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UVM Fruit Blog

Buds swelling in local vineyards

Posted: May 12th, 2020 by fruit

By Terence Bradshaw

Grapevine buds are showing significant swelling in vineyards both in the Champlain Valley and at my house at near-1500 feet in Washington County, so bud break is right around the corner. However, This extended cool weather expected this week will leave those buds in this swollen state for an extended period, which leaves them susceptible to damage from grape flea beetle and climbing cutworms. It may be a good idea to scout vineyards this week; feeding damage on more3 than 2% of buds scouted may indicate a need to treat; carbaryl or a pyrethroid material (Including, for organic growers, Pyranic) would be effective options. However, once vines have pushed 1” or more growth, they are no longer susceptible to damage from these pests, so don’t bother treating if you get that far without having done so.

The window to treat vines with liquid lime sulfur (LLS) is closing as vine growth increases, do not consider applying high doses of that material to vines with green tissue showing. I described the use of LLS in my April 3, 2017 message.

If you will be using glyphosate to manage in-row weeds this spring, your window for safest application to the base of vines is now, before any foliage that is susceptible to herbicide uptake develops. I would still use a shield of some sort to keep the material off of vines.

Reminder: NY-PA Grape IPM Guidelines are available for order at: https://cropandpestguides.cce.cornell.edu/

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.

Cold temperatures, foliar nutrients, and scab

Posted: May 8th, 2020 by fruit

The good thing is that insect and fire blight activity remain pretty low. On the other hand, we have potential for an extended scab event starting today and lasting through the weekend. This is a tough one to plan around. Ascospore maturity is creeping up, and significant wetting, especially today, can discharge a lot of spores. Hours required for infection to occur are likely pretty high, given the cold weather, but it does look like an infection will happen. Orchards should be covered with a fungicide, and a material with kick-back activity applied when the winds die down (Monday?) if there is any question of coverage.

While spraying, any orchards between tight cluster and pink should receive the prebloom nutrient cocktail that will help buds to recover from cold and enhance fertilization during bloom. Zinc and boron are important minerals which will help trees recover from cold damage, and nitrogen is needed at this time of year when rapid growth taxes tree reserves. Refer to Mary Concklin’s quick summary here for more information: http://blog.uvm.edu/fruit/files/2016/04/Tree-Fruit-Foliar-Nutrient-Applications-and-Nutrients-PGRs-for-Frost-Freeze-Situations.pdf.

Speaking of cold, many of us are concerned about the cold that’s coming this weekend. Remember that fruit buds, even at bloom, are hardy to about 28°F, and more closed buds are even hardier. This is expected to be an extended cold period, though, with high wind that could dessicate buds (although a coating of snow ought to keep some moisture in). I think we’ll be on the safer side of the tightrope, given the expected temperatures I’m seeing (30F in Champlain valley and Southern Vermont, 27 inland where buds are more closed, give or take). I’ll talk next week about how to check buds for damage after the fact.

Plan on draining water lines and sprayers today. Better safe than sorry.

Finally, I’ll share some advice I received from Jim Wargo @ Valent USA regarding plant growth regulator use to increase fruit set on apples that have suffered from cold events:

PROMALIN Plant Growth Regulator is well-known as a tool to improve fruit set after a frost. The active ingredients in PROMALIN replaces the hormonal signal that is lost when developing seeds are killed or damaged by low temperatures during bloom, allowing the fruit to grow with reduced or no seeds, and often to normal size. Promalin does not repair or heal damaged flower parts. It simply replaces the hormonal signal that normally comes from the developing ovules (seeds) when pollination and ovule fertilization has been accomplished. But what about cold injury that occurs prior to bloom – at tight cluster to early pink? Anecdotal observations suggest applying Promalin within 24 hours of frost events during these earlier growth stages is less effective or not effective at all. My guess is there are two possible reasons wh. 1) Applying Promalin (a hormonal signal) at a time which is out of step for the normal signaling process that begins after pollination (bloom – petal fall) is not effective at “tricking” the tree. And 2) Promalin applied prior to bloom gets metabolized (broken down) by the plant cells and is no longer present when needed at the post pollination/fertilization time. For perspective, the use pattern of another PGR, ProVide, comes to mind. ProVide (GA4+7) is basically Promalin without the 6BA and is used to reduce skin russeting and scarf skin disorders on apples. Weekly ProVide applications starting at petal fall are needed to sustain sufficient levels of GA4+7 in the plant over the time period when fruitlets are most susceptible to russet. The applied GA’s get metabolized over time which is why multiple applications of low rates work better than a single application of a high rate e.g. 12 oz/A at petal fall. One application of GA4+7 just doesn’t stick around long enough to have the same effect as multiple lower rate applications do.

