UVM Fruit Blog

Fertilizing grapes

June 13, 2014

As we all see our grape canopies exploding with growth at this time of year it is important to consider that the vines have their greatest need for nutrients to support shoot development and blossom fertilization. Without knowing your soil or petiole values, specific recommendations are hard to offer, but here are a few items to consider:

Nitrogenmay only rarely be needed in most mature vineyards, but young vines can often benefit from modest applications. Generally no more than 30 lbs actual N per acre, and more likely 20, will suffice. Let your experience with the vines dictate this, and if you have sufficient growth and crop yield, lay off the nitrogen. Calcium or Ammonium nitrate are good sources.

Potassium may often be deficient, and is most often seen on basal leaves as marginal yellowing or reddening of leaf tissues.

Boron is important for fruit set and calcium transport in grapes, and is frequently deficient in Vermont soils. However, it is very easy to over apply boron, which may lead to toxicity. All nutrient applications should be based on soil and/or plant tissue analysis, but this one is especially important. Boron is often supplemented in vineyards with Solubor, which contains 20% boron by weight. Amounts applied per acre are typically low, 1-3 pounds boron (or 5-15 pounds Solubor) per acre, and may best be applied in irrigation or herbicide water. Foliar applications of boron are very good at correcting deficiencies in the short-term, and may be applied with pest management sprays, If using pesticides in water-soluble bags (like Rally), the boron will prevent dissolution of the bags, so they should be thoroughly mixed until the bag is completely dissolved before adding boron to the tank. Typical rates of foliar boron should be no more than 0.5 pounds of boron per (or 2.5 pounds of Solubor) acre per application.

Magnesium deficiency is common in many vineyards, and is typically pronounced on many of the cold-hardy cultivars. Magnesium is an essential component in chlorophyll, and deficiency symptoms often appear as interveinal chlorosis (yellowing, or sometimes reddening) at leaf margins and between leaf veins. Symptoms are most readily observed on older leaves. Short-term correction of magnesium deficiency can be had with foliar applications of magnesium sulfate (Epsom salts) applied at 5 to 10 pounds per acre. This may be applied with pest management sprays. These sprays may be made 2-3 times at two-week intervals beginning immediately after bloom. Correction of magnesium deficiency in soil may be performed with application of 300 to 600 pounds per acre of magnesium sulfate. If potassium is also low sul-po-mag fertilizer will supply both of those nutrients. In the long-term, if soil pH is low (below 6.2 or so), then dolomitic lime may be applied .

All nutrient additions should be guided by soil and plant tissue analysis. Soil analysis may be conducted at any time, and samples sent to the UVM Agriculture and Environmental Testing Lab.

Petiole analysis may be conducted at two times, and growers should select one and stay consistent in order to compare year-to-year results. Sampling at veraison is the most common and preferred method, but bloomtime sampling may be preferable if there is a suspected nutrient deficiency that may be corrected in the present growing season.

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

Dr. Joe Fiola from the University of Maryland summarized bloom petiole sampling in a recent Timely Viticulture newsletter:

Tissue Sampling

Some early varieties in many vineyards are just starting to bloom. This is a critical time for taking tissue/petiole samples to assess the nutritional status of your vines. The following are some timely considerations.

Grape petiole analysis is recommended along with soil samples and visual observations as part of a complete nutrient management program.
A three year cycle of sampling all of the varieties in a vineyard is typically recommended.
Tissue/petiole analyses reveal the actual nutrients in the vines.
Tissue samples are needed when doing your mandatory Nutrient Management Plan.
Spring tissue sampling is a good time to sample, as you can make nutrient adjustments to the vineyard that will influence this year’s crop quality.
Nitrogen status is best evaluated with tissue sampling not soil sampling.
The time to take spring tissue samples is during full bloom of a particular variety.
Bloom time samples may show more accurate levels of boron and zinc, but are less accurate indicators of potassium status. Where bloom-time analyses indicate borderline potassium nutrient levels, a second sampling is warranted in late summer (70-100 days post bloom).

Some specifics on sampling:

Each sample should be less than 5 acres; less if there are major changes in soil or topography
Sample different varieties separately. Samples should represent plants that are planted on the same soil type and are of the same age, variety and rootstock.
Vines should represent that portion of a block that is maintained under the same cultural practices, i.e. fertilizer, irrigation and vigor control practices. For example, irrigation blocks are not to be combined with non-irrigated blocks even if they are on the same soil type.
Do not sample vines on the border of the block or near dusty roads.
For the bloom-sampling period, sample the petiole of the leaf petiole OPPOSITE the 1st blossom/cluster (see detail on fact sheet linked below).
About 50-75 petioles are needed from varieties with large petioles and about 75-100 petioles are needed from varieties with small petioles.
Gently wash petioles with water and gentle detergent, pat dry and place in OPEN paper bag (lunch, #6 size) to dry for a few days.
There are many labs that can analyze tissue samples (see detail on fact sheet linked below). Call the laboratory to determine current pricing and submission information. http://www.grapesandfruit.umd.edu/Grapes/Pages/SoilTestingLabs.doc

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.

