Month: April 2014

Cutworms and flea beetles in vineyards

April 30, 2014

Monitor vineyards for cutworms and flea beetles during bud swell growth stage
Time spent monitoring vineyards for cutworms and flea beetles can avoid costly pest damage.

Posted on April 29, 2014 by Rufus Isaacs, Michigan State University Extension, Department of Entomology

Bud swell of grapes is being reported in Southwest Michigan, and I have seen wild grape buds starting to reveal some green tissue this week (as of April 29, 2014). This means we are approaching the time when growers should monitor for cutworms and flea beetles, two early season pests that can feed on buds and limit crop yield. There are good rules of thumb for deciding whether damage from these insects warrants control, and information on scouting and other management components from Michigan State University Extension is provided here.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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 newsletter 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.

Scab Management 4/27-29

April 27, 2014-

Anyone who had exposed green tissue on apples yesterday likely saw an apple scab infection period. This is also looking like a cool and wet week ahead, so more infection periods are likely. It looks like the best window for spray applications with low winds will be tonight, April 27, from dusk through early tomorrow morning, and possibly another similar window extending from tomorrow night through Tuesday morning, April 29. If there is any question about spray coverage in your orchard during the past infection period from April 26-27, consider adding a kick-back material to your protectant to improve disease control.

I’ll be out bright and early tomorrow applying mancozeb+Vangard in IPMN blocks and sulfur in our organic blocks.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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 newsletter 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.

Weed Management in Vineyards

April 24, 2014

Now that vines are pruned it is time to shift your thinking to under trellis weed management in the vineyard. Especially in this season where many growers will be leaving shoots low on the trunk to use as replacement parts for cold-injured vines, it is important to avoid herbicide contact with green tissue. Grapes are especially sensitive to many herbicides, so early spring before bud break is a good window for application of materials if you will be using them in the vineyard. Young vines with thin bark on the lower trunk can also be damaged by herbicide contact, so shielded sprayers or waxed trunk guards should be used.

Specific herbicide materials and their use restrictions and guidelines ca be found in Chapter 6 of the New York and Pennsylvania Pest Management Guidelines for Grapes

In February 2013, a Northern Grapes Project Webinar on vineyard groundcover management was offered that can be viewed here:
http://youtu.be/pSNy08aEs4E
Also, slides from vineyard weed identification and management presentations made to growers at the Northwest Michigan Horticultural Research Center from April 17, 2014 are available here:
http://bit.ly/1kdeGWp

The window to best manage weeds with herbicide applications is short, so please consider getting out there in the next couple of weeks. Once weeds get established in the vineyard and vines start growing, under trellis groundcover management becomes very difficult without causing vine injury.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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 newsletter 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.

Green tip apple scab management

April 24, 2014

Orchards in most areas of the state should be showing green tip now, and that means that protection is required to manage apple scab. Many orchards are going into this season with high overwintering inoculum as a result of the wet 2013 growing season, and growers need to be vigilant to manage this season’s disease. Wind conditions look good tomorrow, Friday April 25, for spray applications. However, there is a good chance of frost first thing in the morning. This means that oil should not be applied in sprays for the next couple of days until you have a good window of frost-free weather for 48 hours before and after application. It’s also good to make sure that sprayers are parked in a warm area overnight or all water drained from pumps, hoses, control valves, and booms. I have had booms split when filled with water and held at 28 °F. Remember, stainless steel booms are great for corrosion resistance, but stainless is a relatively brittle metal that easily splits from freeze damage.

Based on scab models run in the NEWA system (http://newa.cornell.edu/) apple scab ascospore maturity ranges from 2% to about 5% in the Champlain and Connecticut River Valleys. Some orchards saw a likely scab infection yesterday if green tissue was showing and mature inoculum present. Inland and upland orchards may just barely be showing green tissue, but upcoming wet weather and moderate temperatures will likely lead to an infection over the weekend.

Orchards are best protected now with copper, EBDC, or Captan fungicides. Do not apply Captan if you have or will be applying oil within 10-14 days before or after application. If orchards were uncovered prior to a likely infection in the past couple of days, Vangard or Scala applied tomorrow will provide some kick-back activity. Any postinfection materials should be combined with a full label rate of a protectant material to minimize the risk of the apple scab fungus developing resistance. Specific rates and use recommendations can be found in the 2014 New England Tree Fruit Management Guide. Please contact me if your guide is out-of-date and you need a new one.

You have calibrated you sprayer, right?

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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 newsletter 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.

Silver tip, copper, oil, and cold temperatures

April 19, 2014
Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

By the time I check the UVM orchards on Monday, I expect we’ll be seeing silver tip on many cultivars. By Friday 4/18, I called Empire and Macoun at silver tip, but most others were still looking tight, although buds were swelling on everything. I call silver tip when the bud scales at the tip of fruit buds first separate, but green tissue is not yet evident when looking at the bud from the side. Bud stage criteria can be viewed here: http://orchard.uvm.edu/uvmapple/hort/99budstage/BudStageCriteria.html

What does this mean for orchard management? The window between silver tip and green tip is perfect for applying copper to suppress fire blight and to act as your first scab spray of the season. 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. But, while early season copper can be an excellent management tool, copper materials can be phytotoxic. That is why the early season spray is made before much green tissue is exposed. If applied when buds are closed, however, then cold temperatures immediately before or after spraying are not a huge concern. In fact, I have in many years had my airblast sprayer fan shroud ice up while applying copper- not an ideal situation, but it can happen at 5 AM when the temperature is 31 F and the velocity of air coming through the shroud contributes to rapid cooling, much like a snow gun on the ski slopes.

