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UVM Fruit Blog

Getting ready for harvest in orchards and vineyards…

Posted: August 8th, 2017 by fruit

By Terence Bradshaw

Mid-August is approaching, and that means that fruit are beginning the ripening process in Vermont orchards and vineyards. This is an important time to plan some final management practices before things get too busy.

Foliar (apple) and petiole (grape) tissue sampling: Now is the time to collect plant tissue samples for nutrient analysis in apples and grapes to best tweak fertility programs next year. If you’re applying fertilizers without tissue samples, you are doing it blind. Samples collected every two, up to three years should be sufficient, unless you are noticing or correcting a particular deficiency. Samples should be collected separately by cultivar, rootstock, and planting system/block- basically, the sample should come from a uniform set of trees/vines. I’ve given instructions separately for grapes and apples in the past, and refer to those now if you need them. Each includes contact information for the appropriate labs that conduct the analyses and also provide important recommendations from them. As for timing, apples leaves are typically collected July 15 – August 15, and grapes at veraison, so we’re on-schedule to do both any time now.

Veraison signifies the beginning of the ripening process in grapes, and we have seen the beginnings of that process for the past few days at the UVM Hort Farm. This is an important time when nutrient flows are changing in the vine. It is especially important that grapes have good access to sunlight during ripening, so continue to position shoots and remove leaves around clusters. This is also a good time to find lagging clusters that are behind the main crop for ripeness and remove them to improve overall fruit quality. Diseased clusters may also be removed at this time.

Disease management remains important- in grapes, we have been seeing more powdery mildew on fruit than we like, and downy mildew and botrytis are also potential problems at this time. And eradicate application of stylet oil or oxidate may be appropriate on PM-infested grapes but only if you can get excellent, thorough coverage. Otherwise one last application of materials labeled against those diseases may be warranted before harvest.

In apples, we have had ample opportunity for infection from the whole range of summer disease: sooty blotch; flyspeck; black rot; bitter rot; etc. A final fungicide application may be warranted to keep fruit clean through harvest, and for wholesale packing orchards, an early September application may be needed on late-ripening cultivars.

ReTain application in apples: ReTain is a commercially available plant growth regulator that delays harvest, reduces drop, and potentially improves fruit quality in apples. It is applied three weeks prior to anticipated harvest, and has a 7-day preharvest interval. Growers should be thinking about their ReTain needs and scheduling in the coming days. Glen Koehler at University of Maine runs a useful model based on reported weather data for the UVM Hort Farm that may help consider when to apply this material in local orchards. Note: ReTain applications are expensive, and are best when carefully timed. I expect to forward some more detailed information in the coming week, so use this information only as a rough guide, and consider how your orchard environment may differ from ours.

“Preliminary McIntosh Harvest Date Forecasts

CAUTION: The estimates shown below are appropriate for long-term planning only. Harvest decisions should only be made on basis of direct orchard observations. Accuracy of these apple maturity estimates can vary between orchards and between years in a single orchard.

Harvest date estimates are based on temperature observations from the first 30 days after Full bloom. Estimates for this location are based on incomplete data until Tuesday, June 13.

To delay single pick harvest up to 7 to 10 days, apply ReTain 21 to 28 days prior to beginning of expected harvest date for untreated fruit.

To delay fruit maturity and improve storage potential of later picked apples (2nd, 3rd, 4th picks), apply ReTain 7 to 14 days prior to beginning of expected harvest date for untreated fruit. This later timing will not delay the start of harvest (1st pick), but will delay maturity for later picks.

Date to apply ReTain to delay first harvest for apples which without treatment would be ready for storage harvest on September 11 is from

Monday August 14 to August 21

Date to apply ReTain to delay maturity for 2nd, 3rd or 4th pick of those apples, without delaying start of harvest maturity, is from Monday, August 28 to September 4. Begin measuring actual McIntosh starch-iodine index no later than Thursday, August 24. The McIntosh maturity date estimate shown below is a preliminary, early-season forecast and in no way a substitute for starch index and other direct observations as harvest nears.

The Michigan formula estimates that non-spur McIntosh will reach starch index 4.0 and start the optimum harvest window for long term storage on Monday, September 11. Cornell Bulletin 221 provides formulas for different locations to estimate date when non-spur McIntosh not treated with ReTain will reach starch index 6.0 and the end of the optimum harvest window for long term storage. Using the Champlain Valley NY formula, McIntosh maturity is forecast to reach starch index 6.0 in South Burlington VT on Thursday, September 21.”

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.

