Fruit IPM Reports

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Agriculture & Gardens > Fruit & Vegetable Crops

Updated every Tuesday through the season, these reports are recorded on the Fruit Pest Hotline by UNH Extension's disease diagnostician in the UNH Plant Diagnostic Lab.

Quick Links to 2024 Reports

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7/02/2024

Fruit IPM Update 

All degree day totals, and model outputs are based on data collected from a NEWA-connected weather station in an orchard in Concord, NH. Be sure to enter your specific biofix dates for your farm for the best results and accuracy.

Today we are at a total of 1514 DD 43F BE and 956 DD 50F BE since January 1, 2024.

Notice: The EPA is soliciting comments regarding Captan fungicide until July 31st. These proposed rule changes would impact tree fruit and grape producers. For details on the proposed changes and how to submit your comments, visit:

https://extension.psu.edu/epa-soliciting-comments-for-captan-fungicide-submit-comments-by-july-31-2024

Apples

Fireblight – Growers continue to report blossom and shoot strike infections. We should be nearing terminal bud set which should bring with it a major decline in any new shoot strikes. Prune out strikes 18-24” below visible symptoms into older wood where possible. If removing an entire branch, leave a small stub as a place for the bacteria to dry out and die before reaching the main leader.

Prohexadione calcium (PhCa) is still an option until terminal bud set at 6-12 ounces per 100 gallons with liquid copper. If the decision is made to apply this mix to a block of trees, wait 5 days for the PhCa to work before pruning out strikes. Some researchers suggest to only cut out shoots with a wet oozing appearance and leave those that appear dry after the treatment above.

Apple scab – Secondary scab is present in some orchards. Recent hot temperatures and fungicide applications seem to have slowed down active infections. In orchards with active secondary infections, continue to maintain coverage, scout to monitor status of infections, and remain mindful of temperatures and rainfall accumulations since your last application of fungicides.

Regional pathologists are recommending materials such as potassium bicarbonate, or the combination 7 + 11 FRAC group materials such as Merivon and Luna Sensation. These materials should also help to control powdery mildew infections.

A recent blog post from Dr. Kari Peter at PSU provides guidance on both scab and fireblight management, along with considerations for scab management programs in future years to minimize infections:

https://extension.psu.edu/2024-disease-update-managing-fire-blight-and-apple-scab-infections

Sooty blotch/Flyspeck – Fruit is susceptible to infections now. Consider your market, last fungicide application timing, leaf wetness hours and rain events when contemplating the need for control. The NEWA SBFS model currently shows a low risk of infection this week.

The NEWA SBFS model currently shows a low risk of infection this week 7/2/2024

Bitter rot

With the arrival of summer weather comes the increased risk of bitter rot. UMass has an excellent fact sheet explaining the key management points to keep in mind here:

https://ag.umass.edu/fruit/fact-sheets/apple-ipm-bitter-rot

Group 7, 11, combinations of the two, along with multi-site materials are rated as having the highest efficacy.

Powdery mildew - Continues to linger in many locations. Prune out infected shoots where possible to reduce inoculum. As mentioned above, the group 7+11 combination products will also provide some control.

Apple maggot fly – Traps should be up in anticipation of flies. We have yet to capture our first fly as of 7/2/24.

Codling moth – Trap captures of male moths have declined significantly over the past week in most locations, likely marking the tail end of the first-generation flight. Today in Concord we are predicted to reach 761 DD 50F BE since biofix (5/18/24). Peak egg hatch of the first-generation CM larvae is predicted at 500-600 DD from biofix, so most eggs from the first flight should have hatched by now in most locations. First insecticide applications for the second generation should be made at about 1,400 DD to 1,600 DD, using the same biofix as previous spray timing.

Obliquebanded leaf roller – So far, we have accumulated 538 DD 43F BE since our first trap catch. Adults are still flying and laying eggs. Peak flight usually occurs within two weeks after the first adult is captured. Eggs begin to hatch at approximately 350 DD base 43F after first trap catch. It is still too early to sample for larvae in orchards that are being monitored to determine if summer control sprays are necessary because most egg masses (about 75%) still have not hatched. Residual activity from an initial protective spray will control early hatching larvae at this time.

Jaime Pinero of UMass Extension reminds us of the following consideration when evaluating the magnitude of OBLR populations:

  • While it is recommended to spray insecticides that target the hatching larvae at 360 DD base 43 after BIOFIX, we also need to consider the magnitude of the OBLR captures. 
  • OBLR undergoes two generations annually, with larvae overwintering as small larvae in trees. They become active upon the trees breaking dormancy, completing their development about two weeks after the apple blossom period.
  • Because high OBLR trap captures often don’t translate to high levels of injury growers are advised to scout for summer generation larvae by examining 10 fruit clusters and 10 terminals on five trees per orchard each week. Using this method, an insecticide application is warranted if three larvae per tree are found. 
  • The second generation's adult flight occurs in August, and larvae hatch in August and September. These young larvae create hibernation sites on twigs or bark to survive the winter. 

Potato leaf hopper – Hopper burn is evident in parts of New England and NY. Management is most important for young trees as they are growing to fill their space. Monitor over the next couple of weeks to see if they show up here in numbers.

Wooly apple aphid – WAA feed on shoots and excrete sugary material which serves to encourage sooty mold. Scout for aerial colonies in leaf axles. Most have been found in branch crotches and pruning stubs to this point in the season. Movento is one of the most effective materials if control is deemed necessary.

Apple maggot fly – We have yet to catch our first fly on unbaited red sticky traps in Merrimack County. We will continue to monitor and report once captures have occurred. Suggested treatment threshold is an average of 2 flies per trap on unbaited traps, and 5 flies per trap when baited. As we anticipate adult fly emergence soon, the article from Michigan State University may be helpful as you consider insecticide choices. Some of the materials listed are rated as highly effective on codling moth as well. A consideration when timing for control of both insect aligns.

https://www.canr.msu.edu/news/managing-apple-maggots-with-insecticides

Peaches

Brown rot – The earliest varieties of peaches in our trial at Apple Hill Farm in Concord, NH tend to ripen around July 26th. That would make this Friday about three weeks from harvest, and the beginning of an important time for the control of this fungus on fruit. There are many fungicide options rated as good or excellent for control a this stage of the season, which can be viewed in the New England Tree Fruit Management Guide here: https://netreefruit.org/stone-fruit/peaches-nectarines/spray-table/6-summer

Japanese beetles are active now. Be sure to monitor peaches, nectarines and other susceptible crops and control as needed.

Blueberries

Early varieties are ripening with the earliest just starting to be harvested in southern NH locations.

Fruits infected with mummyberry are evident throughout the southern half of NH this year. Conditions were favorable for the fungus to cause infections during budbreak through bloom. Sanitation including removal of infected fruit during harvest to the extent possible will help minimize inoculum for next year.

Blueberry maggot - Early varieties are ripening, so knowing if this pest is present will become increasingly important. Unlike SWD, which tends to show up in most locations with berries in NH, blueberry maggot tends to be more site specific, therefore monitoring for presence has great value in IPM programs. Also worth noting is the fact that if you do have populations of this pest, most of the materials rated as highly effective for controlling SWD will also control this pest.

SWD – Populations are increasing quickly now in the southern half of NH. Growers should have traps up to monitor SWD first appearance and consider best timing of controls for all ripening berries.

Cornell provides a timely reminder of best management practices for SWD, along with their updated SWD Insecticide Quick Guide below:

Quick Guide: https://bpb-us-e1.wpmucdn.com/blogs.cornell.edu/dist/f/7312/files/2024/05/Quick-Guide-SWD.pdf

Below are a few reminders of management tactics that should be used to successfully manage SWD this season:

Sanitation – Harvest fruit frequently to prevent populations from building up. If possible, do not leave berries on the ground. Remove infested fruit and freeze, seal in bag and place in the sun or dispose off-site.

Canopy management – Excellent pruning and weed management reduce humidity, creating an environment less conducive to SWD.

Monitoring – Begin to spray as soon as fruits begin to ripen, once SWD has been trapped in your orchard/region.

Rotate active ingredients (IRAC groups) through to harvest for resistance management. Resistance has been documented in other states, rotating is essential for preventing this in our region!

Avoid the temptation to stretch spray intervals! 7-day interval should be the maximum.

Plan out the order of insecticides you will use wisely, so that you save products with a lower PHI for use close to harvest.

Focus on complete coverage, especially in the middle of the canopy where high humidity creates an ideal SWD habitat and be sure to reach to the top of the tree.

If it rains, reapply (according to label instructions).

When choosing insecticides for European Cherry Fruit Fly and native Tephritid fruit fly control, prioritize those that have activity against SWD (more information about ECFF to come in an upcoming Fruit Notes issue).

Exclusion – Polyethylene netting (80 gram or 1.0 x 0.6mm) requires a high upfront installation cost and must be very thoroughly maintained to provide no possible entry to the flies, but if done well can be an extremely effective method of preventing infestation. Exclusion netting must be installed before SWD arrival and must be well maintained.

Strawberries

Harvest of June-bearing is nearly complete, aside from the latest varieties like Malwina. This means the time for renovation is here. For an excellent guide on the process and considerations, visit the following MSU article: https://www.canr.msu.edu/news/renovation-in-perennial-strawberry-fields

Raspberries

The crop looks good overall. Early varieties are ripening in southern locations. The beginning of harvest for early varieties is anticipated next week in the Concord area. SWD has a preference for raspberries, so have you traps up and be prepared to protect ripening berries.

Pesticide Safety Education

Lastly, my colleague Rachel Maccini oversees the Pesticide Safety Education Program in NH. She asked that the following be included in this update for your information.

What license do I need?

In New Hampshire, anyone applying pesticides for producing an agricultural commodity must be licensed as a private applicator. According to state regulations, a private applicator is an individual who uses or oversees the use of pesticides, whether classified as general use or state restricted use, for agricultural production on property they own or rent, or on another's property without monetary compensation, except for personal service exchanges between agricultural producers. An agricultural commodity includes plants, animals, or animal products produced primarily for sale, consumption, propagation, or other use by humans or animals.

Private applicator permits are specific to the commodity produced and there are ten categories: Christmas Trees, Nursery, Greenhouse, Small Fruit, Tree Fruit, Beekeeper, Poultry, Dairy, Vegetable, and Sod, each associated with particular pests and sites. There are two types of pesticide permits: General Use and Restricted Use. A Restricted Use Permit is necessary for individuals using restricted pesticides or applying pesticides in a restricted manner. To obtain a Restricted Use Permit, an applicant must submit an application, exam application, and fees, then schedule a written exam with the Division of Pesticide Control within 30 days of application receipt. Alternatively, the exam can be taken at a county extension office with prior arrangements.

If you have questions about licensing please reach out to Beth Cladwell, Certification Coordinator (licensing), email: beth.k.caldwell@agr.nh.gov or (603) 271-3694.

How do I check to see if a pesticide product is registered in NH?

Pesticides sold within New Hampshire are registered with the Division of Pesticide Control (NH Dept of AGR, Markets & Food). You can check their data base by visiting https://www.agriculture.nh.gov/publications-forms/documents/registered-pesticide-products.pdf

Once you are here you can do control F and type in your EPA Reg. #, if the product was or is registered it will highlight within the document. If the product is not registered in NH, the EPA Reg. # field will highlight red indicating there is no record of that particular product. The product registration information is updated annually around March. If you are interested in a particular product, but do not see it on the list you can reach out to the Division of Pesticide Control (NH Dept of AGR, Markets & Food) for assistance (603) 271-3550.

Where can I obtain a copy of a pesticide label if mine has been damaged or is missing?

If you need to obtain a copy of a pesticide label due to damage or loss of the original, there are several resources available to you. The manufacturer's website is a good starting point, as they often provide downloadable labels for their products. Additionally, the National Pesticide Information Center (NPIC) offers a searchable database where you can find labels for various pesticides.

http://npic.orst.edu/ingred/proddata.html

Another useful resource is the Pesticide Product Label System (PPLS) managed by the U.S. Environmental Protection Agency (EPA), which provides access to current and historical labels.

https://ordspub.epa.gov/ords/pesticides/f?p=PPLS:1

The CDMS (Crop Data Management System) is another great site. https://www.cdms.net/LabelsSDS/home

If these options do not yield results, contacting the retailer or distributor where you purchased the pesticide may provide a quick solution.

I have some old pesticides that I no longer need. How and where can I dispose of them? What do I do?

Disposing of old pesticides requires careful attention to ensure environmental safety and compliance with local regulations. First, check the labels on the pesticide containers for any specific disposal instructions provided by the manufacturer. If these instructions are not available or unclear, your best course of action is to contact your local waste management facility or the environmental health department. Many communities have designated household hazardous waste collection programs that accept pesticides and other hazardous materials. These programs often provide specific drop-off locations or scheduled collection events. It’s crucial not to dispose of pesticides in regular trash, drains, or by pouring them on the ground, as this can cause significant environmental harm.

Household Hazardous Waste Days. Information and collection events can be found here: https://www.des.nh.gov/sites/g/files/ehbemt341/files/documents/hhw-collection-contacts.pdf

Active Hazardous Waste Transporters in New Hampshire: The “Yellow Pages” may have listings for vendors or contact the state of New Hampshire’s Hazardous Waste Hotline at (866) HAZWAST (1-866-429-9278) (toll free in-state 8 am to 4 pm) or (603) 271-2942 for further guidance.

The following list of hazardous waste vendors does not constitute endorsement or preference but represents vendors that may manage pesticide waste:

Maine Labpack Inc.

15 Holly Street, Suite 201

Scarborough, ME 04074

Phone # 207-767-1933

Triumvirate Environmental Inc.

200 Inner Belt Rd

Somerville, MA 02143

Phone #617-628-8098

New England Disposal Technologies Inc.

83 Gilmore Dr

Sutton, MA 01590

Phone #508-234-4440

Toll Free 800-698-1865 Email: sales@NEDTinc.com

Agricultural producers are also encouraged to contact the Division of Pesticide Control at 603-271-7788.

Attention Agricultural Producers:

We are pleased to inform you that the Lakes Region Hazardous Product Facility is now able to handle the disposal of agricultural pesticides. This service is available with prior notice and offers a cost-effective solution for managing your hazardous products.

To ensure a smooth and efficient process, please follow these steps:

Prepare a List: Compile a list of the agricultural pesticides you need to dispose of, including details on the condition and size of each product.

Contact Sara Silk: Reach out to Sara Silk at 651-7530. It is important to do this well in advance of your desired pickup date.

Arrange for Pickup: Discuss the specifics with Sara Silk to arrange for the pickup of your agricultural pesticides.

Fees: Be prepared to pay a fee for this service. However, please note that the fee is significantly lower than what is typically charged for commercial waste disposal.

For further assistance and information, you can also contact the Division of Pesticide Control at (603) 271-7788.

Upcoming Events:

August 21 - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

 

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6/18/2024

Fruit IPM Update 

All degree day totals, and model outputs are based on data collected from a NEWA-connected weather station in an orchard in Concord, NH. Be sure to enter your specific biofix dates for your farm for the best results and accuracy.

Today we are at a total of 1142 DD 43F BE and 681 DD 50F BE since January 1, 2024.

Apples

Fruit continues to drop from thinners and June drop. Many orchards have achieved excellent thinning results this season through applications during bloom, early fruit set and through the optimum thinning window.

Apple scab – Primary infection is completed with secondary scab present now in some orchards. Hot temperatures should slow down active infections. In orchards with active secondary infections, continue to maintain coverage while being mindful of temperatures and rainfall accumulations since your last application of fungicides.

A recent blog post from Dr. Kari Peter at PSU provides guidance on both scab and fireblight management, along with considerations for scab management programs in future years to minimize infections:

https://extension.psu.edu/2024-disease-update-managing-fire-blight-and-apple-scab-infections

Sooty blotch/Flyspeck – Fruit is likely becoming susceptible to infections now. Consider your market, last fungicide application timing, leaf wetness hours and rain events when contemplating the need for control. The NEWA SBFS model currently shows only a moderate risk of infection this week.

The NEWA SBFS model currently shows only a moderate risk of infection this week

Bitter rot

With the arrival of summer weather comes the increased risk of bitter rot. UMass has an excellent fact sheet explaining the key management points to keep in mind here:

https://ag.umass.edu/fruit/fact-sheets/apple-ipm-bitter-rot

Group 7, 11, combinations of the two, along with multi-site materials are rated as having the highest efficacy.

Powdery mildew - Continues to linger in many locations. Prune out infected shoots where possible to reduce inoculum.

Codling moth – We continue to catch moths at significant numbers in the Concord area (16.5 moths/trap/week). Today in Concord we are predicted to reach 488 DD 50F BE since biofix(5/18/24). Peak egg hatch of the first-generation CM larvae is predicted at 500-600 DD from biofix. The coming week should be good timing for a second application in orchards finding similar trapping results.

Obliquebanded leaf roller – We are about a week into trap captures in Concord, and we estimate our biofix date at 6/12/24. The larvae of this moth can cause significant fruit surface damage and foliar feeding. Traps with female sex pheromone are used, which catch male moths. Females lay egg clusters with many eggs (200 or more). Larvae have dark head capsules and dark thoracic plate, which differentiates them from larvae of other species. So far, we have accumulated 167 DD 43F BE. Adults are still flying and laying eggs. Peak flight usually occurs within two weeks after the first adult is captured. No control measures are recommended at this time, because eggs have not yet begun to hatch, this occurs at approximately 350 DD base 43F after first trap catch. It is also too early to sample growing terminals to estimate larval populations.

Potato leaf hopper – seeing hopper burn in NY, management most important on young trees as they are growing to fill their space. Monitor over the next couple of weeks to see if they show up here in numbers.

Wooly apple aphid – Movento is one of the most effective materials. Feed and excrete sugary material which serves to encourage sooty mold. Scout for aerial colonies in leaf axles. Most have been found in branch crotches and pruning stubs to this point in the season.

Peaches

There is a heavy crop of many varieties this year. Lots of fruit is dropping naturally, but if thinning hasn’t been completed yet, sooner rather than later would be best for fruit sizing.

As another reason to thin early, fruits thinned after pit hardening are more likely to become infected with brown rot on the orchard floor and provide a source of inoculum for spread to ripening fruits in the tree; in contrast, fruits thinned prior to pit hardening are much less likely to do so (UMass).

Growers that used Accede as a thinner are reporting positive results. Something to consider in future years?

Many peach varieties have set heavy crops in need of thinning. Photo: Jeremy DeLisle, UNHCE

Many peach varieties have set heavy crops in need of thinning. Photo: Jeremy DeLisle, UNHCE

Blueberries

We have seen a fair amount of Mummyberry throughout the southern half of NH this year. Conditions were favorable for the fungus to cause infections during budbreak through bloom.

Early varieties are starting to show the first bit of color. Later varieties are still fully green.

Blueberry maggot traps should be set up soon. Conversations with growers indicate that early berries will ripen in the next two weeks, so knowing if this pest is present will become increasingly important. Unlike SWD, which tends to show up in most locations with berries in NH, blueberry maggot tends to be more site specific, therefore monitoring for presence has great value in IPM programs.

Some varieties including Bonus and Berkley, among others, have shown a tendency this season to set heavy crop loads of fruit with minimal leaf and vegetative shoot growth. Conversations with growers and regional specialists have yielded no certain reasons for this phenomenon, however, the general consensus has been that maintaining fertility to encourage additional vegetative growth, along with conducting some amount of targeted pruning to thin off some of the crop in varieties that have excessive fruit set in comparison to vegetative growth to support it would be worth a shot. Also consider the impact of these hot dry days on plant stress and maintain adequate soil moisture with irrigation.

SWD pressure is ramping up. Growers should have traps up to monitor SWD first appearance and consider best timing of controls for all ripening berries.

Cornell provides a timely reminder of best management practices for SWD, along with their updated SWD Insecticide Quick Guide below:

Quick Guide: https://bpb-us-e1.wpmucdn.com/blogs.cornell.edu/dist/f/7312/files/2024/05/Quick-Guide-SWD.pdf

Below are a few reminders of management tactics that should be used to successfully manage SWD this season:

Sanitation – Harvest fruit frequently to prevent populations from building up. If possible, do not leave berries on the ground. Remove infested fruit and freeze, seal in bag and place in the sun or dispose off-site.

Canopy management – Excellent pruning and weed management reduce humidity, creating an environment less conducive to SWD.

Monitoring – Begin to spray as soon as fruits begin to ripen, once SWD has been trapped in your orchard/region.

Rotate active ingredients (IRAC groups) through to harvest for resistance management. Resistance has been documented in other states, rotating is essential for preventing this in our region!

Avoid the temptation to stretch spray intervals! 7-day interval should be the maximum.

Plan out the order of insecticides you will use wisely, so that you save products with a lower PHI for use close to harvest.

Focus on complete coverage, especially in the middle of the canopy where high humidity creates an ideal SWD habitat and be sure to reach to the top of the tree.

If it rains, reapply (according to label instructions).

When choosing insecticides for European Cherry Fruit Fly and native Tephritid fruit fly control, prioritize those that have activity against SWD (more information about ECFF to come in an upcoming Fruit Notes issue).

Exclusion – Polyethylene netting (80 gram or 1.0 x 0.6mm) requires a high upfront installation cost and must be very thoroughly maintained to provide no possible entry to the flies, but if done well can be an extremely effective method of preventing infestation. Exclusion netting must be installed before SWD arrival and must be well maintained.

Earliest varieties of blueberries beginning to show color – Photo: Jeremy DeLisle, UNHCE

Earliest varieties of blueberries beginning to show color – Photo: Jeremy DeLisle, UNHCE

Strawberries

Growers continue to report good harvests and the weather has been favorable for u-pick customers. Quality berries are abundant, although reports of suppressed yields, likely from winter damage or stress from the excessive rainfall in 2023 are reported in some locations. Heat this week may bunch harvest of varieties together more than normal. Pick early in the day and frequently to the extent possible to minimize loss.

Raspberries

The crop looks good overall. Berries are sizing up but still green in most locations.

Upcoming Events:

June 19 - Tree Fruit Twilight Meeting at Sunnycrest Farm | Extension (unh.edu)
August 21 - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

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5/09/2023

Hi all!!  

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is May 9th , 2023.

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

In terms of growing degree days in Concord, NH we have accumulated 347 GDD in BE base 43F and 159 GDD in BE base 50F.

Lets jump right into plant pathogen updates for the apple growers.

Apple scab:

With all of that rain we got last week, most of you probably got a spray on last week, and potentially with a kickback product and a multisite spray.  This upcoming week we are drying out a bit and NEWA is not showing any infection events, but remain vigilant and keep an eye out for any lesions on the leaves that could be forming from the infection events we had last week.  Remember that this time of year can be tricky with the rapidly expanding leaves and getting the right amount of coverage to combat the apple scab – spray as close as you can to infection events to cover the most surface area of the leaves as possible.

As always, when using NEWA, make sure you are putting  in the most accurate green tip date and weather station into the models to get the most accurate predictions for your orchard.

Refer to the New England Tree Fruit Guide more information: https://netreefruit.org/apples/diseases/apple-scab

Marssonina (Apple Blotch):

This is a bit of a newcomer in this area but this fungal pathogen is also a concern and can be controlled with many of the same fungicides that control apple scab. The period of main concern is really at the tail end of apple scab season, but be aware and read up here about when and how to best control it.

2023 Disease Update: Disease Conditions Favored for Marssonina Blotch and Apple Scab April 28–May 1 (psu.edu)

Fire blight:

Remember that using the fireblight model in NEWA begins with selecting the current infection pressure from the drop-down menu in the fireblight model. Choose between the three various scenarios based on your specific conditions.

Blossom blight infection risk is tracked by the accumulation of 4-day degree hour totals beginning at bloom. NEWA begins degree hour accumulation on the date of full pink or "first blossom open" for McIntosh apple. It is best if you enter your start date based on blossom dates in your apple or pear orchards and recalculate Cougarblight risk predictions.

The MacIntosh trees in the concord area are blooming, so now is the time to be ready for fire blight infection events.

If your orchard has a history of fire blight infections in previous years, the models show that you have a moderate/high risk for a fire blight infection this week, especially as we get towards the end of the week (around Friday May 12th).  This is because there are probably some lingering cankers in your orchards that will produce the next round of bacteria to infect your trees if they are not treated properly. If you don’t have a history of fire blight, your risk is lower this week.  Be sure to check out NEWA’s forecast and set the parameters for your specific orchards.

If you are interested in using SAR, or Systemic Acquired Resistance products, now could be a good time to apply those ahead of the infection event. These materials get the trees to activate their own defenses against fire blight ahead of the infection event and can be a good “tool in the toolbox” to fight fire blight in your orchards.  SAR products include Actigard, Lifegard and others.  Check out the New England Tree fruit guide for more info!

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

Powdery mildew:

Dry periods during scab season can be a prime time for infection by powdery mildew. Group 3 fungicides used for scab control will also control PM. Consider saving the group 11 fungicides until petal fall for control of summer diseases.

Powdery Mildew | New England Tree Fruit Management Guide (netreefruit.org)

Related Disease note:

Blueberry growers: if the fungal pathogen mummy berry is present in your fields (essentially if you had problems with it last year) it was probably sporulating last week/into this week with that rainy weather we had.  Keep an eye out for the symptoms if you have had issues with it in the past.

For more info, check out:

Over-informed on IPM - Episode 020: Mummy berry and Pollinator Protection | Extension (unh.edu)

Now moving onto the insect pests:

Just a reminder: With bloom, no insecticide sprays should be going out to protect our native pollinators!

Tarnished Plant Bug:

Tarnished Plant Bug captures in white sticky traps have remained very low. Numbers have been suppressed due to cold temperatures.  Be sure to have your traps out.

Tarnished Plant Bug (TPB) | New England Tree Fruit Management Guide (netreefruit.org)

Oriental Fruit Month:

Pheromone traps and mating disruption dispensers should be deployed now. The first catch of moths from the overwintering generation is expected to be soon but none have been caught as of last week. No insecticides need to be applied until eggs begin to hatch; since OFM flight usually begins at bloom, it is not possible to apply an initial spray to kill adults.

Oriental fruit moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

Oblique banded Leaf roller and Red Banded Leaf Roller:

No Oblique banded Leaf rollers caught as of last week.  We did catch a single Red Banded Leaf Roller, but no biofix date for that yet.

Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

Redbanded Leafroller [fact sheet] | Extension (unh.edu)

Codling Moth:

No captures yet. The average 1st catch 475 DD base 43, mating disruption with granulosis virus is a good option, Altocor for 1st gen, Assail for 2nd gen will also control apple maggot. Altacor, Exirel, Verdepryn are worth considering as control options at first hatch for codling moth. These group 28 insecticides have efficacy against many lepidopteran species as well as plum curculio. Codling moth becomes the driver for insect sprays after petal fall along with plum curculio.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

In General:

Bt (Dipel is a good choice early) in the development of lepidopteran pests. Avoid applications during bloom.

Rosey Apple Aphid:

Control can start at pink. Petal fall may be best timing.  Be scouting now to be aware of possible aphid hot spots.

Aphid: Rosy Apple Aphid | New England Tree Fruit Management Guide (netreefruit.org)

European Red Mite:

Look for overwintering eggs now. Treatment windows range from green tip to pink, and then resume after petal fall. Generally, some control before pink combined with concentrated control around petal fall will provide best season-long control.

Mites (European Red Mite [ERM] and Two-spotted Spider Mite [TSSM]) | New England Tree Fruit Management Guide (netreefruit.org)


Additional Notes:

We received a question recently about boron applications for apples. This is an important nutrient for apples for pollen tube development, feeder root growth and translocation of calcium, among other functions. Details about the roles of various macro and micronutrients in apples can be found here: http://fruitadvisor.info/tfruit/clements/articles/nutrientrecs.pdf

Twilight Meetings:

The schedule is out for all of extension’s summer twilight meetings, and I wanted to highlight a few that may be of interest to the folks that tune into this call – the full list of Extensions event offerings this summer can be found on our website!

Tree Fruit meeting at Demeritt Hill Farm, July 15th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at DeMerritt Farm | Extension (unh.edu)

Tree Fruit meeting at Apple Hill Farm, August 17th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

All of the Production agriculture Twilight meetings:

2023 Production Agriculture Summer Twighlight Meeting | Extension (unh.edu)

Thank you for sticking around until the very end!  See you next week!

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6/13/2023

Fruit Pest Hotline IPM Report 6/13/23

Hi all!!  

 

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is June 13th , 2023.

 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

 

In terms of growing degree days in Concord, NH we have accumulated 875 GDD in BE base 43F and 403 GDD in BE base 50F.

Before we get into the pathogens:

Many questions are arising as to management decisions for the season ahead considering the frost damage to fruiting crops throughout New Hampshire.

You can access the suggestions from UNH Extension Staff and Terry Bradshaw up at UVM in previous IPM reports (6/6/23) or here: May 2023 – UVM Fruit Blog

Moving on to the disease updates:

Apple scab:

The rains this week should certainly promote the last of the ascospores to be released.  Maintain protection and continue to scout over the next couple of weeks. Hopefully your orchard is clean of scab and this will mean the end of required control measures for the growing season. While visiting orchards over the past week, Jeremy Delisle spotted some primary scab infections present on leaves. Now is the time to remain diligent and maintain fungicide coverage over the next two weeks with the goal of wiping out these initial infections and putting an end to the need for control through the remainder of the season due to secondary infections.

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

apple scab

Figure 1: Apple scab infection on upper and lower leaf surface, Photo, Jeremy DeLisle, UNH Extension

Marssonina (Apple Blotch):

While we are currently at the very end of primary apple scab season, you should remember that this fungus is also a concern and can be controlled with many of the same fungicides that control apple scab. The period of primary concern is really at the tail end of apple scab season, read up more about it here: Apple Disease - Marssonina Blotch (psu.edu).

Fire Blight:

Continue to scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots at least 12-18 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread, but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial. With a cool and fairly dry bloom period, some growers made in through the prime infection period with just a couple of streptomycin applications. Keep in mind that saving at least one or the four allotted strep sprays in case of hail or damaging wind events is a good insurance strategy.

In her most recent report, Kathleen Leahy reminds us of an article from Good Fruit Grower highlighting recent research comparing cutting and sanitization strategies to find the best removal methods for fire blight strikes. It’s definitely worth the read:

Good to Know: Take a bite out of blight - Good Fruit Grower

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

Moving onto the insect pests:

Plum curculio:

Plum curculio activity is beginning to decline and any curculio remaining in trees will usually not move to other locations.

Plum curculio only need to be controlled until 308 DD have accumulated after petal fall. Make sure that the predicted residual coverage (10-14 days) from the last spray will protect fruit until DD accumulation reaches this value.

In Concord the petal fall date we are using is 5/19/23. From that date, we have accumulated 263 degree days base 50F, and are predicted to have accumulated 307 DD by Friday, June 16th. Egg laying typically stops around 308 degree days after petal fall, at which time the need for targeted control generally stops. With this season progressing slowly so far with these cool temperatures, we are gaining degree days slowly. It looks like we will be nearing the end of oviposition by the end of this week, at which point, we will be able to consider PC control for the season done.  

For this week into next, continue to monitor growing degree days from petal fall using the PC model within NEWA to know when we are approaching the end of oviposition and the need for control. Northern orchards are slightly behind in degree day accumulations, so oviposition will be extended into next week. An observation from the field is that in some orchards with very few viable fruits remaining on the trees after the frost, PC seems to be laying high numbers of eggs in those fruits. This is the behavior that we anticipated. It seems targeted perimeter application of insecticides targeting PC adults at this point in the season is still warranted as we think about reducing this population of insects for next season.  

Remember, if you have applied an effective insecticide with residual activity still present on the trees, that application may take you through the end of oviposition depending on the date of application and the material used.

Plum curculio (PC) | New England Tree Fruit Management Guide (netreefruit.org)

 Codling moth:

In Canterbury, we established the biofix date of 5/26/23 to start the codling moth model within NEWA and have reduced the frequency of trap checking for this insect to once a week. Once sustained trap captures have been observed, enter the biofix date for your farm into the NEWA model to track development of the pest. Southern NH established the biofix of codling moth as of 5/22/23. Southern growers without traps on their farms could enter this date to start the degree day clock running for egg hatch by this pest. NEWA data predicts that the required 220 DD was reached on Sunday, June 11th, and in most orchards in NH, codling moth flight is well underway and egg laying is currently happening.  Today we have accumulated 206 DD base 50F from our biofix and predict we will have reached 250 DD by June 16th, these DD calculations mark the prime window of egg hatch, and the most effective time for controlling the emerging larvae with many of the recommended insecticides.

The take home message: Now, or later this week, is the time to be targeting those emerging codling moth larvae.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

codling moth

Figure 2: Codling moth trap captures for Merrimack County

Want to learn more about DD calculations and how they relate to the codling moth control  recommendations?

Full resource available here: doc_72.pdf (cornell.edu) , see below for the shorter version!

Time insecticide applications based on trap data and degree day (DD) models for egg hatch. Spray timing for these pests is directed at newly hatched larvae, since most insecticides are not effective at controlling adults. There is a lag period for egg hatch after the moths fly. The first spray for CM is recommended at first egg hatch, which occurs 220-250 DD (base 50°F) after sustained trap catch. Timing depends on insecticide choice. Calypso, Assail, Delegate, Altacor, Belt, or Voliam Xpress or Voliam Flexi are most effective when applied at 200-250 DD 50°F after biofix. An additional option is to apply a granulosis virus formulation at 200-250 DD 50°F. High moth pressure requires 2-3 sprays for the first generation, but in lower pressure orchards (with counts of less than 5 moths per trap per week), you can control CM with a single spray timed at 350 DD 50°F.

In apples, 1st generation OFM can be controlled with the petal fall spray. In summer, sprays for OFM in apples are applied 3-4 days after peak trap catch, or 7 days after the start of the 2nd flight.

 Oriental Fruit moth:

Be on the lookout, trap captures are increasing in Merrimac county!

Oriental Fruit Moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

oriental fruit moth

Figure 3: OFM trap captures for Merrimack County

San Jose Scale

First generation crawlers are produced beneath female scale covers during this period. If monitoring for crawlers, double-sided sticky tape traps should be placed around tree limbs at this time.

