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UVM Fruit Blog

Lime sulfur in vineyards question

Posted: April 27th, 2018 by fruit

By Terence Bradshaw

I have discussed the use of lime sulfur in a pre-bud break spray to reduce overwintering disease inoculum on grapes, and this looks like a good time to be thinking about that practice. Multiple people have asked me the same question which tells me that more have it as well, so I may as well answer to the group. The question is about the rainfastness of lime sulfur, and how long it needs to be on the vine before rains come for it to do its job.

Lime sulfur used in a high rate directed application to dormant tissue isn’t acting like your normal protective fungicide. That is, it is not applied to tissue prior to infection to prevent sporulation, like a protective barrier. Its use in this manner is as a postinfection material, meaning that it is working on already established fungal infections. Therefore, as long as it’s on the surface of tissues, and hopefully soaked right into the cracks and crevices where inoculum hide out, it will do its job in fairly short order. Lime sulfur is a caustic material that denatures proteins and degrades cells, it’s not a highly refined biochemical process that’s going on. With that said, I can’t say specifically how long it takes for it to do its job, but I would surmise a few hours, and likely much happens immediately. As I said to one grower who asked me this question, think of lime sulfur more as a sanitizing wash than a fungicide where you want to maintain residue for as long as possible (until you don’t at harvest time that is).

So, today and through the weekend, I would feel comfortable applying any time I have a four-hour dry window. Spraying in the rain will likely dilute the material and reduce efficacy, so I’d avoid that.

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.

Apple Season is right around the corner

Posted: April 20th, 2018 by fruit

By Terence Bradshaw

I’ve been seeing reports from areas south of us- recommendations for first scab spray in Connecticut; green tip on McIntosh in Massachusetts. And yet I awoke to another morning of accumulating snow and temperatures in the 20s. I haven’t seen a colder / slower start to the apple season in my roughly twenty years in this business, but rest assured that the trees will soon awake. We’re looking at a warm and dry trend next week, with temperatures in the 60s by Monday. I’d expect green tissue to be showing in warmer sites by the middle to late next week. That means that the season and all of the management it entails is right around the corner.

While the general rule of thumb is that tree phenology advances with temperatures in the 40s, apple scab inoculum matures at cooler temperatures. That means that overwintering scab inoculum can be ready before the trees are, which makes sense- the fungus evolved to stay just ahead of its host in terms of development. I expect that many orchards had issues with scab last year, and if you saw any on a casual inspection of the orchard or in the packing house, expect for there to be a lot of inoculum ready to infect this spring. This is one of those years to stay ahead of scab.

You can help to clean up inoculum at this time by increasing decomposition of leaf litter. That can be done by either flail mowing leaf debris (and you need to go slow, low, and thorough) or spraying urea (40 lb / 100 gal water to soak leaf litter), or both. If using urea, you should adjust your fertilizer rates downward, but only expect about half of that applied nitrogen in the urea s[pray to be there when the tree needs it in a few weeks.

That said, you need both inoculum (assume it’s there unless you did a Potential Ascospore Dose assessment last fall) and environmental conditions to cause apple scab infection. Starting now, keep an eye on the weather forecast and use NEWA to help guide spray decisions. The best and most conservative strategy is to maintain protective coverage of fungicides on tissues prior to infection to prevent disease rather than fight established infections all season long. The first fungicide application typically made between the silver tip and green tip bud stages is a copper spray which will also help to reduce overwintering fire blight bacteria on the surface of woody tissues. Copper can be applied at the usual, full rates any time before quarter-inch green tip, but once you see the beginning of the ‘mouse ears’ from the first two leaves, know that copper application can lead to fruit russeting (not necessarily an issue with cider apples, but this will quickly downgrade fresh fruit). Dave Rosenberger pulled together an excellent summary of the use of early season copper for scab and fire blight management in the March 25, 2013 issue of Scaffolds. Copper may be applied when there is a threat of freezing weather before or after application.

Oil, however, is a different story when it comes to applications before or after freezing weather. Delayed dormant, silver tip, and green tip are common times to apply an oil spray to help manage mites, aphids, scales, and other overwintering arthropods pests. When oil penetrates cells, it causes phytotoxicity that can affect fruit development, especially when cluster leaves which supply most of the carbo0hydrates to developing fruit early in the season are damaged. Oil is often applied at dilute rates, and the goal for a grower should be to fully saturate the tree as best possible. Application of oil just after or before freezing events (24 hours either way definitely, possibly 48 hours) can cause damage, so if you have seen or are expecting freezing temperatures, put the oil away for a couple of days.

