Fruit IPM Reports

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.

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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.

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

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

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).

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

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.

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

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.

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.

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)

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).

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

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

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 3^rd at Heron Pond Farm in South Hampton, NH. Details are available at the link at the bottom of this page.

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.

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.

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.

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 17^th - 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!

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 25^th , 2023.

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 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.

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. 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

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 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

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

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.

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

Japanese Beetles:

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.

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 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 3^rd 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

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 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.

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 17^th - 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)

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 18^th , 2023.

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.

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:

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.

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:

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.

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

SWD Netting Project

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.

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

Figure 4: Codling moth trap captures for Merrimack County

Oriental Fruit Moth

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

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

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.

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.

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 17^th - 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!

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 11^th , 2023.

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.

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:

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.

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:

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 3^rd 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:

Figure 2: Codling moth trap captures for Merrimack County

Oriental Fruit Moth:

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

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.

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.

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 17^th - 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!

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 27^th , 2023.

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 25^th through June 30^th.

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.

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.

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

Figure 1: Codling moth trap captures for Merrimack County

Oriental Fruit Moth:

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

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

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 17^th 5:30-7:30 pm

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

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

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

June 29^th 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 3^rd at Heron Pond Farm.

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

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 20^th , 2023.

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

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.

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:

Today we have accumulated 303 DD base 50F from our biofix and reached 250 DD by June 16^th, 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:

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)

Figure 2: Codling moth trap captures for Merrimack County

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.

Commercial vs. Home-Made Traps

Making Your Own Traps

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 20^th at Stark Farm. Details are available at the link at the bottom of this page.

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 20^th, 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!

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 13^th , 2023.

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

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.

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.

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 16^th. 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.

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 11^th, 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 16^th, 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)

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!

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)

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

Commercial vs. Home-Made Traps

Making Your Own Traps

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 20^th at Stark Farm. Details are available at the link at the bottom of this page.

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 14^th, 2023

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

June 15^th, 2023

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

June 20^th, 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!

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 6^th , 2023.

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

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.

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 11^th. 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.

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

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 11^th.

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 11^th, 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)

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

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

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.

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 15^th, 2023 5:30-7:30 pm

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

Tree Fruit meeting at Apple Hill Farm, August 17^th, 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 20^th, 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)

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!

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 30^th , 2023.

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 17^th and into the late morning hours of May 18^th 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:

Pruning:

Watering:

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

Fertility:

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.

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

More on thinning:

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.

· 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.

· 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):

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.

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 4^th.

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:

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

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

Tree Fruit meeting at Apple Hill Farm, August 17^th, 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 20^th, 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!

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 23^rd , 2023.

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 17^th and into the late morning hours of May 18^th 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):

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:

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

Insects:

Plum curculio:

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)

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.

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:

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

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

Tree Fruit meeting at Apple Hill Farm, August 17^th, 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!

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 16^th , 2023.

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 12^th 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 18^th 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:

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:

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 12^th 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

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 18^th, 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:

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

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

Tree Fruit meeting at Apple Hill Farm, August 17^th, 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!

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 9^th , 2023.

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):

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.

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 12^th). 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:

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 1^st catch 475 DD base 43, mating disruption with granulosis virus is a good option, Altocor for 1^st gen, Assail for 2^nd 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:

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

Additional Notes:

Twilight Meetings:

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

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

Tree Fruit meeting at Apple Hill Farm, August 17^th, 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!

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 2^nd, 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 4^th. The forecast currently shows a break in the rain by the afternoon of May 4^th. 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 6^th, 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:

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:

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 1^st catch 475 DD base 43, mating disruption with granulosis virus is a good option, Altocor for 1^st gen, Assail for 2^nd 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:

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

Finally:

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

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 26^th. 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!

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 18^th. More rain is predicted later in the week through Monday, April 24^th, so protection going into that stretch with a rain-fast product is advisable.

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.

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).

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:

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):

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.

Past Reports

expand all

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 15^th. 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 28^th 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 28^th 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)

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 28^th 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.

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

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 5^th. 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 26^th to Wednesday the 27^th. 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.

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 19^th) 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.

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, protect ripe fruit when you start seeing and average of 3-5 males per trap. Scentry lures are more sensitive but they also capture a lot more other stuff than the Trece lures. Eastern NY has reported their first capture but we haven’t heard reports of SWD in New England yet. Join our facebook group “SWD Monitoring Support Group” to post your photos or to see what others are seeing.

There will be a virtual tree fruit twilight meeting, Wednesday, June 23rd from 6-8pm, with pesticide applicator credit.

We at extension are saying farewell to George Hamilton and Cheryl Smith who are retiring this week! Please reach out to them directly if you'd like to say hi or I can pass along any message for you. Email me at anna.wallingford@unh.edu.

June 15, 2021

We’ve accumulated 525 base 50 GDD in Durham.

For those of you who are targeting sprays to the first generation of codling moth, that window should be closing soon. For those of you that saw San Jose scale injury last year, those first generation crawlers are likely active now. Refer to the Tree Fruit Guide to select materials and target areas where you saw injury last year.

Those of you with young trees, potato leaf hopper has been reported in the area so now would be a good time to scout those trees for adults or nymphs. Mature apple trees do not need to be protected from leafhoppers but you might think about protecting young trees if you see more than a few of those little neon green nymphs running sideways on the undersides of leaves.

Blueberry maggot models predict flights starting soon. 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, protect ripe fruit when you start seeing and average of 3-5 males per trap. Scentry lures are more sensitive but they also capture a lot more other stuff than the Trece lures. We’re trialing a “dry trap this year” so follow our facebook group “SWD Monitoring Support Group” to post your photos or to see what others are seeing. Eastern NY has reported their first capture but we haven’t heard reports of SWD in New England yet.

There will be a virtual tree fruit twilight meeting, next Wednesday, June 23rd from 6-8pm, with pesticide applicator credit. Put it on your calendar.

June 8, 2021

We’ve seen some hot ones and have accumulated 400 base 50 GDD in Durham.

Apple scab ascospore maturity has reached 100% in most regions of the state. While we really don’t officially call an end to primary infection season until about 10-14 days after we hit 100%, you should be pretty much out of the woods as long as you’ve gotten preventative fungicides on before this week’s rain showers. Scout your orchard over the next few weeks for lesions to determine if you have any concerns for secondary infection. Lesions can be found on terminal foliage in early-developing orchards, and also on the upper side of fruit cluster leaves in later-developing orchards.

Continue to check hotspots and border trees for plum curculio stings but that season should be winding down. If you have a history of codling moth injury – like more than 5% injury in last year’s harvest – and plan on targeting sprays to the first generation soon. For those of you that saw San Jose scale injury last year, we’re coming up on first generation crawlers pretty soon too. Refer to the Tree Fruit Guide to select materials.

Strawberry harvest is underway and other than some sunscald here and there, things have been looking good. Keep your eyes peeled for spider mites and thrips, who love hot, dry conditions. Examine the undersides of 5-10 leaves in 5-10 locations around the field. For two-spotted spider mites, an action threshold of 25% of infested leaves is typical, but also consider that this pest tends to break out in hotspots, so spot treatment might provide sufficient control. Avoid the use of pyrethroids for spider mites as these products tend to cause flare ups in mite populations.

For blueberry and raspberry growers who are monitoring for spotted wing drosophila or blueberry maggot. Start thinking about getting your traps out. I’ll report what we’re seeing regionally on this message but every site is really different for these flies, so monitoring your fruit is best. If you’re using Trece traps, protect ripe fruit as soon as you detect SWD males. If you’re using Scentry traps, protect ripe fruit when you start seeing and average of 3-5 males per trap. Scentry lures are more sensitive but they also capture a lot more other stuff than the Trece lures. We’re trialing a “dry trap" this year so follow our facebook group “SWD Monitoring Support Group” to post your photos or to see what others are seeing.

Looking well ahead in the calendar, there will be another virtual tree fruit twilight meeting June 23rd from 6-8pm, with pesticide applicator credit. Put it on your calendar.

June 1, 2021

We’ve accumulated 620 base 43 GDD here in Durham, 260 GDD in base 50, over a remarkably weird week with some much needed rain! Bumble bees likely took a hit from last year’s drought and cool weather has made blueberry pollination season a bit of a struggle.