Open House 8/25: UVM Apple & Grape Team

Posted: August 8th, 2017 by fruit

University of Vermont Apple and Grape Program Open House

UVM Horticulture Research & Education Center

65 Green Mountain Dr, South Burlington, VT 05403

Friday, August 25. 2:00-4:00 PM

Join Dr. Terence Bradshaw and his colleagues for an open house highlighting research, teaching, and outreach projects of the UVM Apple and Grape Team. This self-guided tour will include chances to see organic apple evaluation, winegrape cultivar assessment, high density tall spindle apple plantings, and unique cider apple production systems. In addition, other partners at Catamount Educational Farm will be available to highlight vegetable crop teaching and research programs.

No RSVP is required, this will be an informal tour useful to commercial growers; fruit and vegetable enthusiasts; UVM faculty, staff, and students; and anyone else interested in sustainable food production in Vermont. Any questions should be referred to Terence Bradshaw, tbradsha.

Orchard pest management, late July

Posted: July 25th, 2017 by fruit

By Terence Bradshaw

Many growers, especially of pick-your-own or retail-sold fruit, are starting to think about wrapping up the pest management season for 2017. Before doing so, it is important to consider late-season insect and disease pests that could affect the crop going into harvest.

Apple maggot numbers ticked up in a lot of orchards last week so most sites that have a problem with that pest have reached the threshold for treatment. AM is relatively easy to manage and there are many materials labeled for doing so- Assail is probably the most commonly-used one, as well as Delegate or Altacor (good if you also have problems with lepidopteran pests), or Avaunt. Pyrethroids are also quite effective against this pest, but they are harsh on beneficial predatory mite species and thus their use after pink bud stage can cause flareups of mites and other secondary pests. Imidan is another old-guard material in the organophosphate class, but its use has been substantially restricted, and as a whole, we are encouraging growers to move past it. Organic growers can use a trapout strategy which would need to have been in place already to be effective; in lieu of that, carefully-timed application of spinosad (Entrust) or pyganic may be effective, although the latter breaks down very quickly in sunlight and thus cannot be counted on for any residual control.

We remain between generations for codling moth in most orchards. It would be best to keep an eye on NEWA for timing the management of the second generation. Application of a material effective against hatching eggs and young instar larvae is best applied at 250 degree days after moths begin flight, which is right about now. That would put us at about the first week of August to treat in warmer production areas of Vermont.

Mites are mostly a non-concern around the state except in certain problem areas, especially where pyrethroid insecticides are used to manage other pests. Scouting is the best way to determine need for treatment at this stage, and should be performed regularly and using the Cornell sequential mite sampling guidelines (here, page 15) as a reference.

Summer diseases-sooty blotch/flyspeck, late-season apple scab (if you didn’t control it in the spring), and rots (particularly black rot in Honeycrisp) are of particular concern, given the wet weather that has continued this season. Maintaining fungicides on a 14-20 day schedule should be the minimum.

Calcium will be important to maintain fruit quality and to reduce bitter pit; it should be in every tank that you’re spraying, especially for large-fruit cultivars.

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.

Midsummer orchard management

Posted: July 9th, 2017 by fruit

By Terence Bradshaw

July 9, 2017

As we move into midsummer, the busy hive of early season pest management is largely behind us, and we just need to keep a few things in mind. On the disease front, sooty blotch and flyspeck have the potential to be a big problem this year, so fungicide coverage should be maintained against those diseases. Use the NEWA model to guide applications, and know that two inches of rain are needed to remove previous spray coverage. These are purely cosmetic diseases (but in bad years the cosmetics are well-beyond consumer acceptance) , so fruit that is definitely destined for cider does not need management for them. Fruit rots may be an issue, especially if some hot weather rolls in. Keep a close eye especially on Honeycrisp, that cultivar may need a specific black rot treatment. I hope scab is under decent management, but where it snuck through, I’m afraid you’re still in the 7-10 day fungicide mode until after terminal shoot buds set. Continue to keep an eye out for fire blight strikes and cut out immediately.

As for insects, apple maggot (AM) is the main one we’re keeping an eye on. If you are planning to use them, red sticky spheres should have been deployed by now to monitor populations and flight to determine the need to treat. One Addison county orchard has already reached treatment threshold, and I expect others to need treatment in the next couple of weeks. But AM isn’t a problem in every orchard, so prophylactic spraying isn’t ideal. Codling moth (CM) has begun its second flight in most orchards, and eggs will be laid and will be hatching in coming weeks, there is no need to manage now. Mites may be a problem in some orchards, I have seen one block which was over threshold for two-spotted spider mites and required treatment already.