San Jose scale (SJS) | New England Tree Fruit Management Guide (netreefruit.org)

Something a little different, but still very good to know:

Monitoring Spotted Wing Drosophila (SWD) with Traps

*recently updated by Anna Wallingford, Assistant State Specialist, Associate Research Professor and excellent entomologist*

Note:  No SWD caught in UNH traps as of today, 6/14/2023

Spotted wing drosophila (SWD) attacks ripening and ripe raspberries, blackberries, blueberries, grapes, cranberries, late cherries, fall strawberries, plums and peaches, plus fruit of many wild hosts. If you wish to protect your fruit from becoming infested, it is critical to set up traps for the insects, and to monitor those traps weekly when you have ripening crop present. The first flies will probably be trapped between July 2 and 12, and numbers will peak in September or October.

These traps ARE NOT TO CONTROL the flies! Once you detect flies, the crop should be protected with insecticides. Most of the good insecticides should give about seven days of protection, but can be washed off by rain. After you spray, set out fresh traps to determine when crops become at risk again.

 Commercial vs. Home-Made Traps

When SWD first appeared in NH, the commercial traps that existed were not effective in comparison with home-made traps. However, effective commercial traps and baits are now available from both Scentry and Trécé, that are hung in jar traps full of soapy water as drowning solution. More recently, Trécé has marketed their lure with red sticky traps as a “dry trap” alternative to traps with water drowning solutions. All trapping types have their own pros and cons in terms of logistics of use but all are excellent at determining presence or absence of flies in susceptible crops.

In our UNH Cooperative Extension monitoring program, we are now using Trécé traps and lures for SWD. These traps are reusable, and are available from standard suppliers of IPM products (e.g. Great Lakes IPM).

When to set up the traps? Do this as soon as fruit starts to ripen. Fruits that ripen before July 1 are not likely to be at risk. You can stop monitoring when harvest of susceptible crops is over for you.

Where to set the traps? Set the traps IN the crop, in the shade, AMONG THE FOLIAGE near fruit. We recommend checking traps every 5-6 days at first, moving to every 3-5 days in August (hot weather). As the weather cools, you can lengthen the check interval. Keep checking as long as you have ripe fruit to protect.

Which crops need protection? The most susceptible crops seem to be raspberries, blueberries and strawberries that ripen in August-September; thin-skinned, dark-colored grapes; and some peaches and plums (especially white-fleshed peaches). We don’t know how heavily currants and cranberries are attacked.

How many traps do I need?  For most plantings, three well-placed traps should be enough and you should base management actions on an average of the number of flies you trap in each block. If you have different crops, you’ll want traps in each crop, because the pattern of attack varies crop-to-crop. If you have different varieties of the same crop, begin monitoring in the first variety to ripen, and move the traps to others with ripe fruit when harvest wanes on that first variety. If your crop is in several blocks that are managed (e.g. sprayed) separately, you will need traps in each block.

How do I check the traps?  Check traps at least once per week. To check the trap, remove the lid, and pour the liquid bait into a shallow white pan or saucer. In bright light, look for the male flies (they are about 2mm long, with light tan body, red/orange eyes, and have a dot near the tip of each wing) with a 2X magnifying glass. When done counting the male SWD’s, write the number down. If you find male flies, your crop is at risk. If your threshold for risk is a little higher, you can wait until you find an average of 5 male SWD in all three traps. Find this example of a sliding scale of risk for SWD infestation in wild blueberry https://extension.umaine.edu/blueberries/factsheets/insects/210-spotted-wing-drosophila/

Making Your Own Traps

From 2012-2016, we and many colleagues across the Northeast set out hundreds of traps, and learned what combinations worked well enough to make trapping a useful tool. Most of these baits relied on odors from fermentation to attract flies, including apple cider vinegar, wine, grape juice, yeasts, sugars, bread doughs, etc. Many of these bait recipes are messy, smell, and trap many non-target insects that make detection of SWD difficult. Poorly set or designed traps do not work well enough to predict when you need to protect crops. If you prefer to make your own traps rather than purchase traps, the following tips may help.

This trap design works well: We use red plastic 18 oz Solo cups with transparent lids. We placed a black band of electrician’s tape a bit below the rim. We used a heated nail to melt 1/8 inch holes in the cup, to allow the insects to get in, and the odor to escape. We don’t make those holes too large, or wasps will get in. We placed the entrance holes in and around that band, about 30 to 35 holes per trap. We leave one sector of the cup without holes, to make it easy to pour out and examine the liquid bait, without spilling any.

Add just a drop or two of liquid soap to the bait. Non-scented soap is preferable as flowery-scented soaps might decrease bait effectiveness. The soap decreases the surface tension of the bait, making it easier for the small flies to fall in and drown.

When we used the dough baits, the solid yeast/dough bait was placed inside a smaller 4-oz lidded cup within the larger 18-oz trap. We cut a hole (1-inch diameter) in the lid. Over the hole we placed fine insect netting, and fastened it with a hot glue gun. The netting is to allow the yeast odor out, but not let flies in. So the assembled trap is a large red cup. Inside that is 2 oz of liquid bait, and floating upright in the liquid bait is the smaller cup with the netted lid.

When check traps containing attractive baits, make sure to collect the old liquid bait in a waste container, and add fresh bait to the trap. Don’t pour the old bait on the ground in your fruit planting, or it will compete with your traps for the flies’ attention.

Point of interest:

UNH Extension, USDA Natural Resources Conservation Service and the NH Conservation Districts have been partnering on a three-year demonstration project investigating the efficacy, ease of use, cost of installation and potential return on investments associated with installing SWD exclusion netting systems on three farms here in NH. Those partner farms are Bascom Road Blueberry Farm in Newport, Stark Farm in Dunbarton, and Heron Pond Farm in South Hampton. To date, the systems have been highly effective at excluding SWD flies, with zero trap captures reported to date, along with no loss due to infested fruit. To learn more about the types of systems being installed and the potential for new construction versus retrofitting existing bird netting structures, join us at our upcoming twilight meeting on June 20th at Stark Farm. Details are available at the link at the bottom of this page.

SWD netting

Figure 4: SWD netting being installed for the second year in a row at Heron Pond Farm in South Hampton, NH. Photo by Jeremy DeLisle, Field Specialist, Food and Agriculture, UNH Extension

Upcoming meetings:

June 14th, 2023

NH Veg and Berry Growers Association Twilight Meeting: New Farm Technology for Veg and Fruit Producers Field Day

 

June 15th, 2023

Tree Fruit Twilight Meeting at DeMerritt Farm | Extension (unh.edu)

 

June 20th, 2023

Blueberry IPM Twilight Meeting at Stark Farm | Extension (unh.edu)

 

RMA Apple Insurance Listening Session: June 27, 2023 : Goffstown, New Hampshire

10:00 a.m. to 12:00 p.m., Hillsborough County Extension Office (Large Conference Room)

329 Mast Rd., Goffstown, NH 03045

No RSVP Necessary!

Summer 2023 Apple Grower Meetings | RMA (usda.gov)

 

Thanks for sticking around until the end!  See you all next week!

 

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5/3/2024

Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team. 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM Reports” or find them on our webpage at https://extension.unh.edu/resource/fruit-ipm-reports

In terms of growing degree days in Concord, NH we have accumulated 245 GDD in BE base 43F and 89 GDD in BE base 50F. These accumulations put us slightly behind the 15 year average and 30 year normal. From here on we will be using the Bakerville-Emin (BE) formula to calculate GDD as it a more precise measurement. More on degree days can be found at About Degree Days | NEWA (cornell.edu).

You can check out the degree day calculator on the Cornell Climate Smart Farming Page to see accumulations to date, 6-day forecasts, 15 year average and 30 year normal. Be sure to change the location to suit your needs.

Visiting our peach and nectarine variety trial today, we are running about 5 days ahead with most varieties in full bloom.

Apples

Apples in Concord range from tight cluster to pink.

Diseases

Apple Scab - The Ascospore Maturity degree day model in NEWA begins at 50% green tip on McIntosh flower buds. To recalculate ascospore maturity for your orchard, enter your green tip date.

Looking at NEWA, on 5/1 as this is written, we are in the middle of an infection event. Comparing the data logged in NEWA (for Concord) with the revised Mills table here, in some instances in the state we have likely met the conditions for an infection. If you were not covered with a protectant fungicide such as Mancozeb, Captan, or combinations of both, consider an application or a protectant mixed with a single site material with kickback activity. Further discussion on good options and considerations for resistance management with kickback (curative) applications can be found here: Post-infection and Curative Activity for apple scab | Cox Program: Tree and Small Fruit Extension Resource Blog (cornell.edu)

I will add that there has been some well-justified discussion around the predicted/recorded infection events in the NEWA scab model and actual observations cross-referenced against the long-standing research-based revised Mills table. In some instances, the temperatures and leaf wetness hours have hovered right on the border of an infection event, and some grower question, rightfully so, if an infection event actually occurred. Under these conditions, we seem to be splitting hairs. If a grower’s PAD (potential ascospore dose) is very low due to no scab pressure in the orchard last year, this warrants further questioning into the need for application of a fungicide under these marginal conditions. Risk tolerance seems to be the key factor in this situation. Bottom line is that if you weren’t covered with a protectant, there is a possibility of an infection. Most kickback materials have a window of 48 hours on the labels. With warmer temperatures and rain predicted as we look into next week, along with ascospore maturity development, the need for protection will increase.

Organic growers can consider either potassium bicarbonate or sulfur for scab control. Apply these materials based on predicted infection events using a forecasting tool such as the one available through NEWA.

Fireblight

As a reminder, the minimum requirements for blossom infection and the order in which they must occur are:

  1. Flowers must be open with petals intact (flowers in petal fall are resistant)
  2. An accumulation of at least 198-degree hours above 65ºF
  3. A wetting, even as dew or rain
  4. An average daily temperature of 60ºF

Prior to bloom, growers who experienced fireblight issues in 2023 could consider one of the plant defense elicitors available. See link just below for details.

Tight cluster is the start of the recommended timing of application for these materials.

For Apogee and Kudos, these are primarily recommended for high vigor trees. 10 days is needed for the full effect of these materials to kick in, so keep that in mind with timing.

An excellent summary about the options for fireblight and scab management can be found here: 2024 Disease Update: Conditions Favorable for Apple Scab and Fire Blight Infection Week of April 15 (psu.edu)

Insects

The UNH IPM Team maintains fruit pest traps at a number of orchards in NH. Most are in the Merrimack and Belknap County areas. We also communicate regularly with crop consultants and regional Extension specialists for input on key management strategies and timing.

Conditions should still be favorable for oil applications this week, with above-freezing night temperatures predicted through the week. Oil will help with control of mites, psylla, scale insects, and woolly aphids.

Look for rosy aphids on fruit clusters on susceptible varieties (Cortland, IdaRed, Gravenstein...) and wooly apple aphids on pruning cuts and branch crotches.

We continue to capture high numbers of red banded leaf roller moths. These are generally controlled by sprays targeted at plum curculio.

We continue to monitor traps for oriental fruit moth (OFM) and oblique banded leaf roller (OBLR). As of May 1st, we have yet to catch our first moths. Trap capture throughout the season will be reported here weekly or as populations shifts occur. Detailed information on IPM for these insects can be found at: https://netreefruit.org/apples/insects

Weeds

There is still time to apply some preemergent herbicides. A great resource is available here:

Spring Orchard Pre-Emergent Herbicides – CCE Eastern NY Commercial Horticulture Program (cornell.edu)

Peaches

With peaches, nectarines, cherries and plums either in bloom or fast approaching, we are within the first window for brown rot control. FRAC groups 3,7,9,11 or combinations of these are affective for brown rot control. The next window of control will occur approximately three weeks prior to harvest. For a complete overview of best management practices for brown rot, visit https://netreefruit.org/stone-fruit/peaches/diseases/brown-rot

Blueberries

Diseases

Mummyberry

Now is a good time to scout for the fruiting cups of this fungus which are likely producing spores. If mulch was applied in the fall of 2023 or early spring of 2024, that practice will likely help greatly in controlling this disease.

Fungicides – Fungicidal control has proven very successful. Fungicides are used at leaf emergence to prevent primary (leaf shoot) infection, and again during bloom to prevent secondary (flower) infection. Since fungicide labels and recommendations may change, consult annually revised extension publications for specific recommendations.

Weeds

You should have a weed management plan in place for the season at this point. Hopefully your mulching is done. For control options with herbicides in both new and established plantings, visit the New England Small Fruit Management Guide here:

Table 36. Weed Management for Highbush Blueberries | Center for Agriculture, Food, and the Environment (umass.edu)

Insects

Winter Moth (Operophtera brumata): This is an important pest of blueberries and other deciduous plants, especially in Southeastern New England. Moths emerge from the soil in late November and may be active into January. Male moths are light brown to tan in color and attracted to lights at night. Females are gray, almost wingless and cannot fly, and may be found on tree trunks. After mating, females deposit tiny eggs in bark crevices or among lichens which overwinter. Eggs begin hatching in late March or early April after the first warm days of spring, generally around 20 Growing Degree Days (GDD) (base 50˚F) or about 200 GDD (base 40˚F). Egg hatch coincides with bud break of McIntosh apple trees. After hatching, larvae wriggle into swelling buds of blueberries and many deciduous tree, and begin feeding. Caterpillars continue feeding on leaves and flowers until late May when they drop to the ground to pupate. Destruction of flower buds can greatly reduce yield.

Winter moth larvae are pale green caterpillars with white longitudinal stripes running down both sides of the body. They are “loopers” or “inchworms” and have just 2 pairs of prolegs. Mature caterpillars are approximately one inch long.

Management: A dormant oil spray to trunks and branches of bushes may be helpful by killing overwintering eggs before hatching. However, some eggs are under bark flaps and loose lichen and may be protected from oil sprays. Caterpillars may also invade blueberries by blowing into plantings from nearby trees. Bacillus thuringiensis (B.t. kurstaki), manages winter moth caterpillars well once caterpillars are feeding on exposed foliage. B.t. and other insecticides are not effective when caterpillars are feeding inside closed buds. Spinosad is another biorational compound that works well against winter moth caterpillars. Finally, tebufenozide (e.g. Confirm) is an insect growth regulator (IGR) that works well on most lepidopteran caterpillars.

Lastly, we’ve included a few pictures of the development stages of various fruits in the Concord area as of 5/1/24.

Honeycrisp Apple

Honeycrisp apple flower cluster at pink stage. Photo Credit: Jeremy DeLisle

Peaches in bloom

Peaches in full bloom. Photo Credit: Jeremy DeLisle

Cherries at white bud stage

Cherries at white bud stage. Photo Credit: Jeremy DeLisle

Plums in full bloom

Plums in full bloom. Photo Credit: Jeremy DeLisle

Blueberries at tight cluster

Blueberries at tight cluster stage. Photo Credit: Jeremy DeLisle

Red raspberry shoot growth

Red Raspberries with one inch of shoot growth. Photo Credit: Jeremy DeLisle

Parasitized peach scale

Peach scale that appear to have been parasitized (see small holes). Photo Credit: Jeremy DeLisle

Block of peaches

A view over the peach block. Photo Credit: Jeremy DeLisle

Upcoming Events:

May 22 - Tree Fruit Twilight Meeting at Kimball Fruit Farm | Extension (unh.edu)

June 19 - Tree Fruit Twilight Meeting at Sunnycrest Farm | Extension (unh.edu)

August 21 - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

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5/14/2024

FRUIT IPM Report

Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team. 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM Reports” or find them on our webpage at https://extension.unh.edu/resource/fruit-ipm-reports

In terms of growing degree days in Concord, NH we have accumulated 400 DD base 43 (BE) and 158 DD base 50 (BE). These accumulations put us slightly behind the 15-year average and 30-year normal.

Cumulative GDD chart

You can check out the degree day calculator on the Cornell Climate Smart Farming Page to see accumulations to date, 6-day forecasts, 15 year average and 30 year normal. Be sure to change the location to suit your needs.

Apples

Apple flower bud development in Concord ranges from pink on later varieties to full bloom on Macintosh.

Diseases

Apple Scab - The Ascospore Maturity degree day model in NEWA begins at 50% green tip on McIntosh flower buds. To recalculate ascospore maturity for your orchard, enter your green tip date.

Looking at NEWA, on 5/14 as this is written, we are in the middle of an infection event. Most growers were likely covered with protectant fungicides as the forecasted rain events approached. If you were not covered with a protectant fungicide such as Mancozeb, Captan, or combinations of both, consider an application or a protectant mixed with a single site material with kickback activity. Remember that the PHI on Mancozeb is 77 days, so keep that in mind from here on out.

Further discussion on good options and considerations for resistance management with kickback (curative) applications can be found here: Post-infection and Curative Activity for apple scab | Cox Program: Tree and Small Fruit Extension Resource Blog (cornell.edu)

Most kickback materials have a window of 48 hours on the labels. With warmer temperatures and rain predicted as we look into next week, along with ascospore maturity development, the need for protection will increase.

Infection Events Summary Chart

*Infection events summary with predictions May 12th – 19th, Concord, NH

Organic growers can consider either potassium bicarbonate or sulfur for scab control. Apply these materials based on predicted infection events using a forecasting tool such as the one available through NEWA.

By Friday, May 19th, we will be approaching the end of the primary scab infection period, with 97% ascospore maturity predicted at that point in Concord. Growers are advised to keep covered with an effective fungicide for about two weeks beyond 100% spore maturity and scout for scab infections during this time.

Fireblight

An infection period is predicted for today, May 14th through May 18th in many locations across NH.

A general rule of thumb is to use streptomycin to protect open blossoms if EIP values are above 70. For locations from southern NH up to Lebanon, this is predicted to be the case for the next 3-4 days.

As explained by Kari Peter, Penn State Extension Tree Fruit Pathologist, A typical streptomycin application gives you 48 hours of protection.

When applying streptomycin, you are killing the bacteria within the flower in that moment, thereby resetting the clock. It is important to apply treatments before any wetting event to eliminate the potential for bacteria to enter the flower nectaries. Even if it rains within 24 hours, you have achieved your protection with that application. Streptomycin does not need to persist like fungicides do to prevent disease.

As a reminder, the minimum requirements for blossom infection and the order in which they must occur are:

  1. Flowers must be open with petals intact (flowers in petal fall are resistant)
  2. An accumulation of at least 198-degree hours above 65ºF
  3. A wetting, even as dew or rain
  4. An average daily temperature of 60ºF

Prior to bloom, growers who experienced fireblight issues in 2023 could consider one of the plant defense elicitors available. See link just below for details.

Tight cluster is the start of the recommended timing of application for these materials.

For Apogee and Kudos, these are primarily recommended for high vigor trees. 10 days is needed for the full effect of these materials to kick in, so keep that in mind with timing.

An excellent summary about the options for fireblight and scab management can be found here: 2024 Disease Update: Conditions Favorable for Apple Scab and Fire Blight Infection Week of April 15 (psu.edu)

A reminder of the various risk levels and what they mean may be helpful. The chart from NEWA explains:

Chart from NEWA - various risk levels

Insects

The UNH IPM Team maintains fruit pest traps in several orchards in NH. Most are in the Merrimack and Belknap County areas. We also communicate regularly with crop consultants and regional Extension specialists for input on key management strategies and timing.

Weeds

There is still time to apply some preemergent herbicides. A great resource is available here:

Spring Orchard Pre-Emergent Herbicides – CCE Eastern NY Commercial Horticulture Program (cornell.edu)

Thinning Comments from May 8, 2024 (Duane Greene) Massachusetts

Most orchards in Massachusetts are at some stage of bloom-petal fall. During this period, pollination occurs, the pollen germinates and grows down the style to the ovary where they fertilize ovules which then develop into seeds. While this is a very active period in the life of the flower/fruitlet, little increase in (receptacle) size occurs. Consequently, the demand for carbohydrates does not increase rapidly. It is not until the receptacle grows to 5-6 mm in diameter does the demand for carbohydrate increase substantially. Until this happens, we place limited importance on the carbohydrate status in a tree. Next week the Apple Carbohydrate Thinning tool on NEWA will assume a role of dominance in making thinning decisions.

During bloom and petal fall, we normally recommend the use of NAA or Amid-Thin as thinners. Check the Guide for thinner rates that are suggested for use on the cultivars you are thinning. Jon strongly suggests the use of NAA on Honeycrisp, primarily for its flower bud formation promotion capability. Although thinning is promoted more when warm temperatures occur at this time of application and immediately following, I suggest that application of thinners should be applied at least once and often twice during this period. Don’t be intimidated by applying thinners early, even when applications are relatively close to one another. Over-thinning is extremely unlikely at this time. You probably will not see the result of bloom-time application of thinners until fruit diameter increases to about 6 mm.

Many have already made a bloom application. Depending on the weather in the next few days, I would also suggest that you may want to make a petal fall application. When I say petal fall, I mean when most of the petals fall off a flower. If we do not experience warm temperatures during this time period, I would apply a thinner anyway. Do not wait for more favorable weather to come. Even if the bloom and petal fall applications do not thin per se they often precondition young fruit so that that they respond to routine 7-10 mm spray thinner applications that will follow.

Peaches

With peaches, nectarines, cherries, and plums either in bloom, we are within the first window for brown rot control. FRAC groups 3,7,9,11, or combinations of these are effective for brown rot control. The next window of control will occur approximately three weeks prior to harvest. For a complete overview of best management practices for brown rot, visit https://netreefruit.org/stone-fruit/peaches/diseases/brown-rot

Oriental Fruit Month:

Pheromone traps and mating disruption dispensers should be deployed now. The first catch of moths from the overwintering generation is expected to be soon but none have been caught in our traps. OFM flight usually begins when trees are in the pink or bloom stage. No insecticides need to be applied until eggs begin to hatch; since OFM flight usually begins at bloom, it is not possible to apply an initial spray to kill adults.

Oriental fruit moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

Oblique banded Leaf roller and Red Banded Leaf Roller:

No trap captures yet but note that the emergence of overwintering larvae is typically completed by the end of bloom.

Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

Oriental Fruit Month:

Pheromone traps and mating disruption dispensers should be deployed now. The first catch of moths from the overwintering generation occurred last week in Concord. OFM flight usually begins when trees are in the pink or bloom stage. No insecticides need to be applied until eggs begin to hatch; since OFM flight usually begins at bloom, it is not possible to apply an initial spray to kill adults.

Oriental fruit moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

Obliquebanded Leaf Roller

No captures yet but note that the emergence of overwintering larvae is typically completed by the end of bloom.

Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

Blueberries

Diseases

Mummyberry

Fungicides – Fungicidal control has proven very successful. Fungicides are used at leaf emergence to prevent primary (leaf shoot) infection, and again during bloom to prevent secondary (flower) infection. Since fungicide labels and recommendations may change, consult annually revised extension publications for specific recommendations.

When choosing a fungicide, select those which have good efficacy against more than one disease if possible. Remember to rotate FRAC groups frequently to minimize the chance of resistance development.

A list of materials and cultural management strategies for Mummyberry and other fungal pathogens, along with insects, can be found in the New England Small Fruit Management Guide here: Table 35. Highbush Blueberry Pest Management Table | Center for Agriculture, Food, and the Environment (umass.edu)

Weeds

For control options with herbicides in both new and established plantings, visit the New England Small Fruit Management Guide here:

Table 36. Weed Management for Highbush Blueberries | Center for Agriculture, Food, and the Environment (umass.edu)

Insects

Strawberries

Just a quick public service announcement that growers should be scouting for mites. Mathew Bley of UMass Extension has been scouting and reports the following from last week in Massachusetts:

Mites

60 strawberry leaves were randomly surveyed at 5 different farms. Mites were identified using a hand-held lens. Cyclamen mites were found on an average of .01 leaves per farm with an average of 0.4 mite per leaf. Two-spotted spider mites were found on an average of .05 leaves per farm with an average of .8 mites per leaf. No predatory mites were observed.

Economic thresholds for Cyclamen mite = 12 leaves per farm with an average of 1 mite per leaf. 

Economic thresholds for Two-spotted spider mites = 15 leaves per farm with an average of 10 mites per leaf.

There’s an app for that!

Many growers may not yet be familiar with the MyIPM app for mobile devices. I personally find it very helpful when identifying insects and diseases, along with developing management strategies, for tree fruit and small fruit pests.

The app is free, and you just have to go to your favorite app store for Mac or Android, search for MyIPM, and download it. One you have it on your device, you can select the crops you are most interested in and download only the information specific to those crops for east access in the field.

MyIPM app reference

 

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5/28/2024

Fruit IPM Update:

All degree day totals, and model outputs are based on data collected from a NEWA-connected weather station in an orchard in Concord, NH. Be sure to enter your specific biofix dates for your farm for the best results and accuracy.

Today we are at a total of 685 DD BE 43F and 365 DD BE 50F since January 1, 2024.

Plum curculio

Adults are currently active and laying eggs in susceptible fruit.

PC activity is highly dependent upon temperatures, particularly at night when adults are most active. PC usually do not feed or oviposit when nighttime temperatures are below 50°F. If the weather is extremely warm after petal fall, the oviposition cycle may be completed in 2 weeks. In cooler seasons, PC may continue to oviposit for 4-6 weeks.

A petal fall spray should control plum curculio (PC) for about 10-14 days. Incidence of observed PC damage is highly variable among different orchards. PC damage usually occurs primarily along the edges of commercial orchards, and noticeable damage occurs in the same locations in orchards year after year, regardless of treatment levels. Therefore, the potential for damage in any particular orchard can be predicted from past observations. Usually, a post-petal fall spray for control of PC is not necessary in low-pressure orchards in which no damage has been observed in the past.

In high-pressure orchards, additional sprays along the perimeter of the orchards should be applied until the oviposition model predicts that control is no longer necessary, which is when at least 308 DD has accumulated after petal fall.

Codling moth

We are using a biofix date of 5/17 for sustained capture for Concord, NH.

Looking at the NEWA (Network for Environment and Weather Applications) models, we are reminded that eggs usually begin to hatch about 220 DD after the first catch and catches of adults should be increasing in pheromone traps. We saw this to be true for us last week. Hopefully, you have traps up and can set your specific biofix to best time CM development in your orchard.

Further, it is recommended to apply the first spray for control of overwintering CM at 250 DD after first catch. In some seasons, plum curculio will still be active at this time and a broad-spectrum material should be selected to control both of these pests at this time in high-risk PC orchards. If internal worm damage has been observed in past years in an orchard, CM populations may be resistant to organophosphate and synthetic pyrethroid insecticides and other classes of materials may be more effective.

Michigan State has a helpful resource addressing insecticide choices, timing, and efficacy, both on CM along with other pest potentially present at the time of application. View it here: https://www.canr.msu.edu/news/codling-moth-management-options-for-michigan-apples

Oriental Fruit Moth

We are using May 15th for sustained capture in Concord, NH.

Moths are still flying, and it is estimated that about 50-60% of OFM eggs from the first generation have hatched.

Check the time elapsed after petal fall to determine the exact timing of this second spray, assuming a petal fall spray for PC effective against OFM has been applied. This second spray should be applied about 10-14 days after petal fall. This second spray against the first generation of OFM is particularly important in high-pressure orchards (past history of OFM fruit damage or high pheromone traps catches, (>10/ trap/ week) to control the remainder of hatching larvae. If this spray is applied at the normal time of a first cover spray (10-14 days after petal fall) it will also control early hatching CM larvae from the first flight of adults. Also, plum curculio may still be active at this interval after PF in cool, rainy seasons.

Apple scab

In many locations throughout the southern half of NH, primary apple scab season should be over. As we head farther north in the state, we see that there may still be some lingering spores to be released during the next rain event. At this point, essentially all ascospores will be released after a daytime rain of greater than 0.10 inch with temperatures above 50 deg F.

Mature ascospores begin to discharge into the air within 30 minutes of rain. When rainfall begins at night, discharge may be delayed until daybreak. Ascospore discharge usually peaks from pink through bloom, and nearly all ascospores have been discharged within 1 or 2 weeks after petal fall.

Good control of primary infections allows use of fungicides to be reduced or omitted during the summer, once ascospores have been depleted and fruit become less susceptible. Control of primary infections has traditionally begun at or shortly after green tip, when the first ascospores become mature.

After ascospores are depleted, continue to monitor scab infection events, and maintain spray coverage accordingly for at least two more weeks. Scout orchards for primary scab infections after this time.

Fireblight

Many orchards have reached petal fall and are beyond the highest risk periods for infections. This year the infection period during bloom has been relatively condensed, and progression through petal fall quickly helped minimize infection periods during bloom. As some orchards still have lingering bloom, they are advised to keep a close eye on the weather forecast and be prepared to protect open blossoms, including rattail bloom, during high-risk periods until complete petal fall. Growers who are not yet at petal fall might still consider an application or two of Actigard according to label directions for enhanced shoot blight control.

Remember to save one of your strep applications for potential trauma events (hail, damaging winds) if possible.

NEWA now has a feature to help you time shoot blight scouting associated with trauma events, and one to help determine when the infection occurred. Here is the link to the fireblight model: https://newa.cornell.edu/fire-blightOnce on this page, users should choose a station from the lefthand sidebar. This will bring up the shoot blight models for use.

Thinning

Orchards are reporting anywhere from zero to three thinner applications at this point. Many are either in or quickly approaching the ideal thinning window, with relatively cool temperatures predicted for the week. Remember to check out the Apple Carbohydrate Thinning model on NEWA to give you a sense of how well your thinners should work given the weather window near which you are applying. Here is a snapshot showing that, given cool temperatures, thinning rates may need to be increased slightly to obtain good results.

Peach leaf curl

Just a quick note to address the peach leaf curl situation showing itself in many locations of the state. This fungus cannot be controlled at this point in the season. The only thing to consider at this point to help the trees deal with some potential leaf loss as a result of this infection would be to minimize stress (water, insects, etc.) and supply an additional round of nitrogen fertilizer to help them replace lost leaves with new growth as the season picks up steam.

Participants that attended the Kimball Fruit Farm Twilight meeting enjoy a tractor ride through the orchard

Participants that attended the Kimball Fruit Farm Twilight meeting enjoying a tractor ride. Photo Credit: Jeremy Delisle

Lastly, we had a good turnout for our twilight meeting at Kimball Fruit Farm last Wednesday evening. We were saved from the 90F heat by a fantastic breeze. With a great lineup of speakers including Brian Roy of Big Sky Solar, Kathleen Leahey of Polaris Orchard IPM, Bo Lui and Amber Vinchesi-Vahl of UNH Extension, Catherine Coverdale of NRCS/Xerces, and Treavor Hardy of Brookdale Fruit Farm. We even had a surprise sighting of the notorious George Hamilton, emeritus UNH Extension Field Specialist, Hillsborough County. Many thanks to David Wadleigh and his crew, along with Carl Hills, for hosting and presenting to us all. Hope to see many of you at the next twilight meeting scheduled for Wednesday, June 19th at Sunnycrest Farm in Londonderry. Details are available here:

https://extension.unh.edu/event/2024/06/tree-fruit-twilight-meeting-sunnycrest-farm

Trevor Hardy of Brookdale Fruit Farm discusses the benefits of Tempus Ag from Toro

Trevor Hardy of Brookdale Fruit Farm discusses the benefits of Tempus Ag from Toro. Photo Credit: Jeremy DeLisle

Joe Rolfe from Stone Mountain Farm scouts for pear psylla

Joe Rolfe from Stone Mountain Farm scouts for pear psylla. Photo Credit: Jeremy DeLisle

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5/16/2023

Hi all!!  

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is May 16th , 2023.

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

In terms of growing degree days in Concord, NH we have accumulated 439 GDD in BE base 43F and 161 GDD in BE base 50F.

Frost:  Potential for Frost Wednesday night (5/17) across most of the state.  Strawberries and potentially blueberries could be at risk of frost damage.  Frost protection measures should be taken, especially for the early strawberry varieties!

Lets jump right into plant pathogen updates for the apple growers.

Apple scab:

When using NEWA, make sure you are putting in the most accurate green tip date and weather station into the models to get the most accurate predictions for your orchard.  My predictions are based off of the concord weather station, with April 12th as the biofix date.

Keep an eye out for any lesions from past infection events on your leaves.

Ascospores are developing slowly under these cool conditions, with 84% of ascospores mature and awaiting our next rain event. The forecast currently shows potential rain on Friday and Saturday, May 19th and 20th. Thursday, May 18th looks dry with low winds, so consider making a fungicide application then. This is the time to use your more effective systemic materials along with a multisite such as Captan or Mancozeb. FRAC group 7 fungicides are preferred during this time of peak scab activity.

Details on rotational options with other FRAC groups can be found here: https://extension.psu.edu/2023-disease-update-scab-and-fire-blight-infections-forecasted-for-the-weekend

As we progress through the pink and bloom stages across the state, consider some of the single site fungicides with the ability to translocate within leaf tissue for added control and some ability to kill very recent infections. An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

Marssonina (Apple Blotch):

This is a bit of a newcomer in this area but this fungal pathogen is also a concern and can be controlled with many of the same fungicides that control apple scab. The period of main concern is really at the tail end of apple scab season, but be aware and read up here about when and how to best control it.

2023 Disease Update: Disease Conditions Favored for Marssonina Blotch and Apple Scab April 28–May 1 (psu.edu)

Fire blight:

Much of the state is in bloom with apples and pears ranging from late pink to petal fall depending on location and variety. We had infection events on May 11,12 and 13. Many growers elected to make a streptomycin application during that timeframe. Those who have experienced high fire blight pressure in recent years may also have included Apogee/Kudos to slow down shoot development and thicken cell walls to prevent against infection. They may also have applied and/or continue to apply the SARs (systemic acquired resistance) inducers Actigard or Regalia.

More information about the use of PGRs and SARs can be found here: Applying Apogee and Actigard to young apple trees - Apples (msu.edu)

As well as here: Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

The take home message is that blossoms that have opened since your last application need to be covered with your material of choice. Continue to watch the weather forecast and cross-reference NEWA to best time applications.