One possible work around for flowers that are damaged prior to bloom is to delay the application of Promalin until full bloom. In other words, do not apply it within 24 hours of the frost event that occurs at tight cluster – early pink. Wait until the trees come in to full bloom, apply a pint of Promalin at that time and then another pint at petal fall. The two applications at bloom and petal fall are within label guidelines. This approach is theoretical, but if we are trying to trick the trees, we need to have the hormones available and in sufficient quantity at the time the tree is deciding what to do with that fruitlet – hang it on or let it go. The tree is not making that decision at pink or prior to that – it’s too early. My recommendation for a 2nd pint at petal fall is to prolong the level of hormones in the plant to further enhance fruit set. As a disclaimer, if flower clusters are damaged beyond repair, no PGR treatment will work. In order to have any effect, injury must be restricted to the reproductive parts of the flower e.g. stigma, style, anther, ovary. If receptacle tissue is damaged, then all bets are off.

ReTain Plant Growth Regulator – How ReTain works to enhance fruit set is completely different than Promalin, and the two should not be used interchangeably. ReTain inhibits ethylene and in turn extends the effective pollination period – defined as the number of days during which pollination is effective in producing a fruit. It is determined by the longevity of the ovules minus the time lag between pollination and fertilization. ReTain will do nothing for flowers that have been damaged by cold injury. In addition to benefitting varieties that are inherently predisposed to poor set e.g. SweeTango, Evercrisp, ReTain may have benefits when pollination conditions are less than ideal – in particular, challenging weather conditions (cool temperatures, strong winds and rain during the bloom period). Honeybee activity is limited during rains and heavy winds and when temperatures are below 65F. This is where ReTain can help, by extending ovule longevity, it broadens the window of opportunity for pollination/fertilization of the ovules by 3 – 5 days. The idea is to get past the challenging weather conditions and still have flowers that are capable of setting fruit.

Recommendations for using ReTain for enhancing fruit set:

  • For varieties that naturally have a long bloom period or in years with poor pollination weather during bloom apply ½ pouch of ReTain when 25 – 30% of king flowers are open and ½ pouch at 75% king bloom. Do not use a surfactant
  • For varieties that have relatively shorter bloom period or in years with more ideal pollination weather apply 1 full pouch of ReTain when 20% of the king bloom is open. Do not use a surfactant

Here is a real-life example of how I decided to make a decision regarding PGR use in my own orchard. I experienced bud damage on my earliest varieties (Empire, McIntosh) from frost events at tight cluster. I was preparing to spray Promalin at bloom, but when the trees started entering king bloom on 5/5, I noticed the damage was not nearly as severe as I had thought. However, the forecast for the next ten days here in CT does not bode well (high/low temps) 60/42, 54/34/, 44/35, 51/42, 50/38, 51/36, 54/41, 56/48, 63/55. The only day that looks to have any decent potential for bee activity is Friday May 15th! I’ve decided to apply ReTain instead of Promalin during bloom to extend flower viability in hopes it warms up to >65F eventually. Mother nature has the final say, all we can do is wait it out. ReTain gives us the ability to broaden the pollination window and play the waiting game…

Along with the PGR applications, I would strongly suggest growers utilize the Warren Stiles foliar nutrition program for enhancing fruit set – urea (3 lb./100 gallons dilute) and boron (0.1 -0.3 lb. B/A) at tight cluster to pink. Followed up by another shot of urea (5 lb/100 gal) and Boron (0.1-0.3 lb B/100 gallons) at petal fall. The Boron will help with pollen germination and pollen tube growth. The urea provides N which is a precursor to polyamines. Polyamines have been shown to extend the effective pollination period by increasing ovule longevity. Zinc chelates may also be applied prebloom – up through tight cluster stage.