Apple scab primary scab season is nearing completion but you are likely still open to risk of infection. An infection event is predicted this week, so think about getting a preventative fungicide ahead of rain showers.

Plum curculio are likely starting to lay their eggs tree fruit. Trees should be protected from egg-laying as soon as fruitlets are ¼” in diameter. We’ve been hearing reports of a pretty light year so far but this cool weather may have slowed things. After that first cover spray, keep your eyes peeled for fresh oviposition scars on border trees to trigger another spray, or just a border spray as this is sufficient for that follow up treatment.

We’ve heard that strawberries are coming in quite well this year! Some comments for strawberry as growth flushes and blossoms open. Tarnished plant bug may be moving in to blooming plantings. Tap flowers over a white surface, like a piece of paper, paper plate, white Frisbee, to see if tiny almost neon-green TPB nymphs jump out. Threshold is reached if 4 or more flower clusters are infested with nymphs out of 30 clusters sampled evenly from across the field.

To scout for spider mites and aphids, examine the undersides of 5-10 leaves in 5-10 locations around the field. For two-spotted spider mites, an action threshold of 25% of infested leaves is typical, but also consider that this pest tends to break out in hotspots, so spot treatment might provide sufficient control. Avoid the use of pyrethroids for spider mites as these products tend to cause flare ups in mite populations.

Looking well ahead in the calendar, there will be another virtual tree fruit twilight meeting June 23rd from 6-8pm, with pesticide applicator credit. Put it on your calendar.

May 25, 2021

Well this season has lurched forward and we’ve accumulated 520 base 43 GDD here in Durham, 200 GDD in base 50.

Risk of blossom blight fireblight infection is wrapping up as the bloom period wraps. We are still within the primary infection period for apple scab so you may want to keep an eye on the weather reports and protect trees before rain showers.

Plum curculio are likely starting to lay their eggs tree fruit. Trees should be protected from egg-laying as soon as fruitlets are ¼” in diameter.

Some reports of young gypsy moth blowing into fruit crops from surrounding wooded habitat. Little furry caterpillars with red and blue dots on their backs. Really only a threat if there are a lot of them but there is a threat if you get a lot blowing into so know how to identify gypsy moth caterpillars.

Some comments for strawberry as growth flushes and blossoms open. Tarnished plant bug may be moving in to blooming plantings. Tap flowers over a white surface, like a piece of paper, paper plate, white Frisbee, to see if tiny almost neon-green TPB nymphs jump out. Threshold is reached if 4 or more flower clusters are infested with nymphs out of 30 clusters sampled evenly from across the field.

Some other damage you might encounter as you scout strawberry: Ragged holes in leaves might be an indication of slug feeding. If you notice that the pedicles, or stems, of developing fruit appear clipped off or dying, this might be strawberry clipper. If you notice the entire plant has been removed from its roots, that might be cutworm.

May 17, 2021

We’ve accumulated 360 base 43 GDD here in Durham, 100 GDD in base 50.

I have an update from our plant pathologist, Dr. Cheryl Smith, reminding us that fireblight risk is very high for anyone in our region with blooming apple trees. It’s best to get a Strep application before an infection event, or wetting period of rain or heavy dew. Strep provides as much as 48 hours of protection. Considering many of you had severe fireflight last year, it would make sense to revisit Dr. Kari Peter’s reccomendations. For young trees, strep plus actiguard applied during bloom can improve tree immune response to infection, For older trees, Apogee or Kudos plus Regalia can be used to boost tree immune response. For both young and mature trees, following with Queva is an option when you’re past full bloom.

There will be a virtual tree fruit twilight meeting this week, Wednesday May 19th @ 6pm. Register for this event at our website or call Jeremy DeLisle for more information at 603-255-3592.

May 11, 2021

We’ve accumulated 270 base 43 GDD here in Durham, 60 GDD in base 50. Things have barely progressed since last week so this message from our plant pathologist, Dr. Cheryl Smith is very similar to last week.

Apple scab ascospore maturation is peaking in many areas so it will be very important for you to watch the weather forecast and get a protectant fungicide out before your next rain shower.

Cool temperatures through our region, means that we did not see any fireblight infection periods last week and risk remains at low this week. However, 2020 was a VERY BAD year for fire blight meaning that risk could be high as soon as temperatures build, so be vigilant and monitor NEWA for fire blight predictions as we approach bloom (enter the date of 1st blossom open for your orchard into the biofix for the fire blight model predictions. Your 1st Strep application should go on during bloom when MaryBlyt EIP ? 100; or Cougar blight shows high risk.

For those of you relying on mating disruption for codling moth, that should be deployed by bloom. For those of you who monitor codling moth, you should have your traps up by now. First trap is anticipated around 200-300 DD(50) and that first capture establishes a biofix. This biofix is important for subsequent degree day accumulation that predicts peak CM flights on your farm through the year.

Now might also be a good time to scout for gypsy moth larvae. Gypsy moth is a rare but potentially damaging pest in the orchard, which can thrive in dry years when its naturally-occurring fungal pathogens aren’t thriving. Larvae are small this time of year but they’re fuzzy and have conspicuous blue and red dots, and easily controlled with Dipel, which contains a bee-safe biocontrol product.

There will be a virtual tree fruit twilight meeting next week, Wednesday May 19th @ 6pm. Register for this event at our website or call Jeremy DeLisle for more information at 603-255-3592.

May 4, 2021

An update from UNH's plant pathologist, Dr. Cheryl Smith

We’ve accumulated 220 base 43 GDD here in Durham, 46 GDD in base 50. Mac phenology ranges from 50% bloom to tight pink (Londonderry to Plainfield). Warmer weather predicted for next week, so things will start to progress quickly.

We’re in the thick of apple scab primary infection period, ascospore maturity ranges from about 20-60%, 36% - 20% (Londonderry to Plainfield) (Walpole at 54%). The NEWA scab models are predicting a scab event that started 5/3 or 5/4 and will continue through 5/5 or 5/6 (Mon-Thur). 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. (newa. cornell.edu)

If you did not have a protectant on in the last 7 days, you may want to consider a kick- back product. If you had NO scab in the orchard last year – you may be able to risk it. But if you have a window – at least get on a rainfast mancozeb. Kari Peter (PA) recommendation: use a rainfast mancozeb (Manzate Pro-Stick, Roper Rainshield, etc.). The rainfast mancozeb gives better control since it can persist longer during rainy, wet periods. Any non-rainfast mancozeb can be made rainfast by adding a spreader sticker (4 fl oz/100 gal).

2020 was a VERY BAD year for fire blight! For those of you in northern regions, it may not be too late to apply a plant activator from tight cluster to pink, in order to activate plant defences prior to bloom. Remember that bloom is the key time for management – flowers must be open for infection to occur. Current risk is low to moderate through 5/9 (Sunday). Be vigilant and monitor NEWA for fire blight predictions as we approach bloom (enter the date of 1st blossom open for your orchard into the biofix for the fire blight model predictions. 1st Strep application should go on when MaryBlyt EIP ? 100; or Cougar blight shows high risk.

Many stone fruit crops are at petal fall. Now is a critical time for managing bacterial spot in peaches, petal fall through shuck split. It also remains a critical time for managing brown rot and peach scabe in stone fruit, from bloom until 3 weeks after bloom and again 3 weeks before harvest. Refer to Tree Fruit guide for materials.

April 27, 2021

We’ve accumulated 166 base 43 GDD here in Durham, 32 GDD in base 50. We are hearing reports of green tissue out in apple, blueberry, and raspberry.

Tree phenology has been slow moving this year but we still need to pay close attention to apple scab infections. Spore maturity varies from 4% to 19% around the state and all locations have a predicted scab event with predicted rain this week. Getting on a protectant before this weeks rain would be a good idea. Captan is a good protectant fungicide. Kari Peter (PA) recommends using a rainfast material like mancozeb (Manzate Pro-Stick, Roper Rainshield, etc.). The rainfast mancozeb gives better control since it can persist longer during rainy, wet periods. Any non-rainfast mancozeb can be made rainfast by adding a spreader sticker (4 fl oz/100 gal). Warmer weather predicted for next week – so spores will mature.

Peach growers. Critical 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. Refer to Tree Fruit guide for materials (several products are excellent for both). The cold/snowy conditions last week might result in some blossom blast so know how to distinguish that from brown rot-infected flowers that have visible spores.