Using the fire blight model in NEWA begins with selecting the current infection pressure from the drop-down menu in the fire blight model. Choose between the three various scenarios based on your specific conditions.

Note about the NEWA Models for fire blight:

Blossom blight infection risk is tracked by the accumulation of 4-day degree hour totals beginning at bloom. NEWA begins degree hour accumulation on the date of full pink or "first blossom open" for McIntosh apple. It is best if you enter your start date based on blossom dates in your apple or pear orchards and recalculate Cougarblight risk predictions.

Typically, the first few blossoms that open are a few days ahead of true first bloom because they are close to sunny large scaffolds or trunks. Fire blight bacteria are rarely active at the very early bloom time, so getting the "first blossom open" date exact is not critical. Continue monitoring the fire blight risk predictions and watching your orchards for secondary bloom because, although infection of secondary bloom may be less dangerous than that of primary bloom, infection of secondary bloom leads to continued high disease activity and higher risk in subsequent years.

Powdery mildew:

Dry periods during scab season can be a prime time for infection by powdery mildew. Group 3 fungicides used for scab control will also control PM. Consider saving the group 11 fungicides until petal fall for control of summer diseases.

Powdery Mildew | New England Tree Fruit Management Guide (netreefruit.org)

Now moving onto the insect pests:

Just a reminder: With bloom, no insecticide sprays should be going out to protect our native pollinators!

Plum curculio:

Control typically begins at petal fall with a whole block spray, followed by 1 or 2 perimeter row sprays depending on the weather and progression of this insect through its’ life cycle. Egg laying typically stops around 308 degree days after petal fall, at which time the need for targeted control generally stops. With this season progressing slowly so far with these cool temperatures, we are gaining degree days slowly. This means that the egg laying period for PC may be extended unless the temperatures drastically warm up.  Some southern NH orchards already have fruit at a susceptible stage for PC damage, as the insect prefers fruit at the 3-5 mm size for egg laying. Temperatures this week will certainly be warm enough for PC activity, so blocks of trees that are past petal fall should be protected.

Plum curculio (PC) | New England Tree Fruit Management Guide (netreefruit.org)

Tarnished Plant Bug:

Tarnished Plant Bug captures in white sticky traps have remained very low. Numbers have been suppressed due to cold temperatures. We have yet to capture our first TPB in Concord or Lebanon

Tarnished Plant Bug (TPB) | New England Tree Fruit Management Guide (netreefruit.org)

Oriental Fruit Month:

Pheromone traps and mating disruption dispensers should be deployed now. The first catch of moths from the overwintering generation is expected to be soon but none have been caught in our traps. OFM flight usually begins when trees are in the pink or bloom stage. No insecticides need to be applied until eggs begin to hatch; since OFM flight usually begins at bloom, it is not possible to apply an initial spray to kill adults.

Oriental fruit moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

Oblique banded Leaf roller and Red Banded Leaf Roller:

No updates on trap numbers of there, but note that the emergence of overwintering larvae is typically completed by the end of bloom.

Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

Redbanded Leafroller [fact sheet] | Extension (unh.edu)

Codling Moth:

In Concord we have yet to establish the biofix to start the codling moth model within NEWA. The biofix was established on Friday, May 12th in Belchertown, MA. Traps should be up and monitored daily in order to best track the development of this insect. Once sustained trap captures have been observed, enter the biofix date for your farm into the NEWA model to track development of the pest as egg laying approaches.

Altacor, Exirel, Verdepryn are worth considering as control options at first hatch for codling moth. These group 28 insecticides have efficacy against many lepidopteran species as well as plum curculio. CM becomes driver for insect sprays after petal fall along with plum curculio.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Rosey Apple Aphid:

Control can start at pink. Petal fall may be best timing.  Be scouting now to be aware of possible aphid hot spots.

Aphid: Rosy Apple Aphid | New England Tree Fruit Management Guide (netreefruit.org)

European Red Mite:

Look for overwintering eggs now. Treatment windows range from green tip to pink, and then resume after petal fall. Generally, some control before pink combined with concentrated control around petal fall will provide best season-long control.

Mites (European Red Mite [ERM] and Two-spotted Spider Mite [TSSM]) | New England Tree Fruit Management Guide (netreefruit.org)


Additional Notes:

Thinning

The opportunity to thin potential fruit load begins at bloom and lasts until 3-4 weeks post petal fall. Consider using the Carbohydrate Thinning Model in NEWA to help make the best thinning management decisions based on factors such as localized weather patterns and other site-specific factors. This UMass resource outlines the best options and key considerations for chemical thinning: Fruit: HRT-Thinning Apples Chemically | Center for Agriculture, Food, and the Environment at UMass Amherst

We received a question recently about boron applications for apples. This is an important nutrient for apples for pollen tube development, feeder root growth and translocation of calcium, among other functions. Details about the roles of various macro and micronutrients in apples can be found here: http://fruitadvisor.info/tfruit/clements/articles/nutrientrecs.pdf

Upcoming meetings:

Carbon Capture for Agricultural Producers (Online): Thursday May 18th, 5:30-7:30 p.m.

Details here: Carbon Capture Seminar for Agricultural Producers | Extension (unh.edu)

RMA Apple Insurance Listening Session:

June 27, 2023 : Goffstown, New Hampshire

10:00 a.m. to 12:00 p.m., Hillsborough County Extension Office (Large Conference Room)

329 Mast Rd., Goffstown, NH 03045

No RSVP required.

Details here: Summer 2023 Apple Grower Meetings | RMA (usda.gov)

Twilight Meetings:

The schedule is out for all of extension’s summer twilight meetings, and I wanted to highlight a few that may be of interest to the folks that tune into this call – the full list of Extensions event offerings this summer can be found on our website!

Tree Fruit meeting at Demeritt Hill Farm, July 15th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at DeMerritt Farm | Extension (unh.edu)

Tree Fruit meeting at Apple Hill Farm, August 17th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

All of the Production agriculture Twilight meetings:

2023 Production Agriculture Summer Twighlight Meeting | Extension (unh.edu)

Thank you for sticking around until the very end!  See you next week!

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7/25/2023

Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is July 25th , 2023.

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

In terms of growing degree days in Concord, NH we have accumulated 1991 GDD in BE base 43F and 1231 GDD in BE base 50F.

Weekly pest and disease update:

Diseases:

Mummy berry on blueberry:

Is being reported from some blueberry plantings. Details about this disease and management strategies can be found here.

This infects new shoots in the very early spring beginning around budbreak. Those infected shoots can then in turn release spores that infect open flowers, eventually resulting in the symptoms you are seeing in your berries. The fruit you see there will eventually shrivel and look like a little grey or black pumpkin. This lies in waiting until next spring for conditions to be just right and releases new spores to continue the cycle. You can read more about the disease here: Microsoft Word - Blueberry IPM - Mummy Berry Final.docx (umass.edu)

This year was certainly a good weather year for this fungus. We had temperatures conducive for extended persistence of apothecia. As noted in the fact sheet below, as apothecia expand, the number of ascospores released increases. Ascospore discharge depends on temperature, relative humidity, and wind speed. Apothecia can persist for about 3 to 4 weeks under cool conditions — 50° to 59°F  — but are shorter lived as temperatures rise. At 68° to 77ºF (20° to 25°C), they may persist for only 1 to 2 weeks.  We had damage from the freeze, which likely damaged plant tissues and made them more susceptible to infection. Did you see many shoot strikes? These would've been visible around the time that flowers were present. The fact sheet below gives detailed information about the disease cycle and includes photos of berries as the life cycle progresses. I know many of you are familiar with this, but there is good information in there and helpful pictures.

https://www.canr.msu.edu/blueberries/uploads/files/E2846%20Mummy%20Berry%20Facts.pdf

A list of fungicides and their efficacy is also included in the fact sheet above.

Mulching with at least 2” of fresh mulch in the fall can also greatly help reduce the number of spores that are able to reach susceptible tissue. This strategy can’t be used year after year due to too much mulch buildup, but if you need to mulch, this fall would be a great time for this reason. Also, picking off as many of those suspicious fruits as possible will only help to reduce potential inoculum for next season.

One last tip…You could collect 10-20 of the mummies and create a “mummy garden”. I know, it sounds funny, but you could place them outside the planting, possibly just nestled in some wood mulch (not fully buried) and use that to track the development of the disease development next year. Once you see the little mushroom cups coming up, it will clue you in as to when you need to treat. Research shows that the fruiting bodies of the fungus (apothecia) need to be at least 1/12” in diameter to produce spores for infection.

Moving onto the apples:

Bitter Rot:

Conditions have been good for this disease with lots of rain, and quite a bit of fruit showing some sort of injury (notably, cracking) that might allow entry to the pathogen. Captan does a pretty good job, especially at slightly elevated rates. PennState cites Merivon/Pristine, Flint/Luna Sensation, Aprovia, and Omega, mixed with Captan as being effective.

For more info: Apple and Pear Disease - Bitter Rot (psu.edu) and Bitter Rot | New England Tree Fruit Management Guide (netreefruit.org)

Apple scab:

 Hopefully your orchard is clean of scab for the growing season. While visiting orchards, Extension staff have seen some scab infections present on leaves. In those orchards, growers will need to remain diligent and maintain fungicide coverage to minimize new infections.

Here is an article addressing control and resistance management strategies for scab:

https://www.canr.msu.edu/news/management_of_apple_scab_in_orchards_with_existing_scab_lesions

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

Our new Plant Diagnostic Lab Director, Dr. Bo Liu, has been busy along with other lab staff members diagnosing all sorts of plant diseases this summer. Below I have included his report along with microscope images provided by his lab of two fungal pathogens, apple scab and Alternaria leaf blotch.

Figure 1: Apple Scab:  Leaf spots with dark brown to black lesions were on apple leaves.

Figure 1: Apple Scab:  Leaf spots with dark brown to black lesions were on apple leaves. Several leaves collected and samples were checked under microscope, observing the microbial structure, and isolations were performed on Potato Dextrose Agar (PDA) for 10 days. A total of 5 lesions were recorded along with the fungal isolates recovered. An overall assessment was made based on the evaluations including signs and symptoms observed on leaf surfaces (Fig. 1), recovery of the organisms involved (Fig. 2)

Figure 2; recovery of organisims involved

Figure 2

Alternaria leaf blotch: Lesions on leaves (figure 3) are circular, necrotic lesions with a light brown interior, and some were surrounded by a darker purple ring. Several leaves collected and samples were checked under microscope (figure 4) for observing the microbial structure, and isolations were performed on Potato Dextrose Agar (PDA) for 10 days.

Figure 3: Symptoms of Alternaria Leaf blotch on apple leaves with circular and necrotic lesions.

Figure 3: Symptoms of Alternaria Leaf blotch on apple leaves with circular and necrotic lesions.

Figure 4: Conidia morphology (Alternaria mali) on the lesions of apple leaves.

Figure 4: Conidia morphology (Alternaria mali) on the lesions of apple leaves.

A small amount of information regarding management of Alternaria can be found here.

Fire blight:

There has been plenty of fireblight popping up on apple orchards around the state from southern New Hampshire all the way up into Carroll County.

Continue to scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots at least 12-18 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial. With a cool and fairly dry bloom period, some growers made in through the prime infection period with just a couple of streptomycin applications. Keep in mind that saving at least one or the four allotted strep sprays in case of hail or damaging wind events is a good insurance strategy.

In a recent report, Kathleen Leahy reminds us of an article from Good Fruit Grower highlighting recent research comparing cutting and sanitization strategies to find the best removal methods for fire blight strikes. It’s definitely worth the read:

Good to Know: Take a bite out of blight - Good Fruit Grower

Another great resource on fireblight management options come from Dr. Kari Peter, Tree Fruit Pathologist at Penn State University. Her presentation from our UNH Fireblight Webinar can be accessed here.

Sooty Blotch and Flyspeck:

Now is the time to think about how you will manage Sooty Blotch and Flyspeck in your orchard. 
Check out the New England Tree fruit management guide for more info (
Sooty Blotch and Flyspeck | New England Tree Fruit Management Guide (netreefruit.org)), and remember that NEWA also provides forecasting and management recommendations for this disease complex:

From NEWA: Sooty Blotch and Flyspeck | NEWA (cornell.edu)

To effectively limit fruit finish blemishes from Sooty Blotch and Flyspeck infection consider making a cover application of one of the following fungicides/tank mixes:

  • 4 oz/100 gal Topsin +1 lb/100 gal. Captan 50W (or Captan-80 10 oz/100 gal); or
  • 0.67 oz/100 gal Flint 50WG; or
  • 1.6 oz/100 gal Sovran WDG; or
  • 6.1 oz/100 gal Pristine WG; or
  • 1 lb/100 gal Captan 50W (or Captan-80 10 oz/100 gal) + 21 fl. oz./100 gal ProPhyt

Figure 1:  Recommendations from NEWA for Sooty Blotch and Flyspeck.

Insects:

Blueberry Maggot Fly

The blueberry maggot degree day model predicts when to set baited traps to monitor for adult flies. This insect has patchy distribution and monitoring will determine if and when it occurs on your farm. Flies typically emerge around 913 degree days base 50˚ F from January 1.

Blueberry maggot flight places the crop at risk from egg-laying females.

Continue to check blueberry traps once or twice per week, as required, and replace traps and baits every third week. If caught, begin insecticide treatment. Maintain an IPM and insecticide program to protect the crop, according to your market requirements. After harvest, remove and discard used traps and bait.

Blueberry Fruit Fly [fact sheet] | Extension (unh.edu)

Apple Maggot Fly

Predicted first emergence of AM occurs after approximately 796 to 1072 degree days have accumulated. Today we have accumulated 1231 DD base 50F from January 1. Set sticky traps along vulnerable field edges. Check at least weekly and not the first date of captures. Enter this into the Apple Maggot tool on NEWA.

The action threshold is an average of 1-2 AMF on the yellow cards or in unbaited sticky spheres, or a cumulative average of 5 AMF per trap on baited spheres. Trap captures for a week following insecticide treatment are ignored. Subsequent sprays can be applied once the threshold is reached again.

Figure 5: Unbaited red sticky sphere for monitoring apple maggot fly in orchards. Photo: Jeremy DeLisle

Figure 5: Unbaited red sticky sphere for monitoring apple maggot fly in orchards. Photo: Jeremy DeLisle

Japanese Beetles:

Adult beetles can be found feeding on foliage and fruit currently throughout most of NH. Many of us are interested in opportunities for mass trapping this pest. Blueberries and raspberries are especially attractive to this insect. There may be hope yet for Japanese beetle traps that can actually help control populations and limit damage to fruiting crops. Visit the link here for more information.

SWD:

Traps should be up now. Trap captures last week were relatively low in the southern half of NH. This does not mean that the threat from this pest is over. More likely, the actions that growers took to control this pest in response to high number the previous week have knocked the population of adults back temporarily.

This morning Extension staff made a site visit to an unsprayed red raspberry planting in the Loudon area. After explaining the importance of frequent picking and cold storage (refrigeration or freezing) as part of the SWD tolerance strategy, I picked the first two ripe berries I saw and was easily able to locate SWD larvae in those ripe berries.

Note: Raspberries and blueberries can tolerate cold storage temperatures close to 32° F, so don't be afraid to put your fruit in a cold storage to keep it crisp and fresh and kill or slow down SWD egg and larval development (NYS IPM).

SWD is primarily a pest of small fruits, but also impacts stone fruits. Considering the fact that most stone fruits were lost due to severe cold this winter, controlling this pest will be generally limited to blueberries, brambles and grapes at this point in the season.

You can find more info about SWD and SWD trap selection in past pest reports, refer to the ones from this past June!

Notes of Interest:

UNH Extension is trialing red sticky traps paired with the Trece Pherocon Peel-Pak lures in 2023. We also work with many growers who use the drowning traps paired with these same lures. In the photo below, the smaller red square is the lure, while the red rectangle is the sticky trap, which gets checked weekly.

Figure 5: Unbaited red sticky sphere for monitoring apple maggot fly in orchards. Photo: Jeremy DeLisle

Figure 6: : New red sticky traps to capture SWD. Photo: Jeremy DeLisle

SWD Netting Project

UNH Extension, USDA Natural Resources Conservation Service and the NH Conservation Districts have been partnering on a three-year demonstration project investigating the efficacy, ease of use, cost of installation and potential return on investments associated with installing SWD exclusion netting systems on three farms here in NH. Those partner farms are Bascom Road Blueberry Farm in Newport, Stark Farm in Dunbarton, and Heron Pond Farm in South Hampton. To date, the systems have been highly effective at excluding SWD flies. To learn more about the types of systems being installed and the potential for new construction versus retrofitting existing bird netting structures, join us at our upcoming twilight meeting on August 3rd at Heron Pond Farm in South Hampton, NH. Details are available at the link at the bottom of this page.

Apple Pests:

Codling moth:

Trap captures finally decreased significantly towards the end of last week. We are currently at 1052 DD past our biofix, indicating that first egg hatch of the second generation should begin soon.  Below is a resource shared by Dr. Jaime Pinero at UMass outlining a control approach based on trap captures and degree day accumulations targeting larvae at egg hatch.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Table of Key events in CM life cycle estimated by use of Biofix1 and subsequently degree days.

Figure 7: Codling moth trap captures for Merrimack County

Figure 7: Codling moth trap captures for Merrimack County

Oriental Fruit Moth:

Oriental Fruit Moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

  Figure 8: Oriental Fruit Moth (OFM) trap captures for Merrimack County

                Figure 8: Oriental Fruit Moth (OFM) trap captures for Merrimack County

Figure 9: UNH Extension Field Technician, Justin Hogg, sets up delta traps to monitor for codling moth in apple orchards. Photo: Jeremy DeLisle

Figure 9: UNH Extension Field Technician, Justin Hogg, sets up delta traps to monitor for codling moth in apple orchards. Photo: Jeremy DeLisle

San Jose Scale:

Pheromone traps should be in place to record the second adult male flight. Note date of first capture of second generation for biofix in NEWA for predicting second generation crawler emergence.

San Jose scale (SJS) | New England Tree Fruit Management Guide (netreefruit.org)

Tissue testing time is here for some crops and coming right up for others.

Directions for taking a plant tissue sample leaf sample in your orchard/garden:

Tips - In general, it is usually best to sample many plants (with only a few leaves from each plant) rather than sample many leaves from only a few plants.

Select the youngest, fully developed (mature) leaves for analysis. Do not select leaves from plants which are mechanically damaged, insect damaged, diseased or dead. Avoid leaves from border plants or leaves which are fully shaded by other foliage. Do not send sample plants that have been under prolonged stress.

Avoid leaves which are contaminated with soil or dust or which have been recently sprayed. In general, plant leaves which have been exposed to normal rainfall are sufficiently clean for analysis. Samples can be washed briefly in a 2% non-phosphorus detergent solution and then rinsed carefully with clear water. However, in many situations the cleaning may do more harm than good.

If you are trying to diagnosis a problem and are sampling plants that are showing an abnormal symptom, follow the above directions, but sample only from plants showing the problem.

Crop Information

Blueberries: sample at least 40 leaves from 10 to 20 plants during the first week of harvest.

Strawberries: sample at least 40 first fully expanded leaves from 10 to 20 plants, after renovation

Brambles: sample at least 60 leaves from 10 to 20 non-fruiting canes during early-mid August.

Grapes: sample 50 to 75 of the youngest full-expanded leaves from 10 to 20 vines at veraison (70 days after bloom, as the first fruit ripens). Separate petioles (leaf stems) from leaves, and send only the petioles for analysis.

Tree fruits: sample 5 leaves from each of 10 trees from late July through early August. Select shoots at eye-level from around the outside of the trees that make a vertical angle of 45-60 degrees to the ground (avoid water shoots or suckers). Collect leaves from the mid-portion of the new shoot growth.

For other crops: Contact your local field specialist or county office to determine the correct sampling procedures. After Collection Samples should be placed in paper bags and air dried (turn the bag frequently) or dried at 200 degrees Fahrenheit.

If you wish to submit sample to UNH for tissue sampling, more information and forms can be found here:

Form: UNH Cooperative Extension - Commercial Plant Tissue Form.pdf - All Documents (sharepoint.com)

Main soil/tissue testing site: Soil Testing Services | Extension (unh.edu)

Upcoming Events

August 3 - Blueberry IPM Twilight Meeting at Heron Pond Farm | Extension (unh.edu)

August 17th - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

See the full list of twilight meetings here:

2023 Production Agriculture Summer Twilight Meeting | Extension (unh.edu)

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6/06/2023

Fruit Pest Hotline IPM Report 6/6/23

Hi all!!  

 

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is June 6th , 2023.

 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

 

In terms of growing degree days in Concord, NH we have accumulated 758 GDD in BE base 43F and 334 GDD in BE base 50F.

Recommendations for frost-damaged orchards and small fruit crops will be gone over at the end of this call.  Similar information can be found in last week’s report!

Jumping into the plant pathogen updates:

Apple scab:

The rains this week should certainly promote the last of the unreleased ascospores to be released.  Maintain protection and continue to scout over the next couple of weeks. Hopefully your orchard is clean of scab and this will mean the end of required control measures for the growing season. While visiting orchards over the past week, I have seen some primary scab infections present on leaves. Now is the time to remain diligent and maintain fungicide coverage over the next two weeks with the goal of wiping out these initial infections and putting an end to the need for control through the remainder of the season due to secondary infections.

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

 

apple scab

Figure 1: Apple scab infection on upper (left photo) and lower (right photo) leaf surface. Credit: Jeremy DeLisle, UNH Extension

Marssonina (Apple Blotch):

While we are currently in the tail end of primary apple scab season, you should remember that this fungus is also a concern and can be controlled with many of the same fungicides that control apple scab. The period of main concern is really at the tail end of apple scab season, but be aware and read up here about when and how to best control it. Keep an eye on any brown lesions beginning to form on your leaves – could be apple scab, could be marssonina!  Apple scab resistant  varieties tend to be the most susceptible to marssonina.

Fire Blight:

Important: Any open blossoms still on trees should be considered vulnerable to infection from fire blight.  At this point we are mainly just seeing open blossoms on newly planted trees from the nursery. These blossoms should have been removed prior to opening to prevent the risk of infection, especially since we don’t want the trees putting energy towards fruit production as this early age. Rather, we want them focused on vegetative growth to fill their allotted space in the orchard. Choose a cool dry day to remove blossoms when risk of infection is lowest.

Consult the NEWA fireblight model to assess risk levels. Consider an application of copper to reduce bacteria in the surface of the tree prior to blossom removal. Clean pruning shears between trees to minimize risk of spreading bacteria from one tree to the next. 

Continue to scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots 12 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial. With a cool and fairly dry bloom period, some growers made in through the prime infection period with just a couple of streptomycin applications. Keep in mind that saving at least one or the four allotted strep sprays in case of hail or damaging wind events is a good insurance strategy.

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

Powdery mildew:

Keep an eye out for any infections in the next few weeks.

Powdery Mildew | New England Tree Fruit Management Guide (netreefruit.org)

 

Insects:

Plum curculio:          

In Concord the petal fall date we are using is 5/19/23. From that date, we have accumulated 195 degree days base 50F, and are predicted to have accumulated 238 DD by Sunday, June 11th. This cool weather this week has us accumulating degree days very slowly. Hearing reports from New York and Pennsylvania, I suppose we should be thankful we are not dealing with the heat they currently are.  Egg laying typically stops around 308 degree days after petal fall, at which time the need for targeted control generally stops. With this season progressing slowly so far with these cool temperatures, we are gaining degree days slowly. It looks like we will be nearing the end of oviposition by the end of next week, at which point, we will be able to consider PC control for the season done.  For this week into next, continue to monitor growing degree days from petal fall using the PC model within NEWA to know when we are approaching the end of oviposition and the need for control.

An observation from the field is that in some orchards with very few viable fruits remaining on the trees after the frost, PC seems to be laying high numbers of eggs in those fruits. This is the behavior that we anticipated. It seems targeted perimeter application of insecticides targeting PC adults at this point in the season is still warranted as we think about reducing this population of insects for next season. 

Plum curculio (PC) | New England Tree Fruit Management Guide (netreefruit.org)

plum cucurlio

Figure 2: Plum Cucurlio damage to Honeycrisp fruitlet, 6/2/23, Photo credit: Jeremy DeLisle, UNH Extension

 

Codling moth:

Codling moth –In Canterbury, we established the biofix date of 5/26/23 to start the codling moth model within NEWA and have reduced the frequency of trap checking for this insect to once a week. Southern NH established the biofix of codling moth as of 5/22/23. Southern growers without traps on their farms could enter this date to start the degree day clock running for egg hatch by this pest.  If you do you’re your own traps, once sustained trap captures have been observed, enter the biofix date for your farm into the NEWA model to track development of the pest. For most orchards in NH, codling moth flight is well underway and egg laying is currently happening. 

Today we have accumulated 138 DD base 50F from our biofix and predict we will have reached 181 DD by June 11th.

We will likely have reached the beginning of egg hatch by late next week, at which time the emerging larvae are most susceptible to control using many of the recommended insecticides. NEWA data predicts that the required 220 DD will be reached by Sunday, June 11th, beginning the period of egg hatch for the first generation of codling moth.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Interested in more details on how degree days are used to inform codling moth management practices?

Cornell has a wonderful fact sheet that talks about this, check out the entire resource at this link: doc_72.pdf (cornell.edu)

 

codling moth

Figure 3: Codling moth trap captures showing sticky trap bottom insert along with pheromone lure, Photo credit: Jeremy DeLisle, UNH Extension

codling moth

Figure 4: Close up of a codling moth from the sticky trap, Photo credit: Jeremy DeLisle

codling moth

Figure 5: Codling moth trap captures for Merrimack County (Credit to Jeremy DeLisle)

Oriental Fruit Moth:

Keep an eye out for them, we are seeing more of them in traps captured in Merrimack County.

 

oriental fruit moth

Figure 6: Oriental Fruit Moth (OFM) trap captures for Merrimack County

A few updates about upcoming events:

RMA Apple Insurance Listening Session:

June 27, 2023 : Goffstown, New Hampshire

10:00 a.m. to 12:00 p.m., Hillsborough County Extension Office (Large Conference Room)

329 Mast Rd., Goffstown, NH 03045

No RSVP required.

 

Details here: Summer 2023 Apple Grower Meetings | RMA (usda.gov)

Twilight Meetings:

The schedule is out for all of extension’s summer twilight meetings, and I wanted to highlight a few that may be of interest to the folks that tune into this call – the full list of Extensions event offerings this summer can be found on our website!

Tree Fruit meeting at Demeritt Hill Farm, July 15th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at DeMerritt Farm | Extension (unh.edu)

Tree Fruit meeting at Apple Hill Farm, August 17th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

Blueberry IPM Twilight Meeting at Stark Farm, June 20th, 2023

Blueberry IPM Twilight Meeting at Stark Farm | Extension (unh.edu)

 

All of the Production Agriculture Twilight meetings:

2023 Production Agriculture Summer Twighlight Meeting | Extension (unh.edu)

 

Lets dive into the frost event everyone has been talking about:

While you all have probably done this already, producers should document damage, contact their insurance providers, and connect with their Extension specialists to evaluate and document damage, and develop appropriate IPM plans for the season based on the situation at their specific locations.

Many questions are arising as to management decisions for the season ahead considering the damage to fruiting crops throughout New Hampshire. Included below are a few suggestions as a start that may be helpful for some crops:

 

I’ll jump into frost damage control/considerations first: *This is a repeat from the last report, but still valuable!

Managing berry planting after frost: (*Northeast Berry Call Recommendations – thanks to all the folks offering advice to the region!)

Pest control:

Plantings with total fruit loss still need to be actively managed for pests and weeds. Potential for botrytis is greater in all affected berries with dead tissue on the plant (black strawberry blossoms, blighted tips of blueberry canes, black bramble flowers). It would be a good idea to spray now for botrytis, especially in strawberries. Other fungal pathogens don’t live in dead tissue as botrytis does, so we only worry about botrytis.

Diseases | Center for Agriculture, Food, and the Environment (umass.edu)

Diseases | Center for Agriculture, Food, and the Environment (umass.edu)

Diseases | Center for Agriculture, Food, and the Environment (umass.edu)

Pruning:

In bush and cane-berries that have a big percentage of crop lost, anticipate summer thinning because extra energy will be allocated to vegetative growth. Perhaps due to the lost crop this year, next year’s crop will be larger.

June-bearing strawberry plantings should not be renovated now if they had total crop loss. They should be renovated in July or August as usual. Additional Nitrogen applications may be helpful in the case of total crop loss by helping the plants put on biomass. Crowns should be cut in half and checked for damage from frost. Depending on the degree of damage there, may have diminishing returns on inputs.

Watering:

Plantings should be watered to minimize drought stress. This might help remaining fruit recover instead of senescing.

Fertility:

 At this point in the season most blueberries have had 1 round of fertilizer applied already. A second round of fertilizer at this point in the season is important because it helps set the fruiting buds. Foliar nutrient sprays are popular amongst growers. Some have seen good results from Megafol (3-0-8). Some growers do 2 applications at a pint/acre each (mid-April and post-bloom), while others do 1 big application at 1 quart/acre each. Some growers also spray potassium on blossoms and developing fruit for winter protection. This is especially done in apples, sometimes on raspberries too. The K+ (potassium) ions prevent the growth of ice-nucleating bacteria; copper sprays work too.

 

Managing tree fruit after frost (Advice from Terence Bradshaw, UVM Extension)

This is just a quick recap, please check out his full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

Thinning:

·      For orchards that have no fruit or heavily damaged fruits (+ 75% ) do not consider thinning this year.

·      For orchards with less than 20%, consider thinning as normal this year.

·      For orchards that have moderate damage between 25 and 75%, the answer is a bit more site-specific. Not thinning those orchards may result in heavy set of small fruit that could promote biennialism, but trees are likely to respond well to thinners applied in the next week, given both the cold damage and the warm sunny, weather that we are expecting coming up.

·      At the UVM Orchard, which experienced moderate fruit damage between 20 and 70%, depending upon cultivar, they decided to apply a low rate of NAA thinner with a low rate of carbaryl insecticide. They have 70 varieties across the whole orchard, and it is difficult to thin based upon variety even in a ‘normal’ year, which is not too different from what many other retail orchards might be dealing with.  It is difficult to provide blanket recommendations to growers given the state of the crop this year.

·      In the end, Dr. Bradshaw recommends trusting your gut – if you have a good crop thin it, if you have a moderate crop consider thinning it lightly as you could always come back in later next week and be better able to visualize the effects of both the frost and any thinner applications you may have applied.

 

Full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

 

More on thinning:

The opportunity to thin potential fruit load begins at bloom and lasts until 3-4 weeks post petal fall. Consider using the Carbohydrate Thinning Model in NEWA to help make the best thinning management decisions based on factors such as localized weather patterns and other site-specific factors. This UMass resource outlines the best options and key considerations for chemical thinning: Fruit: HRT-Thinning Apples Chemically | Center for Agriculture, Food, and the Environment at UMass Amherst

 

Insect management:  (Advice from Terence Bradshaw, UVM Extension)

This is just a quick recap, please check out his full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

·      This will differ depending upon the state of the crop in your orchard.

·      For orchards with a full or even a moderate crop, plan to manage your insect pests as normal this year. Petal fall insecticide sprays should have already gone on in most orchards.

·      Normally petal fall sprays are targeted at European apple sawfly, early emerging codling moth, and plum curculio. All of those pests are fruit feeders so orchards that have no fruit or are assumed to have very little fruit may consider omitting all insecticide applications targeted toward protecting fruit.

·      The difficult situation comes where orchards have a low set of fruit where the expense of the application on a per bushel basis could be quite high but the value of the few apples you have is also high. If there's any question about whether or not you have sufficient crop set in your orchard, it is recommended to go ahead and treat as usual. If you have no crop or nearly no crop, then you may consider omitting those insecticides.

·      However, it is worth it to consider maintaining some coverage primarily for shoot and leaf feeding, lepidopterous caterpillar larvae. That may mean including BT sprays in petal fall, scab, thinning, or other sprays in order to keep down leps like the obliquebanded leaf roller and tent caterpillar.

·      In orchards with little to no crop, the great reduction insecticides used this year may allow beneficial populations to increase substantially, setting you up for a better IPM program next year.

·      It is not recommended to ignore trunk applications of Assail or another appropriate insecticide in young plantings to avoid issues with dogwood and other borers.

 

Full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

Nutrients:  :  (Advice from Terence Bradshaw, UVM Extension)

This is just a quick recap, please check out his full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

·      For trees with normal or moderate crop load, fertilize as you normally would.

·      For trees with little to no crop nitrogen applications should not go on this year unless trees are under-vigorous.

·      For trees with little to no crop this year potassium is not likely to be removed in any significant amount because that is usually removed in harvested fruit. However, it is important to maintain or improve the potassium status in your orchards to ensure that you have an appropriate amount of that nutrient going into next year when it is likely that orchards will have a heavy crop load.

·      He does recommend thinking about applying magnesium potassium fertilizers in the next month or so regardless of crop status.

Thank you for sticking around until the very end!  See you next week!

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7/18/2023

Fruit IPM Report 7/18/23

Hi all!!  

 

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is July 18th , 2023.

 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

 

In terms of growing degree days in Concord, NH we have accumulated 1823 GDD in BE base 43F and 1105 GDD in BE base 50F.

Weekly pest and disease update:

Diseases:

Mummy berry on Blueberry:

 Is being reported from some blueberry plantings. Details about this disease and management strategies can be found here.

This infects new shoots in the very early spring beginning around budbreak. Those infected shoots can then in turn release spores that infect open flowers, eventually resulting in the symptoms you are seeing in your berries. The fruit you see there will eventually shrivel and look like a little grey or black pumpkin. This lies in wait until next spring for conditions to be just right and releases new spores to continue the cycle. You can read more about the disease here: Microsoft Word - Blueberry IPM - Mummy Berry Final.docx (umass.edu)

 

This year was certainly a good weather year for this fungus. We had temperatures conducive for extended persistence of apothecia (spore producing structures). As noted in the fact sheet below, as apothecia expand, the number of ascospores released increases. Ascospore discharge depends on temperature, relative humidity, and wind speed. Apothecia can persist for about 3 to 4 weeks under cool conditions — 50° to 59°F  — but are shorter lived as temperatures rise. At 68° to 77ºF (20° to 25°C), they may persist for only 1 to 2 weeks.  We had damage from the freeze, which likely damaged tissues. Did you see many shoot strikes? These would've been visible around the time that flowers were present. The fact sheet below gives detailed information about the disease cycle and includes photos of berries as the life cycle progresses. I know many of you are familiar with this, but there is good information in there and helpful pictures.