Critical period for disease management in Vermont vineyards

June 9, 2014- At the UVM Hort Farm, we just entered into bloom on our earliest table grapes, and wine grapes are right around the corner. This immediate prebloom period is potentially the most important time to manage diseases in your vineyard this year. This is the time to get
Phomopsis, Black Rot, Powdery Mildew and Downy Mildew under control. This spray and the first post-bloom sprayare considered the most important sprays of the season for disease management.

Good spray options include a combination of a protectant (Captan, which may have a three-day re-entry interval depending on formulation, or mancozebs, whose 66-day preharvest interval make this likely the last time you’ll use them this season.) and systemic (QoI or DMI) fungicide. For DMI materials, Rally is the most commonly used fungicide, but there are several options for QoI materials,: Abound, Quadris (make sure neither of these contacts apples because they are phytotoxic to them), Flint, and Sovran. More details on appropriate fungicide

s can be found on pages 38 & 38 of the 2014 New York and Pennsylvania Pest Management Guidelines for Grapes.

As we get into bloom, vine nutrition becomes an important consideration. Grapes require boron and nitrogen to fertilize blossoms and form fruit, so this is a good time to apply both of those materials in your vineyard. Magnesium is also commonly deficient in Vermont vineyards, so consider applying either Sul-Po-Mag if you also need potassium, or Magnesium sulfate if you just need magnesium. This should be determined using both soil and petiole tests, and I can help you with interpretation of any results you have from the UVM or Dairy One (Cornell) labs.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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.

Fire Blight symptoms now appearing

June 9, 2014-

Fire blight infections caused during bloom should be appearing in infected orchards any time now. If you have susceptible cultivars (Mutsu, Gala, Cortland, Paulared, Ginger Gold, and many others found here), then get out and scout your orchards ASAP. Blossom infections should be removed at least six inches below any signs of symptoms, which include: darkening of shoot tips with distinct ‘shepherd’s crook’, oozing on shoots or fruit, and browning and shriveling of leaves. DO NOT SPRAY STREPTOMYCIN on infected tissue, it will not work and you will be setting yourself up for resistance development. Only in the case of hail storms or extreme wind events which create new infection sites should you apply strep, and that needs to be done within 24 hours of the event.

For more information on fire blight management see:

http://www.caf.wvu.edu/kearneysville/articles/FB-MANAGE00.html

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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.

Thinning and codling moth management in Vermont orchards

June 4, 2014

By now apple fruitlets in the Champlain and Connecticut Valleys should be approaching 10-12 mm size which is the most receptive time for thinner application. Bloom and fruit set have been spotty this season, with large variations across cultivars and even within cultivars on adjacent trees in a row. Still, don’t plan on skimping on thinning. We often see more fruit than we thought we had as they size up. On trees with sparse bloom, given good pollination conditions, more of those fruit will tend to set as well, so those clusters will need thinning. I recommend thinning the whole orchard at a moderate dose (say 1 qt carbaryl plus 2.5 – 5 ppm NAA), then following up more heavily-set trees with hand thinning. Cool days ahead suggest a slight increase in thinner rates may be appropriate to get best results.

Codling moth adults are now flying, and egg hatch has just barely begun. Based on Glen Koehler’s Orchard Radar model, the best timing to apply materials targeted at hatching larvae is next week, followed by a second spray 7-10 days afterward. In orchards with historically low CM populations where a single spray has been effective in managing the first generation this pest, the model suggests application the week of June 16.

Keep covered for plum curculio in the meantime, orchards that had a full-block insecticide applied at or soon after petal fall (that’s all of you, right?) can apply sprays only to the outer two or three rows to maintain efficacy against migrating beetles.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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.

Introduction to (Commercial) Hard Cider

June 3, 2014

I just wanted to drop a quick note to announce that an article I co-authored with other cider-oriented researchers has been posted to eXtension:
http://www.extension.org/pages/70601/an-introduction-to-hard-cider-in-the-us#.U4fbrBbp-DQ

This should be just the beginning of things to come.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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: Managing Winter-Injured Vines

June 3, 2014

At the UVM vineyard we completed shoot thinning late last week after leaving a generous number of buds during dormant pruning. Our concern was winter damage on fruit buds, cordons, and even trunks with a few cultivars. Overall, things look okay for us, although some of the tender table grapes (especially Vanessa) are looking questionable, and the Corot Noir, among the wine grapes, likely suffered some trunk damage that will take some time to see the extent of.