There will be a virtual Tree Fruit IPM webinar next Wednesday 4/28 at 6 pm, featuring our very own Dr. Cheryl Smith who will walk us through NEWA forecasting models for disease management, and a special guest from Rutgers University, Dr. Thierry Besancon who will discuss Integrated Weed Management for Orchards. PAT credit pending. https://extension.unh.edu/events/tree-fruit-virtual-twilight-meeting

Or call Jeremy Delisle at 603-255-3592 for more information.

April 20, 2021

An update from UNH's plant pathologist, Dr. Cheryl Smith

We’ve accumulated 128 base 43 GDD here in Durham, 25 GDD in base 50. We are hearing reports of green tissue out in apple, blueberry, and raspberry. It sounds like most of our peaches made it through last week’s cold weather unscathed but we do expect peach bloom in many areas this week.

Apple scab spore maturity ranges from 2-10% and it looks like we have a few potential infection events in the forecast this week…like right now 4/20-21 and maybe again this weekend 4/24-25. If you can get out with a preventative before rains, that would be ideal, if not get out with a material with some kickback after rains. Scout for infections 9-17 days post-infection (4/22-4/30) and (4/29-5/7) to assess your apple scab conditions.

Now would be the time to get out with a dormant oil application for smothering overwintered spider mite eggs and the overwintered life stage of Comstock mealybug and San Jose scale (blackcaps). Large spray volumes help with good coverage. We recommend 2 gallons of oil per 100 gallons of water from greentip to 1/2" and use 1 gallon as you get closer to tight cluster or if you have any concerns regarding cold temperatures. You should avoid using dormant oils during freezing weather, so you're looking for a 48 hour window of good temps.

If you have a history of Rosy Apple Aphid, you will want to get out and scout fruit clusters between now and pink. Observe 20 or so fruit clusters throughout each block and use an action threshold of an average of one colony per cluster make sure to act before bloom. If this is a chronic problem in your orchard, you might think about broadleaf weed management in the fall as many of these weeds are alternative hosts for the aphids.

Blueberries. For those of you with a history of mummy berry, now is a good time to do some ground management to reduce fungal incoculum. You can cover those overwintered structures with 2-3” of mulch at anytime in the dormant period. Alternatively, cultivation right around bud-break will help destroy or disturb emerging mummies. 50% urea at this time can also help, but avoid applying to wet areas. Scout for apothecia in mummified fruit under the bushes (little brown cup-shaped mushrooms) Refer to the Small Fruit guide for fungicides if you think you need them, begin applying at bud swell.

Looking forward to next week! There will be a virtual Tree Fruit IPM webinar next Wednesday 4/28 at 6 pm, featuring our very own Dr. Cheryl Smith who will walk us through NEWA forecasting models for disease management, and a special guest from Rutgers University, Dr. Thierry Besancon who will discuss Integrated Weed Management for Orchards. PAT credit pending.

April 13, 2021

An update from UNH's plant pathologist, Dr. Cheryl Smith

We’ve accumulated 105 base 43 GDD here in Durham, 25 GDD in base 50. Apricots are blooming and peaches are threatening. I would expect to see some green tissue on apples for many of you so now is the time to go out with copper to clean up overwintered disease inoculum.

Risk models for primary infection period for apple scab begin when 50% of macs are at green tip but risk of infection is very low this week with little ascospore maturity predicted and little rain in the forecast.

Tarnished plant bug is likely getting active in the orchard now. TPB activity is highly dependent on temperature, so that 2 or 3 days of warm (50-60 degrees), sunny weather triggers increased foraging and feeding behavior. White sticky traps can be stapled to stakes or hung on low branches no higher than knee height near orchard perimeter. Use at least one trap per 3 acres and at least 3 traps per monitored block. Action threshold is cumulative average of 5 TPB per trap by Tight Cluster or 8 TPB by Pink. Examine 10 terminals per block for bleeding buds. Action threshold is 2-3 bleeding sites per 10-terminal sample.

April 6, 2021

We’ve accumulated 60 base 43 GDD here in Durham, 15 GDD in base 50. The forecast looks pretty nice this week so I would expect many of you to start seeing green tip any day now.

Risk models for primary infection period for apple scab begin when 50% of macs are at green tip so that’s when we start looking at risk for infection events. Given last year’s drought conditions, most of us will be at pretty low risk to apple scab in 2021, especially if you practice good sanitation.

Delayed-dormant sprays of petroleum oil (green tip through tight cluster) should be considered for smothering overwintered spider mite eggs and the overwintered life stage of Comstock mealybug and San Jose scale (blackcaps). Large spray volumes help with good coverage. We recommend 2 gallons of oil per 100 gallons of water from greentip to 1/2" and use 1 gallon as you get closer to tight cluster or if you have any concerns regarding cold temperatures. You should avoid using dormant oils during freezing weather, so you're looking for a 48 hour window of good temps.

For peaches affected by peach leaf curl and other bacterial disease, copper sprays need to go on before any green tissue emerges. Copper sprays will be important for apple affected by fireblight last year.

Typically we don’t pay much attention to strawberries this time of year but we’ve gotten reports from a strawberry grower who observed some nighttime feeding by winter cutworm. This is a weird one and relatively new to the region but this is the time of year you might see some weird injury. The only way to confirm the species would be to go out at night with your headlamp and catch these caterpillars red-handed…or red-mandibled in this case.

The recording of our recent NH Tree Fruit Grower’s Association Meeting, is available online if you missed it or want to listen back. Kari Peters’s Reqs on Canker Management and Kerik Cox’s reqs on spring disease management are also available online or you can call me at 603-862-1734

Upcoming webinars

Next Tuesday (4/13) noon to 1pm, join our Ag Biz team for Making Sense of Trusts as an Estate Planning Tool

Or call Kelly McAdam at 603-527-5475

Next Wednesday (4/14) noon to 1pm, join entomologists and crop production specialists from the region for Practical Tips for Brassica Insect Pest Management

Or call Shyloh Favreau at 603-862-3200

March 30, 2021

My apologies for the abrupt ending to the season last year. Technical difficulties!

But things are picking up here in Durham, having accumulated 13 growing degree days so far. Now is the time to get serious about dormant sprays if you haven’t already.

Getting Even More Out of Your Cover Crops webinar Thursday April 1, 1:00-2:30 pm or call Carl Majewski at 603-352-4550.

Making Sense of Trusts as an Estate Planning Tool webinar Tuesday April 13, 12:00-1:00 pm or call Kelly McAdam at 603-527-5475.

August 31, 2020

We are hitting the pause button on weekly messages for the season but we will return next year in April.

August 18, 2020

We have accumulated 1800 base 50 growing degree days here in Durham. Drought conditions are creating challenges all over the state, including many reports of overwhelming fall webworm and other defoliating caterpillars. These are sporadic forest insects that typically do not cause a lot of problems in the orchard but a dry spring knocks back the naturally occurring entomopathogenic organisms that typically keep their populations low.

While this is typically the homestretch for orchard crop protection, we’ve have a few pest organisms for your to consider. Unfortunately, many areas have seen enough heat units to consider risk from codling moth’s 3rd generation. If you observed internal worm injury during the first generation, you might considering monitoring and acting on the 3rd.

George Hamilton has reported late instar brown marmorated stink bug in his traps in the southern region of the state, so if you are monitoring for the soon-to-come adult generation in your peaches or apples, now would be the time to get those traps up. For pheromone baited sticky cards, we’re recommending a few traps on wooded border rows and one or two in the center of each block. A border row would be sufficient if you observe an average of 4 BMSB on border row traps. If you’re catching BMSB in the center of the orchard, a full spray would be called for.

All areas are at risk for SWD infestation and risk will remain high until flies enter reproductive diapause in September. Check your guide for information on crop protection materials. Post-harvest refrigeration is critical here.

We are also keeping an eye out for the rarely observed 2nd generation of squash vine borer. This species got started early this year, and we’re hearing reports of a second peak in some areas, which could be an issue in winter squash. Check weekly monitoring data to see the moth activity in your region.

I don’t see too much on the calendar in terms of events but I will be scheduling visits for the annual apple evaluation over the next couple of weeks so give me a holler if you want to make sure you are included.