Regards,

Jim

James Wargo

Territory Manager, Northeast

Valent USA

678-357-2400

jwarg

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.

Thinking about early season grape disease management

Posted: May 5th, 2020 by fruit

By Terence Bradshaw

Despite the bit of snow on my deck this morning, spring is here and vineyards will be waking up soon in Vermont. It’s better to plan ahead than to be reactive to problems after they become established. Therefore, I recommend reading Dr. Katie Gold’s Early Season Grape Disease Management recommendations to help prepare for the season. Dr. Gold is the new grape pathologist at Cornell and replaces Wayne Wilcox, whose spring missives were regular reading for grape growers. It’s great to see that she is continuing that tradition, and that we will continue to have qualified expertise in the northeast to help with grape disease management

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.

SBA EIDL program re-opening for farmers; prebloom orchard activities

Posted: May 4th, 2020 by fruit

By Terence Bradshaw

Earlier today I sent a notice from Tom Berry at Senator Leahy’s office regarding availability of emergency funds to farmers affected financially by the COVID-19 pandemic. That was referencing a re-opening of the portal specifically for farms to apply for funds. If you are an ag business that was unable to take advantage of the SBA EIDL Loan/Advance Program, there is good news! The EIDL Advance/Loan portal will be re-opening shortly (today, May 4th). The re-opening of the portal is for agricultural businesses that were previously ineligible for the program. New non-agricultural business applications will not be accepted. The portal will be opened for a limited period, and it is recommended that you apply as soon as possible. The link to the portal will be: http://www.sba.gov/Disaster

Bud stage for most cultivars at the UVM Horticulture Research and Education Center is tight cluster. Cider cultivars are hanging back at half-inch green tip, and Zestar is ahead of everyone at early pink. This means that it’s time to really think about bloom activities. First, if you use rented beehives for pollination, make sure your hives are lined up. You’ve only got one shot to get those flowers converted into fruit, so make the most of it. Weather looks relatively cool in the days ahead, but I’m not seeing much in the line of hard freezes that concerns me. At this rate, boom is likely to hold off until next week, although that is very site-dependent. Upland and inland orchard still have a ways to go.

Any time now would be a good time to apply foliar zinc, boron, and nitrogen. Wes Autio from UMASS has published a good fact sheet on prebloom foliar nutrients here. Soil applied nitrogen and boron applications may also be applied at any time now.

Insect activity should be picking up in orchards soon. Many orchards choose to apply a pink insecticide prophylactically to manage tarnished plant bug and European apple sawfly, but those pests are best managed based on trap capture data. White sticky traps hung three per ten-acre block at knee height for TPB and head height for EAS may be monitored to assess whether populations are above economic action thresholds. Traps may be ordered from Great Lakes IPM or Gemplers and should be hung as soon as possible if they are not up yet. Thresholds for scouted insects may be found here. For TPB, five captured bugs per trap (eight for retail orchards with higher damage tolerance) is the economic threshold for an insecticide spray at pink. Cool weather this week is expected to keep activity low for the time being. EAS are typically managed at petal fall, and threshold for management is nine per trap averaged over all traps in the block for blocks that received a prebloom insecticide or five per trap for those where no spray was applied at that time.

Codling moth is an increasing pest in Vermont orchards and are best managed using degree day models to time insecticide sprays. CM are monitored using wing traps available from the sources listed above. Traps should be hung at pink and monitored daily to record the first moth capture. I posted a short explanation of the CM biofix to my YouTube channel today.

Some growers may be interested in using mating disruption (MD) against codling moth or dogwood borer this year. We have been deploying MD for several years on an experimental basis at UVM since we had significant damage a number of years ago in the organic orchards, and feel that it has been relatively successful. MD is expensive, however, works best in large contiguous blocks, and should be deployed orchard-wide to be most effective. Eric Boire at Nutrien ((802)759-2022) would be a good contact to explore this option further.

Do I have to remind you that we’re all heading into (or already in) the advanced /accelerated phase of apple scab ascospore maturity? Keep an eye on the weather, and protect ahead of rains. The New England Tree Fruit Management guide has good recommendations based on bud stage for managing this disease.

Fire blight? Still too cool to really be worried at this point. Keep an eye out for warm (>70°F) weather going into bloom and, as always, NEWA is your best bet for tracking disease potential.

