery and downy mildews. However, it does not protect against some key diseases that affect grapes during this window- anthracnose (especially important on Marquette), Phomopsis, and the most difficult to manage organically, black rot. For those diseases, copper has a bit more efficacy, so this is one spray that should include it, if the vines aren’t sensitive to it. Cold-hardy hybrids with considerable labrusca in their parentage (e.g., St Croix, Brianna, other Swenson varieties) are more sensitive to copper than some others. However, copper damage can be reduced by avoiding application during slow drying conditions (there goes my recommendation to spray at dawn…). As always, spraying should be about your fourth  line of defense when managing grapes organically- first consider; then strict weekly sanitation and removal of all diseased tissue; maintain a training system that ensures good air flow; and finally fit a spray program to help manage within that greater IPM (yes, organic systems are IPM too) program.

Finally, this is a good time to consider applying micronutrients to the vineyard. Boron is very often deficient in Vermont soils, and is needed for fruit development at bloom. The best way to assess need and amount to apply is with a recent petiole sample analysis (last year’s, although you could sample at bloom and make a quick correction). Without that, I feel safe recommending 1 lb per acre actual boron (5 lbs per acre Solubor, an OMRI-certified boron source with 20% B) applied in your spray water. The only caution I make there is that boron and water soluble packaging materials (like Rally bags) do not mix- you’ll gum up your sprayer and ruin your day. Apply those separately. Also, this is a pretty low rate of boron I’m recommending, as you can overshoot pretty easily so I do recommend a petiole analysis to tune your application rate before adding any more.

Finally, Wild grape bloom occurred on June 5 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 5 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.

H2A Workers and COVID-Related Health Care Needs

July 26, 2020

Good morning: I’m forwarding this request on from a colleague at UVM Extension. If you use H2A workers on your farm, it is important that you weigh in so that resources may be made available (or developed, if needed) to assist you and your workers with handling issues related to COVID-19. -TB

Does your farm have guest workers (H2A)? Would you or your employees benefit from assistance navigating health care services or COVID related logistics? Is there a need for information, masks or other resources? If so, we want to hear from you and your employees. UVM Extension is assessing health related needs among H2A workers in order to offer support services. Please reply directly to Naomi Wolcott-MacCausland: or 802-503-2078.

VCAAP Relief Payments for Agriculture and Working Lands Businesses—Coming Soon!

August 14, 2020

Forwarding from the VT Agency of Ag, this could be a great opportunity to recoup some COVID-related expenses for your farm business.

Vermont COVID-19 Agriculture Assistance Program (VCAAP) Agriculture and Working Lands Assistance Application

$8.5 Million in CARES Act Coronavirus Relief Funding will soon be available to a wide variety of agricultural, food, and forestry businesses and organizations through the Vermont COVID-19 Agriculture Assistance Program (VCAAP) Agriculture and Working Lands Assistance Application.

General Eligibility Criteria

(1) Farmers, commercial processors, slaughterhouses, farmers’ markets, food businesses, forest products businesses, dairy producers or processors, and agriculture producer associations are eligible.

(2) Your business entity must have gross annual income of at least $10,000 to apply.

(3) Your business must have verifiable losses and/or expenses since March 1, 2020 as a result of the COVID-19 public health emergency.

How To Apply

The Agriculture and Working Lands application will launch the week of August 17, 2020. Please note that state offices are closed on Monday, August 17 for Bennington Battle Day. Check our website and subscribe to our newsletter to be notified when the application is open.

The deadline to apply is October 1, 2020. However, keep in mind that grants will be awarded on a first-come, first served basis, so the application may close prior to October 1 if all funds are expended.

Before applying, applicants should complete a W-9 form and gather documentation of losses and costs incurred since March 1, 2020 that are related to the COVID-19 public health emergency.


Attend a webinar to learn more about the VCAAP Agriculture and Working Lands Assistance Application. A webinar for service providers and partners will be held on August 19. Webinars for applicants will be held on August 21, 24 and 25. Webinars will be recorded and posted to our website.

Contact Us

(802) 828-2430 select #9

New England Apple Crop Insurance Listening Session Notice

June 24, 2020

Forwarding from George Hamilton:




It is VERY important for those of you having Apple Crop Insurance Policies to participate.

Apple marketing is very different here in New England compared to rest of the major apple producing area in the USA.

This looks to be the last chance for orchardists from New England to voice other needs in an apple crop insurance policy that represents the New England  region.

Please mark this session’s date on your calendars (ITS TOMORROW – JUNE 25) and participate, especially if you have apple crop insurance.

Take Care, Keep Safe and Stay Health – Everyone!


Apple Crop Insurance Listening Sessions

June 18, 2020

From: Jake Jacobs
Sent: Thursday, June 18, 2020 11:15 AM
Subject: Apple crop insurance listening sessions

Please share with any interested parties.

Sorry for such short notice on these listening sessions, but I just received the announcements yesterday while I was out of the office.  Just FYI, in the last series of apple crop insurance listening meetings that were set up across the country in 2018, the New England meeting that was held in New Hampshire had the greatest number of apple growers in attendance.

Details on how to join the meetings and call-in numbers are in the attachments.

Thursday, June 18 – Pennsylvania Apple Growers – 12:00 – 1:30 p.m. EST

Thursday, June 25 – New England Apple Growers – 12:00 – 1:30 p.m. EST

Thursday, July 9 – New York Apple Growers – 12:00 – 1:30 p.m. EST