August 3, 2020

We’re seeing a lot of heat and watching for storms coming our way this week but there are many repeats from last week’s message.

If you missed our fire blight webinar with Dr. Kari Peter last week, find a recording by clicking here.

Keep your eyes peeled for apple maggot. Thresholds are 1 fly/trap with no lure, 5 flies/trap with an attractive lure. Codling moth's second generation is likely flying. Best practice is to rotate materials, including materials used during the first generation flight, to avoid resistance.

July 28, 2020

We have accumulated 1270 base 50 growing degree days here in Durham.

A reminder that we will host a fireblight webinar tonight Tuesday July 28, with Dr. Kari Peter, Fruit Pathologist with Penn State University, George Hamilton, Cheryl Smith, & Jeremy Delisle to discuss control options orchardists should be using in trying to control this disease in orchards. Register on the extension website or contact Mary West at 603-796-2152 . No credits but this will be well worth your time.

Apple maggot fly numbers are creeping up. We have heard reports of threshold populations at few sites last week. That’s 1 fly/trap with no lure, 5 flies/trap with an attractive lure. Second generation of codling moth is flying and egg laying will soon follow. Second generation of San Jose scale males are likely flying soon, so not quite time to scout for the susceptible crawler period.

Pretty much everyone in the state is now at risk for SWD infestation. This heat we’re seeing this week will slow egg laying but, when evening temperatures drop back below 80oF, SWD risk will remain high until they enter reproductive diapause in September. Raspberry is by far the most preferred crop and require shorter spray rotations more like every 5 days for good control, versus weekly applications that provide good control in less preferred blueberry crops. Check your guide for information on crop protection materials. It looks like most cherry crops were harvested without much in the way of infestation.

For vegetable crops, we got a notice of confirmed cucurbit downy mildew in Franklin Co, MA.

If you suspect you have downy mildew, our plant diagnostic lab is not currently accepting physical samples but you can submit a digital sample by emailing pdl.digitalsample@unh.edu and Dr. Smith will work to identify your problem.

Our Food Safety Team is hosting a virtual twilight meeting on Managing Humidity & Condensation in Coolers. This is an important topic for anyone using cold storage and will feature Chris Callahan and Andy Chamberlain from UVM’s Ag Engineering team. Register on our website or give Heather Bryant a call at 603-787-6944.

July 20, 2020

Next Tuesday evening (7/28) at 6pm, we will host a fireblight webinar with Dr. Kari Peter, Fruit Pathologist with Penn State University, George Hamilton, Cheryl Smith, & Jeremy Delisle to discuss control options orchardists should be using in trying to control this disease in orchards. Register on the extension website or contact Mary West at 603-796-2152 . No credits but this will be well worth your time.

Second generation flight of codling moth is likely beginning, and egg-laying to proceed. Comstock mealybug’s second generation is right around the corner too, so you might be thinking about scouting your tape traps soon. It’s a good time to scout for scale insects too.

Get those apple maggot traps out. Threshold is one fly per trap with no lure, 5 flies/trap with an attractive lure.

Get serious about protecting peaches from brown rot a couple weeks before harvest.

SWD is present in most regions of the state and risk of infestation is climbing in hotspots. Our research farm in Durham is currently experiencing high pest pressure, traps are capturing an average of 12 males, raspberry infestation is roughly 50% while blueberry infestation is below 3%. At locations with a history of blueberry maggot, degree day calculators predict that most of the state is at peak egg-laying for blueberry maggot as well.

Corn pest pressure was low last week but watch for regional storms blowing up new flights of moth pests by checking our weekly scouting report

George Hamilton will be discussing how to get great spray coverage and sprayer calibration for small scale operations this Wednesday night (7/22) 6:30 - 8:30 pm. We will also be discussing what you need to know if you are considering foggers for high tunnel production. Meg McGrath from Cornell will discuss the theory and legality of using sulfur burners for powdery mildew management. Spoiler alert: please don’t burn sulfur. Representatives from DRAMM and Biosafe will be there to answer questions. 2 PACs available for those who attend the live event.

July 14, 2020

This is a repeat of last week’s reminder as we’re continuing to see sporadic showers and thunderstorms in the region, it’s important for you to track your risk of summer diseases in apple. NEWA shows high risk for sooty blotch and fly speck infections. If you are seeing apple scab lesions in your orchard, you may also be at risk for secondary infections. Fireblight has hit many hard this year so make sure you have strep on hand in case of hail.

It’s too late to act on codling moth but pretty soon might be a good time to scout for infestation in order to determine if you need to target the second generation. You might think about keeping an untreated sentinel tree or two for this purpose, which get fungicide protection but no insecticide treatments. Time to get your apple maggot traps out to track movement of these flies into your orchard.

Start thinking about brown rot protection in peaches soon.

We have detected SWD in the state. Adult flies as well as a few infested raspberries and blueberry samples. Something in the range of 1-2% infestation. If you are monitoring on your farm, this may be a reminder to check those traps often. We will keep you posted as risk climbs through the season.

For those of you finishing up strawberries, make sure to renovate as soon as harvest is done and don’t wait until all of your plots are finished up. The more growth you can put on this summer, the more cold tolerant over the winter and the stronger that crop will be next year.

Squash vine borer trap numbers are climbing in many areas. Check our online resource for data in your area and protect susceptible cucurbit crops from egg laying.

Tomorrow night Wednesday July 15th 6:30-8:30pm, there will be a zoom workshop on Low-Risk Insecticides and a follow-up webinar Wednesday July 22nd, covering sprayers and foggers for small scale operations.

July 7, 2020

We have accumulated 808 base 50 growing degree days here in Durham.

With sporadic showers in the region, it’s important for you to track your risk of summer diseases in apple. NEWA shows risk climbing up for sooty blotch and fly speck. If you are seeing apple scab lesions in your orchard, you may also be at risk for secondary infections. I’ll also repeat last week’s reminder about fireblight and the potential for extreme weather causing entry wounds for the bacteria that causes fireblight. If hail does occur – apply strep within 24 hours. If you applied captan less than 10 days prior to the strep application DO NOT add Regulaid/LI 700 to streptomycin for this emergency spray – captan uptake can cause phytotoxicity marks on fruit). If you have not applied captan within that 10 days ago you can add LI700 to streptomycin.

We have detected SWD in the state. Adult flies as well as a few infested raspberries and blueberry samples. Something in the range of 1-2% infestation if any at all. If you are monitoring on your farm, this may be a reminder to check those traps often. We will keep you posted as risk climbs through the season.

We’ve been hearing lots of reports of gummosis affecting young peach fruit, especially in pesticide-free plantings. This clear, gummy ooze is most likely from some kind of piercing-sucking damage done earlier in the season by tarnished plant bug or one of its relatives. Unfortunately, there is nothing to be done about this injury by the time we see the gummosis and, frankly, this would have been difficult to predict or avoid. It’s a challenging pest to manage.

Some upcoming webinars that might be of interest. There will be a disease management workshop for giant pumpkin growers tonight July 7th 6-8pm. Dr. Shahid will discuss some benefits of applying silicon to plants as part of the Plant Health Webinar Series this Thursday July 9th 7-8pm. Next Wednesday July 15th 6:30-8:30pm, there will be a webinar on Low-Risk Insecticides.

June 30, 2020

We have accumulated 675 base 50 growing degree days here in Durham.

It’s looking to be a tough year for fireblight, seeing lots and lots of strikes in apple orchard. We had some heavy storms over the weekend in many areas, which reminds us to remind you about the potential for extreme weather causing entry wounds for the bacteria that causes fireblight. If hail does occur – apply strep within 24 hours. If you applied captan less than 10 days prior to the strep application DO NOT add Regulaid/LI 700 to streptomycin for this emergency spray. Captan uptake can cause phytotoxicity marks on fruit. If you have applied captan more than 10 days ago you can add LI700 to streptomycin.

If you are seeing apple scab lesions in your orchard, this week’s wet weather could mean secondary infections and a need for fungicides. Check your guide.

According to temperature models, codling moth egg laying is likely peaking in many areas. But monitoring data from on-farm is best. Now might be a good time to think about getting those apple maggot traps ready to deploy.

We have detected SWD in the state this week. Just one. So we’re at very low risk of infestation. If you are monitoring on your farm, this may be a reminder to get your traps out or to check those traps more frequently. Now that we’re seeing some rain and humidity, I would expect that population to start growing quickly. Check our weekly scouting reports for trapping data in your area.