Fortunately, oil can be applied right up to tight cluster-early pink bud stages, and in fact may be more effective then. We should be out of frost risk by then (otherwise we have bigger problems than oil on fruit cluster leaves), so maybe delaying your oil application would be prudent, so long as you can fit it around Captan sprays later in the season. Oil should not be applied within 7-1- days of a Captan or Sulfur spray. For more details on spring oil applications to manage mites and other pests, including rates and spray incompatibility issues, please refer to your 2018 New England Tree Fruit Management Guide.

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.

Apple and blueberry pruning workshop, April 8. Elmore, VT

Posted: April 4th, 2018 by fruit

By Terence Bradshaw

Posting this for Elmore Roots Nursery. If anyone else has similar, financially accessible educational opportunities, feel free to send them to me for distribution. –TB

Pruning Apple Trees and Blueberries, April 8th

1:00 – 3:30 p.m. – Workshop taught by Patrick Sullivan of Ananda Gardens, formerly apple tree pruner at Shelburne Orchards will include pruning and training young fruit trees and restoring old apple trees. The best pruning tools and organic tree foods will be available for purchase at the nursery.

What you’ll need:

Please be sure to wear warm clothes and boots! Even if it is warm in your part of Vermont, you can be sure that it will be much colder at Elmore Roots.

Elmore Roots will be well-stocked with the best Silky saws, pruning shears, loppers and extension pole pruners!

Cost and Registration:

all workshops $15 registration fee; Please call (802-888-3305) or email fruitpal to register.

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.

Important: Government regulations survey

Posted: April 4th, 2018 by fruit

By Terence Bradshaw

I understand survey fatigue- really. This one from my colleague Dr. Meredith Niles may be one of the most important ones you’ll see this year, as it goes across the usual topics and gets at the core of one the most important issues affecting farmers today, regulations. If you have a few minutes, please consider filling it out. It should only take a few minutes, and the data can be extremely useful in guiding current policy development and future policy implementation. –TB

Research Study: Understanding How Government Regulations Affect Farms and Farmers

Description: A new research study at the University of Vermont seeks farmers for two opportunities to understand farmer perspectives about government regulations on their farms. The project is funded by the James M. Jeffords Center for Policy Research at the University of Vermont. The project will also interview state-level policymakers.

Online Survey: Farmers can directly and immediately participate in an online survey about government regulations on their farms by going to: mtniles.

Interviews: We also seek to interview farmers about their experience complying with government regulations on their farm, especially the Required Agricultural Practices (RAPS). Farmers are being sought to represent diverse agricultural industries, production methods, farm sizes, and generation (new farmers, multiple generation farmers). Research will involve an audio-recorded interview, which will take approximately one hour. Farmers will not be identified in the research outcomes and all information will remain anonymous. For their time, farmers will be compensated $50. To express your interest for participating in the project, and schedule a time for an interview, please contact Courtney Hammond Wagner at 802-560-5587 or courtney.hammond.

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.

2018 New England Tree Fruit Management Guide

Posted: April 4th, 2018 by fruit

By Terence Bradshaw

At long last, we have a new printed version available of the New England Tree Fruit Management Guide (NETFMG). This announcement comes with a caveat, however, that this new guide reflects the path that we (the authors include the tree fruit specialists in all six New England States) expect to continue on for the foreseeable future.

Many list subscribers are familiar with the shift since 2015 from a printed guide published in collaboration with Cornell Cooperative Extension to an online guide that is similar in structure and publication to the New England Small Fruit Production Guide. That is, the main guide resides online, in a responsive site that is viewable on mobile devices and can be updated any time between production runs. Every two years, a ‘snapshot’ of the guide is formatted and printed for use by growers who wish to have a hard copy. We have been migrating material over to the electronic NETFMG (netreefruit.org) site, and have taken that snapshot which is available as a print-on-demand booklet here: http://go.uvm.edu/netfmg.

That was my long way of saying that the NETFMG is and always will be available at http://netreefruit.org/, which you should bookmark for regular use. If you’d like a hard copy, know that it will be out of date whenever there’s a change in registered IPM materials or should updated research material be available, and pick it up at the link listed above.