All sprays at this time of year, especially on Honeycrisp and Cortland, should include calcium in them, and applications of Ca may actually drive the spray schedule on those cultivars. Otherwise, keep mowing to improve air movement and reduce disease pressure in the orchard, walk those rows regularly (since you aren’t driving them as much with a sprayer), and keep note of the now incidental pests that are thankfully less common but easily missed, compared to those we all know are in our orchards in spring through fruit set.

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.

Midsummer vineyard management

Posted: July 9th, 2017 by fruit

By Terence Bradshaw

July 9, 2017

Now that the July 4 holiday is past us, it’s time to really think about getting quality into those grapes on the vines. That doesn’t mean that the work that has gone into the 2017 crop hasn’t yet affected quality: the pruning, shoot adjustment, pest management, and other activities that are needed to keep a vineyard in good shape. But the next two months may be the most important in terms of developing high-quality fruit in this (so far) challenging year.

Pest management should continue to focus primarily on disease management. It has been a difficult year so far with all of the rain, and the frequency of it, to maintain fungicide coverage but I have been seeing mostly clean fruit and foliage in vineyards which have maintained an appropriate spray schedule of 4-5 well-selected and –timed fungicides since prebloom. At this point, phomopsis is pretty much done, and black rot will soon be winding down. Powdery and downy mildews (PM?DM) should be the main focus for disease management, as well as botrytis a few weeks down the road. If this wet weather continues, I would recommend a specific botrytis material such as Flint, Rovral, Vangard, Endura, or Pristine before bunch closure (the point where berries size up to the point where spray material cannot penetrate the cluster to protect fruit from infection). As always, check your Pest Management guide (New York & Pennsylvania or New England guides) and the label, rotate fungicide classes to reduce resistance likelihood, and follow all safety precautions when spraying. Organic disease management spray options include copper (DM, a little PM), sulfur (PM), stylet oil (PM, do not spray before or after a sulfur spray), and possibly some of the biologicals but I don’t know enough about them in regards to their performance against these late-season diseases.

Later this week would be a good time to scout clusters for grape berry moth (GBM) webbing which could suggest a need to treat for that insect pest. The threshold for treating this generation is 6% of clusters showing damage, which appears as small bits of webbing in between berries up inside the cluster. GBM is the primary insect pest of established vineyards in Vermont, and if it is the only pest insect need to manage, then some very specific materials with low potential for non-target effects may be used, including lepidopteran-specific materials like Bt, Intrepid, Delegate, or Altacor (the latter has some activity against Japanese beetle). Bt (DiPel and others) and Entrust would be effective materials against GBM for organic growers- the former affects only lepidoptera, while the latter would have some activity against Japanese beetle and some other insects as well.

None of this spray talk makes any sense if good cultural management isn’t practiced, and right now that means getting canopies in shape to best expose fruit to the sun for ripening and to control tangled shoot growth. Regardless of the training system used, this is an important tie to position canes. Most Vermont vineyards use a high wire systems, in which case shoots should be separated from one another and directed downward with some leaf pulling around clusters to put them in 50-100% sunlight. If using a low wire VSP or fan system, canes should be trained upward and, again, leaves pulled around clusters to expose them to sunlight. This is also a good time to remove laterals, non-fruitful canes, and any small clusters that are lagging behind the rest of the crop. This practice will arguably have the greatest effect on improving grape ripeness (assuming you have diseases relatively well-managed) of any you perform this year. It will also greatly improve the effectiveness of any spray materials that you do apply, at they can better penetrate the canopy and the canopy can dry better after wetting, which reduces disease pressure as well.

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.

Hail, tonight and in general

Posted: June 27th, 2017 by fruit

By Terence Bradshaw

June 27, 2017

A pretty strong storm with high winds and hail just blew through East Montpelier and Calais; my colleague up in South Burlington reports barely a puff of wind up there. The point here is that hail may have affected area orchards, but as is usually the case, was highly variable in location and severity. Aside from the crop damage implications, which require a call to your crop insurance agent within 24 hours, there is the potential for fire blight (FB) infection to be spread to damaged fruit and tissues.

However, there are three things that need to be present for trauma-induced FB to occur: 1) active FB infections in the orchard; 2) hail and/or high winds that could cause open wounds to plant tissues, and; 3) sufficient heat for bacteria to multiply and infect. If you have no FB in your orchard or in the immediate vicinity, there is no need to treat. If you missed the storms, again, no need to treat. And the weather has been relatively cool but there have been sufficient warm spells and a warmup is expected on Friday, so that is not a mitigating factor.