June 23, 2020

We have accumulated 540 base 50 growing degree days here in Durham. I don’t think I have to tell you its been extremely dry and we’ve been hearing lots of reports of heat damage, sunscald in many crops.

Dry weather means low risk for summer diseases in apple but trees with a rat tail bloom remain at risk for fireblight. If you are signed up for our Fruit&Veg newsletter, you should have gotten an email with more information about this today.

Codling moth’s first generation is flying and eggs are likely beginning to hatch. Potato leafhopper has arrived in our region. You may have noticed tiny white adults flying around when disturbed or the little neon nymphs that run sideways around leaves. These insects cause piercing-sucking feeding, and the injection of toxic saliva in this process results in hopperburn on leaves. This looks like discolored, crinkled, sometimes downward curling leaves. Look for these symptoms and check on the underside of leaves for the leafhoppers to confirm. There’s no hard threshold but younger, delayed, or stunted plants are more susceptible, so keep an eye out and consult your guide to select your plant protection approach.

For those of you who are targeting piercing-sucking insects in treefruit, like mealybug or scale, Movento, Centaur, Assail, and Sivanto are some of the most reliable products for insects in this group. You might think about rotating one of these pricier products (Centaur or Movento) with a neonicotinoid (IRAC 4). The data look good for a Movento/Sivanto rotation but you should be good with any neonic you have on hand, as long as you use the highest labeled rate. Also, I cannot emphasize this enough! Surfactants and high gallonage are really critical for getting materials where they need to be to be to control these tiny bugs. A rate of 50 gallons per acre or lower might be appropriate for getting good coverage on leaves for fungicide applications but rates of 100-250 gpa are more appropriate for sucking insects. The higher the better.

We are trapping BMSB in many areas at numbers that are not high enough to warrant action but are higher than we normally see this time of year. Peaches and apples will be particularly susceptible crops to monitor through the season for this new pest.

I will also add that we are seeing high numbers of squash vine borer for you pumpkin and squash growers. Check out monitoring data to see if numbers are going up in your area and protect those plants before egg laying starts next week.

June 16, 2020

We have accumulated 395 base 50 growing degree days here in Durham. For apples, peaches, and pears, fruit is set and folks are thinning. The first strawberries were harvested in southern regions last week.

We are always hesitant to declare primary scab season at its end, but the forecast looks pretty dry so there is little risk for new scab infections. Low risk for sooty blotch and flyspeck. As long as your trees are completely done with bloom, there is low risk for fireblight blossom blight. Now might be a good time to scout for fireblight strikes and to prune them out. Remember to cut at least 12-18” below infected area, leave a stub if you can, rather than cut all the way back to the healthy limb, and to sanitize tools between cuts to avoid spreading the pathogen.

Plum curculio egg-laying should be wrapping up but check for fresh oviposition scars, just in case. San Jose scale crawlers may be on the move now. Codling moth is flying now and leafrollers will start flying soon. When targeting the larvae that will soon follow these flights, consider rotational materials like IRAC 28s, i.e. the diamides (Altacor, Exirel, Verdepryn) or, IRAC 5s, i.e. spinetoram (Delegate), spinosad (Entrust/Blackhawk).

Dry weather means you might be seeing more spider mite (speckled leaves & webbing) and thrips damage on strawberry (bronzing of fruit surface). Scout for thrips by tapping flowers over a white surface. Do this in about 20 locations. Threshold is 2-10 thrips per flower. Brigade and Danitol will provide excellent control but Entrust and Radiant will both provide good control with lower impact on pollinators. No matter what, you should be spraying in the evening to reduce non-target impacts on pollinating insects. For new strawberry plantings, irrigation is particularly important with all this dry weather. We have not yet captured SWD in New Hampshire so strawberry is not at risk for SWD infestation.

June 9, 2020

We have accumulated 306 base 50 growing degree days here in Durham.

We are reaching the end of primary scab season but we're not quite done with risk. You may want to get on a protectant ahead of the rain predicted this week. Blooming trees remain at extremely high risk for fireblight infections so keep that in mind too.

Plum curculio may still be active in the orchard so you may want to continue scouting for fresh oviposition scars. According to weather models, codling moth is likely flying now, out meeting that special someone and starting a family. Crop protection materials are targeted for the subsequent egg hatch, 100 -200 DD from your biofix, or sustained trap capture.

If you are monitoring for San Jose Scale, crawlers are likely to be active now. Now might also be a good time to scout water sprouts, pruning wounds, and scars on the inside of the tree canopy for WAA. A horticultural mineral oil or a non-ionic surfactant (like LI-700 or Regulaid) added to any product you are using for scale or aphids will be helpful in improving spray coverage and particularly critical for these tiny bugs

We are hearing lots of reports of winter damage in small fruit crops. If you are seeing unusual stuff, you might check out Cornell’s new berry diagnostic tool which will walk you through diagnosing a problem on your own.

Our third of the season webinar for commercial orchardists will be tomorrow night June 10 5:30-7:30 p.m. This event will include 2PACs and Tree Fruit Insect Updates from Jaime Piñero (UMass) and Anna Wallingford (UNH), a summary of a recent peach variety trial from Tom Callahan (Adams County Nursery) & George Hamilton (UNH), and a summary of resources for responding to COVID-19 from Jeremy Delisle (UNH).

June 2, 2020

We have accumulated 200 base 50 growing degree days here in Durham. Apple and peach have set fruit in the majority of the state and blueberry is blooming in most regions.

We remain at high risk for fireblight infection for varieties that are still blooming. Watch out for that rat-tail bloom!

Apple scab ascospore maturity is also still high. Watch those weather models for infection periods and stay protected.

Plum curculio is active and reports of egg laying have been coming in from many areas. Look for fresh oviposition scars to trigger a control measure and consult your guide for selecting crop protection materials. Continue to scout for those fresh scars over the following weeks and consider a border spray for subsequent controls. New stings are from PC migrating into blocks from wild habitat so a follow up border spray instead of a full spray is normally sufficient. For more on integrating behavioral controls into tree fruit IPM programs, Jaime Pinero (Tree Fruit Entomologist from UMass Extension) will be discussing behavioral controls at our next tree fruit webinar on June 10th 5:30-7:30. 2 PACs. Register at the UNH Extension Website.

For peaches, lesser peach tree borer starts flying around 250-370 (base 50). So if you are monitoring for borers, your traps should be up by now.

While Extension offices remain closed due to concerns regarding COVID-19, we are finding new and creative ways to bring you socially distanced versions for most of our services. We will have a steady stream of really stellar webinars planned through the season and we are still available by phone, text, and email.

May 26, 2020

We have accumulated 96 base 50 growing degree days here in Durham. Apple is blooming in the majority of the state and blueberry is blooming in many southern regions, making blueberries susceptible to mummyberry secondary infections.

Apple scab ascospore maturity is high and the moisture over the weekend means that we are likely coming out of an infection period. Hopefully you were protected with a preventative fungicide applied before the infection event or you should get out there with something with kickback. Consult your guide.

We are also in a period of high risk for fireblight infections, that is blossom blight infections and a bacteriacide should be considered if you haven’t already made your applications last week. Keep an eye on those models for the best information for your location.

See our Extension youtube channel for a tutorial from Cheryl Smith on using NEWA to predict risk for apple scab

and fireblight.

If you are seeing winter injury, you may also be noticing angular leaf spot, lesions on the underside of leaves with a water-soaked appearance. If you are seeing this in a large portions of your planting, but you are also in bloom it will be too late for copper. You might consider oxydate for cleaning up the bacteria that cause this disease.

We're hearing some reports of young gypsy moth blowing into fruit crops from surrounding wooded habitat. Little furry caterpillars with red and blue dots on their backs. One or two are not a threat but a whole lot of them might be a problem, so know how to identify gypsy moth caterpillars.

Due to the public health concern caused by the COVID-19 virus and Governor Sununu's recent Executive Order, UNH Extension offices will remain closed through May 31. Extension staff are planning summer and fall programs with the safety of our staff and public in mind.

That being said there are tons of webinars listed on our events page. Visit https://extension.unh.edu/events.

