June 2014 – UVM Fruit Blog

Summer Pest Management in Vermont Orchards

June 24, 2014

Summer diseases: For management of sooty blotch, fly speck, and black rot on fruit, growers should maintain fungicide protection on apples after each approximately 200 hours of accumulated leaf wetness. That means that after a spray is applied, begin accumulating leaf wetness hours and apply your next fungicide spray before the next 200 hours of wetness occurs. Remember that 1″ of rain washes off about one half of fungicide residue, and after two inches, you can assume that there is nothing left. Fungicide options for summer disease management can be found on pages 151-152 of the New England Tree Fruit Management Guide. Mary Conklin from University of Connecticut Extension recently summarized fungicide options for summer diseases of apples:

“1. Topsin M + Captan: Standard treatment for SBFS and summer fruit rots, but late-season applications of Topsin M are not acceptable for some markets, and the Topsin M label limits applications to a total of 64 oz/A/year. Most growers are finding that Topsin M must be applied at 12-16 oz/A for good results, so that means that this combination can be used no more than 4 or 5 times per year.

2. Captan plus a labeled phosphite fungicide: This combination is just as effective as Topsin M + Captan against SBFS, but the phosphites have little or no activity against black rot. Thus, with this combination, control of black rot and other summer fruit rots is dependent on the rate of Captan that is applied.

3. Inspire Super + Captan: Inspire Super is very effective against SBFS, but like the phosphites, it is less effective than Topsin or strobilurins fungicides for controlling fruit rots. Using Inspire Super during summer may also contribute to selection pressure for DMI-resistant apple scab if primary scab was not completely controlled, although that assumption remains unproven.

4. Flint + Captan, Pristine + Captan, and Merivon + Captan all provide nearly equivalent control of SBFS and summer fruit rots. The latter two have better long-term residual activity than Flint and are therefore preferred for the last spray in August or September, when a long residual is needed to cover the gap until harvest. All of these combinations include strobilurins fungicides (FRAC group 11) and have label limitations on the total number of applications per season and /or the number of sequential applications that are allowed.

5. Fontelis does not have much activity against SBFS and is not recommended during summer.

6. Captan applied alone can be effective if applied at higher rates (4-5 lb/A of Captan 80W) and at no more than 14-day intervals. However, mixing Captan with one of the fungicides mentioned above generally provides better results.”

Apple scab: By now you should have a good idea of whether or not you have scab in your orchard. If not, good for you, scab management is done for 2014. If you do, be sure to maintain residual fungicide coverage until harvest. Any of the above listed summer fungicide materials will protect fruit and developing foliage from new infection from secondary inoculum.

Fire blight: Blight has been appearing in the UVM orchards this season and we have been diligent in cutting it out, as should you if you see it. In blight-affected orchards, application of streptomycin should be considered within 24 hours of a hail storm, but otherwise, no strep should be applied after strikes are observed to reduce the likelihood of the bacteria developing resistance4 to the material. If you have a problem with fire blight in your orchard, trust me- you do not want strep resistance.

Insects:
Codling moth is the primary summer insect of concern right now, so an insecticide in the next spray may be warranted in orchards where this pest is a problem.

Apple maggot traps should be hung any day now and monitored at least weekly. Traps should be placed at the at least four per block in the perimeter of the orchard to catch migrating flies. The threshold for management is one accumulated fly per trap on baited spheres and five accumulated flies per trap on unbaited spheres.

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist

Cold-Hardy Grapes: Cultivar x Region Tasting in Burlington, VT

Curious about cold-hardy cultivars? Interested in the effects of terroir on varietal character? Then join us for a cross-regional tasting of varietal trial wines!

The multistate NE 1020 project was designed to test the performance of interesting grape cultivars, both new and existing, at various sites across the US. The Northern Grapes Project has supported collaborative work between UVM, Cornell University, and the University of Minnesota, resulting in a collection of wines produced from NE 1020 sites spanning the Northeast and Upper Midwest. Join us for a guided sensory evaluation of these wines, which represent a range of cold-hardy cultivars, yeast trials, and production techniques.
The day will kick off with a welcome and introduction by Tim Martison, followed by tastings of dry whites, off-dry and sweet whites, rosés, and dry reds, presented by Anna Katharine Mansfield and Chris Gerling. A tour of the UMV vineyard blocks will close out the day.

Your participation and feedback will help guide future variety trial activities, and will provide you with first-hand experience of varietal and regional expression in these cultivars.

To Register:
Email or call Chrislyn Particka (cap297, 315-787-2449) with the following information:
Name
Affiliation
Address
Phone number
Email address
Dietary restrictions (lunch is provided)

This event is free, but spaces are limited, so you MUST pre-register by 4PM on Thursday, July 10th.

Cultivar x Region Tasting.pdf

VT Grape & Wine Council Annual Conference July 1: SCHEDULE AND REGISTRATION

Our annual conference will be held at the Red School House at Vermont Technical College in Randolph, VT. This year, we’re delighted to have John Thull, vineyard manager at the University of Minnesota Horticulture Research Center, speaking on several aspects of vineyard management. It is a viticulture-focused program this year, since we have the USDA grant for a viticulture expert.

**PLEASE FORWARD WIDELY. SEND TO ALL YOUR CUSTOMERS WHO ASK YOU FOR VITICULTURE ADVICE!

Fire Blight in Vermont Orchards

June 16, 2014

It is becoming apparent that 2014 is sizing up to be one of the more significant fire blight years in Vermont. Luckily, this bacterial disease isn’t as prevalent nor damaging as it is in warmer areas, but its occurrence is increasing in our area, and if your orchard is affected, you need to manage it.

First, I welcome any reports from the field that will help me get a handle on how widespread the situation is. At the UVM Hort Farm orchards, my four usual blocks are affected to varying degrees, and it’s pretty manageable (but then again, we’re only talking about three acres). I am seeing infections mostly on Cortland, Mutsu, and Gala, as well as the newer scab resistant cultivars Crimson Crisp (a real magnet for the disease), Topaz, Winecrisp, and Galarina. I did note a few McIntosh and Empire infections today, but those cultivars are not heavily affected.

As for management strategies, I am going to refer you to Dr. David Rosenberger’s article in the most recent Scaffolds (regular screen version here, mobile/phone formatted version here). For a long-term management strategy, please see Dr. Dan Cooley’s fact sheet, An Annual Fire Blight Management Program.

Correct link for grape tissue sampling factsheet

June 16, 2014

Here is a link to Joe Fiola’s grape petiole and soil sampling factsheet:
https://extension.umd.edu/sites/default/files/_docs/programs/viticulture/TissueSamplingforVineyards060413.pdf

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.

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

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.