 

https://www.canr.msu.edu/blueberries/uploads/files/E2846%20Mummy%20Berry%20Facts.pdf

A list of fungicides and their efficacy is also included in the fact sheet above.

Mulching with at least 2” of fresh mulch in the fall can also greatly help reduce the number of spores that are able to reach susceptible tissue. This strategy can’t be used year after year due to too much mulch buildup, but if you need to mulch, this fall would be a great time for this reason. Also, picking off as many of those suspicious fruits as possible will only help to reduce potential inoculum for next season.

One last tip…You could collect 10-20 of the mummies and create a “mummy garden”. I know, it sounds funny, but you could place them outside the planting, possibly just nestled in some wood mulch (not fully buried) and use that to track the development of the disease development next year. Once you see the little mushroom cups coming up, it will clue you in as to when you need to treat. Research shows that the fruiting bodies of the fungus (apothecia) need to be at least 1/12” in diameter to produce spores for infection.

Moving onto the apples:

Bitter rot:

Conditions have been good for this disease with lots of rain, and quite a bit of fruit showing some sort of injury (notably, cracking) that might allow entry to the pathogen. Captan does a pretty good job, especially at slightly elevated rates. PennState cites Merivon/Pristine, Flint/Luna Sensation, Aprovia, and Omega, mixed with Captan as being effective.

For more info: Apple and Pear Disease - Bitter Rot (psu.edu) and Bitter Rot | New England Tree Fruit Management Guide (netreefruit.org)

Apple scab:

 Hopefully your orchard is clean of scab for the growing season. While visiting orchards, extension staff have seen some scab infections present on leaves. In those orchards, growers will need to remain diligent and maintain fungicide coverage to minimize new infections. . If new infections are showing up in your orchard, control measures are warranted.

Here is an article addressing control and resistance management strategies for scab:

https://www.canr.msu.edu/news/management_of_apple_scab_in_orchards_with_existing_scab_lesions

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

Fireblight:

There has been plenty of fireblight popping up on apple orchards around the state from southern New Hampshire all the way up into Carroll County.

Continue to scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots at least 12-18 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial. With a cool and fairly dry bloom period, some growers made in through the prime infection period with just a couple of streptomycin applications. Keep in mind that saving at least one or the four allotted strep sprays in case of hail or damaging wind events is a good insurance strategy.

In a recent report, Kathleen Leahy reminds us of an article from Good Fruit Grower highlighting recent research comparing cutting and sanitization strategies to find the best removal methods for fire blight strikes. It’s definitely worth the read:

Good to Know: Take a bite out of blight - Good Fruit Grower

Another great resource on fireblight management options comes from Dr. Kari Peter, Tree Fruit Pathologist at Penn State University. Her presentation from our UNH Fireblight Webinar can be accessed here.

 

Sooty Blotch and Flyspeck:

Now is the time to think about how you will manage Sooty Blotch and Flyspeck in your orchard. 
Check out the New England Tree fruit management guide for more info (
Sooty Blotch and Flyspeck | New England Tree Fruit Management Guide (netreefruit.org)), and remember that NEWA also provides forecasting and management recommendations for this disease complex:

From NEWA: Sooty Blotch and Flyspeck | NEWA (cornell.edu)

To effectively limit fruit finish blemishes from Sooty Blotch and Flyspeck infection consider making a cover application of one of the following fungicides/tank mixes:

  • 4 oz/100 gal Topsin +1 lb/100 gal. Captan 50W (or Captan-80 10 oz/100 gal); or
  • 0.67 oz/100 gal Flint 50WG; or
  • 1.6 oz/100 gal Sovran WDG; or
  • 6.1 oz/100 gal Pristine WG; or
  • 1 lb/100 gal Captan 50W (or Captan-80 10 oz/100 gal) + 21 fl. oz./100 gal ProPhyt

Figure 1:  Recommendations from NEWA for Sooty Blotch and Flyspeck.

 

Insects:

SWD – Spotted Wing Drosophila:

Traps should be up now. Trap captures spiked last week in the southern half of NH. To clarify, SWD is primarily a pest of small fruits, but also impacts stone fruits. Considering the fact that most stone fruits were lost due to severe cold this winter, controlling this pest will be generally limited to very late strawberries, blueberries, brambles and grapes.

You can find more info about SWD and SWD trap selection in past pest reports, refer to the ones from this past June!

Notes of Interest:

UNH Extension is trialing red sticky traps paired with the Trece Pherocon Peel-Pak lures in 2023. We also work with many growers who use the drowning traps paired with these same lures. In the photo below, the smaller red square is the lure, while the red rectangle is the sticky trap, which gets checked weekly.

sticky trap

Figure 2: New red sticky traps to capture SWD. Photo: Jeremy DeLisle

SWD Netting Project

UNH Extension, USDA Natural Resources Conservation Service and the NH Conservation Districts have been partnering on a three-year demonstration project investigating the efficacy, ease of use, cost of installation and potential return on investments associated with installing SWD exclusion netting systems on three farms here in NH. Those partner farms are Bascom Road Blueberry Farm in Newport, Stark Farm in Dunbarton, and Heron Pond Farm in South Hampton. To date, the systems have been highly effective at excluding SWD flies. To learn more about the types of systems being installed and the potential for new construction versus retrofitting existing bird netting structures, join us at our upcoming twilight meeting on August 3rd at Heron Pond Farm in South Hampton, NH. Details are available at the link at the bottom of this page.

Blueberry Maggot Fly:

Traps should be up now. Flight is expected this week if not already occurring in some locations. Details on monitoring and management can be found here.

 

Apple Maggot

Predicted first emergence of AM occurs after approximately 796 to 1072 degree days have accumulated. Today we have accumulated 931 DD base 50F from January 1. Set sticky traps along vulnerable field edges. Check at least weekly and not the first date of captures. Enter this into the Apple Maggot tool on NEWA.

The action threshold is an average of 1-2 AMF on the yellow cards or in unbaited sticky spheres, or a cumulative average of 5 AMF per trap on baited spheres. Trap captures for a week following insecticide treatment are ignored. Subsequent sprays can be applied once the threshold is reached again.

sticky shphere trap

Figure 3: Unbaited red sticky sphere for monitoring apple maggot fly in orchards. Photo: Jeremy DeLisle

Codling moth:

We continue to catch CM in Canterbury and Concord. Below is a resource shared by Dr. Jaime Pinero at UMass outlining a control approach based on trap captures and degree day accumulations targeting larvae at egg hatch.

Traps are up and we have caught very few OBLR. Controls should be timed with egg hatch. Continue to monitor traps, establish the biofix date on your farm, and enter into the NEWA model to track development based on growing degree days.

https://newa.cornell.edu/obliquebanded-leafroller

 

codling moth

 

codling moth

Figure 4: Codling moth trap captures for Merrimack County

Oriental Fruit Moth

Oriental Fruit Moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

oriental fruit moth

Figure 3: Oriental Fruit Moth (OFM) trap captures for Merrimack County

field tech

Figure 5: UNH Extension Field Technician, Justin Hogg, sets up delta traps to monitor for codling moth in apple orchards. Photo: Jeremy DeLisle

San Jose Scale – Apples:

Pheromone traps should be in place to record the second adult male flight. Note date of first capture of second generation for biofix in NEWA for predicting second generation crawler emergence.

 

Tissue testing time is here for some crops and coming right up for others.

Directions for taking a plant tissue sample leaf sample in your orchard/garden:

Tips - In general, it is usually best to sample many plants (with only a few leaves from each plant) rather than sample many leaves from only a few plants.

Select the youngest, fully developed (mature) leaves for analysis. Do not select leaves from plants which are mechanically damaged, insect damaged, diseased or dead. Avoid leaves from border plants or leaves which are fully shaded by other foliage. Do not send sample plants that have been under prolonged stress.

Avoid leaves which are contaminated with soil or dust or which have been recently sprayed. In general, plant leaves which have been exposed to normal rainfall are sufficiently clean for analysis. Samples can be washed briefly in a 2% non-phosphorus detergent solution and then rinsed carefully with clear water. However, in many situations the cleaning may do more harm than good.

If you are trying to diagnosis a problem and are sampling plants that are showing an abnormal symptom, follow the above directions, but sample only from plants showing the problem.

Crop Information

Blueberries: sample at least 40 leaves from 10 to 20 plants during the first week of harvest.

Strawberries: sample at least 40 first fully expanded leaves from 10 to 20 plants, after renovation

Brambles: sample at least 60 leaves from 10 to 20 non-fruiting canes during early-mid August.

Grapes: sample 50 to 75 of the youngest full-expanded leaves from 10 to 20 vines at veraison (70 days after bloom, as the first fruit ripens). Separate petioles (leaf stems) from leaves, and send only the petioles for analysis.

Tree fruits: sample 5 leaves from each of 10 trees from late July through early August. Select shoots at eye-level from around the outside of the trees that make a vertical angle of 45-60 degrees to the ground (avoid water shoots or suckers). Collect leaves from the mid-portion of the new shoot growth.

For other crops: Contact your local field specialist or county office to determine the correct sampling procedures. After Collection Samples should be placed in paper bags and air dried (turn the bag frequently) or dried at 200 degrees Fahrenheit.

If you wish to submit sample to UNH for tissue sampling, more information and forms can be found here:

 

Form: UNH Cooperative Extension - Commercial Plant Tissue Form.pdf - All Documents (sharepoint.com)

Main soil/tissue testing site: Soil Testing Services | Extension (unh.edu)

Upcoming Events

August 3 - Blueberry IPM Twilight Meeting at Heron Pond Farm | Extension (unh.edu)

August 17th - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

See the full list of twilight meetings here:

2023 Production Agriculture Summer Twilight Meeting | Extension (unh.edu)

 Thanks for tuning in!

Back to Top


7/12/2023

Fruit IPM Report 7/11/23

Hi all!!  

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is July 11th , 2023.

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

In terms of growing degree days in Concord, NH we have accumulated 1600 GDD in BE base 43F and 931 GDD in BE base 50F.

Weekly pest and disease update:

Mummy berry:

Mummy berry is being reported from some blueberry plantings. Details about this disease and management strategies can be found here.

Diseases | Center for Agriculture, Food, and the Environment (umass.edu)

Bitter rot:

Conditions have been good for this fungal disease with lots of rain, and quite a bit of fruit showing some sort of injury (notably, cracking) that might allow entry to the pathogen. Captan does a pretty good job, especially at slightly elevated rates. PennState cites Merivon/Pristine, Flint/Luna Sensation, Aprovia, and Omega, mixed with Captan as being effective.

Symptoms will appear now-August, with fruit getting more susceptible as they mature. Bitter rot is more common on light or bicolored fruit such as Empire, Honeycrisp, McIntosh, Sunrise, Paula red and Jonagold.

Bitter Rot | New England Tree Fruit Management Guide (netreefruit.org)

Apple scab:

The weather this week has been conducive to infection periods. If new infections are showing up in your orchard, control measures are warranted.  Most orchards are free of it, but extension staff have seem some lesions out in the field when scouting. In those orchards, growers will need to remain diligent and maintain fungicide coverage to minimize new infections.

Here is an article addressing control and resistance management strategies for scab:

https://www.canr.msu.edu/news/management_of_apple_scab_in_orchards_with_existing_scab_lesions

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

Fire blight:

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

Continue to scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots at least 12-18 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial. With a cool and fairly dry bloom period, some growers made in through the prime infection period with just a couple of streptomycin applications. Keep in mind that saving at least one or the four allotted strep sprays in case of hail or damaging wind events is a good insurance strategy.

In a recent report, Kathleen Leahy reminds us of an article from Good Fruit Grower highlighting recent research comparing cutting and sanitization strategies to find the best removal methods for fire blight strikes. It’s definitely worth the read:

Good to Know: Take a bite out of blight - Good Fruit Grower

Sooty Blotch and Flyspeck:

Now is the time to think about how you will manage Sooty Blotch and Flyspeck in your orchard. 
Check out the New England Tree fruit management guide for more info (
Sooty Blotch and Flyspeck | New England Tree Fruit Management Guide (netreefruit.org)), and remember that NEWA also provides forecasting and management recommendations for this disease complex:

From NEWA: Sooty Blotch and Flyspeck | NEWA (cornell.edu)

To effectively limit fruit finish blemishes from Sooty Blotch and Flyspeck infection consider making a cover application of one of the following fungicides/tank mixes:

  • 4 oz/100 gal Topsin +1 lb/100 gal. Captan 50W (or Captan-80 10 oz/100 gal); or
  • 0.67 oz/100 gal Flint 50WG; or
  • 1.6 oz/100 gal Sovran WDG; or
  • 6.1 oz/100 gal Pristine WG; or
  • 1 lb/100 gal Captan 50W (or Captan-80 10 oz/100 gal) + 21 fl. oz./100 gal ProPhyt

Figure 1:  Recommendations from NEWA for Sooty Blotch and Flyspeck.

Insects

Apple Maggot

Predicted first emergence of AM occurs after approximately 796 to 1072 degree days have accumulated. Today we have accumulated 931 DD base 50F from January 1. Set sticky traps along vulnerable field edges. Check at least weekly and note the first date of captures. Enter this into the Apple Maggot tool on NEWA.

The action threshold is an average of 1-2 AMF on the yellow cards or in unbaited sticky spheres, or a cumulative average of 5 AMF per trap on baited spheres. Trap captures for a week following insecticide treatment are ignored. Subsequent sprays can be applied once the threshold is reached again.

Apple Maggot tool on NEWA: Apple Maggot | NEWA (cornell.edu)

Apple maggot fly (AM) | New England Tree Fruit Management Guide (netreefruit.org)

 SWD – Spotted Wing Drosophila:

Traps should be up now. Trap captures spiked last week in the southern half of NH. To clarify, SWD is primarily a pest of small fruits, but also impacts stone fruits. Considering the fact that most stone fruits were lost due to severe cold this winter, controlling this pest will be generally limited to very late strawberries, blueberries, brambles and grapes.

For more information about making your own SWD traps or purchasing them, refer to past reports or refer to: Fruit: Spotted Wing Drosophila Management | Center for Agriculture, Food, and the Environment at UMass Amherst.

Point of Interest: SWD Exclusion Netting Systems

UNH Extension, USDA Natural Resources Conservation Service and the NH Conservation Districts have been partnering on a three-year demonstration project investigating the efficacy, ease of use, cost of installation and potential return on investments associated with installing SWD exclusion netting systems on three farms here in NH. Those partner farms are Bascom Road Blueberry Farm in Newport, Stark Farm in Dunbarton, and Heron Pond Farm in South Hampton. To date, the systems have been highly effective at excluding SWD flies, with zero trap captures reported to date, along with no loss due to infested fruit. To learn more about the types of systems being installed and the potential for new construction versus retrofitting existing bird netting structures, join us at our upcoming twilight meeting on August 3rd at Heron Pond Farm in South Hampton, NH. Details are available at the link at the bottom of this page.

Blueberry Maggot Fly:

 Traps should be up now. Flight is expected this week if not already occurring in some locations. Details on monitoring and management can be found here.

Fruit: Blueberry IPM - Blueberry Maggot Fly | Center for Agriculture, Food, and the Environment at UMass Amherst

Codling moth:

codling moth

 

codling moth

Figure 2: Codling moth trap captures for Merrimack County

Oriental Fruit Moth:

Oriental Fruit Moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

oriental fruit moth

Figure 3: Oriental Fruit Moth (OFM) trap captures for Merrimack County

Extension traps are continuing to catch Codling moths in Canterbury.  

The chart below summarizes control recommendations based on monitoring, biofix date and seasonal weather (DD accumulations). This chart was summarized by Dr. Jaime Pinero, UMass Extension Entomologist.

Oblique Banded Leaf Rollers:

Traps are up and we have finally caught our first and only OBLR. Controls should be timed with egg hatch. Continue to monitor traps, establish the biofix date on your farm, and enter into the NEWA model to track development based on growing degree days.

https://newa.cornell.edu/obliquebanded-leafroller

 

San Jose Scale: (Apples)

First generation nymphs should soon be secreting new scale covers and developing into adults. The time for controlling first generation nymphs is ending. Pheromone traps should be in place in time to record the second adult male flight.

San Jose scale (SJS) | New England Tree Fruit Management Guide (netreefruit.org)

 

Tissue testing time is here for some crops and coming right up for others.

Directions for taking a plant tissue sample leaf sample in your orchard/garden:

Tips - In general, it is usually best to sample many plants (with only a few leaves from each plant) rather than sample many leaves from only a few plants.

Select the youngest, fully developed (mature) leaves for analysis. Do not select leaves from plants which are mechanically damaged, insect damaged, diseased or dead. Avoid leaves from border plants or leaves which are fully shaded by other foliage. Do not send sample plants that have been under prolonged stress.

Avoid leaves which are contaminated with soil or dust or which have been recently sprayed. In general, plant leaves which have been exposed to normal rainfall are sufficiently clean for analysis. Samples can be washed briefly in a 2% non-phosphorus detergent solution and then rinsed carefully with clear water. However, in many situations the cleaning may do more harm than good.

If you are trying to diagnosis a problem and are sampling plants that are showing an abnormal symptom, follow the above directions, but sample only from plants showing the problem.

Crop Information

Blueberries: sample at least 40 leaves from 10 to 20 plants during the first week of harvest.

Strawberries: sample at least 40 first fully expanded leaves from 10 to 20 plants, after renovation

Brambles: sample at least 60 leaves from 10 to 20 non-fruiting canes during early-mid August.

Grapes: sample 50 to 75 of the youngest full-expanded leaves from 10 to 20 vines at veraison (70 days after bloom, as the first fruit ripens). Separate petioles (leaf stems) from leaves, and send only the petioles for analysis.

Tree fruits: sample 5 leaves from each of 10 trees from late July through early August. Select shoots at eye-level from around the outside of the trees that make a vertical angle of 45-60 degrees to the ground (avoid water shoots or suckers). Collect leaves from the mid-portion of the new shoot growth.

For other crops: Contact your local field specialist or county office to determine the correct sampling procedures. After Collection Samples should be placed in paper bags and air dried (turn the bag frequently) or dried at 200 degrees Fahrenheit.

If you wish to submit sample to UNH for tissue sampling, more information and forms can be found here:

 

Form: UNH Cooperative Extension - Commercial Plant Tissue Form.pdf - All Documents (sharepoint.com)

Main soil/tissue testing site: Soil Testing Services | Extension (unh.edu)

 

Upcoming Events

August 3 - Blueberry IPM Twilight Meeting at Heron Pond Farm | Extension (unh.edu)

August 17th - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

See the full list of twilight meetings here:

2023 Production Agriculture Summer Twilight Meeting | Extension (unh.edu)

 

 

Thanks for tuning in!

Back to Top


6/27/2023

Fruit IPM Report 6/27/23

Hi all!!  

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is June 27th , 2023.

 While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

 In terms of growing degree days in Concord, NH we have accumulated 1193 GDD in BE base 43F and 622 GDD in BE base 50F.

Tissue Testing: Blueberry Leaf tissue testing: now & over the next few weeks is a good time to submit a sample to get an idea of any changes you may need to make to your fertilization scheme.

Soil Testing Forms | Extension (unh.edu)

Jumping into the disease update:

Apple scab:

Hopefully your orchard is clean of scab and this week will mean the end of required control measures for the growing season. While visiting orchards over the past week, scouts have spotted some scab infections present on the leaves. In those orchards, growers will need to remain diligent and maintain fungicide coverage to minimize new infections.

Here is an article addressing control and resistance management strategies for scab:

https://www.canr.msu.edu/news/management_of_apple_scab_in_orchards_with_existing_scab_lesions

The weather this week has been conducive to infection periods. If new infections are showing up in your orchard, control measures are warranted. The NEWA model for Concord shows infection events each day from June 25th through June 30th.

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

 Fire blight:

Continue to scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots at least 12-18 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial. With a cool and dry bloom period, some growers made it through the prime infection period with just a couple of streptomycin applications. Keep in mind that saving at least one or the four allotted strep sprays in case of hail or damaging wind events is a good insurance strategy.

In a recent report, Kathleen Leahy reminds us of an article from Good Fruit Grower highlighting recent research comparing cutting and sanitization strategies to find the best removal methods for fire blight strikes. It is worth the read:

Good to Know: Take a bite out of blight - Good Fruit Grower

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

 Sooty Blotch and Flyspeck:

Now is the time to think about how you will manage Sooty Blotch and Flyspeck in your orchard.  Check out the New England Tree fruit management guide for more info (Sooty Blotch and Flyspeck | New England Tree Fruit Management Guide (netreefruit.org)), and remember that NEWA also provides forecasting and management recommendations for this disease complex:

From NEWA: Sooty Blotch and Flyspeck | NEWA (cornell.edu)

To effectively limit fruit finish blemishes from Sooty Blotch and Flyspeck infection consider making a cover application of one of the following fungicides/tank mixes:

  • 4 oz/100 gal Topsin +1 lb/100 gal. Captan 50W (or Captan-80 10 oz/100 gal); or
  • 0.67 oz/100 gal Flint 50WG; or
  • 1.6 oz/100 gal Sovran WDG; or
  • 6.1 oz/100 gal Pristine WG; or
  • 1 lb/100 gal Captan 50W (or Captan-80 10 oz/100 gal) + 21 fl. oz./100 gal ProPhyt

 Moving onto the Insects:

Apple Maggot

By the end of today we are predicted to have accumulated 706 DD base 50F from January 1, and the predicted first emergence of apple maggot occurs after approximately 796 to 1072 degree days have accumulated… indicating that traps should be up this week. The first apple maggot flies were captured in Massachusetts this week.

Apple maggot fly (AM) | New England Tree Fruit Management Guide (netreefruit.org)

 SWD – Spotted Wing Drosophila:

For the second week in a row our IPM scout has reported zero trap captures in seven traps spread over four farms in southern NH. Traps should be up now, as we typically start to catch this insect this week into next in the southern half of NH. To clarify, SWD is primarily a pest of small fruits, but also impacts stone fruits. Considering the fact that most stone fruits were lost due to severe cold this winter, controlling this pest will be generally limited to very late strawberries, blueberries, brambles and grapes.

 Codling moth:

In Canterbury, we established the biofix date of 5/26/23 to start the codling moth model within NEWA for apples and have reduced the frequency of trap checking for this insect to once a week. Once sustained trap captures have been observed, enter the biofix date for your farm into the NEWA model to track development of the pest.

Egg hatch is well underway. Control sprays critical, apply a second spray 10-14 days after the initial egg hatch spray. In Codling moth high-risk orchards, you can also consider choosing products that also target OFM and Plum curculio.

The chart below summarized control recommendations based on monitoring, biofix date and seasonal weather (DD accumulations). This chart was summarized by Dr. Jaime Pinero, UMass Extension Entomologist.

table

 

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)
 

codling moth

Figure 1: Codling moth trap captures for Merrimack County

Oriental Fruit Moth:

Oriental Fruit Moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

oriental fruit moth

Figure 2: Oriental Fruit Moth trap captures for Merrimack County

Oblique Banded Leaf Rollers:

Traps are up but we have yet to catch OBLR. Controls should be timed with egg hatch. Continue to monitor traps, establish the biofix date on your farm, and enter into the NEWA model to track development based on growing degree days.

https://newa.cornell.edu/obliquebanded-leafroller

Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

San Jose Scale

First generation nymphs should soon be secreting new scale covers and developing into adults. The time for controlling first generation nymphs is ending. Pheromone traps should be in place in time to record the second adult male flight.

San Jose scale (SJS) | New England Tree Fruit Management Guide (netreefruit.org)

 

Upcoming meetings:

All Production Ag Twilight Meetings: 2023 Production Agriculture Summer Twilight Meeting | Extension (unh.edu)

 

Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

Apple Hill Farm, Concord, NH

August 17th 5:30-7:30 pm

 

Produce Food Safety and Insurance Twilight Meeting | Extension (unh.edu)

June 29th 6-8 pm in Lancaster NH – Register online.

 

Mid-Season Corn Checkup and Pest Scouting, Stuart Farm | Extension (unh.edu)

June 29th 11 am – 1 pm

Stratham, NH

 

Thanks for sticking around!

 

Monitoring Spotted Wing Drosophila (SWD) with Traps (recently updated by Anna Wallingford, Assistant State Specialist, Associate Research Professor, and excellent entomologist)

Spotted wing drosophila (SWD) attacks ripening and ripe raspberries, blackberries, blueberries, grapes, cranberries, late cherries, fall strawberries, plums and peaches, plus fruit of many wild hosts. If you wish to protect your fruit from becoming infested, it is critical to set up traps for the insects, and to monitor those traps weekly when you have ripening crop present. The first flies will probably be trapped between July 2 and 12, and numbers will peak in September or October.

These traps ARE NOT TO CONTROL the flies! Once you detect flies, the crop should be protected with insecticides. Most of the good insecticides should give about seven days of protection, but can be washed off by rain. After you spray, set out fresh traps to determine when crops become at risk again.

Commercial vs. Home-Made Traps

When SWD first appeared in NH, the commercial traps that existed were not effective in comparison with home-made traps. However, effective commercial traps and baits are now available from both Scentry and Trécé, that are hung in jar traps full of soapy water as drowning solution. More recently, Trécé has marketed their lure with red sticky traps as a “dry trap” alternative to traps with water drowning solutions. All trapping types have their own pros and cons in terms of logistics of use but all are excellent at determining presence or absence of flies in susceptible crops.

In our UNH Cooperative Extension monitoring program, we are now using Trécé traps and lures for SWD. These traps are reusable, and are available from standard suppliers of IPM products (e.g. Great Lakes IPM).

When to set up the traps? Do this as soon as fruit starts to ripen. Fruits that ripen before July 1 are not likely to be at risk. You can stop monitoring when harvest of susceptible crops is over for you.

Where to set the traps? Set the traps IN the crop, in the shade, AMONG THE FOLIAGE near fruit. We recommend checking traps every 5-6 days at first, moving to every 3-5 days in August (hot weather). As the weather cools, you can lengthen the check interval. Keep checking as long as you have ripe fruit to protect.

Which crops need protection? The most susceptible crops seem to be raspberries, blueberries and strawberries that ripen in August-September; thin-skinned, dark-colored grapes; and some peaches and plums (especially white-fleshed peaches). We don’t know how heavily currants and cranberries are attacked.

How many traps do I need?  For most plantings, three well-placed traps should be enough and you should base management actions on an average of the number of flies you trap in each block. If you have different crops, you’ll want traps in each crop, because the pattern of attack varies crop-to-crop. If you have different varieties of the same crop, begin monitoring in the first variety to ripen, and move the traps to others with ripe fruit when harvest wanes on that first variety. If your crop is in several blocks that are managed (e.g. sprayed) separately, you will need traps in each block.

How do I check the traps?  Check traps at least once per week. To check the trap, remove the lid, and pour the liquid bait into a shallow white pan or saucer. In bright light, look for the male flies (they are about 2mm long, with light tan body, red/orange eyes, and have a dot near the tip of each wing) with a 2X magnifying glass. When done counting the male SWD’s, write the number down. If you find male flies, your crop is at risk. If your threshold for risk is a little higher, you can wait until you find an average of 5 male SWD in all three traps. Find this example of a sliding scale of risk for SWD infestation in wild blueberry https://extension.umaine.edu/blueberries/factsheets/insects/210-spotted-wing-drosophila/

Making Your Own Traps

From 2012-2016, we and many colleagues across the Northeast set out hundreds of traps, and learned what combinations worked well enough to make trapping a useful tool. Most of these baits relied on odors from fermentation to attract flies, including apple cider vinegar, wine, grape juice, yeasts, sugars, bread doughs, etc. Many of these bait recipes are messy, smell, and trap many non-target insects that make detection of SWD difficult. Poorly set or designed traps do not work well enough to predict when you need to protect crops. If you prefer to make your own traps rather than purchase traps, the following tips may help.

This trap design works well: We use red plastic 18 oz Solo cups with transparent lids. We placed a black band of electrician’s tape a bit below the rim. We used a heated nail to melt 1/8 inch holes in the cup, to allow the insects to get in, and the odor to escape. We don’t make those holes too large, or wasps will get in. We placed the entrance holes in and around that band, about 30 to 35 holes per trap. We leave one sector of the cup without holes, to make it easy to pour out and examine the liquid bait, without spilling any.

Add just a drop or two of liquid soap to the bait. Non-scented soap is preferable as flowery-scented soaps might decrease bait effectiveness. The soap decreases the surface tension of the bait, making it easier for the small flies to fall in and drown.

When we used the dough baits, the solid yeast/dough bait was placed inside a smaller 4-oz lidded cup within the larger 18-oz trap. We cut a hole (1-inch diameter) in the lid. Over the hole we placed fine insect netting, and fastened it with a hot glue gun. The netting is to allow the yeast odor out, but not let flies in. So the assembled trap is a large red cup. Inside that is 2 oz of liquid bait, and floating upright in the liquid bait is the smaller cup with the netted lid.

When check traps containing attractive baits, make sure to collect the old liquid bait in a waste container, and add fresh bait to the trap. Don’t pour the old bait on the ground in your fruit planting, or it will compete with your traps for the flies’ attention.

Point of interest:

UNH Extension, USDA Natural Resources Conservation Service and the NH Conservation Districts have been partnering on a three-year demonstration project investigating the efficacy, ease of use, cost of installation and potential return on investments associated with installing SWD exclusion netting systems on three farms here in NH. Those partner farms are Bascom Road Blueberry Farm in Newport, Stark Farm in Dunbarton, and Heron Pond Farm in South Hampton. To date, the systems have been highly effective at excluding SWD flies, with zero trap captures reported to date, along with no loss due to infested fruit. To learn more about the types of systems being installed and the potential for new construction versus retrofitting existing bird netting structures, join us at our upcoming twilight meeting on August 3rd  at Heron Pond Farm.

SWD netting

Figure 3: SWD netting being installed for the second year in a row at Heron Pond Farm in South Hampton, NH. Photo by Jeremy DeLisle, Field Specialist, Food and Agriculture, UNH Extension

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6/20/2023

Fruit IPM Report 6/20/23

Hi all!!  

  Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is June 20th , 2023.

 While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

 In terms of growing degree days in Concord, NH we have accumulated 1020 GDD in BE base 43F and 499 GDD in BE base 50F.

 We are in a bit of a lull right now – so I  have a shorter update for all of you!

Jumping into the disease updates:

Apple scab:

While primary infection is over at this point, some orchards are still seeing scab on leaves and fruitlets.

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

apple scab

Figure 1: Apple scab infection on upper and lower leaf surface, Photo, Jeremy DeLisle, UNH Extension

Fire blight:

Continue to scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots at least 12-18 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread, but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial. With a cool and fairly dry bloom period, some growers made in through the prime infection period with just a couple of streptomycin applications. Keep in mind that saving at least one or the four allotted strep sprays in case of hail or damaging wind events is a good insurance strategy.

In her most recent report, Kathleen Leahy reminds us of an article from Good Fruit Grower highlighting recent research comparing cutting and sanitization strategies to find the best removal methods for fire blight strikes. It’s definitely worth the read:

Good to Know: Take a bite out of blight - Good Fruit Grower

 

Moving onto the insect pests:

Plum curculio

Pest status: Plum curculio activity is beginning to decline and any curculio remaining in trees will usually not move to other locations.

Plum curculio only need to be controlled until 308 DD have accumulated after petal fall. Make sure that the predicted residual coverage (10-14 days) from the last spray will protect fruit until DD accumulation reaches this value.

In Concord the petal fall date we are using is 5/19/23. From that date, we have accumulated 388 degree days base 50F. Egg laying typically stops around 308 degree days after petal fall, at which time the need for targeted control generally stops. According to the models, we can consider PC control for the season done – in Concord.

For this week into next, continue to monitor growing degree days from petal fall using the PC model within NEWA to know when you are approaching the end of oviposition and the need for control. Northern orchards are slightly behind in degree day accumulations, so oviposition might be extended a bit longer, but you should be there soon.

 An observation from the field is that in some orchards with very few viable fruits remaining on the trees after the frost, PC seems to be laying high numbers of eggs in those fruits. This is the behavior that we anticipated. It seems targeted perimeter application of insecticides targeting PC adults at this point in the season is still warranted as we think about reducing this population of insects for next season.  

Remember, if you have applied an effective insecticide with residual activity still present on the trees, that application may take you through the end of oviposition depending on the date of application and the material used.

 

Codling moth:

In Canterbury, we established the biofix date of 5/26/23 to start the codling moth model within NEWA and have reduced the frequency of trap checking for this insect to once a week. Once sustained trap captures have been observed, enter the biofix date for your farm into the NEWA model to track development of the pest. For most orchards in NH, codling moth flight is well underway and egg laying is currently happening.  

Today we have accumulated 303 DD base 50F from our biofix and reached 250 DD by June 16th, marking the prime window of egg hatch and the most effective time for controlling the emerging larvae using many of the recommended insecticides.

We are still seeing high trap captures for the first generation of codling moth in Merrimac county (see Figure 2). This means that egg laying is still occurring, and controls will need to be applied for an extended time period. Southern NH established the biofix of codling moth as of 5/22/23. Southern growers without traps on their farms could enter this date to start the degree day clock running for egg hatch by this pest.

Trapping in the orchard is the best way to know what is happening with populations of insects in your specific location. Consider adding a few traps to your orchard to better understand the dynamics of key insect pests from one season to the next.