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.

SBA EIDL program open for agricultural sign-up

Posted: May 4th, 2020 by fruit

Forwarding from Tom Berry in Senator Leahy’s office:

Agricultural programs were excluded from the first round of applications for this program. That was changed in the subsequent action by Congress. Now SBA is opening applications exclusively for agriculture. The portal is otherwise closed while SBA works through a backlog, and the reopening seems to be exclusive to agriculture.

Those who are inclined to apply should do so as soon as possible.

Tom

(802) 355-2213

20-38-05 04 20 EIDL reopening.pdf

Safely Selling Local Food at Farm Stands and CSAs — Wed 5/6 12-1pm

Posted: April 30th, 2020 by fruit

Visit http://go.uvm.edu/sellvtfood for more info.

Safely Selling Local Food at Farm Stands and CSAs during COVID-19

When: Wednesday, May 6, 12-1 PM

Where: You can call in by phone or connect through your computer on Zoom. Register here.

Demand for local food is surging, and many Vermont farms are heeding the call to feed their communities. They have adapted time and again to the evolving COVID-19 situation to ensure the safety of their food, customers, employees, and farms. They’re even selling products from other farms, along with their own meat, dairy, produce, maple, etc.

Join us online or by phone for a discussion about COVID-19 best practices for farmstands and CSA models. We’ll give an update on the latest guidelines – whatever they are on May 6.

Presenters include:

  • Sara and James from Trillium Hill Farm in Hinesburg
  • Ashlyn and Abraham from Rebop Farm in Brattleboro
  • Kristina from the Vermont Agency of Ag
  • Bill from NOFA-VT

Register in advance for this meeting: https://uvmextension.zoom.us/meeting/register/tJYpceGtrT4vGNzEs07bb0MCwTB0JzTY8e2V

After registering, you will receive a confirmation email containing information about joining the meeting. Feel free to send Lisa.Chase questions in advance.

This conversation is part of the Sourcing & Selling Vermont Food in the Time of COVID-19 Series being developed by a team from UVM Extension, the Vermont Agency of Agriculture, Vermont Farm to Plate, Vermont Fresh Network, NOFA-VT and other partners to help Vermont’s farm and food system build resiliency and support safety in these challenging times. Visit http://go.uvm.edu/sellvtfood for more info.

To request a disability-related accommodation to participate in this program, please contact Becky Bartlett at 802-257-7967 so we may assist you.

UVM Extension helps individuals and communities put research-based knowledge to work. Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. University of Vermont Extension, Burlington, Vermont. 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.

Video: Early season insect monitoring in orchards

Posted: April 29th, 2020 by fruit

As we shift into a new (not really) world of online content delivery, I’ll be beefing up the content on the UVM Orchard YouTube channel. Here’s a Video I did yesterday where I checked early season insect traps for European apple sawfly and tarnished plant bug.

U-Pick Farms: COVID-19 Recommendations and Webinar Tomorrow

Posted: April 29th, 2020 by fruit

Upcoming Webinar on U-Pick

If you have questions about these recommendations, Laura McDermott, CCE Berry Specialist with the ENY Horticulture Team, is hosting a webinar.

Best Management Practices for U-Pick During the COVID-19 Pandemic

Thursday, April 30, from 12:30 p.m. to 1:30 p.m.

· Join via Zoom online at:

· Or dial by phone: 1-646-518-9805 Meeting ID: 955 1458 6018

· Join via Skype for Business at:

From Cornell University’s Marvin Pritts:

Dear farmers and friends,

For 8 years, I had the pleasure of operating a U-Pick strawberry farm here in the Ithaca area. I took deep pride in the strawberries we grew and the experience we provided to all of our visitors. The sense of community created fed our spirit as they filled their buckets!

U-Pick is a critical direct marketing approach for many of our small farms and provides customers with a unique connection to fresh produce grown close to home. The time spent outdoors gathering one’s own produce is a chance to share in our local bounty, support our farmers, and stock up for the future.

U-Pick farms from around the country have reported an increase in customers who are hungry for all of these opportunities during this pandemic. What will it take to be ready for our U-Pick season?

In light of what we understand about the spread of COVID-19, new management practices will be needed to protect your U-Pick farm team and your customers. This will take some more planning as well as possibly adding more staff to your team.

