Forwarding from the VT Agency of Agriculture. -TB
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Fast-track Your VCAAP Application
Fall post-harvest herbicide application
[tree fruit, IPM]
Passing this on from Mary Concklin at UCONN.
Herbicide Applications this Fall
There are a couple of times during the year when the timing of herbicides will have the largest positive impact on your weed management – fall and spring. Herbicides applied at other times during the season are good for eliminating those few pesky weeds that managed to sneak through, often times because of extended wet periods.
Summer annual weeds: they likely died off with a hard frost earlier this fall. Pre-emergent herbicides applied this fall will help to control new annual weed germination in the spring. It is also easier to apply this time of the year than during the busy wet spring when, in some years, it is difficult to get into the fields before germination occurs.
Fall applications: For all perennial weeds, a combination of pre- and post-emergent materials will provide the best results as long as the application is made while the emerged weeds are still alive. Applications made after they have been hit with a hard frost can be with pre-emergent materials only which aims at moving the herbicide into the root zone and impacting emergence in the spring.
Some materials perform better in the fall because of their mode of action. Glyphosate/Roundup is a systemic that moves into the plant. In late summer and fall, plants are moving food reserves to the roots. Glyphosate applied at this time will also move to the root system and kill the plant. In the spring, movement is upward in plants as they grow, so glyphosate applications made at that time have less of a chance of giving you the results you are looking for.
Organic growers also have organic herbicides available. These are contact not systemic materials and work best when applied to young weeds for knockdown. They will need to be re-applied several times throughout the growing season.
Brad Majek, Rutgers, offers the following about timing:
Apply herbicides to the tree row in established orchards twice annually, in late fall and in late spring. Herbicides applied in late October or early November control winter annuals, certain perennials, and early season summer annuals. Spring herbicide applications extend summer annual weed control through harvest. Advantages of two herbicide applications per year include:
1. Control of winter annual weeds, including camphorweed, wild lettuce and horseweed (marestail) and summer annual weed control for the same cost as most single application weed control programs.
2. Improved spring labor and equipment distribution requirements by controlling early summer annual weeds with residual herbicides applied the previous fall, thus delaying the need to spray in the spring until May or early June.
3. Increased consistency of weed control treatments, especially control of summer annual weeds when dry weather follows the spring herbicide application.
4. Decreased risk of crop injury, since each herbicide application must last less than a full year. Herbicides can be alternated and rates can be reduced or split to improve crop safety.
5. Decreased competition from established winter annual weeds and summer annual weed seedlings in March, April, and May for fertilizer and water when the trees begin to grow.
Late Fall Herbicide Applications should include a translocated post emergence herbicide, and a residual broadleaf herbicide. A residual grass herbicide may also be applied in the fall. Apply 2,4-D to control emerged winter annual broadleaf weeds tank-mixed with Princep for residual control. Consider a labeled glyphosate product if perennial weeds are present and treatment is recommended in the fall. The use of a grass herbicide in the fall depends on the product chosen. Kerb 50WP is the only grass herbicide that must be applied in the fall, if it is used, to control certain cool season perennial grasses. An additional residual annual grass herbicide is needed in the spring to provide full season summer annual grass control following a fall application of Kerb 50WP. Solicam 90DF, Surflan 80WP, Devrinol 50WP and Prowl 4EC (non-bearing only) are annual grass herbicides that should be applied in late fall or as a split application, half in the fall and the second half in the spring. Use the split application when grass pressure is heavy for best results. The use of these herbicides in spring only has resulted in inconsistent weed control when dry weather followed the application.
Information on tree fruit herbicides may be found at: https://netreefruit.org/weeds
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.
Helping out Champlain Orchards
I am passing this request from UVM Extension on to the greater fruit growing community. It is rare that I use this list to promote a specific farm, and this should not be read as preferential treatment. What happened at Champlain could have happened on any of our farms, and this is a chance to support each other as a farming community, and to consider what we may need if such a situation befalls any of us. I’ve talked with Ginger and she has indicated that much of the need involves housing upgrades, including dishwashers and laundry facilities to help the workers maintain quarantine while keeping the farm running. She suggested, and I agree, that mundane features like this are something that all farms that have communal housing may want to consider moving forward. Take care, everyone, and please let me know if you have any issues or concerns.