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 phtotoxicity that can affect frui development, especially when cluster leaves which supply most of the carbo0hydrates to developing fruit early in the season are damaged. Oil is often appluied 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 2014 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 newsletter 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.

Update: Pruning winter-damaged vines

April 15, 2014
Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

First, the good news- it looks like the long-range cold temperature prediction for this Thursday that I mentioned last week won’t be as bad as my weatherman thought, so feel free to prune your vines this week. The bad news- if your vineyard is anything like the UVM vineyard, you’re likely looking at significant winter bud damage out there.

We calculated our primary bud damage in two ways after last Saturday’s assessment: first using the basal five buds per cane, and again using just the bottom two. Our table grapes are looking rough, even considering just the two basal buds that would normally be retained on spurs. Winegrapes are looking a bit better, but I’m still concerned. I did not include nor yet calculate secondary bud damage, but a glance through the data shows that there are a number of buds with only tertiary or even no buds surviving. We have not yet cut into trunks or cordons, but I suspect that some vines are damaged there as well.

The take home message here for your pruning consideration, is to be cautious but thorough. Consider leaving extra retained buds on your vines this year, I would suggest more spurs rather than fewer but longer spurs. If cane pruning, consider leaving a few extra canes and be wary of bud survival as you move farther out from the basal nodes. It’s easier to thin shoots later than to add back the ones you cut off now. However, you’ll need to be thorough now and as the growing season progresses to remove ALL dead wood from the canopy, including stubs of old spurs, dead cane ends, and ends of cordons. This tissue is where disease inoculum, especially phomopsis, overwinters. Removal of that dead wood is your first line of defense against this disease that seems to be more prevalent than it used to be.

This may also be the year that you’ll need to use those replacement parts that we speak of- I mean renewing trunks and cordons. If there’s a good shoot emerging low on the trunk from last year’s retained renewal spur, keep it. You can cut it later if need be. Same for any healthy canes (i.e. those not dead after the 8-10th node) that emerge from the head renewal zone. Those may be laid down later to regrow cordons if necessary. Trunk and cordon damage may not show for some time, so don’t be too hasty to assume that everything is healthy, and that you won’t need those spare parts this year.

Please read my April 3 post which includes the latest Northern Grapes Project newsletter for more information on assessing bud injury and adjusting pruning.

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 newsletter 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.

Winter cold and pruning grapevines

April 11, 2014
Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

I just want to drop a quick note to growers after hearing the weather forecast this morning. We have not yet performed our winter bud damage at the UVM vineyard, but will be collecting canes today and assessing tomorrow. I noticed a lot of dead cane ends while walking through the vineyard this week, and I’m anticipating a fair amount of damage to what would be retained nodes. My bigger concern is the roller coaster weather ahead of us. Temperatures are forecast at 75 degrees on Monday, which will surely deacclimate vines to some degree, but the scarier part is that Thursday morning the potential low, according to the European weather model, may be as low as 5 degrees. Vines pruned just prior to that event, especially in a warm spell, will be more cold tender going into that cold morning. I know everyone wants to get out and get their pruning done, but it may be wise to either hold off on pruning early next week. If you really need to get some work done, consider long pruning and leave at least 8-10 nodes that you can remove later.

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 newsletter 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 apple disease management

April 9, 2014

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist
Spring looks to be here, as temperatures are gradually warming up, or at least staying out of the frigid zone. At the UVM Hort Farm, trees are still dormant, although I’ve seen a little swelling on Empire and Macoun. Still, green tip looks to be a week or two off (more likely two) in the Champlain Valley. There’s a great article in the April 7 Scaffolds Newsletter from Terence Robinson and Mario Miranda at Cornell University that walks us through the dormancy and bud development process to predict bud break: http://www.scaffolds.entomology.cornell.edu/2014/SCAFFOLDS%204-7-14.pdf.

In the next few weeks, get your pruning wrapped up, brush pushed out, and sprayers calibrated and tuned up. Leaves can still be flail mowed or urea applied to leaf litter to aid in scab inoculum decomposition. Copper will be ready to be applied any time now that you can get into the orchard. Anyone with concern about fire blight in their plantings should be applying copper at label rates between silver tip and green tip to reduce overwintering inoculum. Copper also acts as your green tip scab spray, so this isn’t an extra trip through the orchard.