May 19, 2020

We have accumulated 67 base 50 growing degree days here in Durham, 242 in base 43. Southern areas are reporting full bloom in apple and pear, while northern areas are seeing their first blooms opening up. Peaches and nectarines are reaching fruit set in Hollis.

Many areas have reported freezing temperatures recently and may see some freeze injury to fruit blossoms or new growth. For most crops it is best to let plants grow through potential injury but assessing freeze damage in apple blossoms now will be important for making thinning decisions, which happens to be a topic covered in our Tree Fruit webinar tomorrow evening May 20, 5:30-7:30. 2 PACs on offer.

Apple scab ascospore maturity is high in most regions of New Hampshire and this weekend’s rain likely triggered an infection event. If you did not get a preventative fungicide out, get out there with something with some kick-back. Consult the NE Pest Management Guide.

Fireblight blossom blight models start when the first blossom opens so please visit the NEWA website and customize the risk model to suit your location. You can enter data about the severity of fireblight in your neighborhood last year as well as your bloom date. Check those models often through bloom and keep your eye out for rain in the forecast.

Codling moth traps should be out by now and biofixes are being logged in areas south of us. Monitoring on-farm is best but we will be reporting on regional degree day accumulation to estimate egg hatch. If you are using mating disruption, those dispensers should be out now too.

In observance of Memorial Day, our weekly morning Open Forum session will be moved to Tuesday morning next week.

May 12, 2020

These cold temperatures have us holding our breath this week, hoping to avoid freeze injury. Cold temperatures delay development of early season infections, like apple scab and fireblight, or brown rot in peaches. However, we are expecting warm weather next week so get ready for things to pick up very fast and check your models often.

Apple scab ascospore maturity is high in southern regions, around 60% in Durham, and reaching moderately high in northern regions. The forecast predicts infection periods by the end of the week so most folks should be getting on a protectant, when they can find a break in this wind.

Fireblight is not a concern this week but something to plan on worrying about as soon as trees start blooming. You may want to double check to make sure you have a bacteriacide on hand if and when you need it.

If you are using mating disruption for codling moth or for trunk borers, make sure to get your dispensers out before bloom.

The Open Forum session will host a webinar Wednesday, 05/13/2020, 7:00pm - 8:30pm, Best Practices for Pick-Your-Own Operations to Protect Customers and Staff from COVID-19. This will be a good resource making the right choices for your farm and also a good summary of state advisories in northeastern states. You can register to attend these zoom meetings and they will also be recorded if you can’t make it at those times.

Tree Fruit Webinar for Commercial Orchardists Wed, 05/20/2020 5:30pm - 7:30pm. You must pre-register and attend this even during the session for credit, but portions of this meeting will be available as recordings later.

May 5, 2020

A beautiful weekend accumulated us a whopping 32 base 50 growing degree days in Durham, 47 in Hollis. Unfortunately it sounds like more cold temperatures are predicted for the rest of the week.

Apple scab ascospore maturity is estimated from 37-49% in our most southern regions but remains low in northern regions, 4% in North Haverill. For southern regions of the state, ascospore maturity is predicted to surpass 50-60% by the end of the week and there is also rain in the forecast, which could mean an infection event and protectant should be applied by the 6th or 7th this week. Be on the lookout for new infection periods next week - It looks like it will be warmer and rainy. Check your closest NEWA station for the best information for your area.

Note: the Hollis NEWA station is down until further notice. Use the Goffstown or Tyngsboro, MA stations as an alternative.

Strawberry: As new growth starts to flush, keep an eye out for spider mites and aphids. Examine the undersides of 5-10 leaves in 5-10 locations around the field. For two-spotted spider mites, an action threshold of 25% of infested leaves is typical, but also consider that this pest tends to break out in hotspots, so spot treatment might provide sufficient control. Avoid the use of pyrethroids for spider mites as these products tend to cause flare ups in mite populations.

Some really terrific webinars are slated for our Wednesday evening Open Forum sessions coming up: this week we have a webinar on how to get you farm set up for Adding SNAP/EBT Sales, Wed, 05/06/2020, 7:00pm - 8:00pm. The following Wednesday, 05/13/2020, 7:00pm - 8:30pm, a webinar on Best Practices for Pick-Your-Own Operations to Protect Customers and Staff from COVID-19. This will be a good resource for making the right choices on your farm and also a good summary of state advisories in the region. You can register to attend these zoom meetings live and they will also be recorded if you can’t make it at those times.

Our Tree Fruit Webinar for Commercial Orchardists will be held Wed, 05/20/2020 5:30pm - 7:30pm. You must pre-register and attend the live session of this webinar for pesticide applicator credit, but portions of this meeting will also be available as recordings if that does not apply to you.

April 28, 2020

Yikes! Still not a whole lot to report this week with these cold temperatures. Durham has accumulated. Apples are holding steady somewhere between greentip and tight cluster in southern regions of the state.

Despite potential apple scab infection events for many areas this week, ascospore maturity remains low for most, spore discharge will be low (0-3%). If you had fungicide on prior to 4/26 then you are good. If your scab control was good last year, you may be able to wait this one out, otherwise making an application prior to rain on 4/29 may be a good idea. Remember to check the NEWA station closest to you, enter the date of green tip for your orchard for the best information for your site. Unfortunately, the Hollis NEWA station is down until further notice. Use the Goffstown or Tyngsboro, MA stations as an alternative.

PA research suggests bloom is important time for management of bitter rot and possibly Marssonina leaf blotch. If either of these diseases were a problem in your orchard last year, then be sure to include a group 7 fungicide in your pink to bloom-time applications. A protectant (such as mancozeb is suggested as a tank mix). Remember that the protectants alone also provide moderate protection for the fruit rots (bitter, black & white rot).

Here’s a link to a quick disease update and NEWA tutorial delivered by Cheryl Smith at our last webinar/twilight meeting. This recording, as well as an insect pest update and a summary of all the new resources available to farmers responding to the COVID-19 crisis are available at UNH Extension's YouTube channel.

For peaches, bloom is a key time for brown rot control. Wet weather and favorable temps for infection predicted through May 2. Refer to the guide for products.

Due to concerns regarding COVID-19, all in-person Extension events have been canceled through May 4th but many scheduled events will be shifted to web versions.

There will be a webinar tomorrow night (4/29) @7:00pm - 8:00pm on What farms and small businesses NEED to know to comply with the Family First Corona Virus Response Act. Don’t Ignore it! You can find the link to register on our extension website:

A big congratulations to George Hamilton, our Food & Agriculture Field Specialist in Hillsborough County, who has just been selected as the 2020 Northeast Region National Association of County Agricultural Agents Hall of Fame recipient. This national association recognizes George’s demonstrated dedication and effective leadership, as an outstanding educator and to outstanding humanitarian service. George could not be more deserving of this honor and we could not be more proud of our colleague and mentor. Drive by his house and honk your horn if you get a chance!

April 21, 2020

It has remained pretty chilly! So not too much progress in crop development or degree day accumulations. However, George’s reports from Hollis tell us that Macs are at ½ inch green to tight cluster, peaches are somewhere between ¼ inch green to pink, and apricots are blooming.

Looking at the NEWA apple scab monitoring system, if your greentip date was the first week of April, ascospore maturity remains low – between 5-8%. If you had good control last year and have kept up on your sanitation practices, not much to worry about yet. If you had a scab problem last year, and did not do any sanitation, you may want to apply a preventative product before the rains in the forecast the end of this week. The end of this week might be a good time to apply an oil as well. Check the forecast for freezing temperatures. Remember to check the NEWA station closest to you, enter the date of green tip for your orchard for the best information for your site.

Our colleagues are conducting a survey for cider producers and would also like to hear reports on bud dates for specialty cider cultivars .

Brambles: Now might be a good time to consider anthracnose, if you had problems with anthracnose last year (fruit are withered, dry & seedy, or have shrunken brown drupelets) or you have noticed lots of overwintered lesions (small, rough, sunken cankers) on canes as you pruned. Early season action is best, if you think you have a problem. See the Fruit Guide for more.

Due to concerns regarding COVID-19, all in-person Extension events have been canceled through May 4th but many scheduled events will be shifted to web versions.

In lieu of our scheduled April 22nd twilight meeting we will be offering a Tree Fruit Webinar for Commercial Orchardists with 2 pesticide applicator credits on offer. That's tomorrow night from 5:30 - 7:30 pm. Log in a few minutes early if you're a first time zoom user.