I have been scouting some orchards in the state and have seen sporadic FB, including in our own UVM orchards. Still, even if sporadic and you were affected by the storm (and I don’t mean rain and a little wind, I mean hail and ‘whip the trees around’ wind) treatment is justified. By now growers should know the FB status in your orchards. If there is any question, consider treating. But if there is no FB, there is no need to spray.

Materials need to go on within 24 hours of a trauma event. Streptomycin is the gold standard and should be the only material considered if you aren’t certified organic. If organic, Serenade or Cueva + Double Nickel may be effective but I am not guaranteeing excellent results.

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.

Borers and moths, plus a little on orchard diseases

Posted: June 26th, 2017 by fruit

By Terence Bradshaw

June 26, 2017

There’s pretty much no question that apple scab ascospore release is done now, and only lesions from that primary scab season that became established in the trees can continue to spread the disease. There is a bit of scab out there; if you have any, then keep covered with Captan for about four weeks until those lesions are finished spreading secondary spores. Sooty blotch and flyspeck are going to be active this year, and if you’ve had more than 2” of rain since a fungicide, it would be prudent to apply one soon against those diseases.

Apple maggot traps should be up now in Vermont orchards. These red sticky spheres should be hung in a very clearly visible location at the corners of a block and baited to better attract flies to them- see last week’s message for more details. Codling moths may need management if you haven’t yet done so, but the window to manage the first generation is closing rapidly. Another set of insects to consider targeting soon are dogwood borer (DWB) and roundheaded apple borer(RAB). The former is a clearwing moth that looks like a wasp upon first sight, and its larvae tunnel in trunks, especially in burr knots on rootstocks, and cause a general decline in tree health. The latter is a beetle whose larvae tunnel into trunk tissue and hollow out trees, especially those between 3-8 years of age, and can eventually kill the tree. Infestations can be found by looking closely for a roughly 1/4” drill hole low on the trunk with frass coming out. If you see that, the larvae is either in there or has already done the damage and left. RAB tend to affect low-spray orchards most, especially those surrounded by woods and with brushy undergrowth. For both insects, a directed trunk spray right about now is the best option. Older (>7 year-old) trees may not be as susceptible to damage; young trees should be protected if you have ever had problems. Many growers aren’t familiar with either- in a typical orchard in which insecticides are applied, RAB is typically controlled, DWB is more subtle however, and we have caught the adult moths in every orchard we have monitored in the state this year. The Cadillac material for effectiveness is chlorpyrifos (Lorsban, also sold as a generic), but it is one of the old, highly toxic organophosphate materials that we would rather see left to history. That said, especially on young, high-density (and thus high-investment) orchards, it could greatly improve tree health moving forward. Chlorpyrifos can only be used once per year, and after bloom, only in a directed (i.e., handgun-applied) trunk spray with no contact to fruit or foliage. Cultural practices that can improve control include maintaining clean ground under the trees (you should be able to clearly see all trunks) to reduce refuge sites and increase biological control from birds, etc; removing solid trunk guard like the white spiral wraps during the growing season to expose the trunks; or (conversely) maintaining tight weave window screen trunk guards and closing the tops with elastic bands to prevent intrusion from above.

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.

Disease management still critical in grapes

Posted: June 26th, 2017 by fruit

By Terence Bradshaw

June 26, 2017

No one needs me to tell them that this has been a wet spring and now early summer. Most grapes are approaching, in, or maybe just exiting bloom across the state, and disease pressure continues to be possibly the highest of the season. Fungicide coverage should be maintained on 7-10 day intervals, depending on rainfall (1” removes about half of a material from the canopy, 2” and you’re no longer covered at all). The diseases of concern right now include all of the major ones: black rot; phomopsis; powdery mildew; downy mildew; anthracnose; and botrytis, so make sure any materials you apply cover the whole spectrum. Spray choices should include a contact material like Captan or a mancozeb (probably the last chance to use the latter, and watch the long preharvest interval); plus a second specific activity toward Black rot, downy mildew, and/or powdery mildew, like an SDHI (Luna Experience); strobilurin (Flint or Sovran); DMI (Rally, Tebustar); or a combo material like Revus Top, Pristine, or Inspire Super. Be sure to rotate between fungicides, never applying anything other than sulfur, copper, Captan, or mancozebs in more than two back-to-back sprays.

For organic growers, this is going to be a difficult season. Sulfur may be used now but will really only manage powdery mildew; copper materials may be the most effective against downy with a little activity against powdery and black rot, which will continue to be very hard to manage on an organic schedule in this wet year. Sanitation must be performed regularly to reduce disease inoculum in the canopy, that means pulling every leaf with visible lesions as it develops and destroying it. In a year like this, you may face significant vine defoliation using this method, but it will be your first line of defense.