 More information from Cornell about codling moth Degree Day calculations:

Time insecticide applications based on trap data and degree day (DD) models for egg hatch. Spray timing for these pests is directed at newly hatched larvae, since most insecticides are not effective at controlling adults. There is a lag period for egg hatch after the moths fly. The first spray for CM is recommended at first egg hatch, which occurs 220-250 DD (base 50°F) after sustained trap catch. Timing depends on insecticide choice. Calypso, Assail, Delegate, Altacor, Belt, or Voliam Xpress or Voliam Flexi are most effective when applied at 200-250 DD 50°F after biofix. An additional option is to apply a granulosis virus formulation at 200-250 DD 50°F. High moth pressure requires 2-3 sprays for the first generation, but in lower pressure orchards (with counts of less than 5 moths per trap per week), you can control CM with a single spray timed at 350 DD 50°F.

In apples, 1st generation OFM can be controlled with the petal fall spray. In summer, sprays for OFM in apples are applied 3-4 days after peak trap catch, or 7 days after the start of the 2nd flight. In peach orchards, look for flagging shoots from larval activity in tips of new shoots. Full resource available here: doc_72.pdf (cornell.edu)

codling moth

Figure 2: Codling moth trap captures for Merrimack County

 

oriental fruit moth

Figure 3: Oriental Fruit Moth (OFM) trap captures for Merrimack County

San Jose Scale:

First generation crawlers are produced beneath female scale covers during this period. If monitoring for crawlers, double-sided sticky tape traps should be placed around tree limbs at this time.

San Jose scale (SJS) | New England Tree Fruit Management Guide (netreefruit.org)

 

Monitoring Spotted Wing Drosophila (SWD) with Traps (recently updated by Anna Wallingford, Assistant State Specialist, Associate Research Professor and excellent entomologist)

Spotted wing drosophila (SWD) attacks ripening and ripe raspberries, blackberries, blueberries, grapes, cranberries, late cherries, fall strawberries, plums and peaches, plus fruit of many wild hosts. If you wish to protect your fruit from becoming infested, it is critical to set up traps for the insects, and to monitor those traps weekly when you have ripening crop present. The first flies will probably be trapped between July 2 and 12, and numbers will peak in September or October.

These traps ARE NOT TO CONTROL the flies! Once you detect flies, the crop should be protected with insecticides. Most of the good insecticides should give about seven days of protection, but can be washed off by rain. After you spray, set out fresh traps to determine when crops become at risk again.

Commercial vs. Home-Made Traps

When SWD first appeared in NH, the commercial traps that existed were not effective in comparison with home-made traps. However, effective commercial traps and baits are now available from both Scentry and Trécé, that are hung in jar traps full of soapy water as drowning solution. More recently, Trécé has marketed their lure with red sticky traps as a “dry trap” alternative to traps with water drowning solutions. All trapping types have their own pros and cons in terms of logistics of use but all are excellent at determining presence or absence of flies in susceptible crops.

In our UNH Cooperative Extension monitoring program, we are now using Trécé traps and lures for SWD. These traps are reusable, and are available from standard suppliers of IPM products (e.g. Great Lakes IPM).

When to set up the traps? Do this as soon as fruit starts to ripen. Fruits that ripen before July 1 are not likely to be at risk. You can stop monitoring when harvest of susceptible crops is over for you.

Where to set the traps? Set the traps IN the crop, in the shade, AMONG THE FOLIAGE near fruit. We recommend checking traps every 5-6 days at first, moving to every 3-5 days in August (hot weather). As the weather cools, you can lengthen the check interval. Keep checking as long as you have ripe fruit to protect.

Which crops need protection? The most susceptible crops seem to be raspberries, blueberries and strawberries that ripen in August-September; thin-skinned, dark-colored grapes; and some peaches and plums (especially white-fleshed peaches). We don’t know how heavily currants and cranberries are attacked.

How many traps do I need?  For most plantings, three well-placed traps should be enough and you should base management actions on an average of the number of flies you trap in each block. If you have different crops, you’ll want traps in each crop, because the pattern of attack varies crop-to-crop. If you have different varieties of the same crop, begin monitoring in the first variety to ripen, and move the traps to others with ripe fruit when harvest wanes on that first variety. If your crop is in several blocks that are managed (e.g. sprayed) separately, you will need traps in each block.

How do I check the traps?  Check traps at least once per week. To check the trap, remove the lid, and pour the liquid bait into a shallow white pan or saucer. In bright light, look for the male flies (they are about 2mm long, with light tan body, red/orange eyes, and have a dot near the tip of each wing) with a 2X magnifying glass. When done counting the male SWD’s, write the number down. If you find male flies, your crop is at risk. If your threshold for risk is a little higher, you can wait until you find an average of 5 male SWD in all three traps. Find this example of a sliding scale of risk for SWD infestation in wild blueberry https://extension.umaine.edu/blueberries/factsheets/insects/210-spotted-wing-drosophila/

Making Your Own Traps

From 2012-2016, we and many colleagues across the Northeast set out hundreds of traps, and learned what combinations worked well enough to make trapping a useful tool. Most of these baits relied on odors from fermentation to attract flies, including apple cider vinegar, wine, grape juice, yeasts, sugars, bread doughs, etc. Many of these bait recipes are messy, smell, and trap many non-target insects that make detection of SWD difficult. Poorly set or designed traps do not work well enough to predict when you need to protect crops. If you prefer to make your own traps rather than purchase traps, the following tips may help.

This trap design works well: We use red plastic 18 oz Solo cups with transparent lids. We placed a black band of electrician’s tape a bit below the rim. We used a heated nail to melt 1/8 inch holes in the cup, to allow the insects to get in, and the odor to escape. We don’t make those holes too large, or wasps will get in. We placed the entrance holes in and around that band, about 30 to 35 holes per trap. We leave one sector of the cup without holes, to make it easy to pour out and examine the liquid bait, without spilling any.

Add just a drop or two of liquid soap to the bait. Non-scented soap is preferable as flowery-scented soaps might decrease bait effectiveness. The soap decreases the surface tension of the bait, making it easier for the small flies to fall in and drown.

When we used the dough baits, the solid yeast/dough bait was placed inside a smaller 4-oz lidded cup within the larger 18-oz trap. We cut a hole (1-inch diameter) in the lid. Over the hole we placed fine insect netting, and fastened it with a hot glue gun. The netting is to allow the yeast odor out, but not let flies in. So the assembled trap is a large red cup. Inside that is 2 oz of liquid bait, and floating upright in the liquid bait is the smaller cup with the netted lid.

When check traps containing attractive baits, make sure to collect the old liquid bait in a waste container, and add fresh bait to the trap. Don’t pour the old bait on the ground in your fruit planting, or it will compete with your traps for the flies’ attention.

Point of interest:

UNH Extension, USDA Natural Resources Conservation Service and the NH Conservation Districts have been partnering on a three-year demonstration project investigating the efficacy, ease of use, cost of installation and potential return on investments associated with installing SWD exclusion netting systems on three farms here in NH. Those partner farms are Bascom Road Blueberry Farm in Newport, Stark Farm in Dunbarton, and Heron Pond Farm in South Hampton. To date, the systems have been highly effective at excluding SWD flies, with zero trap captures reported to date, along with no loss due to infested fruit. To learn more about the types of systems being installed and the potential for new construction versus retrofitting existing bird netting structures, join us at our upcoming twilight meeting on June 20th at Stark Farm. Details are available at the link at the bottom of this page.

SWD netting

Figure 4: SWD netting being installed for the second year in a row at Heron Pond Farm in South Hampton, NH. Photo by Jeremy DeLisle, Field Specialist, Food and Agriculture, UNH Extension

Upcoming meetings:

All Production Ag Twilight Meetings: 2023 Production Agriculture Summer Twilight Meeting | Extension (unh.edu)

 

June 20th, 2023

Blueberry IPM Twilight Meeting at Stark Farm | Extension (unh.edu)

 

RMA Apple Insurance Listening Session:

June 27, 2023 : Goffstown, New Hampshire

10:00 a.m. to 12:00 p.m., Hillsborough County Extension Office (Large Conference Room)

329 Mast Rd., Goffstown, NH 03045

No RSVP Required

 

Thanks for sticking around!

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8/8/2023

In terms of growing degree days in Concord, NH we have accumulated 2,367 GDD in BE base 43F and 1,503 in BE base 50F.

Weekly pest and disease update:

Diseases:

Exobasidium on blueberries

Blueberry growers should keep their eyes peeled for a new disease on highbush blueberries called Exobasiduim. This has primarily been known as a southern disease until recently. Last season, UNH Field Specialists found this disease in a planting near Concord, NH. This year, it has popped up again near the border of NH and Maine. Included below is a link to more information about the fungal disease, as well as pictures taken in the field in 2022 (Figures 1 and 2).

Exobasidium on blueberry leaf from field in 2022. Photo by Jeremy DeLisle @ 2023 University of New Hampshire

Figure 1: Exobasidium on blueberry leaf from field in 2022. Photo by Jeremy DeLisle.@ 2023 University of New Hampshire

Exobasidium on blueberry fruit from field in 2022. Photo by Jeremy DeLisle.

Figure 2: Exobasidium on blueberry fruit from field in 2022. Photo by Jeremy DeLisle. @ 2023 University of New Hampshire

More information about Exobasidium can be found here: Exobasidium leaf and fruit spot of blueberry | NC State Extension Publications (ncsu.edu)

 

More information about Exobasidium here: Exobasidium leaf and fruit spot of blueberry | NC State Extension Publications (ncsu.edu)

Bitter rot on apples

Conditions have been good for this disease with plenty of rain and humidity, and quite a bit of fruit showing some sort of injury (notably, cracking) that might allow entry to the pathogen. Captan does a pretty good job, especially at slightly elevated rates. Penn State cites Merivon/Pristine, Flint/Luna Sensation, Aprovia, and Omega, mixed with Captan as being effective. Pay attention to pre-harvest intervals for fungicides as harvest approaches.  Additional information about the biology and management of this disease can be found here: https://ag.umass.edu/fruit/fact-sheets/apple-ipm-bitter-rot. Figure 3 is an example of a fully developed bitter rot infection on an apple.

Figure 3. Fully developed infections of apple bitter rot on apple cultivar ‘Empire’ with abundant spores of fungus that allows secondary, new infections on other apple fruit. Photo credit Aćimović S. G., 2019.

Figure 3. Fully developed infections of apple bitter rot on apple cultivar ‘Empire’ with abundant spores of fungus that allows secondary, new infections on other apple fruit. Photo credit: Aćimović S. G., 2019.

A photo comparison of apple bitter rot and bitter pit, associated with calcium deficiency of the fruit, can be found here: https://twitter.com/FruitDiseases/status/1436764151335071753

Insects:

Blueberry Maggot Fly

The blueberry maggot degree day model predicts when to set baited traps to monitor for adult flies. This insect has patchy distribution and monitoring will determine if and when it occurs on your farm. Flies typically emerge around 913 degree days base 50˚ F from January 1. Blueberry maggot flight places the crop at risk from egg-laying females.

Continue to check blueberry traps once or twice per week, as required, and replace traps and baits every third week. If caught, begin insecticide treatment. Maintain an IPM and insecticide program to protect the crop, according to your market requirements. After harvest, remove and discard used traps and bait.

Details on monitoring and management can be found here.

Spotted Wing Drosophila

While many blueberry varieties are past their peak harvest season, late-season varieties are still very much at risk. This warm, damp weather pattern we are having has been quite favorable for the development of this insect.

Traps placed at several farms in southern NH showed high captures of over 40 male SWD flies in four locations. These high captures were in control traps, placed outside of production areas. Captures inside plantings where control measures have been implemented have been much lower, indicating that controls are working. This is to say that the risk to ripening fruit, especially late blueberries and fall raspberries, is still high.

Also of interest, our three SWD netting demonstration sites are working quite well to exclude this little insect again this year. Timing of applying the netting is critical and should occur as soon after pollination is complete as practical to increase the chances of fully excluding this pest. Growers report excellent yields and high quality berries from all three netting demonstration locations.

Note: Raspberries and blueberries can tolerate cold storage temperatures close to 32° F, so don't be afraid to put your fruit in a cold storage to keep it crisp and fresh and kill or slow down SWD egg and larval development (NYS IPM).

SWD is primarily a pest of small fruits, but also impacts stone fruits. Considering the fact that most stone fruits were lost due to severe cold this winter, controlling this pest will be generally limited to blueberries, brambles and grapes at this point in the season.

UNH Extension is trialing red sticky traps paired with the Trece Pherocon Peel-Pak lures in 2023. We also work with many growers who use the drowning traps paired with these same lures. In Figure 4, the smaller red square is the lure, while the red rectangle is the sticky trap, which gets checked weekly.

New red sticky traps to capture SWD. Photo by Jeremy DeLisle @ 2023 University of New Hampshire

Figure 4: New red sticky traps to capture SWD. Photo credit: Jeremy DeLisle.

Japanese Beetles

Adult beetles can be found feeding on foliage and fruit currently throughout most of NH. Many of us are interested in opportunities for mass trapping this pest. Blueberries and raspberries are especially attractive to this insect. There may be hope yet for Japanese beetle traps that can actually help control populations and limit damage to fruiting crops. Visit the link here for more information.

Apple Maggot Fly

We have started to capture AMF with varying catch numbers from one farm to the next. Traps should be up now to monitor populations.

Predicted first emergence of AM occurs after approximately 796 to 1072 degree days have accumulated. Today we have accumulated 1,503 DD base 50F from January 1. Set sticky traps along vulnerable field edges. Check at least weekly and note the first date of captures. Enter this into the Apple Maggot tool on NEWA.

The action threshold is an average of 1-2 AMF on the yellow cards or in unbaited sticky spheres, or a cumulative average of 5 AMF per trap on baited spheres. Trap captures for a week following insecticide treatment are ignored. Subsequent sprays can be applied once the threshold is reached again.

Apple Maggot Fly (AM)--New England Tree Fruit Management Guide (netreefruit.org)

Codling moth

Trap captures have remained low this week (Figure 5). We are currently at 1,322 DD past our biofix. Continue to monitor traps for moth captures to mark the start of the second generation flight, which is anticipated to start soon. First egg hatch of second generation should begin 250 DD after sustained trap captures, which may be a time to treat in orchards with a crop and high captures. A second spray may be needed in high pressure orchards 10-14 days later. So far, we have not seen a significant uptick in CM moth captures indicating the flight of a second generation. We anticipate this will occur soon and continue to monitor to best inform management decisions.

Average codling moth trap captures for the 2023 season provided by Jeremy DeLisle.  Brown Marmorated Stink Bug We have yet to capture BMSB this season. We anticipate those numbers to start to increase over the next couple of weeks. Apple growers should monitor using either pyramid-style traps or clear sticky cards, especially near areas of the orchard or specific varieties where this insect has been documented in past seasons. A comparison of the two types of traps most commonly used can be found

Figure 5. Average codling moth trap captures for the 2023 season provided by Jeremy DeLisle.

Brown Marmorated Stink Bug

We have yet to capture BMSB this season. We anticipate those numbers to start to increase over the next couple of weeks. Apple growers should monitor using either pyramid-style traps or clear sticky cards, especially near areas of the orchard or specific varieties where this insect has been documented in past seasons. A comparison of the two types of traps most commonly used can be found here: Simpler trap for monitoring brown marmorated stink bugs eyed - Fruit Growers News

Tissue testing time is here for some crops and coming right up for others.

Directions for taking a plant tissue leaf sample:

Tips - In general, it is usually best to sample many plants (with only a few leaves from each plant) rather than sample many leaves from only a few plants.

Select the youngest, fully developed (mature) leaves for analysis. Do not select leaves from plants which are mechanically damaged, insect damaged, diseased or dead. Avoid leaves from border plants or leaves which are fully shaded by other foliage. Do not send sample plants that have been under prolonged stress.

Avoid leaves which are contaminated with soil or dust or which have been recently sprayed. In general, plant leaves which have been exposed to normal rainfall are sufficiently clean for analysis. Samples can be washed briefly in a 2% non-phosphorus detergent solution and then rinsed carefully with clear water. However, in many situations the cleaning may do more harm than good.

If you are trying to diagnosis a problem and are sampling plants that are showing an abnormal symptom, follow the above directions, but sample only from plants showing the problem.

Crop Information

Blueberries: sample at least 40 leaves from 10 to 20 plants during the first week of harvest.

Strawberries: sample at least 40 first fully expanded leaves from 10 to 20 plants, after renovation

Brambles: sample at least 60 leaves from 10 to 20 non-fruiting canes during early-mid August.

Grapes: sample 50 to 75 of the youngest full-expanded leaves from 10 to 20 vines at veraison (70 days after bloom, as the first fruit ripens). Separate petioles (leaf stems) from leaves, and send only the petioles for analysis.

Tree fruits: sample 5 leaves from each of 10 trees from late July through early August. Select shoots at eye-level from around the outside of the trees that make a vertical angle of 45-60 degrees to the ground (avoid water shoots or suckers). Collect leaves from the mid-portion of the new shoot growth.

For other crops: call 603-862-3203 to determine the correct sampling procedures. After Collection Samples should be placed in paper bags and air dried (turn the bag frequently) or dried at 200 degrees Fahrenheit.

Access the submission form here: https://extension.unh.edu/sites/default/files/migrated_unmanaged_files/Resource002488_Rep3658.pdf

Click Here to See Upcoming Agriculture Events

See the full list of twilight meetings here:

2023 Production Agriculture Summer Twilight Meeting | Extension (unh.edu)

 

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4/23/2024

Hi all!!

Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team. 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM Reports” or find them on our webpage at https://extension.unh.edu/resource/fruit-ipm-reports

In terms of growing degree days in Concord, NH we have accumulated 169 GDD in BE base 43F and 5 GDD in BE base 50F.

 Also check out the degree day calculator on the Cornell Climate Smart Farming Page to see accumulations to date, 6-day forecasts, 15 year average and 30 year normal. Be sure to change the location to suit your needs.

Weekly Pest Update: 

 Apple:

 Apple Scab:

The apple scab fungus overwinters in infected leaves that have fallen to the ground. In these leaves, from autumn to early spring, the fungus mates, resulting in the development of what are termed ascospores, which cause primary infections. Ascospores mature as spring progresses with a few ascospores usually maturing by bud break (green tip). The proportion of ascospores maturing progresses slowly until about the tight cluster stage of blossom development. At this point in the season, protectant fungicides should be in place prior to the next predicted scab infection period, as ascospores will continue to mature until the next event.

Organic growers can consider either potassium bicarbonate or sulfur for scab control. Apply these materials based on predicted infection events using a forecasting tool such as the one available through NEWA.

Apples are generally in the quarter to half-inch green stage across the southern half of the state, with some later varieties slightly behind.

At this point, most growers who planned to apply dormant copper for apple scab and fireblight have already done so. Risk of fruit russeting increases from this point forward, so proceed with caution and choose materials accordingly.

So far we have had one primary scab infection event that lasted a few days, along with sporadic potential infection events depending on location. When this occurred, many orchards had very little green tissue exposed, and NEWA predicted the ascospore maturity at 2-3 percent. Pretty low percentage and a small target for those spores to find. Some growers have gone in with protectant fungicides such as Mancozeb, Captan, or combinations of both. The model in NEWA currently predicts 14% ascospore maturity with a cumulative discharge of 7% by 4/24.

Other growers who were uncovered with protectant fungicides over the past couple of days are taking the weather window today to apply protectants and perhaps include a kickback material such as a Syllit, Vangard or Scala. Orchards with no scab last season may have elected to wait to apply fungicides due to minimal overwintering inoculum expected, little green tissue exposed, and cool temperatures during wetting periods.

Lastly, it is recommended to save the FRAC group 7 fungicides for pink through petal fall, as these materials combined with a multi-site material such as mancozeb or Captan will provide the best efficacy against scab during peak pressure, along with protection against Marssonina blotch.

Fireblight: 

Dormant copper applications should be completed at this time. The closer we get to bloom, growers will need to consider their choice of copper materials if included in their programs to minimize the risk of fruit russeting.

Prior to bloom, growers who experienced fireblight issues in 2023 could consider one of the plant defense elicitors available, including LifeGard, Vacciplant or Apogee/Kudos. Tight cluster is the recommended timing of application for these materials.

For Apogee and Kudos, these are primarily recommended for high vigor trees. 10 days is needed for the full effect of these materials to kick in, so keep that in mind with timing.

Although a little early, an excellent summary about the options for fireblight and scab management can be found here: 2024 Disease Update: Conditions Favorable for Apple Scab and Fire Blight Infection Week of April 15 (psu.edu)

Learn how to identify fire blight cankers. Scout orchard blocks for active, oozing fire blight cankers. Determine and record each orchard blocks' fire blight history to use in the blossom blight tool, as shown:
--No fire blight in your neighborhood last year.
--Fire blight occurred in your neighborhood last year (default).
--Fire blight is now active in your neighborhood.

At silver tip apply a copper spray to clean up inoculum on tree surfaces. At bloom, apples and pears become susceptible to blossom blight infections. First blossom open begins the critical period for protection during bloom, which is when blossom blight risk is calculated.

Insects:

The UNH IPM Team maintains fruit pest traps at several orchards in NH. Most are in the Merrimack and Belknap County areas. We also communicate regularly with crop consultants and regional Extension specialists for input on key management strategies and timing.

Kathleen Leahy of Polaris IPM reminds us that conditions should be favorable for oil applications this week, with above-freezing night temperatures predicted through the week. Oil will help with control of mites, psylla, scale insects, and woolly aphids.

Start looking for rosy aphids on fruit clusters on susceptible varieties (Cortland, IdaRed, Gravenstein...)

UNH Extension has been busy hanging traps for lepidopteran pests and have our first captures of redbanded leaf roller (RBLR) moths.

The redbanded leafroller overwinters as a pupa within folded leaves on the ground. Spring emergence of the adults begins at the early green tip stage of bud development and peaks at the tight cluster and pink stages. Adults are considered to be weak fliers, therefore most egg laying will be on the trunks and scaffold limbs of apple trees.

Egg laying starts soon after emergence and continues into bloom. An average egg mass contains 40-45 eggs. Incubation lasts from 14-21 days. Hatching begins as early as trees start to bloom, but usually peaks at petal fall.

Our factsheet on RBLR can be accessed here: Redbanded Leafroller [fact sheet] | Extension (unh.edu)

We are also hanging traps this week for oriental fruit moth (OFM) and oblique banded leaf roller (OBLR). We may be on the early side, but better early than late. Trap capture throughout the season will be reported here weekly or as population shifts occur.

 We have continued to find populations of scale insects on both apples and peaches across the state. Many conversations seem to lead back to a reduction in the use of oil over time, allowing populations to build. Oystershell scale on apples and white peach scale on peaches have been the predominant pests noted. 

Oystershell scales (Lepidosaphes ulmi) are brown and shaped like an oyster shell about 1/8" long. They are found on twigs of lilac, ash, redbud, dogwood, poplar, willow, horse chestnut, elm, beech, walnut, cotoneaster, apple, birch, pachysandra, and other species. They overwinter as white eggs under the scale coverings. The eggs hatch in May, around the same time lilac blooms begin to fade. They achieve maturity by August. There is one generation per year.

Please refer to the New England Tree Fruit Management Guide for specific materials and rates recommended for managing scale insects. Established populations may require dormant or delayed dormant oil application and insecticide application targeting crawlers. For best results, apply horticultural oil (3 gallons per 100 gallons of water for heavy infestation; otherwise use 2 gallons per 100 gallons of water) around half-inch green. Apply insecticide when crawlers become visible.

Weeds

There is still time to apply preemergent herbicides. A great resource is available here: Spring Orchard Pre-Emergent Herbicides – CCE Eastern NY Commercial Horticulture Program (cornell.edu)

Blueberries:

Mummy Berry

Mummy berry is caused by the plant pathogenic fungus Monilina vaccinii-corymbosi. Infected berries from the previous year are the initial source of infection. In early spring, small cup-shaped spore-bearing structures called apothecia are produced from overwintering mummies on the ground.

These mummies break dormancy around the same time that the blueberry buds begin to swell in spring. Mummies develop mature apothecia about one month later, when blueberry leaf shoots are emerging. Spores (ascospores) produced by the apothecia are liberated during cool, wet weather and are carried by air currents to the young emerging leaf and flower shoots.

These spores infect the young shoots, and the secondary spores (conidia) are produced in great abundance on infected tissue. These conidia are carried mainly by pollinating insects to open flowers, where they infect developing fruit in the flower stage. During harvest, infected berries become light cream-color rather than normal blue and drop to the ground. These infected berries, if left on the ground, persist as overwintering mummies and provide a source of disease the following year. Source: NCSU

While we have dry conditions this week, it’s a good time to scout for the fruiting cups of this fungus which will produce spores soon.

Management: Fungicidal control has proven very successful. Fungicides are used at leaf emergence to prevent primary (leaf shoot) infection, and again during bloom to prevent secondary (flower) infection. Since fungicide labels and recommendations may change, consult annually revised extension publications for specific recommendations.

Insects:

Winter Moth (Operophtera brumata) is an important pest of blueberries and other deciduous plants, especially in Southeastern New England. Moths emerge from the soil in late November and may be active into January. Male moths are light brown to tan in color and attracted to lights at night. Females are gray, almost wingless and cannot fly, and may be found on tree trunks. After mating, females deposit tiny eggs in bark crevices or among lichens which overwinter. Eggs begin hatching in late March or early April after the first warm days of spring, generally around 20 Growing Degree Days (GDD) (base 50˚F) or about 200 GDD (base 40˚F). Egg hatch coincides with bud break of McIntosh apple trees. After hatching, larvae wriggle into swelling buds of blueberries and many deciduous tree, and begin feeding. Caterpillars continue feeding on leaves and flowers until late May when they drop to the ground to pupate. Destruction of flower buds can greatly reduce yield.

Winter moth larvae are pale green caterpillars with white longitudinal stripes running down both sides of the body. They are “loopers” or “inchworms” and have just 2 pairs of prolegs. Mature caterpillars are approximately one inch long.

Management: A dormant oil spray to trunks and branches of bushes may be helpful by killing overwintering eggs before hatching. However, some eggs under bark flaps and loose lichen may be protected from oil sprays. Caterpillars may also invade blueberries by blowing into plantings from nearby trees. Bacillus thuringiensis (B.t. kurstaki), manages winter moth caterpillars well once caterpillars are feeding on exposed foliage. B.t. and other insecticides are not effective when caterpillars are feeding inside closed buds. Spinosad is another biorational compound that works well against winter moth caterpillars. Finally, tebufenozide (e.g. Confirm) is an insect growth regulator (IGR) that works well on most lepidopteran caterpillars.

Weeds

You should have a weed management plan in place for the season at this point. Hopefully your mulching is done. For control options with herbicides in both new and established plantings, visit the New England Small Fruit Management Guide here: Table 36. Weed Management for Highbush Blueberries | Center for Agriculture, Food, and the Environment (umass.edu)

Upcoming Events:

April 23 - Tree Fruit Twilight Meeting at Alyson's Orchard | Extension (unh.edu)

May 22 - Tree Fruit Twilight Meeting at Kimball Fruit Farm | Extension (unh.edu)

June 19 - Tree Fruit Twilight Meeting at Sunnycrest Farm | Extension (unh.edu)

August 21 - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

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5/20/2024

Tree Fruit IPM Report 

Apples

Fireblight is on everyone’s minds right now. The temperatures this week bring with them an increased risk of infection to unprotected blossoms provided we have enough moisture to move bacteria into them. As of Monday morning (5/20/24) there was a very heavy dew and plants were significantly wet.

While some varieties in southern NH are already at petal fall, much of the state as we move north to Concord, over to Lebanon, and even on up to Coos County, are still in bloom.

Many growers are using the NEWA model to predict infections and help with decision-making for control of fireblight. Be sure to check the models often, as they have been bouncing back and forth a fair bit due to marginal temperatures/heat units, as well as the constantly changing precipitation forecast.

Here is an example of the results table for Concord, NH:

NEWA model with an example of the results table for Concord, NH

Another reminder…once an open blossom is sprayed with streptomycin it is protected from fireblight. You do not need to respray the same flowers even if a rain event occurs within 24 to 48 hours. Most pathologists agree that there is never a need to apply strep at less than a three-day interval. The heat units required for population to build back up after an application are simply not typically met in less than three-day intervals.

Here is a snapshot of the Cougarblight Risk chart. Notice that the first red bar this week is on 5/21, as this is when we are predicted to meet our 4-day degree hour requirement for infection:

​​​​​​A snapshot of the Cougarblight Risk chart

I was privy to a recent conversation where pathologists were asked about the 24-hour kickback ability of strep to control infections. The consensus was that pushing that window out to 24 hours is probably to maximum window that will safely control infections after an infection event.

In addition to the management plan from Dr. Kari Peter at Penn State which I’ve shared in previous updates, detailed information about the incorporation of Apogee/Kudos and copper, along with strep as part of a management plan, as well as how to use Apogee/Kudos  as a rescue treatment in shoot blight situations can be found here:

Note of caution: Do not apply Apogee on Empire, Stayman, or Winesap apple trees as it can cause fruit cracking.

Question of the day: A grower recently asked about compatibility of streptomycin and Apogee in a tank mix with the idea being that the strep would control fireblight infections on open blossoms and the Apogee with provide some control for potential shoot strikes in the near future. This approach is possible and recommended by some Extension pathologists. The label goes on to say that if the water source used for spray applications contains high levels of calcium carbonate (hard water), add one pound of ammonium sulfate (AMS) for every pound of Apogee. Use high quality spray grade AMS to avoid plugging nozzles.

Further, timing is important for applications of Apogee. A publication by Dr. George Sundin of Michigan State University states, “Timing is critical for Apogee applications. The first application should be made at petal fall of the king bloom to coincide with the earliest period of most rapid shoot growth. If desired, growers can apply Apogee two or three more times at 2-week intervals after the king bloom petal fall application.” View the full publication here: Sundin-Pages-9-14-from-NYFQ-Book-Summer-2014-3.pdf (nyshs.org)

Early shoot blight infection, unprotected pears

Early shoot blight infection, unprotected pears. Photo: Jeremy DeLisle

 Apple Scab

NEWA models show that we are nearing the end of primary season with nearly all ascospores mature at this point. I’ve found infections from primary season in unsprayed orchards just showing up last week, so growers should be scouting now to see how their control measures worked out. If you’re clean at this point, it’s likely that protection for a couple more weeks will wrap up the scab season for you. If you think you may have had a gap in coverage, consider including a single-site scab specific fungicide.

Early apple scab infection

Early apple scab infection. Photo Credit: Jeremy DeLisle

 Plum curculio

Curculio is becoming active and with the hot temps predicted this week they will be on the move in some orchards. We’ll be awaiting petal fall for the whole orchard spray, and not before, to ensure the protection of pollinators. After the whole block cover spray at petal fall, we’ll monitor the perimeter for fresh egg laying scars to determine the need for follow-up sprays, likely only to the border rows.

 Plum curculio egg laying scar on pear

Plum curculio egg laying scar on pear. Photo: Jeremy DeLisle

Codling moth

We finally captured out first codling moth in our traps in Merrimack County as of today, May 20th. We’ll keep a close eye on the traps for the next couple of days to ensure sustained catch and set our biofix date in NEWA. Depending on how quickly petal fall comes around, it may line up nicely to apply a material that has efficacy against both PC and CM.

Wooly apple aphids

I’ve seen a few woollies here and there developing their “wool” on old pruning cuts mostly. Petal fall will be your best opportunity for control if populations are concerning.

Wooly apple aphid aerial colony forming

Wooly apple aphid aerial colony forming. Photo: Jeremy DeLisle

Peach leaf curl

This season seems to be a significant one for peach leaf curl infections. Some specialists feel this has to do with the fact that spray schedules were lessened last season due to losing the crop to the freeze event. The question has come up asking if perhaps some of our brown rot fungicide applications could also be helping to suppress leaf curl. Either way, growers should likely plan both a fall and spring application this year and into 2025 to help ensure this fungal disease is kept in check.

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5/23/2023

Hi all!!  

 

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is May 23rd , 2023.

 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

 

In terms of growing degree days in Concord, NH we have accumulated 519 GDD in BE base 43F and 196 GDD in BE base 50F.

Lets dive into the frost event everyone has been talking about:

The frost event that occurred very late Wednesday, May 17th and into the late morning hours of May 18th caused extensive and quite variable damage across New Hampshire farms. Low temperatures reported ranged from 31F in Farmington to as low as 23F in Lebanon. While we had already lost our peach crop back on a single night in February, apples, pears, blueberries, strawberries and grapes were relatively undamaged until last week. While initial assessments are still underway, and damage varies considerably across locations and varieties, there was significant damage to apples, blueberries, and unprotected strawberries. We are not as certain about grapes and brambles at this point, but some potential damage is expected. Producers should document damage, contact their insurance providers and connect with their Extension specialists to evaluate and document damage, and develop appropriate IPM plans for the season based on the situation at their specific locations. Many questions are arising as to management decisions for the season ahead. Included below are a few resources as a start that may be helpful for some crops:

Apple Thinning Recommendations After the Frost: A Case-by-Case Scenario – Wisconsin Fruit

After the Freeze 2020 | Purdue University Facts for Fancy Fruit

Disease management after bad frost events? – Virginia Grape Disease Updates (grapepathology.org)

Strawberry Disease Management | Purdue University Facts for Fancy Fruit

 

Jumping into the plant pathogen updates:

Apple scab:

 50% Macintosh green tip date was established on 4/12 in Concord. This is the biofix to start the apple scab model in NEWA. Enter the date that this occurred in your orchards for the best accuracy from the model. The rains last week triggered a large ascospore release with 85% mature and ready to go prior to the rain event. Dry weather leading up to that point allowed for the accumulation of ascospores that were just waiting for moisture to be released. This is the time to use your more effective systemic materials along with a multisite such as Captan or Mancozeb. FRAC group 7 fungicides are preferred during this time of peak scab activity. Details on rotational options with other FRAC groups can be found here: https://extension.psu.edu/2023-disease-update-scab-and-fire-blight-infections-forecasted-for-the-weekend. We are now nearing the end of the primary scab season, with approximately 94% of ascospores mature as we head into a predicted infection event on Wednesday May 24th. Once this event has passed, maintain protection for approximately two weeks to ensure the last of the ascospores are controlled.