-Terry
By now most of you have probably heard that some of the Jamaican crew members at Champlain Orchards have contracted COVID.
Many of us have worked with Champlain Orchards over the years through our jobs in Extension, and some of us have even had the privilege of working alongside the Jamaican guys as fellow employees of the orchard. They are an amazing group of people, and it is hard to imagine how challenging it must be to be dealing with the pandemic while so far from friends and family.
You can find out more about the situation on Champlain Orchard’s website. While the state is helping in some ways, there is still going to be considerable cost associated with taking care of the men, making adaptations to housing to keep everyone as safe and able to quarantine as possible, etc..If you would like to help, you can make donations by scrolling down to the green button at the bottom of the webpage.
These funds will go towards purchasing supplies for the crew, and making improvements to labor housing. If you have ideas of other kinds of assistance you may be able to offer, please contact marketing to help coordinate.
GINGER NICKERSON|FOREST PEST EDUCATION COORDINATOR
she/her pronouns (why is this here?)
VT Urban & Community Forestry Program
University of Vermont Extension
327 US-302, Barre, VT 05641
Mon – Thurs: 802-476-2003 (Please note I do not work on Fridays) │ www.vtcommunityforestry.org
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.
COVID resources
By now it’s likely that everyone in the Vermont orchard community has heard news of a COVID outbreak among the harvest crew at Champlain Orchards in Shoreham. I write this with respect for the Champlain Orchard community, and humility regarding the potential for an outbreak when we are doing the best we can. A farm isn’t that different than a college campus, and this only highlights how easily any of us can wind up in a tough situation.
The Vermont Agricultural and Public Health communities are providing support to Champlain and to other growers. Addison District State Senator Ruth Hardy has issued a communication to constituents outlining the services being provided. For many of our smaller pick-your-own orchards, the low crop and high demand have led to a shortened season, and many shops have already closed up for the season. But for those who are still harvesting, and especially who still have crews in bunkhouses, it’s critically important to follow CDC guidance as I outlined in a previous post.
Finally, on a good note, the Vermont Agency of Agriculture, Food, and Markets has announced an extension to November 15 of the Vermont Covid-19 Agricultural Assistance Program. VAAFM personnel had contacted me earlier in the season because few growers had signed onto the program, which wasn’t too surprising given the timing during harvest. The purpose of VCAAP grants is to stabilize agricultural businesses and organizations based on their lost revenues and expenses related to the COVID-19 public health emergency. Please consider applying for this program, more information is available at: https://agriculture.vermont.gov/covid-19-information/vermont-covid-19-agriculture-assistance-program
Take care out there,
Terry
Health Services for H2A Workers
Passing on from Naomi Wolcott-MacCausland at UVM Extension. -TB
UVM Extension wants to make sure H2A workers are as healthy as possible during this busy time of year and into the future. The fall flu season combined with COVID is potentially a huge threat to the success and viability of farms and we want to help reduce this risk. We are making available FREE health services on and off-farm in the coming weeks and are doing a health needs assessment to help us make decisions about future services.
WHAT WE CAN DO FOR YOU THIS FALL:
· Send an immigrant farmer outreach nurse to the farm for health screenings
· Arrange free telehealth visits for workers
· Provide COVID educational resources, screen potentially symptomatic workers by phone, and coordinate on-farm COVID testing for symptomatic workers
· Provide information about local flu clinics accessible to your crew (and when possible coordinate on farm flu clinics)
WHAT WE NEED FROM YOU:
· Input of farm owners regarding their view of the health care needs of H2A workers
· Input of H2A workers regarding their health care needs and barriers to care
HOW DO I PARTICIPATE?
Farm owners or managers:
Use this jennica.stetler. Either way, we’ll be in touch with you.