Other than disease management, this is a great time to work on weed control and training young vines to the top wire. Canopy management should take a back seat for now, at the shoots are not lignified at their bases and thus are quite brittle.

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.

Orchard management- June 18, 2017

Posted: June 18th, 2017 by fruit

By Terence Bradshaw

June 18, 2017

I am doing some last minute preparations for my summer cold-climate viticulture course which starts this week (and still has a few slots if you’re interested), so this will be relatively brief. Codling moth (CM) should be tended to in most orchards in the warmer valleys this week if you have any question about them being a problem- and they are an increasing problem. candidates to use. Plum curculio and European apple sawfly should be all done doing their damage by now, so it’s just CM and some other leps that you’d be managing. This should be a great week to target first generation egg hatch, and CM-specific materials like granulosis virus (effective against CM only, with some efficacy against Oriental fruit month OFM), growth regulators (Intrepid, Esteem), and reduced-risk materials like Altacor and Assail would be good candidates at this time.

We are trapping all sorts of other moths, including lesser apple worm and OFM, which may be managed similar to CM, generally.

Apple maggot traps should be hung soon. These red sticky balls can be purchased from Great Lakes IPM or Gemplers. Buy the inexpensive ones and throw them out, we have spent countless hours over the years scrubbing the old wooden spheres in various solvents and the (literal) headache just isn’t worth it. Traps should be hung at least four per managed block, preferably at the corners of the orchard adjacent to woods or other overwintering areas. Organic growers with small plantings may ‘trap out’ by using a (much) larger number of traps as described here. Most growers find it easier to use the traps to monitor the flight of the flies and time a spray application, which may (hopefully) be timed to manage second generation codling moth as well later in July.

Diseases: this is the week to scout you orchard carefully for apple scab; if you have more than 1% of leaves affected, you’ll need to keep a protectant like Captan on until the terminal buds set and leaves become less susceptible. Fire blight is popping up, we are finding it in the usual trees at the UVM Hort Farm and cutting it out. Please let me know about anything bigger than a sporadic infection in the usual hot spots. Sooty blotch and flyspeck aren’t a problem right now. Frankly, unless you find scan, I’d put the fungicides away for now.

Water if you need to; apply calcium in most every spray and extra calcium in Honeycrisp. You can apply potassium-based fertilizers any time, that large crop this year will draw a lot out of the tree/soil. Of course your cation (calcium/potassium/magnesium) applications should be based on soil and, even better, foliar samples. Those will be ready to take in mid-July.

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.

Wild grape bloom starts the clock for grape berry moth management

Posted: June 12th, 2017 by fruit

By Terence Bradshaw

June 12, 2017

There is a wild grape that overhangs the South Burlington bike path just east of the UVM Hort Farm that I run by several days per week. Last Friday, June 9, it went into bloom (it was not blooming on my run the day before). Why is this important?

Grape berry moth is likely the most injurious pest of grape fruit in northern New England and New York. It is relatively easy to manage, often with a single application of a lepidopteran (caterpillar)-specific material. The first overwintering generation is rarely significant enough to warrant a management spray except in vineyards that have had extreme damage in previous years. Each generation requires about 820 degree days (base 47°F, or DDb47°F) to complete, and the first generation typically emerges around the time of wild grape bloom. So if we use June 9 as our ‘biofix’ and track DDb47°F, we can estimate the best time to treat for the more damaging later generations.

This is made easy by the Network for Environment and Weather Applications (NEWA) system, which I coordinate for Vermont. The network includes ten on-site weather stations (all located at orchards) and six airports, and imports data in near real-time for use in pest models. It is free to use, and growers can locate the site nearest them and develop a best-guess of phomopsis, black rot, and downy mildew infection periods as well as a sense of the grape berry moth generational development.

Remember, however the important components of Integrated Pest Management (IPM): cultural controls such as sanitation and good canopy management can reduce disease inoculum and insect pests while reducing canopy moisture and humidity; and most cold-climate grape cultivars are more resistant to the main diseases of black rot, powdery mildew, phomopsis, and downy mildew than V/ vinifera or even older French American and other hybrids with a substantial amount of vinifera in their parentage. So a ‘clean’ vineyard will have less need to spray when a model says a disease infection occurred, and a vineyard of cold climate cultivars is even better off. Remember the basics from our basic spray strategy for cold-climate grapes in Vermont: keep covered immediate prebloom and post bloom, plus another application or two 7-10 days apart after that. Build up from there as needed based on your vineyard history or unique cultivar susceptibility.

-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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