To help you plan your 2014 fungicide schedule, here’s nice overview article on Fungicide Considerations for Tree Fruit in 2014 from David Rosenberger and Kerik Cox, also from Cornell University. Go to page four of the March 24 Scaffolds newsletter: http://www.scaffolds.entomology.cornell.edu/2014/SCAFFOLDS%203-24-14.pdf. Remember that the article was written for a New York audience, and so does not reference some of the other fungicide options available to Vermont growers. The SDHI fungicides Luna Sensation and Merivon most come to mind.

Happy spring, now get beck to work!

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 newsletter 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.

Diversified fruit and veg farm crop insurance: Please read

April 6, 2014
Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

PLEASE consider spending a couple of minutes of your time for this. Ag research only works when its beneficiaries, i.e., farmers, participate. –Thanks, Terry

Jen Miller, a grad student at UVM, is doing a survey examining crop insurance on diversified fruit and vegetable farms as a risk management tool. She is looking for your honest feedback.

This goals of this project are to examine:

– Methods vegetable and fruit growers are using to manage production risk

– Vegetable and fruit farmers’ experience with, and perception of crop insurance policies

– How well crop insurance programs serve vegetable and fruit growers

Responses are being collected from vegetable and fruits farmers in the Northeast.

Please take a few minutes and go to the following link https://survey.uvm.edu/index.php/257185/lang-en

Where trade names or commercial products are used for identification, no discrimination is intended and no endorsement is implied.
Always read the label before using any pesticide.
The label is the legal document for the product use.
Disregard any information in this newsletter 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.

Northern Grapes Project: Assessing Bud Injury and Adjusting Pruning

April 3, 2014
Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

I am forwarding this from the Northern Grapes Project mailing list. LOTS of great information to consider as you get into your dormant pruning. In cold years like this one, it is critical to do some bud counts before pruning. -TB

News You Can Use

The Northern Grapes Project is starting a new outreach effort, created at the request of our Project Advisory Council. News You Can Use will provide you with brief, timely information, generated via research conducted as part of the Northern Grapes Project, as well as material derived from other sources. News You Can Usewill be published around the first of every month, and will be sent via email and posted on the project website and Facebook pages. Please let us know what you think!

Assessing Bud Injury and Adjusting Pruning

After the extreme cold temperatures much of the US experienced this winter, many grape growers are concerned about winter injury to buds and trunks. Here in the Finger Lakes region of New York, for example, up to 90% of the primary buds on some V. vinifera cultivars were killed.

Cold-hardy University of Minnesota and Swenson cultivars can withstand much colder temperatures than most other grapes, but it’s still advisable to assess your grapes for winter damage before pruning, and adjust your bud number accordingly. If more than 20% of the buds are dead, you’ll want to leave more buds to maintain a normal cropping level.

Here are some online resources to explore to learn more about how to assess winter injury and manage winter-damaged vines.

Assessing Winter Cold Injury to Grape Buds

Cornell University, Pool and Martinson

(http://www.fruit.cornell.edu/grape/pool/winterinjurybuds.html)

Includes photos of live vs. dead buds, information on how many extra buds to leave when pruning, and links to videos that explain how to evaluate bud damage.

Evaluating Bud Injury and Adjusting Pruning

Cornell University, Martinson

(http://blogs.cornell.edu/nnygrapeupdate/2014/02/28/evaluating-bud-injury-and-adjusting-pruning/)

Blog post with instructions for assessing damage and managing damaged vines.

Cold Injury in Grapevines

eXtension.org, Chien and Moyer

(http://www.extension.org/pages/63372/cold-injury-in-grapevines#.UzwTDPldWJc)

Includes photos of damaged buds and trunks, as well as links to other good resources.

Evaluating Grape Bud Damage Prior to Winter Pruning

Colorado State University, Caspari and Larsen

(http://agronomy.unl.edu/c/document_library/get_file?uuid=912db951-022b-487e-9823-fbb8b5835523&groupId=4128273&.pdf)

This document has photos of the same bud as a series of cuts is being made. This will help you learn what’s too shallow, what’s just right, and what’s too deep.

Ohio Grape-Wine Electronic Newsletter, Special Issue 17 January 2014

Ohio State University, Dami

(http://www.oardc.ohio-state.edu/grapeweb/images/OGEN_17_Jan_2014_Dami.pdf)

Contains information on how to assess for bud damage, how to adjust pruning, and links to other resources. Also includes the article “Pruning Grapevines after Winter Injury” that Dr. Imed Dami wrote for “Wines and Vines” trade magazine a few years ago.

Anatomy of Grapevine Winter Injury and Recovery

Cornell University, Goffinet

(http://www.hort.cornell.edu/goffinet/Anatomy_of_Winter_Injury_hi_res.pdf)

This is a long, and quite technical paper, but has a lot of good photos and in-depth information, including how vines are constructed, what tissues are susceptible to cold, the process of vine cold acclimation, a description of cold injury in the various organs, and the mechanisms the vine uses to heal (if possible) cold-injured structures.

Chrislyn A. Particka, PhD

Extension Support Specialist

Cornell University

Department of Horticultural Sciences

630 W. North Street

Geneva, NY 14456

cap297

315-787-2449 (desk)

315-787-2216 (fax)

www.northerngrapesproject.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 newsletter 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.