H2A workers:
We would like to conduct these assessments in person at a time that is most convenient for the farm and workers while masked and practicing physical distancing. We hope to arrange these in person visits through farm owners or managers. You can help us do this by taking the survey or emailing jennica.stetler.
Vineyard Management at Veraison
August 4, 2020
Grapes are at or near veraison in Vermont vineyards, which signals the start of fruit ripening. This is an important time of year for a few activities. First, bird damage can be expected to begin and increase as fruit ripen. Birds will harvest your berries just a day or two before you’re ready to, so if you don’t have damage yet, don’t think you’re out of the woods. Netting is the best method of protection. Auditory scare calls, propane cannons, and inflatable ‘used car lot’ balloons are sometimes used as well, but their effectiveness is questionable and their annoyance factor significant. Dr. Alan Eaton from the University of New Hampshire wrote a good guide on prevention of bird damage in fruit plantings, available at: https://extension.unh.edu/resources/files/Resource001797_Rep2514.pdf.
Disease management: as fruit ripen, they will become more susceptible to the various bunch rots, including botrytis, ripe rot, and sour rot, and canopies can be affected by late-season downy and powdery mildew. Good cultural management for all of these includes keeping the canopy open, ensuring that clusters can ‘see the sun’ by shoot combing / thinning, removal of leaves, and pruning of laterals. There may be a few sprays warranted at this time, with some big caveats. Copper, sulfur, and captan should be avoided as we approach harvest, as they can either inhibit fermentation of contribute to off-flavors in the finished wine. Consider preharvest intervals, too. Visible downy mildew can be managed through leaf removal, or application of one of the various Phosphorous acid products (e.g., Rampart, Fosphite). Some other materials that have efficacy against DM may be found in the New England Small Fruit guide. Be sure to rotate fungicide resistance classes (FRAC codes). There may be a bit of powdery mildew in the vineyard as well, that can typically be managed with a thorough application of stylet oil, applied as soon as it is observed in the vineyard. Botrytis can be specifically managed with fungicides, but it will be difficult to get into any closed clusters like Petite Pearl, and that disease is best managed during the immediate postbloom window. Remember that not all varieties are equally susceptible to disease, and loose-clustered varieties tend to have less issues with botrytis overall. There is some concern regarding spotted wing drosophila (SWD) and its potential to damage ripening fruit, which leads to sour rot infections. This invasive pest has been seen in high numbers in the region this year, but that does not suggest cause for alarm among the vineyard community. SWD have lower preference for grapes than for other soft fruit, and winegrapes that will be processed immediately after harvest are less prone to damage from secondary diseases. Still. Good vineyard sanitation is key in managing this pest. Any damaged clusters with cracked fruit should be removed from the vineyard in the weeks between veraison and ripening, as these attract SWD and other rot-bearing fruit flies. SWD have a preference for protected, shady areas in the canopy, so, again, keeping clusters exposed to sun is a helpful practice. While there are many insecticides labeled for control of SWD, I do not recommend their use in vineyards in any but the most specific cases.
Now is the time for plant tissue testing as well. Petiole samples may be collected at bloom or veraison, and comparisons between years or blocks should be based on the same time of collection. 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 is the Cornell Nutrient Analysis Laboratory . Please note that they now have partnered with Agro-One Services. It is recommended that you contact them before you send any samples to confirm that recommendations will be sent along with the analysis and to confirm costs.
Video about petiole sampling: https://www.youtube.com/watch?v=8EHbojLfXek
Start making plans for harvest and crush now. This may be a good time to thin out any lagging ‘green’ clusters that developed from secondary buds and are lagging in ripeness. Remember, you’re looking for crop uniformity. You can estimate yield by counting clusters on a few representative vines and multiplying by the typical cluster weight for your vineyard. If this is unknown, use 0.25 pounds (113 grams) per cluster, which is the average we have recorded at the UVM vineyard for Minnesota cultivars from 2010-2015. Your formula should look like this:
Estimated tons/acre = average # clusters/vine * 0.25 lbs/cluster * # vines per acre /2000 (pounds per ton)
For the UVM vineyard, where we have 726 vines per acre [43560 sq feet/acre / (6 feet between vines * 10 feet between rows)] = 726, the crop estimate for 50 clusters per vine is:
4 tons/acre = 50 * 0.25 * 726 / 2000
Four tons per acre is a good crop for mature, healthy vines for most cold climate cultivars; some vigorous vines in good health may support higher crop yield but I wouldn’t push mush more than 5.5 tons per acre lest you compromise ripening. If you have too many clusters, thin out the smallest and greenest ones to get your target cluster number. This exercise will help you plan lugs, bins, and tank space, as well as allow you to communicate that information to any wineries you plan to sell to.