With that said, please read the attached article from Dr. Tim Martinson as part of the Northern Grapes Project on how to manage winter injured vines now that they are growing (or not).

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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.

NGP_Managing Winter Injured Vines.pdf

Sprayer calibration workshops in New Hampshire this week

June 1, 2014

George Hamilton from University of New Hampshire Extension will be hosting a sprayer calibration workshops this week. For more information, email: George.Hamilton

Guest presenter – Dr. Jason S.T. Deveau, Application Technology Specialist, OMAFRA, Simcoe Station, Ontario

Tuesday – June 3

9:00 – noon Classroom – Georges Office UNH Cooperative Extension – Hillsborough County
329 Mast Road – Room 101 Goffstown, NH 03045

– Review of Air Blast Sprayer 101/ Boom Sprayer Questions
– Questions from what we have learned from calibrations in the field

Tuesday – June 3

1:30 – Farm (Fruit) Apple Hill Farm, Concord
– Primarily Air Blast
o Backwards walkthrough of calibration process
o Calculate what grower is spraying
o Coverage where is the spray ending up

Wednesday – June 4

– Wilson Farm, Litchfield, NH
– Raspberries/Strawberries
o Boom
o Air Shear – Cannon
– Vegetable

Wednesday – June 4
– 4 pm twilight meeting with growers – Blueberry Farm
– Durocher Farm, Litchfield, NH

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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.

Petal Fall and Hail Damage Management

May 27, 2014

I’ve heard reports of possible hail damage from today’s storms, particularly in Addison County (although I would appreciate word from any other affected areas). Mary Conklin from UConn Extension just offered this advice to growers similarly hit recently in Connecticut:

1. Fireblight susceptible pears and apples should receive a strep spray within 24 hours of the hail storm if damage occurred. However, if you applied Apogee you should be covered because it protects against Fireblight.

2. If you have young trees that have not received Apogee AND had Fireblight last year (or your neighbor has/had Fireblight) AND were hit with hail – apply Strep within 24 hours of the hail storm.

3. Apple varieties still in bloom (there aren’t many locations with bloom still on) that were hit with hail need strep applied within 24 hours.

4. The fruit of stone fruits that are cut should have fungicide coverage maintained to prevent rot fungi from taking hold if you plan to harvest any of it.

5. Perennial canker/Cytospora canker fungi will move into trees through wounds, including those caused by hail. Pruning out damaged or broken limbs will help to prevent this destructive disease from taking hold.

6. Severe hail damage that causes young tree leaders to break: re-leader them ASAP.

7. Blueberries with hail damage are more susceptible to Phomopsis because the organism is more likely to infect where canes are damaged. In addition, spores are released between bud swell and petal fall and blueberries are in bloom now. If you (or your neighbors) have or had Phomopsis in the past, maintain fungicide coverage.

8. Call your crop insurance rep.

With that out of the way, this is a good week to get your petal fall coverage on. Apple scab, while most ascospores should be spent in the Champlain and Connecticut valleys, should be protected against for another 7-10 days. Powdery mildew is a concern at this time, as is cedar apple rust. DMI and, to a somewhat lesser degree against rust, Strobilurin fungicides, are effective, but be sure to mix with a protectant to reduce risk of fungicide resistance in your orchard. Petal fall insects (plum curculio, sawfly, early codling moth) need tending to.

Thinning is a real crap shoot this year, with extremely variable bloom and moderate to good to poor pollination weather, depending on site and cultivar. Cool, cloudy days of late suggest that moderately higher rates of thinners should be applied, but low blossom density on some cultivars may negate that. I would suggest a cautious approach and suggest following the recommendations in the 2014 New England Tree Fruit Management Guide. For most varieties, that would be 2-3 oz Fruitone plus 1 pint Sevin per 100 gallons dilute (based on tree row volume). Notice that’s by the book, I’m not pushing a more aggressive strategy unless you indeed had a good to great bloom.