On a final note- it looks like there’s time to wrap up pruning in a reasonable time, because cooler-than-normal temperatures predicted for the foreseeable future should be conducive to a quiet and on-schedule bud break. If you have a chance to drag out your sprayers on a warm day and get them calibrated, that wouldn’t be a bad idea, but know that you’ll likely need to drain any water out of the plumbing before storing away for any of the remaining frosty nights. I’ve cracked a spray manifold after a 27° night, so it doesn’t take much.

-TB

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.

Early season vineyard management

Posted: April 4th, 2018 by fruit

By Terence Bradshaw

We’ve got just about one month to go before vines start to wake up and start doing their thing for the 2018 season. That’s one month to wrap up your pruning, clear the brush, and get things in order before the seasonal management activities start in earnest.

Late winter is a good time to review your previous season’s spray records and to identify any gaps that may have led to disease issues. Because 2017 was so wet in the early season, there was a lot of opportunity for disease to get established in area vineyards. Remember that we have recently updated two disease management documents for Vermont and area grape growers: a table of relative disease susceptibility of cold-climate cultivars and an initial IPM strategy for cold climate winegrapes. More information on general viticulture and other small fruit production can be found in the 2018 New England Small Fruit Management Guide , and the 2018 New York and Pennsylvania Pest Management Guidelines for Grapes are now available and should be used in combination with specific pesticide labels to select pesticide materials for use in your IPM program.

I am including a comment I made last year that may be especially relevant in the coming month to help with disease management:

One pesticide spray that is often considered by growers is a late dormant application of lime sulfur (LS) which aids in inoculum reduction against many diseases, especially phomopsis and anthracnose. Growers who have had more than a passing amount of either of those diseases, as well as organic growers with more limited choice of materials during the growing season may consider applying this practice, but I make that recommendation with several caveats. While LS is an organically-approved pesticide, it is one of the most acutely toxic materials I have ever used, and demands special considerations for its use. It is also a restricted-used spray material, so unlicensed applicators may not purchase or apply it. LS (active ingredient calcium polysulfide) is very caustic; spray mixtures tend to have pH around 10-11, and that characteristic is what gives it its sanitizing effect as a biocide. Contact with skin or especially eyes must be avoided, and it is pretty noxious even through a respirator. This material demands respect. While those effects will dissipate in the field after sufficient washoff and degradation by rain and other elements, I would only plan on applying after pruning is finished so not to muck around in it after application. In fact, very thorough pruning out of all dead and diseased wood is an important cultural disease control practice, and if you have a lot of such wood left in the vineyard, spraying your way around pruning it out won’t help.

LS is typically labeled for application at "15-20 gallons per acre in sufficient water for coverage" (Miller Liquid Lime Sulfur). That is a very high amount of LS, and would be difficult to apply and very costly when applied to large acreages. The key is to fully soak all woody tissues in the vineyard. This may mean aiming all nozzles at the cordons, but that would leave the trunks uncovered. Alternatively, the sprayer could be operated to cover the whole zone from the fruiting wire down, which would waste a tremendous amount of spray. The best application may come from a careful handgun application, which will take a long time and should be done with full protective gear including heavy nitrile gloves, full face shield and respirator, and Tyvek or other chemical-resistant, disposable coveralls. It is hard to say how much you would apply per acre in a directed spray, since that would be much more efficient with less wasted spray than an airblast application. My suggestion would be to apply a 10% solution (1 gallon LS to 9 gallons water) by handgun to cordons and trunks in a very thorough soaking spray. If you need to use an airblast to cover more ground, I would concentrate my nozzles toward the cordons but leave one or two directed toward the trunks, that will waste spray between vines but will allow you to cover ground much quicker. Because of the reduction in efficiency, I would calibrate to apply ten gallons of LS per acre in at least fifty gallons of water.

Remember, this stuff is caustic, stinky, and degrades just about everything it touches. It’s also quite phytotoxic- application at these rates to vines after bud break will cause leaf damage if not outright defoliation. I have used a lot of LS during the growing season in organic apple production, and don’t recommend it there unless absolutely necessary. I do not have experience using it in-season (post-bud break) on grapes, so this recommended spray must be applied during the window between pruning and bud break. The spray, if left on tractors and in sprayer plumbing, will corrode hoses, gaskets, and even stainless steel. It must be thoroughly rinsed from sprayer systems and the rinsate applied back out in the vineyard, not dumped on the ground. Some growers have applied a film of vegetable oil via backpack prayer to tractors and sprayers before an LS application to prevent it from soaking into and corroding steel and other materials on equipment. It’s that bad, and I could show you sprayer hitches, mix screens, and ceramic nozzles that have been degraded by it.