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 http://www.uvm.edu/~fruit/grapes/gr_ipm/RelativeDiseaseRatings2017.pdfsusceptibility; 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.
Pre-Harvest Juice Testing For Ripeness
August 30, 2020
Heat accumulation is up overall this year, and we are about ten days ahead of ‘normal’ in South Burlington. As harvest approaches, it’s important to keep and eye on three important parameters of juice chemistry: soluble solids (sugar), pH, and titratable acidity. These values should be checked at least weekly against your target levels for the wine style you are aiming for. Last year, we published a fact sheet the details the methods for completing these tests: http://www.uvm.edu/~fruit/pubs/UVMFRT006_PreharvestGrapeTesting.pdf
Good luck with the harvest.
Early Summer Vineyard Management
June 29, 2020
July 1 brings a number of early summer vineyard tasks to think about. First, be sure to keep up with your disease management: sanitation, especially in organic vineyards, and sprays as needed. We’re still in that critical window where all or the main diseases (except maybe Phomopsis) are active. See our initial diseases management guide, or the New York guide for details. Also, the material in Cornell professor Katie Gold’s early season disease management recommendations is still relevant.
As for horticulture, there are a number of activities to stay on top of. Petiole samples to assess vine nutrient status may be collected now where vineyards are in bloom, or at veraison. Stick to the same timing in your vineyard if you are going to compare samples year to year. Details here. Keep vines, especially young or struggling ones, watered during this drought. Manage weeds, especially, again, on young vines. Established vines tend to compete better for water and nutrients, but tall weeds growing up into the canopy will increase disease pressure.
Finally, shoots will soon lignify at their bases and be strong enough for combing without breaking them off. The goal, for vines on a high wire cordon system, is to separate each shoot and direct it downward, thus exposing fruit to sunlight and making a more manageable canopy. 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.
Vineyard Management
June 7, 2020
First, sorry about lumping the grape growers in with my last apple email. I do know that you’re (mostly) separate entities with separate needs. That said, the importance of staying on top of disease management now is just as much there. We’re entering the critical immediate prebloom period in vineyards, when they are susceptible to pretty much all of the major diseases we face: black rot, Phomopsis. Powdery mildew, and early downy mildew. For non-organic growers, and combination of a protectant (captan or mancozeb) and a systemic / ‘kickback’ active material like a strobilurin, DMI, or SDHI would be warranted now and in the next application 7-10 days fr4om now. Be sure, especially with that latter group of materials, to rotate fungicide resistance classes so that you’re not using any class (e.g., 3 for DMIs, 7 for SDHIs, and 11 for strobilurins) more than twice back-to back. Some materials have more restrictive seasonal application caps- always check your label. For organic growers, I would recommend rotating copper and Serenade or bicarbonate (like Armicarb O or equivalent) on a fairly tight 5-7 day schedule. Then again, the dry weather has been nice for managing diseases. Organic growers need to really pay attention to sanitation and removed any diseased tissue as soon as it’s seen, and scouting should be done weekly.
I saw a good bit of grape tumid gallmaker in our UVM vineyard last week, enough that we treated for it. Usually, this insect is a curiosity, but we have seen and had others report that losses can be as high as 50% of fruit clusters ruined by the insect. Keep an eye out for it (pictures in the link posted) and consider treatment if more than 5% of fruit clusters or 15% of leaves are affected. Organic growers will need to crush galls by hand, non-organic can treat with Movento or Assail.
Get your shoots thinned. This will make life so much easier later this summer.