Consider some of the single site fungicides with the ability to translocate within leaf tissue for added control and some ability to kill very recent infections. An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

Marssonina (Apple Blotch):

While we are currently in the tail end of primary apple scab season, you should remember that this fungus is also a concern and can be controlled with many of the same fungicides that control apple scab. The period of main concern is really at the tail end of apple scab season, but be aware and read up here about when and how to best control it. Keep an eye on any brown lesions beginning to form on your leaves – could be apple scab, could be marssonina!  Apple scab resistant  varieties tend to be the most susceptible to marssonina.

Fire Blight:

Much of the state is past bloom with apples and pears ranging from late bloom to fruit set depending on location and variety. We had infection events on May 11,12 and 13. Many growers elected to make a streptomycin application during that timeframe. Temperatures have been too cool beyond that event to worry much about infection. With warm temperatures predicted next week, any open flowers should be protected. Check the NEWA models for infection risk in relation to the crop development stage at your orchard. The take home message is that blossoms that have opened since your last application need to be covered with your material of choice. Continue to watch the weather forecast and cross-reference NEWA to best time applications.

Important: Any open blossoms still on trees should be considered vulnerable to infection from fireblight. Jeremy Delisle spoke with Penn State Tree Fruit Pathologist, Kari Peter on 5/22/23, and she explained that the nectaries on remaining flower blossoms are still open and present a potential infection pathway for fireblight. Continue to watch NEWA models until petal fall is complete and protect flowers as usual based on predicted risk and infection events.

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

Powdery mildew:

Dry periods during scab season can be a prime time for infection by powdery mildew. Group 3 fungicides used for scab control will also control PM. Consider saving the group 11 fungicides until petal fall for control of summer diseases. Sulfur is also a good choice for PM control in conventional and organic orchards.

Powdery Mildew | New England Tree Fruit Management Guide (netreefruit.org)

 

Insects:

Plum curculio:

Control typically begins at petal fall with a whole block spray, followed by 1 or 2 perimeter row sprays depending on the weather and progression of this insect through its’ life cycle. Egg laying typically stops around 308 degree days after petal fall, at which time the need for targeted control generally stops. With this season progressing slowly so far with these cool temperatures, we are gaining degree days slowly. This means that the egg laying period for PC may be extended unless the temperatures drastically warm up.  Some southern NH orchards already have fruit at a susceptible stage for PC damage, as the insect prefers fruit at the 3-5 mm size for egg laying. Temperatures this week will certainly be warm enough for PC activity, so blocks of trees that are past petal fall should be protected. While few egg laying scars have been found while scouting orchards, Plum curculio will certainly be active this week.

Plum curculio (PC) | New England Tree Fruit Management Guide (netreefruit.org)

 

Codling moth:

In Concord we have yet to establish the biofix to start the codling moth model within NEWA. Southern NH has established the biofix from sustained trap captures of codling moth as of 5/22/23. Southern growers without traps on their farms could enter this date to start the degree day clock running for egg hatch by this pest, which is expected at 220 –250 DD at 50F from sustained catch.

Traps should be up and monitored daily in order to best track the development of this insect. Once sustained trap captures have been observed, enter the biofix date for your farm into the NEWA model to track development of the pest as egg laying approaches.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Interested in more details on how degree days are used to inform codling moth management practices?

Cornell has a wonderful fact sheet that talks about this, check out the quick summary below or check out the entire resource at this link: doc_72.pdf (cornell.edu)

Time insecticide applications based on trap data and degree day (DD) models for egg hatch. Spray timing for these pests is directed at newly hatched larvae, since most insecticides are not effective at controlling adults. There is a lag period for egg hatch after the moths fly. The first spray for CM is recommended at first egg hatch, which occurs 220-250 DD (base 50°F) after sustained trap catch. But the timing depends on insecticide choice. Rimon (which is more ovicidal) should be applied at 75-100 DD 50°F after CM biofix; for Calypso, Assail, Delegate, Altacor, Belt, or Voliam Xpress or Voliam Flexi, 200-250 DD 50°F after biofix. An additional option is to apply a granulosis virus formulation at 200-250 DD 50°F. High moth pressure requires 2-3 sprays for the first generation, but in lower pressure orchards (with counts of less than 5 moths per trap per week), you can control CM with a single spray timed at 350 DD 50°F. Research in Washington and Michigan has shown that codling moth mating and egg laying activities take place primarily during a four-hour period, beginning around dusk, if temperatures are above 60°F during that period. Temperatures below 60°F impede male activity and prevent mating, so a cooler spring will delay significant egg hatch for the first generation. If weather data is available to predict this, it can be incorporated into the degree day model as egg hatch will occur 220 DD 50°F after the first flight when evening temperatures >60F. The first insecticide spray for OFM in peaches is recommended at 175 DD (base 45°F) after biofix (petal fall) and a second spray 10-14 days later, until trap counts subside; in apples, 1st generation OFM can be controlled with the petal fall spray. In summer, sprays for OFM in apples are applied 3-4 days after peak trap catch, or 7 days after the start of the 2nd flight.

 

Thinning

After the frost event on 5/18/23, most growers are holding off on thinning for now. We are at an interesting spot, still assessing fruit damage, while still waiting to see how much of the apple crops will survive and remain on the trees to be considered “set”. More information is expected this week. UNH Extension has been in communication with Dr. Duane Green of UMass, and anticipate recommendations and considerations given the conditions experienced in New Hampshire and New England this spring.

The opportunity to thin potential fruit load begins at bloom and lasts until 3-4 weeks post petal fall. Consider using the Carbohydrate Thinning Model in NEWA to help make the best thinning management decisions based on factors such as localized weather patterns and other site-specific factors. This UMass resource outlines the best options and key considerations for chemical thinning: Fruit: HRT-Thinning Apples Chemically | Center for Agriculture, Food, and the Environment at UMass Amherst

 

RMA Apple Insurance Listening Session:

 

June 27, 2023 : Goffstown, New Hampshire

10:00 a.m. to 12:00 p.m., Hillsborough County Extension Office (Large Conference Room)

329 Mast Rd., Goffstown, NH 03045

No RSVP required.

 

Details here: Summer 2023 Apple Grower Meetings | RMA (usda.gov)

Twilight Meetings:

The schedule is out for all of extension’s summer twilight meetings, and I wanted to highlight a few that may be of interest to the folks that tune into this call – the full list of Extensions event offerings this summer can be found on our website!

Tree Fruit meeting at Demeritt Hill Farm, July 15th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at DeMerritt Farm | Extension (unh.edu)

Tree Fruit meeting at Apple Hill Farm, August 17th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

 

All of the Production agriculture Twilight meetings:

2023 Production Agriculture Summer Twighlight Meeting | Extension (unh.edu)

 

Thank you for sticking around until the very end!  See you next week!

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6/04/2024

Fruit IPM Update:

All degree day totals, and model outputs are based on data collected from a NEWA-connected weather station in an orchard in Concord, NH. Be sure to enter your specific biofix dates for your farm for the best results and accuracy.

Today we are at a total of 828 DD 43F BE and 463 DD 50F BE since January 1, 2024.

Plum curculio

Adults are currently active and laying eggs in susceptible fruit.

PC activity is highly dependent upon temperatures, particularly at night when adults are most active. PC usually do not feed or oviposit when nighttime temperatures are below 50°F. We did have some recent nighttime temps in the 40’s, so this may prolong egg laying slightly, although daytime temperature may make up for the low night temps. If the weather is extremely warm after petal fall, the oviposition cycle may be completed in 2 weeks. In cooler seasons, PC may continue to oviposit for 4-6 weeks.

A petal fall full-orchard spray should control plum curculio (PC) for about 10-14 days. Incidence of observed PC damage is highly variable among different orchards. PC damage usually occurs primarily along the edges of commercial orchards, and noticeable damage occurs in the same locations in orchards year after year, regardless of treatment levels. Therefore, the potential for damage in any particular orchard can be predicted from past observations. Usually, a post-petal fall spray for control of PC is not necessary in low-pressure orchards in which no damage has been observed in the past.

In high-pressure orchards, after the full-orchard petal fall spray, additional sprays along the perimeter of the orchards should be applied until the oviposition model predicts that control is no longer necessary, which is when at least 308 DD has accumulated after petal fall.

In Concord today we are predicted to reach 174 DD 50F BE. We have been accumulating around 20-degree days each day on average. If this holds true for the next 7 days, we should be approaching the end of the PC oviposition period by the end of next week. Plan your scouting and applications accordingly. Continue to monitor fruit clusters on the perimeter of orchard blocks for fresh egg laying activity and consider an additional application of an insecticide if found.

For those looking to improve their monitoring of PC going forward, here is a resource which clearly defines the protocol: https://ag.umass.edu/fruit/fact-sheets/apple-ipm-plum-curculio-monitoring-using-lures

Codling moth

We are using a biofix date of 5/17 for sustained capture for Concord, NH.

Looking at the NEWA (Network for Environment and Weather Applications) models, we are reminded that eggs usually begin to hatch about 220 DD after the first catch and catches of adults should be increasing in pheromone traps. We saw this to be true for us last week. Hopefully, you have traps up and can set your specific biofix to best time CM development in your orchard.

Further, it is recommended to apply the first spray for control of overwintering CM at 250 DD after first catch. In Concord today, we are predicted to reach 280 DD, so many of the eggs laid by this first generation have begun hatching this week. Control is important this week. These larvae will likely cause fruit to drop if infested. The next critical opportunity for control of hatching larvae will be around 1400 to 1600 DD base 50F BE after the initial biofix date used to start the model running.  

Michigan State has a helpful resource addressing insecticide choices, timing, and efficacy, both on CM along with other pest potentially present at the time of application. View it here: https://www.canr.msu.edu/news/codling-moth-management-options-for-michigan-apples

Oriental Fruit Moth

May 15th is our biofix for OFM in Concord, NH.

Moths are still flying, and it is estimated that about 50-60% of OFM eggs from the first generation have hatched. Insecticides targeted at CM will control OFM.

Check the time elapsed after petal fall to determine the exact timing of this second spray, assuming a petal fall spray for PC effective against OFM has been applied. This second spray should be applied about 10-14 days after petal fall. This second spray against the first generation of OFM is particularly important in high-pressure orchards (past history of OFM fruit damage or high pheromone traps catches, (>10/ trap/ week) to control the remainder of hatching larvae. If this spray is applied at the normal time of a first cover spray (10-14 days after petal fall) it will also control early hatching CM larvae from the first flight of adults. This should be right about now in Concord.

OBLR

We have yet to catch oblique banded leaf roller in our traps in Merrimack County. I have heard reports from regional IPM specialists that they have caught perhaps their first single moth. I’ll update our trapping results next week.

Apple scab

Primary scab season is over. Ascospores were essentially all released on May 18. If you are unsure whether ascospores have been depleted in your orchard, enter your green tip date to recalculate ascospore maturity for your orchard.

Good control of primary infections allows use of fungicides to be reduced or omitted during the summer, once ascospores have been depleted and fruit become less susceptible. Control of primary infections has traditionally begun at or shortly after green tip, when the first ascospores become mature.

After ascospores are depleted, continue to monitor scab infection events, and maintain spray coverage accordingly for at least one more week. Scout orchards for primary scab infections after this time. If you do have scab lesions showing up now, there is a predicted infection event June 6th and 7th, so be sure to protect for that in advance.

Fireblight

We are beyond the highest risk periods for blossom infections.

There have been some reports from surrounding states of shoot strikes beginning to show up. Be sure to scout regularly and cut out strikes as soon as possible if they show up. Prioritize young orchards first to prevent strikes from reaching the central leader. Then move on to mature high density and semi-dwarf plantings. The latest recommendations suggest cutting 18” or more below visible symptoms. Remember that Actigard is labeled for what is commonly referred to as the paint method. See label for clarification: https://www.syngenta-us.com/current-label/actigard_50wg

NEWA now has a feature to help you time shoot blight scouting associated with trauma events, and one to help determine when the infection occurred.

Example of NEWA feature that helps you time shoot blight scouting associated with trauma events, and one to help determine when the infection occurred.

Thinning

Orchards are reporting anywhere from zero to three thinner applications at this point. Many are either in or slightly past the ideal thinning window. Remember to check out the Apple Carbohydrate Thinning model on NEWA to give you a sense of how well your thinners should work given the weather window near which you are applying. A guide for thinning material and timing, along with rates can be found here. From what I’ve seen, many orchards are happy with their thinning results at this point. Applications of NAA alone or with carbaryl, and in many cases again with carbaryl alone have produced good results. The fruit I’ve measured is in the range of 9 to 18 mm depending on variety.

Enhancing return bloom of apples

While we are still early for this yet, it seems appropriate to put the subject out for consideration. Not knowing how many NH growers implement the practice of applying hormonal type chemical thinners including NAA and ethephon, it seems like a topic of interest to some based on conversations around biennial cropping, especially in Honeycrisp. If a grower were interested, applications are recommended to begin when king fruit are 30-35 mm. The number of applications varies by variety. Details can be found here. Additional research and recommendations specific to Honeycrisp can be found here.

Honeycrisp fruitlets nicely thinned. Photo: Joe Rolfe, Stone Mountain Farm, Belmont, NH

Honeycrisp fruitlets nicely thinned. Photo: Joe Rolfe, Stone Mountain Farm, Belmont, NH

Peach leaf curl

Just a quick note to address the peach leaf curl situation showing itself in many locations of the state. This fungus cannot be controlled at this point in the season. The only thing to consider at this point to help the trees deal with some potential leaf loss as a result of this infection would be to minimize stress (water, insects, etc.) and supply an additional round of nitrogen fertilizer to help them replace lost leaves with new growth as the season picks up steam.

Upcoming Events:

June 19 - Tree Fruit Twilight Meeting at Sunnycrest Farm | Extension (unh.edu)
August 21 - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

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5/02/2023

Hi all!!  

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is May 2nd, 2023.

 While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit pest hotline transcripts” to find them on our webpage. 

 In terms of growing degree days in Concord, NH we have accumulated 191 GDD in BE base 43F and 73 GDD in BE base 50F.

Lets jump right into plant pathogen updates for the apple growers.

Apple scab:

 The 50% Macintosh green tip date was established on 4/12 in Concord. This is the biofix to start the apple scab model in NEWA. Enter the date that this occurred in your orchards for the best accuracy from the model. Ascospores are developing slowly under these cool conditions, with around 31% of spores expected to be discharged by the end of the predicted infection event running through Thursday, May 4th. The forecast currently shows a break in the rain by the afternoon of May 4th. This will be a good time to reapply fungicides and possibly use one of the materials with kickback activity depending on how well you were going into this rainy stretch and your scab pressure from last season.

Preventative fungicides such as Captan, Mancozeb or combinations of these and similar multi-site products are good choices at this stage in the season. Captan 80 and Mancozeb at 2.5 and 3 lbs/ac respectively, reapplication if more than 1”. Consider mixing these materials with a single site fungicide from group 3 as we approach pink into bloom, as this is when the maximum amount of ascospores are released. With warmer temperatures coming in on Saturday, May 6th, a wetting event will require fewer hours to cause an infection. Hopefully we will start to dry out in time for bloom in most locations.

As we get reach pink and bloom stages with long periods of leaf wetness, consider some of the single site fungicides with the ability to translocate within leaf tissue for added control and some ability to kill very recent infections. An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

 Marssonina (Apple Blotch):

While we are currently in the first half of apple scab season, you should remember that this fungus is also a concern and can be controlled with many of the same fungicides that control apple scab. The period of main concern is really at the tail end of apple scab season, but be aware and read up here about when and how to best control it.

2023 Disease Update: Disease Conditions Favored for Marssonina Blotch and Apple Scab April 28–May 1 (psu.edu)

Fire blight:

Remember that using the fireblight model in NEWA begins with selecting the current infection pressure from the drop-down menu in the fireblight model. Choose between the three various scenarios based on your specific conditions.

Blossom blight infection risk is tracked by the accumulation of 4-day degree hour totals beginning at bloom. NEWA begins degree hour accumulation on the date of full pink or "first blossom open" for McIntosh apple. It is best if you enter your start date based on blossom dates in your apple or pear orchards and recalculate Cougarblight risk predictions.

Typically, the first few blossoms that open are a few days ahead of true first bloom because they are close to sunny large scaffolds or trunks. Fire blight bacteria are rarely active at the very early bloom time, so getting the "first blossom open" date exact is not critical. Continue monitoring the fire blight risk predictions and watching your orchards for secondary bloom because, although infection of secondary bloom may be less dangerous than that of primary bloom, infection of secondary bloom leads to continued high disease activity and higher risk in subsequent years.

Reports from southern NH indicate that the first king blossoms on early varieties such as Zestar! are just barely starting to open as of May 1. Pay attention to those Macintosh trees as we enter the beginning of next week to get an accurate date for the biofix for this model in NEWA. Temperatures will be just warm enough by the middle of next week to start paying attention for infection events. One good thing about this cool weather is that it has ruled out fireblight infections up until now. Next week we should start to pay attention in earnest.

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

 Powdery mildew:

Dry periods during scab season can be a prime time for infection by powdery mildew. Group 3 fungicides used for scab control will also control PM. Consider saving the group 11 fungicides until petal fall for control of summer diseases.

Powdery Mildew | New England Tree Fruit Management Guide (netreefruit.org)

 Now moving onto the insect pests:

Tarnished Plant Bug:

Tarnished Plant Bug captures in white sticky traps have remained very low. Numbers have been suppressed due to cold temperatures.

Tarnished Plant Bug (TPB) | New England Tree Fruit Management Guide (netreefruit.org)

Oriental Fruit Month:

 Pheromone traps and mating disruption dispensers should be deployed at the beginning of the pink bud stage. The first catch of moths from the overwintering generation is expected to be soon. Flight of OFM usually begins when trees are in the pink or bloom bud stages. No insecticides need to be applied until eggs begin to hatch; since OFM flight usually begins at bloom, it is not possible to apply an initial spray to kill adults.

 Oriental fruit moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

 Oblique banded Leaf roller and Red Banded Leaf Roller:

high numbers in NY. This isn’t necessarily an indicator of what we will see in NH, but we should have our traps out and eyes open.

Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

Redbanded Leafroller [fact sheet] | Extension (unh.edu)

For the Oblique banded Leaf roller, almost all overwintering larvae have emerged by the end of the pink bud stage. Overwintering larvae can be sampled starting at the pink bud stage. A control spray can be applied during pink if larval populations exceed a threshold of 3% clusters infested with live larvae.

Codling Moth:

The average 1st catch 475 DD base 43, mating disruption with granulosis virus is a good option, Altocor for 1st gen, Assail for 2nd gen will also control apple maggot. Altacor, Exirel, Verdepryn are worth considering as control options at first hatch for codling moth. These group 28 insecticides have efficacy against many lepidopteran species as well as plum curculio. Codling moth becomes the driver for insect sprays after petal fall along with plum curculio.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

In General:

Bt (Dipel is a good choice early) in the development of lepidopteran pests. Avoid applications during bloom.

Rosey Apple Aphid:

Control can start at pink. Petal fall may be best timing.  Be scouting now to be aware of possible aphid hot spots.

Aphid: Rosy Apple Aphid | New England Tree Fruit Management Guide (netreefruit.org)

European Red Mite:

Look for overwintering eggs now. Treatment windows range from green tip to pink, and then resume after petal fall. Generally, some control before pink combined with concentrated control around petal fall will provide best season-long control.

Mites (European Red Mite [ERM] and Two-spotted Spider Mite [TSSM]) | New England Tree Fruit Management Guide (netreefruit.org)

 Finally:

We received a question recently about boron applications for apples. This is an important nutrient for apples for pollen tube development, feeder root growth and translocation of calcium, among other functions. Details about the roles of various macro and micronutrients in apples can be found here: http://fruitadvisor.info/tfruit/clements/articles/nutrientrecs.pdf

 Thank you for sticking around until the very end!  See you next week!

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4/25/2023

Hi all!!

Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is April 25, 2023.

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM Reports” to find them on our webpage or visit: https://extension.unh.edu/resource/fruit-ipm-reports

In terms of growing degree days in Concord, NH we have accumulated 222 GDD in BE base 43F and 98 GDD in BE base 50F.

Home | NEWA (cornell.edu)

Lets jump right into plant pathogen updates for the apple growers.

For Apple Scab:

The 50% Macintosh green tip was established on 4/12 in Concord, so 4/12 is the biofix date to start using the scab model in NEWA if you are located around Concord.  Enter the date that this occurred in your orchards for the best accuracy from the model. 

The rain the past few days meant that most folks around the state had an apple scab infection period over the weekend, definitely on Sunday, and NEWA predicts that infection period will extend into tomorrow, April 26th.   Now is the time to consider if you need to spray any kickback products on your trees to address the spores released during this infection event – remember, the closer to the actual day of infection, the more effective that kickback product will be. 

An excellent description of the factors to consider for best fungicide selections can be found the New England Tree Fruit Management Guide, which can be found online at: https://netreefruit.org/apples/diseases/apple-scab

 For Fire Blight:

Right now, you want to be scouting for oozing cankers left in the orchards – these cankers indicate ongoing infections and will be a source of inoculum this spring. 

Copper applications between silver tip and ½’ green tip are used to reduce overwintering fire blight bacteria (and apple scab).

NEWA’s fire blight forecasting model begins with selecting the current infection pressure from the drop-down menu in the fire blight model. Choose between the three various scenarios based on your specific conditions at your orchard for the most accurate predictions. You will also want to input the start date of the first blossom open for your own orchards to make sure the model is accurate. 

The cooler temperatures this week mean that the fire blight infection risk is low – but remember that risk with increase significantly once the temps warm up and more blossoms open – so make sure that you have plan for infection events in the near future.

Moving on from the pathogens, and onto the insect pests:

I don’t have too many updates from last week, and just as a reminder, much more information on these pests (including recommended chemical controls) can be found in the transcripts posted online of this call. Simply google “UNH Fruit IPM Reports” to find them on our webpage.

Pear psylla:

Should be addressed early, scout for eggs on buds and leaves, new eggs light yellow, older are darker yellow. Nymphs are showing up in NY, so they are on their way.

Pear psylla | New England Tree Fruit Management Guide (netreefruit.org)

San Jose Scale:

Consider the treatment of blocks where populations are building. An application of dormant oil or an effective insecticide directed against the overwintering immatures under the ‘black cap’ scale covers on trunks and scaffold branches between the half-inch green and tight cluster stages will effectively reduce the potential for serious infestations later in the season. Prebloom sprays are more effective if applied dilute, at high volume; for severe infestations, follow up with summer applications of appropriate materials. Suggested action threshold: 3-6 encrusted areas per tree. Esteem/Centaur and oil is a good combo early.

San Jose scale (SJS) | New England Tree Fruit Management Guide (netreefruit.org)

Dogwood Borer:

Reminder that mating disruption works well for this pest. Trunk sprays are recommended between pink and mid-June.

Borers | New England Tree Fruit Management Guide (netreefruit.org)

European Red Mite:

Minimal numbers found to date. Look for overwintering eggs around the base of limbs on main trunk. Treatment windows range from greet tip to pink, and then resume after petal fall. Generally, some control before pink combined with concentrated control around petal fall will provide best season-long control.

Mites | New England Tree Fruit Management Guide (netreefruit.org)

Tarnished plant bug:

 Sticky traps should be out now, broadleaf weeds in orchard and along perimeter are common. Look for feeding damage to buds now.

Tarnished Plant Bug (TPB) | New England Tree Fruit Management Guide (netreefruit.org)

Red Banded Leaf Roller:

Are laying eggs and larvae beginning to hatch in NY. RBLR causes damage at feeding sites under leaves resting on fruit.

Redbanded Leafroller [fact sheet] | Extension (unh.edu)

Codling Moth:

Currently overwintering in the pupal stage. First adult capture usually occurs at 220 DD – 50F BE. Concord is at roughly 98 DD 50 BE at the this time, so not quite there. Pheromone traps should be in place before the first apple blossoms open. Mating disruption dispensers should also be put in the orchard before the first blossoms open for seasonal disruption programs.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Spotted Tentiform Leaf Miner:

 Moth flight beginning. The first flight of STLM adults usually begins between the green tip and half-inch bud stage. No control measures are recommended against adults. It is very difficult to predict larval infestation levels from adult catches in pheromone traps. Sometimes catches may be very high, but if conditions are unfavorable for oviposition during the flight in the spring (cold, rainy, and windy weather – just like we had this week!), very few eggs are laid and subsequent larval populations will be low.

Leafminers (LM) | New England Tree Fruit Management Guide (netreefruit.org)

Green speckled fruit worm:

Are laying eggs and larvae beginning to hatch in NY.

Speckled green fruitworm | New England Tree Fruit Management Guide (netreefruit.org)

Oriental Fruit Moth:

 No OFM flight is expected currently. Pheromone traps and mating disruption dispensers should be deployed at the beginning of the pink bud stage.

 Oriental Fruit Moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

 Oblique banded leaf roller (OBLR):

 Overwintering OBLR larvae usually begin to emerge at the half-inch green growth stage. No control measures are recommended at this time because most overwintering larvae have not yet emerged and will escape residual effectiveness of most insecticides.

 Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

 That’s all that I have for the hotline this week!

As always, refer to the tree fruit guide for more info and recommendations:

 New England Tree Fruit Management Guide | (netreefruit.org)

 See you all next week!

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4/18/2023

Hi all!!

Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team. 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit pest hotline transcripts” to find them on our webpage.

In terms of growing degree days in Concord, NH we have accumulated 126 GDD in BE base 43F and 70 GDD in BE base 50F.

Home | NEWA (cornell.edu)

Lets jump right into plant pathogen updates for the apple growers.

For Apple Scab:

The 50% Macintosh green tip was established last week on 4/12 in Concord, so 4/12 is the biofix date to start using the scab model in NEWA if you are located around Concord.  Enter the date that this occurred in your orchards for the best accuracy from the model. 

Ascospores are developing slowly, with around 3% of spores expected to be discharged by the end of the predicted infection event running through Tuesday, April 18th. More rain is predicted later in the week through Monday, April 24th, so protection going into that stretch with a rain-fast product is advisable.

Preventative fungicides such as Captan, Mancozeb or combinations of these and similar multi-site products are good choices at this stage in the season. Captan 80 and Mancozeb at 2.5 and 3 lbs/ac respectively, reapplication if more than 1”.

 Remember that Captan and oil should not be applied within 7-10 days of one another to prevent phytotoxicity, particularly after a frost or slow drying conditions.

As we get reach pink and bloom stages with long periods of leaf wetness, consider some of the single site fungicides with the ability to translocate within leaf tissue for added control and some ability to kill very recent infections.

It is also worth noting is that some fungicides such as the groups 3, 7, 9 and 11 have activity on other fungal pathogens of controlled during this time of year, such as powdery mildew, rusts, black and white rot. Single site fungicides should be added around bloom or if several days of rain are predicted.

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

 For Fire Blight:

Scout for oozing cankers left in the orchard after dormant season pruning as these cankers are an indicator of ongoing infections. Copper applications between silver tip and ½’ green for reduction of overwintering fire blight bacteria (and apple scab).

NEWA’s fire blight forecasting model begins with selecting the current infection pressure from the drop-down menu in the fire blight model. Choose between the three various scenarios based on your specific conditions.

Blossom blight infection risk is tracked by the accumulation of 4-day degree hour totals beginning at bloom. NEWA begins degree hour accumulation on the date of full pink or "first blossom open" for McIntosh apple. It is best if you enter your start date based on blossom dates in your apple or pear orchards and recalculate Cougar blight risk predictions.

Typically, the first few blossoms that open are a few days ahead of true first bloom because they are close to sunny large scaffolds or trunks. Fire blight bacteria are rarely active at the very early bloom time, so getting the "first blossom open" date exact is not critical. Continue monitoring the fire blight risk predictions and watching your orchards for secondary bloom because, although infection of secondary bloom may be less dangerous than that of primary bloom, infection of secondary bloom leads to continued high disease activity and higher risk in subsequent years.

More info can be found here: Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

 Now moving onto the insect pests. 

As a reminder, much more information on these pests (including recommended chemical controls) can be found in the transcripts posted online of this call. Simply google “UNH Fruit pest hotline transcripts” to find them on our webpage.

Pear psylla:

Should be addressed early, scout for eggs on buds and leaves, new eggs light yellow, older are darker yellow. Nymphs are beginning to show up this week in NY, which is an early indicator of development for us here in NH.

Pear psylla | New England Tree Fruit Management Guide (netreefruit.org)

 San Jose Scale:

Consider the treatment of blocks where populations building. An application of dormant oil or an effective insecticide directed against the overwintering immatures under the ‘black cap’ scale covers on trunks and scaffold branches between the half-inch green and tight cluster stages will effectively reduce the potential for serious infestations later in the season. Prebloom sprays are more effective if applied dilute, at high volume; for severe infestations, follow up with summer applications of appropriate materials. Suggested action threshold: 3-6 encrusted areas per tree. SJS – Overwintering. Esteem/Centaur and oil is a good combo early.

San Jose scale (SJS) | New England Tree Fruit Management Guide (netreefruit.org)

Dogwood Borer:

Reminder that mating disruption works well for this pest. Trunk sprays are recommended between pink and mid-June.

Borers | New England Tree Fruit Management Guide (netreefruit.org)

European Red Mite:

Minimal numbers found to date. Look for overwintering eggs around the base of limbs on main trunk. Treatment windows range from greet tip to pink, and then resume after petal fall. Generally, some control before pink combined with concentrated control around petal fall will provide best season-long control.

Mites | New England Tree Fruit Management Guide (netreefruit.org)

Tarnished plant bug:

 Sticky traps should be out now, broadleaf weeds in orchard and along perimeter are common. Look for feeding damage to buds now. 3 timings beginning at TC, P, PF, pyrethroids work well.

Tarnished Plant Bug (TPB) | New England Tree Fruit Management Guide (netreefruit.org)

Red Banded Leaf Roller:

 Are laying eggs and larvae beginning to hatch in NY. RBLR causes damage at feeding sites under leaves resting on fruit.

Redbanded Leafroller [fact sheet] | Extension (unh.edu)

Codling Moth:

Currently overwintering in the pupal stage. First adult capture usually occurs at 220 DD – 50F BE. Concord is at roughly 84 DD 50 BE at the this time, so not quite there. Pheromone traps should be in place before the first apple blossoms open. Mating disruption dispensers should also be put in the orchard before the first blossoms open for seasonal disruption programs.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Spotted Tentiform Leaf Miner:

 Moth flight beginning. The first flight of STLM adults usually begins between the green tip and half-inch bud stage. No control measures are recommended against adults. It is very difficult to predict larval infestation levels from adult catches in pheromone traps. Sometimes catches may be very high, but if conditions are unfavorable for oviposition during the flight in the spring (cold, rainy, and windy weather), very few eggs are laid and subsequent larval populations will be low.

Leafminers (LM) | New England Tree Fruit Management Guide (netreefruit.org)

Green speckled fruit worm:

Are laying eggs and larvae beginning to hatch in NY.

Speckled green fruitworm | New England Tree Fruit Management Guide (netreefruit.org)

Oriental Fruit Moth:

 No OFM flight is expected currently. Pheromone traps and mating disruption dispensers should be deployed at the beginning of the pink bud stage.

 Oriental Fruit Moth (OFM) | New England Tree Fruit Management Guide (netreefruit.org)

 
Oblique banded leaf roller (OBLR):

 Overwintering OBLR larvae usually begin to emerge at the half-inch green growth stage. No control measures are recommended at this time because most overwintering larvae have not yet emerged and will escape residual effectiveness of most insecticides.

 Obliquebanded leafroller (OBLR) | New England Tree Fruit Management Guide (netreefruit.org)

 

Notes on the control of Lepidopteran Pests:

Bt (Dipel is a good choice early) can be helpful, but avoid applications during bloom.

Altacor, Exirel, Verdepryn are worth considering as control options at first hatch for codling moth. These group 28 insecticides have efficacy against many lepidopteran species as well as plum curculio. Codling moth becomes driver for insect sprays after petal fall along with plum curculio.

Rosey Apple Aphid control can start at pink. Petal fall may be best timing.

As always, refer to the tree fruit guide for more info and recommendations!

 New England Tree Fruit Management Guide | (netreefruit.org)

 One Final announcement:

 SEEKING PARTICIPANTS FOR A STATEWIDE NATIVE BEE PROJECT!

 Shyloh Favreau, a M.S. student at UNH (you may know him as the Extension Program Manager for our Soil Testing Service) is looking for apple orchards across New Hampshire to participate in his thesis project investigating the native bee communities during peak apple bloom, 2023. This project would involve a couple (4 people at most) of Extension staff and undergraduate students coming to your orchard once or twice during peak bloom to collect bees in nets and bowls with a follow up survey later in the season. Please reach out to Shyloh for more details and if you would like to participate in his study. Cell phone: 828-964-8404, Email: Shyloh.Favreau@unh.edu.

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5/30/2023

Hi all!!  

 

 Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team.   Today is May 30th , 2023.

 

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

 

In terms of growing degree days in Concord, NH we have accumulated 634 GDD in BE base 43F and 260 GDD in BE base 50F.

Lets dive into the frost event everyone has been talking about:

The frost event that occurred very late Wednesday, May 17th and into the late morning hours of May 18th caused extensive and quite variable damage across New Hampshire farms. While we had already lost our peach crop back on a single night in February, apples, pears, blueberries, strawberries and grapes were relatively undamaged until last week. While initial assessments are still underway, and damage varies considerably across locations and varieties, there was significant damage to apples, blueberries, and unprotected strawberries. We are not as certain about grapes and brambles at this point, but some potential damage is expected. Producers should document damage, contact their insurance providers, and connect with their Extension specialists to evaluate and document damage, and develop appropriate IPM plans for the season based on the situation at their specific locations.

I’ll jump into frost damage control/considerations first:

Managing berry planting after frost: (*Northeast Berry Call Recommendations – thanks to all the folks offering advice to the region!)