This is a great time to try the apple carbohydrate thinning model on NEWA (click on the ‘crop management’ tab at the top of the page) to assess the relative stress level of your trees to tweak thinner rates. Remember, fruit and shoot development at this time demand more resources (photosynthate) than the tree produces. Cool weather with moderate sunlight and a fairly low crop load reduce stress on the trees and make thinners less effective, all things being equal.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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 disease management in Vermont vineyards

May 21, 2014-

Risk for cutworms and flea beetles has diminished as vines have surpassed the 1″ shoot growth stage in many Vermont vineyards. Now is the time to turn your focus toward disease management. I’ll put it simply: the next four fungicide applications, combined with good vineyard sanitation, will ‘set the stage’ for your vineyard in 2014 as far as diseases are concerned.

Disease Management at the 3-5 Inch Shoot Growth Stage – The following was written by Dr. Wayne Wilcox of Cornell University and appeared in the article “Grape Disease Control, 2013”: [Note: Ph = Phomopsis; PM=
powdery mildew; BR= black rot; DM= downy mildew]

“3 – to 5-INCH SHOOT GROWTH. A criticaltime to control Ph rachis infections if it’s raining or likely to be soon, especially in blocks with any history of the disease. Early is better than late if it looks like some rain is setting in. Late is much better than nothing if those are the only two options , i.e., you’re past this stage, haven’t gotten anything on, and wonder whether it’s too late . This spray can provide significant benefit against fruit infections as well, since many of them originate from movement into the berries from infected rachises and berry stems. Also an important time to control basal shoot infections, since this is where the fungus will establish itself for the future if infected tissue is retained in canes, spurs, or pruning stubs.

Now is the time to start thinking about control of PM on vinifera varieties if temperatures remain above 50 °F for long stretches of the day… This spray is much more likely to be important in vineyards that had significant PM last year (we’re talking late season foliar disease more than fruit infections here) than in those that were “clean ” into the fall; however, it may be beneficial even in relatively clean blocks of highly susceptible cultivars, which tend to be relatively valuable as well… If already spraying for Ph, most growers of highly susceptible (and valuable) varieties include something for PM while they’re at it. I would too.

In NY, spending extra money for BR control is almost never justified this early unless you’re trying to clean up a severe problem block AND weather is wet and reasonably warm. In general, the farther south you go, the more important early sprays can become. Still too early for DM.

Disease Management options for the 3-5 Inch Shoot Growth stage are listed on pages 55-58 of the printed version of the 2014 New York and Pennsylvania Pest Management Guidelines for Grapes.

Unless you have had issues with anthracnose or extensive black rot on your vineyard, an application of a protectant fungicide such as mancozeb or captan should be sufficient at this time.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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.

Tree Fruit Meeting tomorrow May 21, Walpole, NH

May 20, 2014

Sorry for the late announcement- tomorrow evening George Hamilton from UNH Cooperative Extension will host a joint twilight meeting with UMASS fruit team members at Alyson’s Orchard in Walpole, NH:

Tree Fruit Twilight Meeting
(Wednesday 05/21/2014 – 05:00 PM – 08:00 PM)

Topics to be Covered:

Overview of the Farm and Walking Tour of the Orchard
Integrated Pest Management Considerations for Apple & Peach Disease Problems
Integrated Pest Management Considerations for Tree Fruit Insect Problems
Chemical Apple Thinning Considerations

Speakers:

Carl Majewski, UNH CE Extension Educator Agricultural Resources in Cheshire County
Homer Dunn – Orchard Manager of Alyson’s Orchard, Walpole, NH – 30 years of experience and manager of the last five to ten years
Jon Clement, Tree Fruit Extension Specialist University of Massachusetts – Amherst
Bill Lord, UNH Cooperative Extension Fruit Specialist, Emeriti
George Hamilton, UNH Cooperative Extension – Extension Educator
Dr. Daniel R. Cooley, University of Massachusetts -Plant Pathology, Associate Professor
Department of Plant, Soil and Insect Sciences
Arthur Tuttle, University of Massachusetts – IPM Field Leader Plant Pathology
Dr. Alan Eaton, Extension Fruit Entomology Specialist and Extension I.P.M. Coordinator
UNH Cooperative Extension
Dr. Duane Greene, University of Massachusetts -Professor of Pomology, Department of Plant, Soil, & Insect Sciences

Come prepared for the weather conditions of the day.

2 Pesticide Applicator Credits have been approved

Location:

Alyson’s Orchard – 615 Wentworth Road, Walpole NH 03608

For more information:

George Hamilton

George.Hamilton@unh.edu

603-641-6060

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

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.

Tree Fruit Twilight Meeting (Wednesday 05/21/2014 – 05:00 PM – 08:00 PM)

For more information:

Tree Fruit Twilight Meeting
(Wednesday 05/21/2014 – 05:00 PM – 08:00 PM)