Our statewide Farm Product Map has gone live, but it is not too late to get your farm on this map if your are not already listed. Search “NH Farm Products Map” and filling out an online survey or contact Mary West at 796-2151 for more information.

April 14, 2020

We are still slow on accumulating base 50 growing degree days – this is the scale most commonly used for tracking insect development. However, looking at base 43 GDD, we have accumulated 70 in Durham, and our Hollis station has accumulated 108 base 43 GDD, where George reported apricots in bloom over the weekend as well as some plums at green tip to tight cluster. George posts photos and updates on his facebook page, if you are interested. Greentip in apple has been reported in some varieties this week in Hollis, Londonderry, Walpole, and Concord. It looks like kind of chilly weather in the forecast this week, which might slow this progress down a little bit and keep an eye on the forecast for freezing temperature when you are applying dormant oils.

Apple scab spore maturity is 2-5% so, even though the heavy rains we experienced yesterday indicate an infection period, this spore maturity is very low. If you had good control last year and have kept up on your sanitation practices, maybe don’t worry about infection periods until we get to 15% spore maturity. If you had a scab problem last year, and did not do any sanitation, and did not have any protection prior to yesterday’s rain…you may want to put on a material with some kickback. Otherwise scout for infections 9-17 days post-infection (4/22-4/30). Remember to check the NEWA station closest to you, enter the date of green tip for your orchard for the best information for your site.

For blueberry growers with a history of mummy berry – and there were probably a lot of you considering our conditions last year: Mummies that remain on the ground below plants are sources of fungal spores that might cause new infections this year so sanitation practices will be helpful. A 2” layer of new mulch is enough to bury these mummies before budbreak. A 50% Urea application can help burn mummies, but avoid wet areas. Cultivation at budbreak can help disturb/destroy emerging mummies (not useful prior to budbreak. Start your fungicide regime as early as bud swell and scout for apothecia (little brown cup-shaped mushrooms) as the season progresses. Refer to the fruit guide to select crop protection materials.

Due to concerns regarding COVID-19, all in-person Extension events have been canceled through May 4th but many scheduled events will be shifted to web versions.

Webinars:

Reaching Your Customers in Times of Social Distancing will be held during our typical Wednesday evening Farmer Open Forum this week, that’s Wednesday (4/15) at 7 – 8 pm. This webinar will feature members of our Ag Business team as well as several farmers in the region.

Leveraging Grants During Challenging Times this Friday (4/17) at 10:30-11:30 am.

In lieu of our scheduled April 22nd twilight meeting we will be offering a Tree Fruit Webinar for Commercial Orchardists with 2 pesticide applicator credits on offer.

April 7, 2020

In Durham, we have accumulated about 2 base 50 growing degree days, 11 in Hollis. Apples are mostly at silver tip. Peach, sweet cherry, and plum buds are moving into bud swell but George has reported some varieties of plum in early tight cluster down in Hollis. Blueberry buds are at bud swell to early green tip depending on the variety.

We’re getting reports of red-banded leafroller flight, as expected. According to accumulated degree days we should be expecting egg-laying for the first generation of pear psylla, if there are any pear growers out there.

Now is the time to get serious about dormant sprays if you haven’t already. Copper sprays need to go on before any green tissue emerges, for fireblight management in apple and for peaches affected by bacterial peach leaf curl last year. Delayed-dormant sprays of petroleum oil (green tip through tight cluster) should be considered for smothering overwintered spider mite eggs and the overwintered life stage of San Jose scale and Comstock mealybug. Large spray volumes are recommended for getting really good coverage and the standard rate is 2 gallons per 100 gallons of water until half-inch green or 1 gallon per 100 gallons of water at tight cluster. The lower concentration lowers risk for phytotoxicity as more new growth emerges. Applying dormant oils with 48 h of freezing temperatures should also be avoided. The forecast looks downright balmy down here in Durham, but keep an eye out on your forecast for freezing temperatures.

UNH Cooperative Extension is developing a statewide New Hampshire Farm Products Map. This tool will make it easy for farmers to update their information on an interactive online map so that consumers can quickly and easily learn where and how to purchase their products in light of the changing situation associated with COVID-19. The map itself will go live next week. Get your farm’s information listed by searchign “NH Farm Products Map” and filling out an online survey. Contact Mary West at 796-2151 for more information.

Due to concerns regarding COVID-19, all in-person Extension events have been canceled through May 4th but many scheduled events will be shifted to web versions.

Extension has also been hosting Open Forums for NH Farmers, which will now be held Mondays at 10am and Wednesdays at 7pm. Search “UNH Farmer Forum” to find details for calling in to ask questions or to hear how other farmers are handling new challenges.

There will be a webinar on Boom Sprayer Calibration next Monday (4/13), 1:00pm-2:30pm, with 1.5 Pesticide Applicator Credits on offer. Contact Carl Majewski at 352-4550 for more information.

There will be a webinar on Reaching Your Customers in Times of Social Distancing, featuring a panel of growers from New England. Wed, 04/15/2020, 7:00pm - 8:00pm

March 31, 2020

In Durham, we have not yet accumulated any base 50 growing degree days. However the weather station in Hollis has accumulated 11 degree days and George is reporting bud swell in peach and blueberry, as well as some Zestars that are threatening green tip.

Now is the time to get serious about dormant sprays if you haven’t already. For peaches affected by peach leaf curl last year, copper sprays need to go on before any green tissue immerges. Delayed-dormant sprays of petroleum oil (green tip through tight cluster) should be considered for for smothering overwintered spider mite eggs and the overwintered life stage of San Jose scale and Comstock mealybug. Large spray volumes help with good coverage.

Due to concerns regarding COVID-19, all in-person Extension events have been canceled through May 4th but many scheduled events will be shifted to web versions, including some opportunities for pesticide applicator recertification credits. Extension has also been hosting Open Forums for NH Farmers, which will now be held Mondays at 10am and Wednesdays at 7pm. Search “UNH Farmer Forum” to find details for calling in to ask questions or to hear how other farmers are handling new challenges.

2019

August 12, 2019

DD accumulation since 1Jan in Durham (base50) = 1554

I expect that early maturing apple varieties are coming in soon. Apple Maggot populations may have peaked in many areas but continue to monitor traps, even if you have already treated. Consider a border spray instead of the full field if you hit threshold again.

Redbanded leafroller flights subside between 1400-1800 GDD, while obliquebanded leafroller’s second flight starts somewhere around 1400-1800 GDD.

We here at extension are monitoring populations of brown marmorated stinkbug. I haven’t seen anything that would raise alarmbells yet but consider making sure you know what they look like. The dead give away, especially on nymphs is the white bit in between antennae or leg segments. To me it looks like a farmer’s tan but kind of like on their knees…if that makes any sense. Stayed tuned for more from us if we detect anything worrisome.

SWD populations have reached that point when we stop monitoring traps and consider all ripe thin-skinned fruits at high risk for SWD infestation. Weekly treatment is recommended for blueberries and at least weekly treatment for raspberries and blackberries. Consult your guide for information on crop protection materials and make sure to rotate classes. Post-harvest handling can be very important for light infestation so harvest often and refrigerate as soon as you can for as long as you can. Most eggs and small larvae will be killed by several days at 34F. Urge pick-your-owners to refrigerate or freeze whatever they don’t eat the day they pick.

Something else you can be on the lookout for in blueberry this time of year is blueberry stem gall wasp, which sounds like its showing up here and there. Tiny wasps lay eggs plants during the spring and their offspring develop in kidney-shaped galls. The galls turn red by this time of year and turn brown/black when the plants go dormant. Galls can be pruned out during the winter but they’re the most conspicuous during this time of year.

August 5, 2019

DD accumulation since 1Jan in Durham (Base50) = 1426

We’re in the home stretch for apple pests and not too much to report this week. Fair weather has made for low disease pressure but may make good conditions for mites. Threshold for mites is generally 7.5 mites per leaf. Apple maggot traps should be checked regularly. Threshold is 5 flies/trap with a lure, 1 fly/trap without a lure.

It sounds like peach harvest is starting in some varieties. Peach tree borer flights are likely subsiding.