Pest control:

Plantings with total fruit loss still need to be actively managed for pests and weeds. Potential for botrytis is greater in all affected berries with dead tissue on the plant (black strawberry blossoms, blighted tips of blueberry canes, black bramble flowers). It would be a good idea to spray now for botrytis, especially in strawberries. Other fungal pathogens don’t live in dead tissue as botrytis does, so we only worry about botrytis.

Pruning:

In bush and cane-berries that have a big percentage of crop lost, anticipate summer thinning because extra energy will be allocated to vegetative growth. Perhaps due to the lost crop this year, next year’s crop will be larger.

June-bearing strawberry plantings should not be renovated now if they had total crop loss. They should be renovated in July or August as usual. Additional Nitrogen applications may be helpful in the case of total crop loss by helping the plants put on biomass. Crowns should be cut in half and checked for damage from frost. Depending on the degree of damage there, may have diminishing returns on inputs.

Watering:

Plantings should be watered to minimize drought stress. This might help remaining fruit recover instead of senescing.

Fertility:

 At this point in the season most blueberries have had 1 round of fertilizer applied already. A second round of fertilizer at this point in the season is important because it helps set the fruiting buds. Foliar nutrient sprays are popular amongst growers. Some have seen good results from Megafol (3-0-8). Some growers do 2 applications at a pint/acre each (mid-April and post-bloom), while others do 1 big application at 1 quart/acre each. Some growers also spray potassium on blossoms and developing fruit for winter protection. This is especially done in apples, sometimes on raspberries too. The K+ (potassium) ions prevent the growth of ice-nucleating bacteria; copper sprays work too.

 

Managing tree fruit after frost (Advice from Terence Bradshaw, UVM Extension)

This is just a quick recap, please check out his full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

Thinning:

·      For orchards that have no fruit or heavily damaged fruits (+ 75% ) do not consider thinning this year.

·      For orchards with less than 20%, consider thinning as normal this year.

·      For orchards that have moderate damage between 25 and 75%, the answer is a bit more site-specific. Not thinning those orchards may result in heavy set of small fruit that could promote biennialism, but trees are likely to respond well to thinners applied in the next week, given both the cold damage and the warm sunny, weather that we are expecting coming up.

·      At the UVM Orchard, which experienced moderate fruit damage between 20 and 70%, depending upon cultivar, they decided to apply a low rate of NAA thinner with a low rate of carbaryl insecticide. They have 70 varieties across the whole orchard, and it is difficult to thin based upon variety even in a ‘normal’ year, which is not too different from what many other retail orchards might be dealing with.  It is difficult to provide blanket recommendations to growers given the state of the crop this year.

·      In the end, Dr. Bradshaw recommends trusting your gut – if you have a good crop thin it, if you have a moderate crop consider thinning it lightly as you could always come back in later next week and be better able to visualize the effects of both the frost and any thinner applications you may have applied.

 

Full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

 

More on thinning:

The opportunity to thin potential fruit load begins at bloom and lasts until 3-4 weeks post petal fall. Consider using the Carbohydrate Thinning Model in NEWA to help make the best thinning management decisions based on factors such as localized weather patterns and other site-specific factors. This UMass resource outlines the best options and key considerations for chemical thinning: Fruit: HRT-Thinning Apples Chemically | Center for Agriculture, Food, and the Environment at UMass Amherst

 

Insect management:  (Advice from Terence Bradshaw, UVM Extension)

This is just a quick recap, please check out his full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

·      This will differ depending upon the state of the crop in your orchard.

·      For orchards with a full or even a moderate crop, plan to manage your insect pests as normal this year. Petal fall insecticide sprays should have already gone on in most orchards.

·      Normally petal fall sprays are targeted at European apple sawfly, early emerging codling moth, and plum curculio. All of those pests are fruit feeders so orchards that have no fruit or are assumed to have very little fruit may consider omitting all insecticide applications targeted toward protecting fruit.

·      The difficult situation comes where orchards have a low set of fruit where the expense of the application on a per bushel basis could be quite high but the value of the few apples you have is also high. If there's any question about whether or not you have sufficient crop set in your orchard, it is recommended to go ahead and treat as usual. If you have no crop or nearly no crop, then you may consider omitting those insecticides.

·      However, it is worth it to consider maintaining some coverage primarily for shoot and leaf feeding, lepidopterous caterpillar larvae. That may mean including BT sprays in petal fall, scab, thinning, or other sprays in order to keep down leps like the obliquebanded leaf roller and tent caterpillar.

·      In orchards with little to no crop, the great reduction insecticides used this year may allow beneficial populations to increase substantially, setting you up for a better IPM program next year.

·      It is not recommended to ignore trunk applications of Assail or another appropriate insecticide in young plantings to avoid issues with dogwood and other borers.

 

Full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

Nutrients:  :  (Advice from Terence Bradshaw, UVM Extension)

This is just a quick recap, please check out his full post: VT Apple IPM: Management in light of a difficult crop situation – UVM Fruit Blog

·      For trees with normal or moderate crop load, fertilize as you normally would.

·      For trees with little to no crop nitrogen applications should not go on this year unless trees are under-vigorous.

·      For trees with little to no crop this year potassium is not likely to be removed in any significant amount because that is usually removed in harvested fruit. However, it is important to maintain or improve the potassium status in your orchards to ensure that you have an appropriate amount of that nutrient going into next year when it is likely that orchards will have a heavy crop load.

·      He does recommend thinking about applying magnesium potassium fertilizers in the next month or so regardless of crop status.

 

Included below are some other great resources you may find helpful:

Apple Thinning Recommendations After the Frost: A Case-by-Case Scenario – Wisconsin Fruit

After the Freeze 2020 | Purdue University Facts for Fancy Fruit

Disease management after bad frost events? – Virginia Grape Disease Updates (grapepathology.org)

Strawberry Disease Management | Purdue University Facts for Fancy Fruit

 

Jumping into the plant pathogen updates:

Apple scab:

We are now essentially in the very tail end of primary scab season. All but the very last of the ascospores should be release with the next rain. Maintain protection and continue to scout over the next couple of weeks. Hopefully your orchard is clean of scab and this will mean the end of required control measures for the growing season.

An excellent description of the factors to consider for best fungicide selection can be found here: https://netreefruit.org/apples/diseases/apple-scab

Marssonina (Apple Blotch):

While we are currently in the tail end of primary apple scab season, you should remember that this fungus is also a concern and can be controlled with many of the same fungicides that control apple scab. The period of main concern is really at the tail end of apple scab season, but be aware and read up here about when and how to best control it. Keep an eye on any brown lesions beginning to form on your leaves – could be apple scab, could be marssonina!  Apple scab resistant  varieties tend to be the most susceptible to marssonina.

Fire Blight:

Much of the state is past bloom with apples and pears ranging from late bloom to fruit set depending on location and variety. Check the NEWA models for infection risk in relation to the crop development stage at your orchard. Continue to watch the weather forecast and cross-reference NEWA to best time applications.

Important: Any open blossoms still on trees should be considered vulnerable to infection from fireblight.

Fire Blight | New England Tree Fruit Management Guide (netreefruit.org)

Now is the time to scout for shoot strikes. 1-2 weeks after petal fall, scout orchards for shoot blight, including rootstock sucker infections. Prune and remove infected shoots 12 inches below the infected margin during cool, dry weather.

Pruning is particularly useful when blossom blight is well controlled and canker blight infections are thus the main source of inoculum for disease spread during the summer. Pruning can help limit disease spread, but will be most effective if practiced rigorously during the first few weeks after bloom; pruning will do little to slow disease spread if delayed until a large number of infections are visible.

Routine use of antibiotics to prevent shoot blight spread during the summer is not effective or recommended. However, applications to protect new wounds immediately following a hailstorm can be very beneficial; check current recommendations.

 

Powdery mildew:

Dry periods during scab season can be a prime time for infection by powdery mildew. Group 3 fungicides used for scab control will also control PM. Consider saving the group 11 fungicides until petal fall for control of summer diseases. Sulfur is also a good choice for PM control in conventional and organic orchards. This week may be the best opportunity to control PM, so consider choosing a fungicide with good efficacy against both this disease and scab.

 

Powdery Mildew | New England Tree Fruit Management Guide (netreefruit.org)

 

Insects:

Plum curculio:          

In Concord the petal fall date we are using is 5/19/23. From that date, we have accumulated 117 degree days base 50F, and are predicted to have accumulated 198 DD by Sunday, June 4th.

Control typically begins at petal fall with a whole block spray, followed by 1 or 2 perimeter row sprays depending on the weather and progression of this insect through its’ life cycle. Egg laying typically stops around 308 degree days after petal fall, at which time the need for targeted control generally stops. With this season progressing slowly so far with these cool temperatures, we are gaining degree days slowly. This means that the egg laying period for PC may be extended unless the temperatures drastically warm up.  Some southern NH orchards already have fruit at a susceptible stage for PC damage, as the insect prefers fruit at the 3-5 mm size for egg laying. Temperatures this week will certainly be warm enough for PC activity, so blocks of trees that are past petal fall should be protected. While few egg laying scars have been found while scouting orchards, Plum curculio will certainly be active this week.

Plum curculio (PC) | New England Tree Fruit Management Guide (netreefruit.org)

Codling moth:

In Canterbury we finally established the biofix date of 5/26/23 to start the codling moth model within NEWA. We will now reduce the frequency of trap checking for this insect to once a week. Once sustained trap captures have been observed, enter the biofix date for your farm into the NEWA model to track development of the pest as egg laying approaches. You would need to be trapping yourself to have the most accurate date for your farm.

Southern NH established the biofix of codling moth as of 5/22/23. Southern growers without traps on their farms could enter this date to start the degree day clock running for egg hatch by this pest, which is expected at 220 –250 DD base 50F from sustained catch.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Interested in more details on how degree days are used to inform codling moth management practices?

Cornell has a wonderful fact sheet that talks about this, check out the quick summary below or check out the entire resource at this link: doc_72.pdf (cornell.edu)

Time insecticide applications based on trap data and degree day (DD) models for egg hatch. Spray timing for these pests is directed at newly hatched larvae, since most insecticides are not effective at controlling adults. There is a lag period for egg hatch after the moths fly. The first spray for CM is recommended at first egg hatch, which occurs 220-250 DD (base 50°F) after sustained trap catch. But the timing depends on insecticide choice. Rimon (which is more ovicidal) should be applied at 75-100 DD 50°F after CM biofix; for Calypso, Assail, Delegate, Altacor, Belt, or Voliam Xpress or Voliam Flexi, 200-250 DD 50°F after biofix. An additional option is to apply a granulosis virus formulation at 200-250 DD 50°F. High moth pressure requires 2-3 sprays for the first generation, but in lower pressure orchards (with counts of less than 5 moths per trap per week), you can control CM with a single spray timed at 350 DD 50°F. Research in Washington and Michigan has shown that codling moth mating and egg laying activities take place primarily during a four-hour period, beginning around dusk, if temperatures are above 60°F during that period. Temperatures below 60°F impede male activity and prevent mating, so a cooler spring will delay significant egg hatch for the first generation. If weather data is available to predict this, it can be incorporated into the degree day model as egg hatch will occur 220 DD 50°F after the first flight when evening temperatures >60F. The first insecticide spray for OFM in peaches is recommended at 175 DD (base 45°F) after biofix (petal fall) and a second spray 10-14 days later, until trap counts subside; in apples, 1st generation OFM can be controlled with the petal fall spray. In summer, sprays for OFM in apples are applied 3-4 days after peak trap catch, or 7 days after the start of the 2nd flight.

 

Now just a few updates about upcoming events:

RMA Apple Insurance Listening Session:

June 27, 2023 : Goffstown, New Hampshire

10:00 a.m. to 12:00 p.m., Hillsborough County Extension Office (Large Conference Room)

329 Mast Rd., Goffstown, NH 03045

No RSVP required.

 

Details here: Summer 2023 Apple Grower Meetings | RMA (usda.gov)

Twilight Meetings:

The schedule is out for all of extension’s summer twilight meetings, and I wanted to highlight a few that may be of interest to the folks that tune into this call – the full list of Extensions event offerings this summer can be found on our website!

Tree Fruit meeting at Demeritt Hill Farm, July 15th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at DeMerritt Farm | Extension (unh.edu)

Tree Fruit meeting at Apple Hill Farm, August 17th, 2023 5:30-7:30 pm

Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

 

Blueberry IPM Twilight Meeting at Stark Farm, June 20th, 2023

Blueberry IPM Twilight Meeting at Stark Farm | Extension (unh.edu)

 

All of the Production agriculture Twilight meetings:

2023 Production Agriculture Summer Twighlight Meeting | Extension (unh.edu)

 

Thank you for sticking around until the very end!  See you next week!

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8/21/2023

Hi everyone!  

Welcome back to the NH Fruit Pest hotline, which is produced by staff members from the UNH Cooperative Extension Food and Agriculture team. Today is August 21st, 2023.

While these recordings will highlight what you need to be looking for out in the field, I highly encourage you to find the transcripts online, as they will have more details and links about many of the pests, products, and models I’ll be describing in this call. Simply google “UNH Fruit IPM reports” to find them on our webpage. The transcript for this call may not be up until Wednesday afternoon.

In terms of growing degree days in Concord, NH we have accumulated 2,712 GDD in BE base 43F and 1,776 in BE base 50F.

Weekly pest and disease update:

Diseases:

Exobasidium on blueberries

Blueberry growers should keep their eyes peeled for a new disease on highbush blueberries called Exobasidium. This has primarily been known as a southern disease until recently. Last season, UNH Field Specialists found this disease in a planting near Concord, NH. This year, it has popped up again near the border of NH and Maine. Included below are a links to more information about the fungal disease, as well as pictures taken in the field in 2022 (Figures 1 and 2).

Exobasidium on blueberry leaf from field in 2022. Photo by Jeremy DeLisle @ 2023 University of New Hampshire

Figure 1. Exobasidium on blueberry leaf from field visit in 2022. Photo credit: Jeremy DeLisle.

Exobasidium on blueberry from field visit in 2022. Photo credit: Jeremy DeLisle.

Figure 2. Exobasidium on blueberry from field visit in 2022. Photo credit: Jeremy DeLisle.

More information about Exobasidium here: Exobasidium leaf and fruit spot of blueberry | NC State Extension Publications (ncsu.edu)

Bitter rot on apples

Conditions have been good for this disease with plenty of rain and humidity, and quite a bit of fruit showing some sort of injury (notably, cracking) that might allow entry to the pathogen. Captan does a pretty good job, especially at slightly elevated rates. PennState cites Merivon/Pristine, Flint/Luna Sensation, Aprovia, and Omega, mixed with Captan as being effective. Pay attention to pre-harvest intervals for fungicides as harvest approaches.  Additional information about the biology and management of this disease can be found here: https://ag.umass.edu/fruit/fact-sheets/apple-ipm-bitter-rot. Figure 3 is an example of a fully developed bitter rot infection on an apple.

Fully developed infections of apple bitter rot on apple cultivar ‘Empire’ with abundant spores of fungus that allows secondary, new infections on other apple fruit. Photo credit: Aćimović S. G., 2019.

Figure 3. Fully developed infections of apple bitter rot on apple cultivar ‘Empire’ with abundant spores of fungus that allows secondary, new infections on other apple fruit. Photo credit: Aćimović S. G., 2019.

A photo comparison of apple bitter rot and bitter pit, associated with calcium deficiency of the fruit, can be found here: https://twitter.com/FruitDiseases/status/1436764151335071753

Apple Anthracnose

We have recently diagnosed symptoms on mature apple trees as caused by apple anthracnose. While more than one species of fungi can cause what we call apple anthracnose, in this case it was caused by one of the Neofabraea fungi species.  This disease can cause perennial cankers as well as bull’s eye rot in apples. As outlined in this blog post from Cornell University, the following control measures are recommended:

How do I prevent and control Apple Anthracnose/Bull’s Eye Rot?

– Avoid planting cultivars that are highly susceptible to anthracnose (e.g., ‘Empire’, ‘Gala’, ‘Spartan’)1

– Scout consistently and prune cankerous branches

– Cut out cankers with a pruning knife with several extra inches of buffer

– Remove and burn trees with extreme infections

– Screen new incoming plant material for cankers

– Keep fruit dry after harvest

– Control woolly apple aphids

Botryosphaeria Canker

For the control of Botryosphaeria canker:

(1) Remove and dispose of dead or dying branches, prune a few inches below the canker on infected tree and shrub branches. Protect healthy trees by only using sanitized pruning equipment.

(2) Irrigate at regular intervals during extended dry periods to minimize drought stress.

(3) Fertilize if soil mineral levels are inadequate, maintain a layer of well-composted organic mulch over the root zone to retain soil moisture and limit mechanical wounds.

(4) Regular satiation pruning should take place to remove low-level infections that may be present in the canopy.

(5) Avoid pruning during wet periods in the spring.

Additional details can be found here: HS1265/HS1265: Fungal Gummosis in Peach (ufl.edu)

Insects:

Spotted Wing Drosophila

While many blueberry varieties are past their peak harvest season, late-season varieties are still very much at risk. This warm, damp weather pattern we are having has been quite favorable for the development of this insect.

Captures inside plantings where control measures have been implemented have been much lower, indicating that controls are working. This is to say that the risk to ripening fruit, especially late blueberries and fall raspberries is still high.

Note: Raspberries and blueberries can tolerate cold storage temperatures close to 32° F, so don't be afraid to put your fruit in a cold storage to keep it crisp and fresh and kill or slow down SWD egg and larval development (NYS IPM).

Apple Maggot Fly

AMF captures have remained low at our trapping locations in Merrimack County, averaging well below one fly per trap. The action threshold is an average of 1-2 AMF on the yellow cards or in unbaited sticky spheres, or a cumulative average of 5 AMF per trap on baited spheres. Trap captures for a week following insecticide treatment are ignored. Subsequent sprays can be applied once the threshold is reached again.

Apple Maggot Fly (AM)--New England Tree Fruit Management Guide (netreefruit.org)

Codling moth

Trap captures have remained low this week. We are currently at 1,431 DD past our biofix. Continue to monitor traps for moth captures to mark the start of the second generation flight. First egg hatch of second generation should begin 250 DD after sustained trap captures, which may be a time to treat in orchards with a crop and high captures. A second spray may be needed in high pressure orchards 10-14 days later. So far, we have not seen a significant uptick in CM captures indicating a significant flight of a second generation. We WILL continue to monitor to best inform management decisions.

Coding Moth Trap Captures - Average per Trap

Coding moth trap captures average per trap. Showing a spike of captures in July 5th with over 40 moths captured. Each previous trap dates June 28th and July 12th reported 25 captures

Brown Marmorated Stink Bug

BMSB captures have been very low so far this season. We anticipate those numbers to start to increase over the next couple of weeks. Apple growers should monitor using either pyramid-style traps or clear stick cards, especially near areas of the orchard or in specific varieties where this insect has been documented in past seasons. A comparison of the two types of traps most commonly used can be found here: Simpler trap for monitoring brown marmorated stink bugs eyed - Fruit Growers News

Upcoming Events:

AUGUST 22, 2023 | 6:00 - 8:00PM

NH Giant Pumpkin Growers Association Twilight meeting

AUGUST 23, 2023 | 4:00 - 6:00PM

Tunnel Twilight Series: Disease ID and Management

AUGUST 23, 2023 | 5:30 - 7:00PM

Twilight Meeting for Greenhouses, Nurseries and Garden Centers

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8/1/2023

In terms of growing degree days in Concord, NH we have accumulated 2,209 GDD in BE base 43F and 1,393 in BE base 50F.

Weekly pest and disease update:

Diseases:

Mummy berry on blueberry:

Is being reported from some blueberry plantings. Details about this disease and management strategies can be found here.

This infects new shoots in the very early spring beginning around budbreak. Those infected shoots can then in turn release spores that infect open flowers, eventually resulting in the symptoms you are seeing in your berries. The fruit you see there will eventually shrivel and look like a little grey or black pumpkin. This lies in waiting until next spring for conditions to be just right and releases new spores to continue the cycle. You can read more about the disease here: Microsoft Word - Blueberry IPM - Mummy Berry Final.docx (umass.edu)

This year was certainly a good weather year for this fungus. We had temperatures conducive for extended persistence of apothecia. As noted in the fact sheet below, as apothecia expand, the number of ascospores released increases. Ascospore discharge depends on temperature, relative humidity, and wind speed. Apothecia can persist for about 3 to 4 weeks under cool conditions — 50° to 59°F — but are shorter-lived as temperatures rise. At 68° to 77ºF (20° to 25°C), they may persist for only 1 to 2 weeks.  We had damage from the freeze, which likely damaged tissues and made them more susceptible to infection. Did you see many shoot strikes? These would've been visible around the time that flowers were present. The fact sheet below gives detailed information about the disease cycle and includes photos of berries as the life cycle of mummy berry progresses. I know many of you are familiar with this, but there is good information in there and helpful pictures.

https://www.canr.msu.edu/blueberries/uploads/files/E2846%20Mummy%20Berry%20Facts.pdf

A list of fungicides and their efficacy is also included in the fact sheet above.

Mulching with at least 2” of fresh mulch in the fall can also greatly help reduce the number of spores that are able to reach susceptible tissue. This strategy can’t be used year after year due to too much mulch buildup, but if you need to mulch, this fall would be a great time for this reason. Also, picking off as many of those suspicious fruits as possible will only help to reduce potential inoculum for next season.

One last tip…You could collect 10-20 of the mummies and create a “mummy garden”. I know, it sounds funny, but you could place them outside the planting, possibly just nestled in some wood mulch (not fully buried), and use that to track the development of the disease next year. Once you see the little mushroom cups coming up, it will clue you in as to when you need to treat. Research shows that the fruiting bodies of the fungus (apothecia) need to be at least 1/12” in diameter to produce spores for infection.

Exobasidium

Blueberry growers should keep their eyes peeled for a new disease on highbush blueberries called Exobasiduim. This has primarily been known as a southern disease until recently and last season, UNH Field Specialists found this disease in a field near Concord, NH. This year, it has popped up again near the border of NH and Maine. Included below is a link to more information about this fungal disease, as well as pictures taken in the field in 2022 (Figures 1 and 2).

Exobasidium on blueberry leaf from field in 2022. Photo by Jeremy DeLisle @ 2023 University of New Hampshire

Figure 1: Exobasidium on blueberry leaf from field in 2022. Photo by Jeremy DeLisle.@ 2023 University of New Hampshire

Exobasidium on blueberry fruit from field in 2022. Photo by Jeremy DeLisle.

Figure 2: Exobasidium on blueberry fruit from field in 2022. Photo by Jeremy DeLisle. @ 2023 University of New Hampshire

More information about Exobasidium can be found here: Exobasidium leaf and fruit spot of blueberry | NC State Extension Publications (ncsu.edu)

Insects:

Blueberry Maggot Fly

The blueberry maggot degree day model predicts when to set baited traps to monitor for adult flies. This insect has patchy distribution and monitoring will determine if and when it occurs on your farm. Flies typically emerge around 913 degree days base 50˚ F from January 1. Blueberry maggot flight places the crop at risk from egg-laying females.

Continue to check blueberry traps once or twice per week, as required, and replace traps and baits every third week. If caught, begin insecticide treatment. Maintain an IPM and insecticide program to protect the crop, according to your market requirements. After harvest, remove and discard used traps and bait.

Details on monitoring and management can be found here.

Spotted Wing Drosophila

Traps should be upfor SWD. Trap captures last week were moderate in the southern half of NH. This does not mean that the threat from this pest is over. More likely, the actions that growers took to control this pest in response to high numbers the previous week have knocked the population of adults back temporarily. Some growers report having excellent success suppressing populations by rotating insecticides from different IRAC groups.

Also of interest, our three SWD netting demonstration sites are working quite well to exclude this little insect again this year. Timing of netting application is critical, and should occur as soon after pollination is complete as is practical to increase the chances of fully excluding this pest.

To learn more about the types of systems being installed and the potential for new construction versus retrofitting existing bird netting structures, join us at our upcoming Twilight Meeting on August 3rd at Heron Pond Farm in South Hampton, NH. Details are available at the link at the bottom of this page.

Note: Raspberries and blueberries can tolerate cold storage temperatures close to 32° F, so don't be afraid to put your fruit in a cold storage to keep it crisp and fresh and kill or slow down SWD egg and larval development (NYS IPM).

SWD is primarily a pest of small fruits, but also impacts stone fruits. Considering the fact that most stone fruits were lost due to severe cold this winter, controlling this pest will be generally limited to blueberries, brambles and grapes at this point in the season.

You can find more information about SWD and SWD trap selection in past pest reports, refer to the ones from June 2023.

Notes of interest: UNH Extension is trialing red sticky traps paired with the Trece Pherocon Peel-Pak lures in 2023. We also work with many growers who use the drowning traps paired with these same lures. In Figure 3 below, the smaller red square is the lure, while the red rectangle is the sticky trap, which gets checked weekly.

New red sticky traps to capture SWD. Photo by Jeremy DeLisle @ 2023 University of New Hampshire

Figure 3: New red sticky traps to capture SWD. Photo by Jeremy DeLisle.

Apple Maggot Fly

We have started to capture AMF with varying catch numbers from one farm to the next. Traps should be up now to monitor populations.

Predicted first emergence of AM occurs after approximately 796 to 1072 degree days have accumulated. Today we have accumulated 1,393 DD base 50F from January 1. Set sticky traps along vulnerable field edges. Check at least weekly and note the first date of captures. Enter this into the Apple Maggot tool on NEWA.

The action threshold is an average of 1-2 AMF on the yellow cards or in unbaited sticky spheres, or a cumulative average of 5 AMF per trap on baited spheres. Trap captures for a week following insecticide treatment are ignored. Subsequent sprays can be applied once the threshold is reached again.

Apple Maggot Fly (AM)--New England Tree Fruit Management Guide (netreefruit.org)

Codling moth

Trap captures have remained low this week. We are currently at 1,213 DD past our biofix. Continue to monitor traps for moth captures to mark the start of the second generation flight, which is anticipated to start soon. First egg hatch of second generation should begin 250 DD after sustained trap captures, which may be a time to treat in orchards with a crop and high captures. A second spray may be needed in high pressure orchards 10-14 days later.  Below is a resource shared by Dr. Jaime Pinero at UMass outlining a control approach based on trap captures and degree day accumulations targeting larvae at egg hatch. Great resources in report online and in the New England Tree Fruit Management Guide.

Codling moth (CM) | New England Tree Fruit Management Guide (netreefruit.org)

Key events in CM life cycle estimated by use of Biofix 1 and subsequently accumulated degree days. These estimates are adapted from Michigan State University and Cornell University. 

[Data table pending]

UNH Extension Field Technician, Justin Hogg, sets up delta traps to monitor for codling moth in apple orchards. Photo by Jeremy DeLisle. @ 2023 University of New Hampshire

Figure 4: UNH Extension Field Technician, Justin Hogg, sets up delta traps to monitor for codling moth in apple orchards. Photo by Jeremy DeLisle.

Japanese Beetles

Adult beetles can be found feeding on foliage and fruit currently throughout most of NH. Many of us are interested in opportunities for mass trapping this pest. Blueberries and raspberries are especially attractive to this insect. There may be hope for Japanese beetle traps that can actually help control populations and limit damage to fruiting crops. Visit the link here for more information.

Tissue testing time is here for some crops and coming right up for others.

Directions for taking a plant leaf tissue sample in your orchard/garden:

Tips - In general, it is usually best to sample many plants (with only a few leaves from each plant) rather than sample many leaves from only a few plants.

Select the youngest, fully developed (mature) leaves for analysis. Do not select leaves from plants which are mechanically damaged, insect damaged, diseased or dead. Avoid leaves from border plants or leaves which are fully shaded by other foliage. Do not send sample plants that have been under prolonged stress.

Avoid leaves which are contaminated with soil or dust or which have been recently sprayed. In general, plant leaves which have been exposed to normal rainfall are sufficiently clean for analysis. Samples can be washed briefly in a 2% non-phosphorus detergent solution and then rinsed carefully with clear water. However, in many situations the cleaning may do more harm than good.

If you are trying to diagnosis a problem and are sampling plants that are showing an abnormal symptom, follow the above directions, but sample only from plants showing the problem.

Crop Information

Blueberries: sample at least 40 leaves from 10 to 20 plants during the first week of harvest.

Strawberries: sample at least 40 first fully expanded leaves from 10 to 20 plants, after renovation.

Brambles: sample at least 60 leaves from 10 to 20 non-fruiting canes early-mid August.

Grapes: sample 50 to 75 of the youngest full-expanded leaves from 10 to 20 vines at veraison (70 days after bloom, as the first fruit ripens). Separate petioles (leaf stems) from leaves and send only the petioles for analysis.

Tree fruits: sample 5 leaves from each of 10 trees from late July through early August. Select shoots at eye-level from around the outside of the trees that make a vertical angle of 45-60 degrees to the ground (avoid water shoots or suckers). Collect leaves from the mid-portion of the new shoot growth.

For other crops: Contact your local field specialist or county office to determine the correct sampling procedures. After collection, samples should be placed in paper bags and air-dried (turn the bag frequently) or dried at 200 degrees F.

If you wish to submit a sample to UNH for tissue testing, more information and forms can be found here:

Form: UNH Cooperative Extension - Commercial Plant Tissue Form.pdf - All Documents (sharepoint.com)

Main soil/tissue testing site: Soil Testing Services | Extension (unh.edu)

Upcoming Events

August 3 - Blueberry IPM Twilight Meeting at Heron Pond Farm | Extension (unh.edu)

August 17th - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

See the full list of twilight meetings here:

2023 Production Agriculture Summer Twilight Meeting | Extension (unh.edu)

Thanks for tuning in!

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6/12/2024

Fruit IPM Update:

All degree day totals, and model outputs are based on data collected from a NEWA-connected weather station in an orchard in Concord, NH. Be sure to enter your specific biofix dates for your farm for the best results and accuracy.

Today we are at a total of 996 DD 43F BE and 576 DD 50F BE since January 1, 2024.  

Apples

Codling moth – We have accumulated about 380 DD since biofix (May 18th). The latest larvae are hatching and will begin feeding on fruit. Protectants should already have been on in many locations. Yet to find frass or larvae in scouted orchards. To determine if you have CM larvae, look for tunneling larvae with dry frass and feeding on seeds in center of fruit. Larval feeding causes reddened marks on skin where it enters fruitlets. Larvae don’t digest first bites of apple as they enter, allowing it to resist insecticide application as it enters fruit.

Adult flights of this first generation declined somewhat over the past week. During this period the majority of eggs are likely to hatch, so control is critical at this time.

Apply a second spray 10-14 days after the initial spray that was timed at first hatch (200-220 DD after biofix), to provide protection during this critical time period. In high-pressure orchards, it may be particularly important to apply other classes of materials to replace organophosphates or synthetic pyrethroids.

Use same active ingredient for second application to first generation. Delegate for 2nd generation is IRAC 28, this and Altacor also effective for OBLR if present. 

Oblique banded leaf roller – Adults from the overwintered larvae are just becoming active now. We had our first moth capture in Concord on June 11th. UMass has an excellent fact sheet which covers how to best time controls of hatching larvae paired with trapping for moths and using the NEWA model for optimum timing. Bt and many other products are effective for larvae applied at 360 DD 43F BE after biofix. As of today we have only 37 DD since biofix.

Plum curculio – Plum curculio activity should begin to decline soon and any curculio remaining in trees will usually not move to other locations.

Plum curculio only need to be controlled until 308 DD have accumulated after petal fall. Make sure that the predicted residual coverage (10-14 days) from the last spray will protect fruit until DD accumulation reaches this value. According to the NEWA model, we are predicted to reach this accumulated value by Friday, June 14th.

Larvae are likely tunneling now.  Thiamethoxan (Actara) and similar materials are curative, meaning that tunneling larvae are often killed off.

Scab – begin scouting fruit to access control and calibration. Did your fungicide applications reach to tops of your trees? Active and burned-out lesions may be apparent now. Hight temps this week work in our favor for suppressing and killing lesions. Use extra caution when combining Captan with penetrants and/or foliar nutrients as chances of phytotoxicity increase with high humidity and slow drying conditions. Insprire super and Aprovia are good options with a penetrant such as Regulaid to move into plant tissue with increased efficacy.

Powdery mildew – Continues to be widespread, although it seems to be drying off in some cases. Prune out where possible. Captan is not effective against PM.  Flint, Cevya, Luna Sensation and and many other fungicides in IRAC groups 3, 7, 11 or combination materials are all effective.

Fireblight – Prune out strikes as soon as possible on cool dry days. Don’t do this until dew is off the trees. Opinions differ in regard to the benefit of sanitizing tool between cuts. Some research shows little to no benefit. Other pathologists still recommend it. Either way, cutting out strikes and trying to cut back into at least 2-year-old wood is key to slowing to progression of infections. Apogee or Kudos may be a consideration to continue to hold back shoot growth and thicken cell walls to reduce incidence of further shoot strikes.

Black rot – mummies providing inoculum for leaf spots currently. Frogeye leaf spot lesions are beginning to show up in some locations.  

Sooty blotch/fly speck – Protectants should be providing control up until now. Might consider applications if this is something you typically control for. Time since last application and minimal rain keeping at bay up until this week.

Wooly apple aphid – Coming up from roots and preparing to form aerial colonies.

San Jose scale – look for small red lesions where scale are feeding on fruit soon. Will be developing and feeding on fruit over the next month or so. Movento is a good material that will get protected scale on branch crotches, etc., due to being systemic. Esteem is an excellent material during crawler emergence. Besige and Endigo are also options.

European apple sawfly - early damage may be apparent over the next couple of weeks depending on PF control.

Rosey apple aphids – Exude toxins as they feed that deform leaves and fruit, neonicsc (Admire good choice), Provado (causes flaring of mites). Nicotine increases heartrate, mites stimulated to mate and lay eggs at a higher level. Loss of chloroplasts due to feeding resulting in loss of carbohydrates, color, size and overall quality of fruit. High temps, dry weather and dusty conditions are beneficial for mite populations. Rotate materials by IRAC codes. 

Blueberries

Mummyberry – We are seeing a fair amount of infections in plantings throughout southern NH this year. 2023 was a banner year for infections, which likely increased inoculum levels going into this season.