With all that said, LS is extremely effective as a preventative practice to reduce disease inoculum, and I still recommend its use in vineyards where anthracnose and/or phomopsis have gotten a bit out of control. Just be careful out there and treat it with the same (and a little more) respect that you should retreat any pesticide.”

Good luck with your vineyard activities in the coming weeks, and let’s all hope for a ‘normal’, gradual spring warm-up.

-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.

recruiting farmers- regulations research study

Posted: November 1st, 2017 by fruit

Farmers face regulation on a variety of topics. How do these regulations impact agriculture? How long does it take to comply and what does it cost? Are there strategies that could simply regulatory frameworks? Are there ways to make compliance more efficient? Researchers at UVM want to hear from Vermont farmers about how much time and what kind of actions are required to comply with different regulations. This information may identify pathways for regulation changes and gives farmers a voice in expressing how regulations affect their farm. If you are interesting in sharing your perspective, please contact Dr. Meredith Niles at 802-656-4337 or mtniles to schedule an interview. She will travel to your farm for convenience. All individual information will remain anonymous in the reporting of results. Farmers will be compensated with $50 for their time. Interviews will begin in November 2017 and take place through the Winter of 2017.

Meredith T. Niles, PhD

Assistant Professor

Food Systems Program

Department of Nutrition and Food Sciences

350 Carrigan Wing, Marsh Life Sciences Building

University of Vermont

mtniles

Office: 802-656-4337

www.meredithtniles.com

Farmer Recruitment_Policy Stacking.pdf

Final mention for now: A succinct guide to FSMA compliance for small farms

Posted: October 26th, 2017 by fruit

By Terence Bradshaw

Only when describing a new Federal initiative can we say the a 35-page guide is succinct, but this is an excellent resource that should answer many questions about implementation of the Food Safety Modernization Act and how it applies to your farm:

http://go.uvm.edu/fsmashortguide

-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.

Registration Open- New England Fruit & Vegetable Meetings December 12-14

Posted: October 26th, 2017 by fruit

By Terence Bradshaw

Online registration is now open for the 2017 New England Fruit and Vegetable Meetings in Manchester, NH, to be held December 12-14. As usual, there will be sessions for growers of all scales, scopes, and specialty crops, including two sessions each for apples and grapes, a stone fruit session, a cider and cider apple session moderated by me, and numerous other vegetable and general farm management topics. This is one of my favorite meetings of the year, and I look forward to seeing many familiar faces there.

Registration information may be found at: https://newenglandvfc.org/registration

Hotel information: https://newenglandvfc.org/accommodations

See you in December,

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.

Food safety meeting November 7 & 8

Posted: October 26th, 2017 by fruit

By Terence Bradshaw

I have received a number of questions regarding the November 7&8 Food Safety Training hosted by UVM Extension that I mentioned in a post this week. Below I summarize some quick answers from myself and UVM Extension’s Hans Estrin to the more common ones:

1. Will this training be offered again?

This training is offered again and again across the country and world (see Produce Safety Alliance schedule). It is unlikely, however that Vermonters will ever find a course SO close and almost fully subsidized!

2. What farmers need to take this?

Farms covered under the Food Safety Modernization Act (FSMA) produce rule MUST take it. That means any farm that sells more than $25,000 annually in ‘covered produce’, which includes fresh produce. If you sell less than $25,000 in edible produce. Producers who sell between $25k and $500k may fall into a ‘qualified exemption’ category, but the producer must still comply with rules surrounding the exemption. A quick chart regarding exemptions is available here. It is recommended for any other produce grower, and especially growing farms or farm somewhere near the 500K cut –off or those with sales below that who utilize wholesale markets.

3. Will CAPS suffice (no, if you’re not exempted or qualified exempt)?

No. This refers to the UVM Extension / VT Vegetable and Berry Growers Association Community Education for Produce Safety program. CAPS and Produce Safety Alliance training are different things. CAPS is a comprehensive program and with a certificate. PSA grower training is an extended education (standardized) presentation with mandatory attendance for covered farms. SO….CAPS is a good foundation for FSMA compliance, but does NOT substitute for the official grower training.

Answers to many Frequently Asked Questions regarding FSMA may be found here.

I will offer a word of warning passed on from Hans: this is, unfortunately, going to be a fairly bureaucratic training that is required for many producers as this Federal law continues to be implemented. It may be difficult to sit through, but the trainers are doing their best to make the information as useful as possible to growers. -TB

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.

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