To help you, we have created this set of best management practices (BMPs) for operating a U-Pick farm during COVID-19. Our team included me, Marvin Pritts (Cornell Berry Specialist), Elizabeth Bihn (Produce Safety Alliance), Laura McDermott (ENY Horticulture Team Berry Specialist) and Esther Kibbe (Harvest NY Berry Specialist).

These BMPs focus on handwashing, physical distancing, and sanitation of surfaces. There are several tactics that should be implemented before the season begins. Developing a clear communication strategy with your customers will be central to making sure that everyone understands, before they arrive at the farm, that we are in this together.

The online BMPs will be updated weekly based upon any new guidance we receive from NYSDAM or NYDOH. There is also a PDF version that you can download and share with your staff, since this will take a team effort.

Oil application and expected rains Sunday-Monday

Posted: April 24th, 2020 by fruit

By Terence Bradshaw

It didn’t take long after I posted my last recommendations for someone to point out to me that it’s unlikely that apple scab ascospores can be released through two inches of snow. Point taken. This cool weather has put things into that slow, on-hold pattern a bit, but activity will pick up today and tomorrow as temperatures get into the 50s. In warmer southern Vermont predicted ascospore maturity is getting up around 10%, which is when we should be taking scab more seriously. In the Champlain Valley, where ascospore maturity is estimated around 5-7%, buds appear to be hovering around the half-inch green stage. Upland and inland, still at silver tip. Rains Sunday and Monday are expected to bring an infection period, so orchards with significant tissue exposed should be covered with a fungicide in the next two days.

Weather is looking good for oil application today and tomorrow, assuming that your site isn’t expecting freezing weather in the next couple of days. I am a proponent for putting oil on as late as possible, up to tight cluster or even pink. The rate should be adjusted down as buds open more: 2-3 gallons per 100 gallons water (straight % in tank, not adjusted for tree for volume or per acre) is good from dormant through green tip; 2 % GT-tight cluster; and 1% as you approach pink. Oil should be put on dilute- slow down and open up your nozzles if you can. For most orchards, 100 gallons of water per acre should be the minimum for applying oil. That means recalibrating your sprayer in many cases.

For growers with substantial bud development and concern about cold temperatures the past week, you may want to pinch some buds and look for browning in the developing ovaries…or not. There’s not much you’ll do about it now, anyway, but come bloom, it would be wise to observe flowers and be ready to adjust thinning if more than 20-30% damage is observed. I’m pretty hopeful that most sites have been fine, the critical temperature for 90% bud kill at tight cluster is 21°F, although some damage may be seen at 28. For half inch green, we can expect buds to be all right down as low as 23 or even colder. Trees at silver or green tip should be fine. Remember, if you suspect bud damage from cold temperatures, it is important to contact you crop insurance agent ASAP to get the claims process started.

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.

Grape Grower Webinars Planned for April 22 and May 13

Posted: April 21st, 2020 by fruit

By Terence Bradshaw

Passing on information on two informative webinars that local growers should find useful.- TB

The University of Minnesota Extension and University of Wisconsin-Madison Division of Extension are teaming up to offer two webinars/Q&A sessions for grape growers in April and May. The goal of these events is to help growers refine their early season vineyard management plan and ask questions. We will focus on key tasks and sprays that must be completed between bud swell and bloom.

In the first 30 minutes of each webinar, you will hear from UMN and UW experts on topics like insect, disease, and weed management; soil fertility; and other critical vineyard tasks like vine planting technique. The second 30 minutes is reserved for open Question and Answer time.

April 22 @ 1:00pm CDT: What To Do Now – Grape Bud Swell

REGISTER HERE: z.umn.edu/Grape1

May 13 at 1:00pm CDT: What To Do Now – Early Season Fungicides & Planting Grapevines

REGISTER HERE: z.umn.edu/Grape2

For more information on the topics that will be covered, please click the registration links above.

Speakers include Amaya Atucha (UW-Madison), Matt Clark (UMN), Jed Colquhoun (UW-Madison), Christelle Geudot (UW-Madison), Annie Klodd (UMN), and John Thull (UMN)

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.

Contact Us ©2010 The University of Vermont – Burlington, VT 05405 – (802) 656-3131
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