An excellent fact sheet on this disease can be found here:

https://www.canr.msu.edu/blueberries/uploads/files/E2846%20Mummy%20Berry%20Facts.pdf

If frost occurred in your planting and tissue damage resulted, that too may contribute to infections.

Cultural/Biological tactics for Mummyberry control include:

  • Plant resistant varieties whenever possible.
  • Prune bushes to open the canopy to light, air, and spray penetration.
  • Cultivate beneath plants in fall and again in early spring to disrupt overwintering inoculum.
  • Apply a 3-4” layer of mulch material over the soil surface in early spring before fruiting bodies emerge to create a physical barrier to spore release.
  • Application of 50% urea at a rate of 200lbs/A prior to budbreak can decrease the number of viable fruiting bodies (avoid applications to areas with standing water, come back to those once they dry up).

Create a mummyberry plot! The University of Maine has detailed instructions about how to create a monitoring plot for your farm so that you can better track the progression of this disease next season with conditions specific to your farm. See their blog post here:

https://extension.umaine.edu/blueberries/2015/09/17/how-to-put-out-a-mummy-berry-plot/

SWD – We caught our first flies this week in southern NH. Strawberry growers should be monitoring now to detect flies since they have ripe fruit. Blueberries are still likely too firm and green for flies to attack in all locations, but as they begin to show color growers should monitor traps and consider protections.

Growers using exclusion netting for SWD are encouraged to get that up early this season. Crop development seems to be running 7-10 days early, and insects are as well.

Two excellent resources for selecting insecticides effective against SWD are the 2024 Cornell SWD Selection Guide found here:

https://bpb-us-e1.wpmucdn.com/blogs.cornell.edu/dist/f/7312/files/2024/05/Quick-Guide-SWD.pdf

And the MyIPM app where you can access a lot of information about SWD management, including insecticide selection options, IRAC codes and efficacy ratings. Find details here: Home - MyIPM

Upcoming Events:

June 19 - Tree Fruit Twilight Meeting at Sunnycrest Farm | Extension (unh.edu)
August 21 - Tree Fruit Twilight Meeting at Apple Hill Farm | Extension (unh.edu)

Past Reports

2022

August 2, 2022

The apple maggot numbers continue to be low in traps this year – keep an eye out for them – they may show up, they may not!

The codling moths may be approaching their second generation in the next few weeks, but for folks that have had an issue with codling moths in the past, mid-august is a good time to treat with products like Altacor or Delegate.  You will also want to keep an eye on the calyx end of your fruit for frass, as this can indicate that there was first generation larval activity present earlier in the season.

Keep an eye out for the San Jose scale, and remember that you can use NEWA to help track the development and management strategies for the scale.  If you have been using Assail in your orchard for apple magot control you will probably have good control of the San Jose scale as well.

The Brown Marmorated stink Bug might be bigger issue this year with the drought. As other host trees dry out, they could migrate into orchards sooner than we expect them to.  Keep scouting for them, especially in stone fruit orchards, as these are the most at risk right now.

Additionally keep an eye out for bird damage.  Your fruits are a tempting source of moisture in these dry conditions.

Finally, I’m excited to announce that the UNH Plant Diagnostic Lab will be open and accepting Samples as of Monday August 15th.  We will accept mailed-in samples and walk-ins in our new lab space in Barton Hall.  Sample submission forms will be posted on the lab website closer to out opening date.  Any questions can be directed to me, Madie Hassett, at madeleine.hassett@unh.edu.  I’ll post my phone number up here as soon as that gets set up next week!

I want to thank everyone who has been listening to these calls all summer.  I know the timing was a little variable for the last few weeks in Maine, but now that I’m back at UNH this call should be updated every Tuesday night or Wednesday morning.

For the diseases, remember that you can use NEWA to calculate your risk of summer diseases like sooty blotch and flyspeck.  Some areas of the state have seen severe weather already and may see some later this week, so be ready to react to a traumatic event like hail in your orchards if that happens.  As always, consult the Tree Fruit Guide for guidance on what to use to protect your orchards!

For the Peach growers specifically, now is the time to consider preharvest brown rot controls.

For the insect pests,

Apple maggot numbers appear to be lower than last week.  Any rain we get this week might bring up the numbers a bit, so keep an eye out for them!

Mites are out and causing trouble in some spots – this includes red, two-spotted, and rust mites.  Keep an eye out for excessive bronzing or hotspots of mites in your orchards.  Some control may be carried out by natural predators like predatory thrips, so keep an eye out for those when you are scouting as well!  You can spot treat or spray your whole orchards, depending on how many mites and the level of bronzing/damage you are dealing with.

Keep up with the scouting and treatments for Pear Psylla.

Finally, for the stone fruit growers, plant bugs and stink bugs are waking up – consider how you want to scout and treat these insect pests.  Refer to the tree fruit guide for more information!

That’s all that I have for Pathogens and Pests:  

For events, there will be the combined fruit and Vegetable twilight meeting at the end of the month on Thursday July 28th from 5-7:30 pm at Brookdale Fruit Farm in Hollis, NH.  Contact Jeremy Delisle for more information about the event! 

New Hampshire Tree Fruit & Vegetable Twilight Meeting | Extension (unh.edu) 

Finally, the Plant Diagnostic Lab at UNH is still closed, so continue to send your samples to the UMaine Plant Diagnostic Lab.  We expect the UNH Lab to open back up in mid-to-late August, so stay tuned for more info on that! 

 

July 12, 2022

For the diseases, even though it has been relatively dry and we have not gotten a lot of rain, keep an eye on the duration of leaf wetness in some areas.  Long enough period of leaf wetness can lead to issues with a number of summer diseases, and you may want to adjust your spray schedule accordingly.

We also sent out a pest alert for the vegetable growers for cucurbit downey mildew.  There is low risk for growers in Southern NH, but if there is an infection event, expect symptoms to start on approx. 5 days.  I’ll add a link to the alert to the online transcript of this call if you would like to learn more.

Back to the pest info for fruit growers:

 

For the apple maggot fly, they are here and emerging regardless of the lack of rainy conditions.  If you have had issues with them in the past, keep an extra close eye out for them and be sure to be checking your traps or untreated trees for them.  There are a few hotspots around the state but generally the numbers have been low and orchards have not hit the threshold to spray yet, but that time will come soon, so be ready for it!

 

Mite numbers have begun to grow – both the red and two-spotted mites.  Two ways to deal with mites are to do targeted spot-treatments if you can identify hotspots with mite issues, or you can treat your entire orchard with a miticide.  You will want to treat the whole orchard if you are seeing mite numbers over the threshold or if early stress (like bronzing) is present in your orchard. The two-spotted mites are more likely to be kept in check by natural predators like predatory thrips, so you may want to keep an eye out for natural predation occurring as well!

 

Woolly aphids are here, a bit earlier than usual, so keep an eye on them.  It can be tricky to determine what the threshold is to spray – there is not a lot of info out there – but the sooner you can catch them and spray if needed, the better. The general guidance is to stop using pyrethroids to control for the woolly aphid. Other than pyrethroids, effective control material you can use include neonics (and other IRAC4’s) as well as Assail, Movento, Closer/Transform and Diazinon. Remember these are just general recommendations, be sure to refer to the tree fruit guide and product labels to make sure you are using the best product for your situation.

 

Finally, the adult Japanese beetles are emerging now.  While your grapes are at risk, they have also been known to damage honey crisp apples.  Most orchard insecticides are effective against Japanese beetles.

 

That’s all that I have for Pathogens and Pests:

 

For events, there will be the combined fruit and Vegetable twilight meeting at the end of the month on July 28th from 5-7:30 at Brookdale Fruit Farm in Hollis, NH.  Contact Jeremy DeLisle for more information about the event!

 

New Hampshire Tree Fruit & Vegetable Twilight Meeting | Extension (unh.edu)

 

Finally, the Plant Diagnostic Lab at UNH is still closed, so continue to send your samples to the UMaine Plant Diagnostic Lab.  We expect the UNH Lab to open back up in mid-to-late August, so stay tuned for more info on that

July 5, 2022

Hello all, Welcome back to the NH Fruit pest hotline! 

I have a short post this week –  

For the pathogens, 

Keep an eye out for Powdery Mildew infections.  A few have been reported around the state. Powdery mildew can be found at the end of poorly growing shoots that may have curled up leaves and the distinctive white spores or webbing if the infection is severe enough.  If you had it last year, be sure to keep an eye out for it this year and refer to the tree fruit guide for control options! 

The time to think about Sooty blotch and flyspeck is getting closer, but remember that you can use  NEWA and use their models to calculate the risk of sooty blotch and flyspeck for your specific orchard, based on the petal fall date and closest weather station.  Link here: https://newa.cornell.edu/sooty-blotch-flyspeck

For the insects, 

Potato Leafhoppers are here and active but are really only a concern for young trees that could become stressed out from large populations of the pest. 

Pear Psylla is out in full force.  If you are using chemical controls, its always a good idea to switch what products/chemicals you are using between the different generations of psylla, if possible! 

The Obliquebanded leafroller eggs will be hatching soon.  If you had an issue with them in the past, get ready to spray for them now or very soon, if you have not had an issue in the past, you can wait a bit longer and scout for the larvae before you decide how to spray! 

Finally, apple maggot traps can be put up now.  Typically, the reusable traps are more effective than the disposable ones, but anything is better than nothing!   

Now for a few announcements: 

The UNH Plant Diagnostic Lab will be open and accepting samples in mid-late August.  Stay tuned for more info and continue to send samples to the UMaine lab. You can contact me at madeleine.hassett@unh.edu with any questions and visit the Umaine diagnostic lab website for directions on how to submit samples. 

There is going to be a Combined Fruit and Vegetable Twilight meeting on July 28th from 5-7:30 pm at Brookdale Fruit Farm.  Contact Jeremy DeLisle with any questions about this event! 

  Last but not least, UNH cooperative extension has many open positions – including a new state specialist in plant pathology, state specialist in Entomology and IPM, and a state specialist in Soil Health.  Check out our main website, or UNH’s job website for more information about these positions and feel free to spread the word about these positions!  

Link: https://extension.unh.edu/about/jobs 

That’s all that I have for today! 

June 28, 2022

For the pathogens of concern,

Apple growers should keep an eye out for lingering apple scab lesions.

Now is also the time to look for Powdery mildew infections – they have been popping up around the state. Powdery mildew can be found at the end of poorly growing shoots that may have curled up leaves and the distinctive white spores or webbing if the infection is severe enough.  If you had it last year, be sure to keep an eye out for it this year and refer to the tree fruit guide for control options!

Sooty blotch and flyspeck will become an issue later on in the summer but remember that you can also hop onto NEWA and use their models to calculate the risk of sooty blotch and flyspeck for your specific orchard, based on the petal fall date and closest weather station.  Link here: https://newa.cornell.edu/sooty-blotch-flyspeck.

For the insects,

 

Potato Leafhoppers are here and active but are really only a concern for young trees that could be stressed out from large populations of the pest, so keep an eye out for those!

 

Pear Psylla is out in full force.  If you are using chemical controls, its always a good idea to switch what products/chemicals you are using between the different generations of psylla, if possible!

 

The Obliquebanded leafroller eggs will be hatching soon.  If you had an issue with them in the past, get ready to spray for them in the next week or so, if you have not had an issue, you can wait a bit longer and scout for the larvae before you decide how to spray!

 

Finally, apple maggot traps can be put up now or in the next week or so.  Typically, the reusable traps are more effective than the disposable ones, but anything is better than nothing!  Traps can be purchased from Great Lakes IPM and Gemplers.

 

Now for a few announcements:

 

The UNH Plant Diagnostic Lab will not be accepting samples until the end of the summer.  We are searching for a new director.  All NH samples will be sent to the Umaine diagnostic lab until further notice.  I will be heading up to Maine for the summer to help them handle the sample load.  You can contact me at madeleine.hassett@unh.edu with any questions and visit the Umaine diagnostic lab website for directions on how to submit samples.

Last but not least, UNH cooperative extension has many open positions – including a new state specialist in plant pathology, state specialist in Entomology and IPM, and a state specialist in Soil Health.  Check out our main website, or UNH’s job website for more information about these positions and feel free to spread the word about these positions!

Link: https://extension.unh.edu/about/jobs

June 21, 2022

For the pathogens of concern,

The Primary season for apple scab is over but keep an eye out for any remaining lesions.  As we get deeper into the summer, Sooty blotch and flyspeck are the main diseases to worry about, as well as Powdery Mildew and fruit rots.  Refer to the tree fruit guide for more info on how to control for these pathogens.  You can also hop onto NEWA and use their models to calculate the risk of sooty blotch and flyspeck for your specific orchard, based on the petal fall date and closest weather station.  Link here: https://newa.cornell.edu/sooty-blotch-flyspeck.

For the insects,

Potato Leafhoppers have been spotted in a few places, as well as aphids, so keep an eye out for them, especially in young trees with a lot of new growth or trees with damage from fire blight.  Aphids are typically controlled via predation, but they can replicate very quickly in the right spot.

Mites are also in the area, if you do have them, you can spot treat before they get bad.  The threshold for treatment is 2-3 mites per leaf but that will increase to 5 mites per leaf as the season progresses – see the tree fruit guide for more info!

Be scouting for Pear Psylla eggs and Nymphs and be ready to treat with the appropriate chemical control or to prune out shoots with large infestations.

Finally, it’s a little early to be thinking about the apple maggot fly but if you need to order traps, now it the time to do it!

Now for a few announcements:

The UNH Plant Diagnostic Lab will not be accepting samples this summer.  We are searching for a new director.  All NH samples will be sent to the Umaine diagnostic lab until further notice.  I will be heading up to Maine for the summer to help them handle the sample load.  You can contact me at madeleine.hassett@unh.edu with any questions and visit the Umaine diagnostic lab website for directions on how to submit samples.

Finally, UNH cooperative extension has many open positions – including a new state specialist in plant pathology, state specialist in Entomology and IPM, and a state specialist in Soil Health.  Check out our main website, or UNH’s job website for more information about these positions and feel free to spread the word about these positions!

Link: https://extension.unh.edu/about/jobs

June 14, 2022

For the pathogens of concern, 

For the apple growers: 

For Fire Blight, trim out any infections that you suspect are blight and be sure to sterilize your trimmers between cuts.  Levels of infection are variable across the state!   

For apple scab, continue to scout for those lesions.  Remember that any sprays used to protect from scab will last longer now that the trees have stopped growing (unless there is a heavy rain event).  Refer to the tree fruit guide for recommendations. 

There are a few reports of Powdery Mildew infections popping up.  Severely infected shoots can be trimmed out to reduce the inoculum loads and significant infections can be treated with fungicides (refer to the tree fruit guide!) 

For the cherry growers – now is the time to think about brown rot and if you need to be controlling for that in your orchards.   

For the insects, 

We are just coming to the end of plum curculio season but keep an eye out for them and treat them if you find them, especially on perimeter rows. 

Obliquebanded Leafrollers have been found in southern NH, so be thinking about your plan to control those!   

Codling months have mostly finished or just about to finish their first flight and the eggs will begin to hatch now or very soon – plan to cover for these soon if you are concerned about them. 

Potato Leafhoppers have also been found in southern NH – these are generally not too much of an issue but keep an eye out for them on young trees. 

On Pears, Psylla eggs are out and now is the time to spray for them if you find them - refer to the tree fruit guide for more info.  Another method of control for Psylla is to prune them out if you can correctly time it with when most of the eggs have been laid – which will probably be by the end of next week. 

Last but not least, the UNH Plant Diagnostic Lab will not be accepting samples this summer.  We are searching for a new director.  All NH samples will be sent to the Umaine diagnostic lab until further notice.  I will be heading up to Maine for the summer to help them handle the sample load.  You can contact me at madeleine.hassett@unh.edu with any questions and visit the Umaine diagnostic lab website for directions on how to submit samples. 

June 7, 2022

Hello all, Welcome back to the NH Fruit pest hotline! 

For the diseases: 

Primary Apple scab season is over - but keep an eye out for lesions forming from the last few infection events and in areas where you suspect your coverage may not have been complete.  The rainy weather coming later this week could cause some issues, so keep an eye on the NEWA predictions for your area! 

For Fire blight, symptoms are beginning to pop up all over the state.  Try to prune these out as soon as you spot them and make sure to sterilize your pruner between cuts.  Remember that if your blossoms are gone, you should not use streptomycin unless we have a trauma event.  

For the pests, 

Plum Curculio populations are beginning to decline in some areas but there are reports of recent damage in some areas – so keep an eye out for the egg layering scars and treat as needed with border sprays or spot treatments. 

Keep an eye out for codling moths, especially if you had an issue with them in previous years.  Some of the earlier areas may be able to begin treatments this week, other areas will begin next week.   

Finally, 

Some growers have been applying fruit thinning sprays to their orchards.  You can refer to the tree fruit guide for more info on these sprays.   Another resource that some folks have been asking about is using Ethephon as a rescue thinning option for fruit larger than 12 mm.  Umass extension has a fact sheet about this, that can be found on their site, and I’ll also include the link to the fact sheet in the transcript of this call that will be posted to the extension site. 

Fruit: Late-season "Rescue" Thinning with Ethephon | Center for Agriculture, Food, and the Environment at UMass Amherst 

Last but not least, the UNH Plant Diagnostic Lab will not be accepting samples this summer.  We are searching for a new director.  All NH samples will be sent to the Umaine diagnostic lab until further notice.  I will be heading up to Maine for the summer to help them handle the sample load.  You can contact me at madeleine.hassett@unh.edu with any questions and visit the Umaine diagnostic lab website for directions on how to submit samples. 

That’s all that I have for today! 

May 24, 2022 

In terms of growing degree days here in Durham, we have accumulated 277 GDD in base 50° F and 576 GDD in base 43°F.   

 For the apple growers, we are finally nearing the end of the primary scab season.  Growers should remain protected with a fungicide for 2 weeks after the end of primary season and continue to scout for lesions during this time. 

 According to NEWA, there could be another scab infection event Friday into Saturday.  This event should release all the remaining ascospores. 

 

In terms of Fire Blight, Continue to protect open blossoms and rat tail blooms with streptomycin. Actigard and/or Apogee or Kudos can still be used for added protection or if fire blight pressure was high in your orchards last season. 

 Looking at the NEWA models and using the Durham weather station, there is a very high risk of a fire blight infection event this weekend, so keep an eye on the models for your specific area! 

 That’s all that I have for diseases, for the pests, 

 We have received reports of active plum curculio sings at several orchards in NH.  A whole orchard spray is recommended as a first cover right after petal fall, followed by up to two perimeter sprays to get growers beyond the main PC damage period.  Refer to the tree fruit guide for more info. 

 Finally, if you have physical plant disease samples that you would like to be diagnosed, those are still going to be sent to the clinic at UMaine for diagnosis.  You can visit their website for more information on that. 

May 17, 2022 

In terms of growing degree days here in Durham, we have accumulated 207 GDD in base 50° F and 459 GDD in base 43°F.   

For the apple growers: 

Today was the last day of an extended scab infection period, and it looks like we could have another infection event on Thursday May 19th.  As always, you should continue to monitor NEWA using your closest weather station and be prepared to apply protectant fungicides or get back in with a material with kickback efficacy soon after an infection. Some folks have seen scabs from the last few infection events appear on their trees, so be sure to keep scouting for those. 

Switching over to fire blight:  

We are just at the end an extended period of high fire blight risk, especially if you have a history of fire blight in your orchard.  If you are using NEWA to calculate your fire blight risk, be sure to choose the weather station closest to you and add the most accurate historical fire blight info into the model. Fire Blight | NEWA (cornell.edu) 

In periods of high risk for fire blight, Streptomycin is the material of choice when the trees are in bloom or if you are responding to a traumatic weather event (like hail).  When the risk of infection is low (EIP values from 40-70) other options include some coppers such as Cueva, Serenade or Double Nickle.  Refer to the tree fruit guide for more information and other control options! 

NEWA is showing that there could be another infection event over the weekend, so keep an eye on the models and react appropriately. 

That’s all that I have in terms of Pathogens – now for the pests! 

For the plum growers: Plum curculio will be active soon – once the petals fall and the bees move on, be ready to treat them. 

For the pear growers: Pear Psylla nymphs have begun to hatch and have been spotted in a few orchards.  Now is a good time to target them before they have a chance to disperse and reproduce.   

Finally, if you plan to target Peachtree/dogwood borers with mating disruption techniques, now is the time to put out the ties – this warm weather is perfect for them and perfect for us to disrupt their flights!   

As always, refer to the tree fruit guide for more info on any of these pests or pathogens New England Tree Fruit Management Guide | (netreefruit.org) 

 In terms of events: 

There will be a Tree Fruit Twilight meeting at Butternut Farm in Farmington on May 19th from 5:30-7:30pm. Topics will include land clearing for orchard expansion, seasonal plant pathology and IPM updates. Contact Jeremy Delisle at 603-255-3592 with any questions or more info about this event.  Here is the link to the twilight meeting info for ease of access: NH Tree Fruit Twilight Meeting | Extension (unh.edu) 

  Just a reminder that the plant diagnostic lab has a new location on the Durham Campus in Barton Hall.  The lab will not be accepting samples from the public until June. Contact Dr. Ali at Emran.Ali@unh.edu or your local extension agent with any questions. 

May 10, 2022 

In terms of growing degree days here in Durham, we have accumulated 109 GDD in base 50° F and 314 GDD in base 43°F.   

 

For the apple growers: 

 

The next potential apple scab infection event looks like Saturday night into Sunday morning. Ascospore maturity continues to increase and is currently at 83% in Concord, NH. This could be a significant one release of ascospores. Growers should continue to monitor NEWA and local weather conditions and be prepared to apply protectant fungicides or get back in with a material with kickback efficacy soon after an infection. Now is when may also start to notice lesions beginning to form from the last few infection events. Keep an eye out for them! 

 

Switching over to fire blight:  

 

NEWA shows that the potential is there for a fireblight infection event beginning mid to late this week. While temperatures will be high enough, the question remains if there will be a wetting event. EIP values will be above 70 on Friday and Saturday, and the material of choice for protecting blossoms at this EIP level is streptomycin. At lower EIP values ranging from 40-70, other options include some coppers such as Cueva, Serenade or Double Nickle.

 If you are using NEWA to calculate your fire blight risk, be sure to choose the weather station closest to you and add the most accurate historical fire blight info into the model. Fire Blight | NEWA (cornell.edu)

 For growers considering the use of Apogee and Actigard for shoot blight control in young high density plantings, the recommended time to start applications is at king bloom petal fall. Recommended rates are 2 oz of Apogee and 1 oz of Actigard per acre per week for 3-4 consecutive weeks. Stop or extend the interval if conditions are hot and dry. Extend application for one additional week if it is rainy and temps are in the 70s-80s. 

 

 Finally, for the stone fruit growers, with the rainy weather coming this weekend you need to be thinking about brown rot and bacterial spot. Refer to the tree fruit guide for more info about treatments for those. 

 

That’s all that I have in terms of Pathogens – now for the pests! 

 

Traps for the Tarnished Plant Bug and European apple sawfly have shown no captures at this point in the season, probably due to the cool weather. 

 

Now is also the time to keep an eye out for rosy aphids, mites, and pear psylla eggs (look for their nymphs on the undersides of the leaves). 

 

In terms of events: 

 

There will be a Tree Fruit Twilight meeting at Butternut Farm in Farmington on May 19th from 5:30-7:30pm. Topics will include land clearing for orchard expansion, seasonal plant pathology and IPM updates. Contact Jeremy Delisle (DE-LILE) at 603-255-3592 with any questions or more info about this event.  Here is the link to the twilight meeting info for ease of access: NH Tree Fruit Twilight Meeting | Extension (unh.edu) 

 Finally, The Plant Diagnostic lab has a new location on the Durham Campus in Barton Hall.  The lab will not be accepting samples from the public until June. Contact Dr. Ali at Emran.Ali@unh.edu or your local extension agent with any questions. 

May 3, 2022 

 In terms of growing degree days here in Durham, we have accumulated 17 GDD in base 50° F and 175 GDD in base 43°F.   

For the apple growers, the most important thing to note is that there is an ongoing apple scab infection period that started on Monday May 2nd and is forecasted to extend until Thursday May 5th.  If you did not have a protectant on it may be time to go in with an eradicant, and remember that scab from the event we had last week may be showing up soon. Remember to check the NEWA station closest to you, enter the date of green tip for your orchard into the biofix for the apple scab model predictions and refer to the tree fruit guide for more info about treatments. 

 

Thinking about Fire Blight: Remember that bloom is the key time for management – flowers must be open for infection to occur.  Be vigilant and monitor NEWA for fire blight predictions as we approach bloom, especially if your area had high levels of fire blight last year. (If you use NEWA, enter the date of 1st blossom open for your orchard into the biofix date for the fire blight model predictions).  

 

For the Peach growers: Now is a critical time for managing bacterial spot in peaches, from petal fall through shuck split. It also remains a critical time for managing brown rot and peach scab in stone fruit, from bloom until 3 weeks after bloom and again 3 weeks before harvest. Refer to Tree Fruit guide for materials. 

 

For the pear growers, protectant sprays for Fabraea leaf spot will need to be applied soon if that is an issue in your orchards.  Refer to the tree fruit guide for more information  

 

In terms of Pest monitoring:   

 

Now is a great time to put out white sticky traps for TPB – the Tarnished Plant Bug - and EAS - the European apple sawfly – to get an idea of what is out there. 

 

If you have a history of Rosey apple aphid or Pear thrips, you may out to get out scouting for those as well.   

 

There will be a Tree Fruit Twilight meeting at Butternut Farm in Farmington on May 19th from 5:30-7:30pm. Topics will include land clearing for orchard expansion, an update on peach tree borer alternative control methods study, and seasonal plant pathology and IPM updates. Contact Jeremy Delisle at 603-255-3592 with any questions or more info about this event.     

The Plant Diagnostic lab has a new director, Dr. Emran Ali, and a new location on the Durham Campus in Barton Hall.  The diagnostic lab will not be accepting samples from the public until June. Contact Dr. Ali at Emran.Ali@unh.edu with any questions.  

April 27, 2022 

In terms of growing degree days here in Durham, we have accumulated 17 GDD in base 50° F and 144 GDD in base 43°F.   

 

For the apple growers, the most important thing to note is that there was an apple scab infection event from Tuesday the 26th to Wednesday the 27th.  Now is the time to keep an eye out for scab and treat as needed, and to keep an eye on future infection events in order to keep up with protective treatments.

 

Additionally, if you have had issues with Powdery Mildew in the past, remember that pre-bloom is a critical time to control for that.  Refer to the Tree Fruit guide for materials.

 

Peach growers: Reminder that the important time for brown rot management is bloom – 3 weeks post bloom. (and again 3 weeks before harvest). If you have a history of peach scab, this is something to think about now and refer to the Tree Fruit guide for materials.

 In terms of Pest monitoring: 

 

Now is a great time to put out white sticky traps for TPB – the Tarnished Plant Bug - and EAS - the European apple sawfly – to determine how they’ll need to managed later on in the season.   

If you have a history of Rosey apple aphid, you may out to get out scouting for those soon as well. 

There will be a Tree Fruit Twilight meeting at Butternut Farm in Farmington on May 19th from 5:30-7:30pm. Topics will include land clearing for orchard expansion, an update on peach tree borer alternative control methods study, and seasonal plant pathology and IPM updates. Contact Jeremy Delisle at 603-255-3592 with any questions or more info about this event.   

The Plant Diagnostic lab has a new director, Dr. Emran Ali, and a new location on the Durham Campus in Barton Hall.  The diagnostic lab will not be accepting samples from the public until June. Contact Dr. Ali at Emran.Ali@unh.edu with any questions.

 That is all for now! 

April 19, 2022 

Hello all, welcome back to the NH Fruit pest hotline!    

In terms of growing degree days here in Durham, we have accumulated 16 GDD in base 50° F and 120 GDD in base 43°F.   

 

For the apple growers: be aware that the cool rainy weather we had today (Tues April 19th) is a possible apple scab infection event.  Some growers in Southern NH have already made copper applications for preventative apple scab and fire blight control.  Now is the time to keep an eye out for scab and treat as needed. It is still a good time to chop up any fallen leaves from last year in the orchard to reduce apple scab inoculum. 

 

For the blueberry growers: For those of you with a history of mummy berry, if you haven’t already, now is a good time to cover those overwintering fungal structures with 2-3” of mulch to reduce the inoculum load. You can scout for the apothecia (little brown cup-shaped mushrooms) in mummified fruit under the bushes. Cultivation right around bud-break will also help destroy or disturb emerging mummies. Refer to the Small Fruit guide for fungicides if you think you need them. 

 

 In terms of Pest monitoring: 

 

Now is a great time to put out white sticky traps for TPB – the Tarnished Plant Bug - and EAS - the European apple sawfly – to determine how they’ll need to managed later on in the season.   

 

If you have a history of Rosey apple aphid, you may out to get out scouting for those soon as well. 

 

There will be a Tree Fruit Twilight meeting at Butternut Farm in Farmington on May 19th from 5:30-7:30pm. Topics will include land clearing for orchard expansion, an update on peach tree borer alternative control methods study, and seasonal plant pathology and IPM updates. Contact Jeremy Delisle at 603-255-3592 with any questions or more info about this event. 

The Plant Diagnostic lab has a new director, Dr. Emran Ali, and a new location on the Durham Campus in Barton Hall.  The diagnostic lab will not be accepting samples from the public until June. Contact Dr. Ali at Emran.Ali@unh.edu with any questions.

That is all for now! 

 April 12, 2022 

Hello all, welcome back to the NH Fruit pest hotline!    

In terms of growing degree days here in Durham, we have accumulated 12 GDD in base 50° F and 90 GDD in base 43°F.  

 For the apple growers, we are at about 50% green tip in Macintosh in southern NH. You can monitor your own Macs for 50% green tip and enter that as the bio fix date in the apple scab NEWA model if you use that! Now is also a good time to chop up remaining leaves in the orchard to reduce apple scab inoculum. It is a good idea to have your sprayer in good operating condition, but no fungicides are needed quite yet. UMass Extension monitors apple scab ascospore development, and reports that the number of mature ascospores is very low with only minimal green tissue is showing. Therefore, wait to apply fungicides and monitor the scab model in conjunction with actual bud development in your own orchards.   

 In terms of events:  

 There will be a Tree Fruit Twilight meeting at Butternut Farm in Farmington on May 19th from 5:30-7:30pm. Topics will include land clearing for orchard expansion, peach tree borer control alternatives study update, seasonal plant pathology and IPM updates. Contact Jeremy Delisle at 603-255-3592 with any questions or more info about this event.  

 

There is also an online webinar about managing Weeds in pastures and Hayfields on April 20th, 2022 from 6-7:30 pm. The webinar is free, but online pre-registration is required, and it is worth 1.5 Pesticide Applicator credits upon completion.  Contact Carl Magewski at 603-788-4550 or Nicholas Rowley at 603-788-4962 for more information.  

That is all for now! Get out and enjoy this beautiful spring weather!  

April 5, 2022 

Hello all, welcome back to the NH Fruit pest hotline!

There are not too many updates today, as our season is just getting started.

In most apple growing regions, the trees are currently at silver tip, and we expect to be at green tip very soon.  More on this next week.

The Plant Disease Diagnostic lab has a new director, Dr. Emran Ali, and a new location on the Durham Campus in Barton Hall.  The diagnostic lab will not be accepting samples from the public until June. Contact Dr. Ali at Emran.Ali@unh.edu with any questions.

The 2022 New Hampshire Fruit Growers Association Annual Meeting is thisThursday at McKenzie's Farm in Milton NH.  If you have questions about the event, you may contact the NHFGA Secretary, Samantha Fay at (603) 552-8062.

And that is all that I have for this update, stay tuned for more next week!

July 6, 2021

This week’s forecast looks pretty wet so now would be a good time to consider your history of summer diseases, like sooty blotch and flyspeck. Consult the Tree Fruit Guide for materials to protect plots with a history of economic injury.

It’s also time to start thinking about getting out your apple maggot traps.

For small fruit growers, this week’s moisture will likely bring out spotted wing drosophilia in full force, putting most of the state into low to nearly high risk of infestation. We’ve been recommending weekly sprays to protect against low risk populations and 5 day rotations to folks who are seeing more than 10 males/trap/week. Consult the Small Fruit guide for materials.

For grape growers, now might be a good time to scout clusters for signs of grape berry moth infestation. Treatment might be considered if more than 6% of clusters are damaged by larvae and that treatment should be timed for about 800 DD after biofix. Biofix is the date you first trapped grape berry moth on your farm or, for this particular species, when you notice wild grapes blooming. For example, biofix occurred in early June in Durham, so today we are about 679 GDD from biofix with a few hundred more GDD to accumulate before treating for second generation larvae.

 

June 29, 2021

We’ve accumulated 787 base 50 GDD in Durham.

This hot, dry weather means low risk of summer disease infections but high risk for mite flare ups.

For small fruit growers, we have started to detect very low numbers of SWD in southern regions of the state. The silver lining in this week’s heat is that SWD do not lay eggs when evening temperatures are above 80F, which we’ve achieved a few times this week. Join our facebook group “SWD Monitoring Support Group” to post your photos or to see what others are seeing.

 

June 22, 2021

We’ve accumulated 650 base 50 GDD in Durham.

We have been hearing reports of many fireblight strikes in several orchards. Now might be a good time to scout the orchard and prune out small strikes, making sure to cut about a foot below where you see visible symptoms and clean those tools between cuts. If a tree is too severely infected to effectively remove symptomatic shoots, flag that tree for removal.

This hot dry weather may be causing mite flares for some of you. Check the Tree Fruit Guide for recommendations on materials, and keep in mind that these mites can affect trees in hotspots so spot treatment might be sufficient in many situations.

SWD traps should be out by now. Whatever style of trap you’re using, its best to use the average from at least three traps per plot. If you’re using Trece traps, protect ripe fruit as soon as you detect SWD males. If you’re using Scentry traps or homemade traps with yeast bait, pro