July 30, 2019

DD accumulation since 1Jan in Durham (base50) = 1260

We expect apple maggot peak catch somewhere between 1430-1800 GDD but as a reminder, apple maggot thresholds are 5 flies per trap, if you are using a lure. If you are not using a lure, the threshold is an average of 1 per trap.

This hot weather could be favorable for red mites. Threshold is generally 7.5 mites per leaf.

Peak flight for codling moth is expected somewhere around 1300-1800 GDD, so likely sometime this week. Redbanded leafroller’s second generation peak flight is likely winding down now.

SWD numbers are approaching their exponential climb and we are detecting low infestations in most locations throughout the state. Ripe fruit should be protected from egg-laying from here on, especially in raspberry. Post harvest handling can be very important for light infestation so harvest often and refrigerate as soon as you can for as long as you can. Most eggs and small larvae will be killed by several days at 34F. Urge pick-your-owners to refrigerate or freeze whatever they don’t eat the day they pick.

For those of you who know a new farmer, let them know that New Farmer school is starting in August. Registration is $250 (scholarships available) for 6 sessions through the fall months and topics cover a diverse array of topics critical to starting a farm business.

July 22, 2019

DD accumulation since 1Jan in Durham (base50) = 1124

Keep your eyes peeled for fireblight strikes, pruning out when you need to. Keep checking your apple maggot traps. I’ve been hearing low numbers so far but, like everything else this year, their development might be delayed. All the more reason to monitor your own pest populations. Threshold trap numbers are an average of 5 apple maggot flies per trap, if you are using a lure. If you are not using a lure, the threshold is an average of 1 per trap. Consult your guide for protection materials.

San Jose scale’s and codling moth’s second generation flight normally starts somewhere around now, 1050- 1300 GDD for male scale insects and 1030-1500 GDD (base 50) for codling moth. Speaking of codling moth, Jaime Pinero at UMass is interested in testing local populations of codling moth and oriental fruit moth for signs of chemical resistance. So if you find any fruit with internal feeders, think about hanging on to those and give me a call or an email. Anna.Wallingford@unh.edu. While, it might be too late to treat for many of the major leafrollers, their damage becomes more conspicuous in the orchard around now. Scouting to identify problems early might be a good idea.

Strawberry growers, prompt renovation is critical to getting your strawberries ready for overwintering and next year’s fruit set. If you have a history of black vine weevil, controlling for this pest during renovation can be important to limiting their spread. If not, its always a good idea to scout new growth after renovation for their feeding, characteristic notching on leaves.

SWD trap numbers are slowly climbing and I’ve detected some light larval infestation from fruit collected here at our research farm, so it’s time to start protecting ripe blueberries and raspberries from SWD egg-laying as they come in. Consult your guide for protection materials and consider more than one option as class rotation for resistance management is important here. Also, considering this has been a particularly bad year for mummyberry, getting dropped fruit out of blueberry plantings could be a worthwhile activity to reduce SWD habitat and reduce mummyberry inoculum for next year.

For pumpkin growers - Squash vine borer numbers remain very high! Consult the weekly scouting reports to see the pest pressure nearest you and consult your Veg guide for crop protection materials.

July 15, 2019

DD accumulation since 1Jan in Durham (base50) = 947.

Apple maggot is likely active now. Threshold trap numbers are an average of 5 apple maggot flies per trap, if you are using a lure. If you are not using a lure, the threshold is an average of 1 per trap. Consult your guide for protection materials.

Codling moth’s first generation is likely subsiding now, while obliquebanded leafroller is likely flying now and Oriental fruit moth will likely be starting its second flight soon.

For grape growers, now would 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 around the middle of June in Durham, so we are about 655 GDD from biofix with a few hundred more GDD to accumulate before treating for second generation larvae.

Japanese beetles and their cousins are flying now. This group, aka scarab beetles, spend most of their life below ground as white grubs that eat grass roots. They emerge once every year to eat just about everything and make big gross cuddle puddles everywhere before returning to the ground. I know it’s hard to hear because they are so conspicuous but, unless you are protecting young or stunted plants or you see that fruit is being affected, this group rarely does enough foliar damage to justify treatment of mature plants. If you do treat, be mindful that certain broad-spectrum insecticides, pyrethroids in particular, can cause secondary outbreaks of pests like aphids when they are used repeatedly.

SWD has been detected in several locations in southern New Hampshire but in very low numbers and has not yet been detected in fruit.

For any pumpkin growers, squash vine borer monitoring in the state continues to find very high numbers.

As far as events go, Steve Roberge is giving at tick talk at the Olivia Rodham Memorial Library in Nelson on Thursday evening at 7pm. There are swine producer’s field days this week so please contact 603-679-5616 for more information on that.

July 8, 2019

DD accumulation since 1Jan in Durham is (base 43) = 1350, (base50) = 793.

Expect apple maggots to start flying between 760-1200 GDD (base 50). Hang three volatile-baited sphere traps on the outside row facing the most probable direction of AM migration (towards woods or abandoned apple trees, or else on the south-facing side). Check traps regularly, once or twice a week, to get a total number of flies caught; and a spray is advised when average is 5 or more. If you are not using an attractive lure, this threshold is 1 fly per trap. The adult fly is ¼ Inch long, smaller than a common housefly. It’s black with white lines on its abdomen and its wings have zig-zaging black bands.

Comstock mealybug flight peak occurs between 931-1143 GDD (base 50), so those of you who are planning on targeting summer crawlers should put out tape traps soon. You will be looking for tiny orange nymphs to time your spray. Consult your guide for protection materials.

It’s a good time to scout for fireblight strikes and remove infected tissue from the orchard. Remember to cut at least 12-18” below infected area, leave a stub rather than cut all the way back to the healthy limb, and to sanitize tools between cuts to avoid spreading the pathogen.

While you’re out there, now is also a good time to scout for mites affecting apple – look for bronzing on leaves then look closer for mites on the undersides of leaves. The threshold is 5 active mites per leaf but remember, spot treatment might be an option for areas where you missed an oil treatment in early spring.

For small fruit growers, SWD has been detected in the state but in very low numbers and no fruit infestation has yet been observed.

For curcubit growers, squash vine borer is flying and it looks like numbers are quite high. Consult your veg guide for crop protection options.

There is a Tree Fruit twilight meeting Wednesday July 10th, 5:30-7:30 at Sunnycrest Farm, located at 59 High Range Rd, Londonderry, NH 03053. Orchard Weed Sprayer calibration. Two Pesticide Applicator recertification credits will be available.

July 1, 2019

DD accumulation since 1Jan in Durham is (base 43) = 1134, (base50) = 626.

Severe storms were reported in southern New Hampshire over the weekend. Damaged apple and pear trees should be treated with a streptomycin product within 24 hours to prevent fireblight transmission through open wounds in those trees. With regular wet weather, NEWA models also predict high risk levels sooty blotch and flyspeck infections so consult your management guide for crop protection materials.

Codling moth are likely flying in apple orchards now, so control of larvae could be warranted. In particularly high pressure situations, time a second spray 10-14 days after the first and rotate material to avoid chemical resistance. Apple maggot emergence is expected soon – at around 800-1300 GDD (base50) – so get monitoring traps ready.

Peach trees damaged by weather events are susceptible to fruit rot fungi so a high rate of Captan is recommended to keep spore build up in check. Those of you monitoring for peach tree borer should have your traps up by now as we expect flights to begin in July.

With the delay in the season, it’s possible that late maturing strawberries may be affected by spotted wing drosophila this year. SWD was not detected in our traps last week but expect updates to this soon.

There is a twilight meeting at 5:30 tonight (July 1) in Litchfield NH at Wilson Farm on Charles Bancroft Highway to e wildlife concerns for vegetable and small fruit crops, with pesticide applicator credits.

A tree fruit twilight meeting will be held next Wednesday July 10 at Sunnycrest Farm in Londonderry, with PAC, featuring orchard weed sprayer calibration, irrigation systems, and mid-season IPM topics.

Tonight and tomorrow night our dairy livestock and forage crops team will be hosting mid-season corn check up and pest scouting events held at 11am in Woodsville and Penacook. PAC. Contact 352-4550 for more information.

June 25, 2019

DD accumulation since 1Jan in Durham is (base 43) = 984, (base50) = 518.

San Jose scale male flight is likely wrapping up at somewhere between 515-769 GDD (base 50), which means the first generation of crawlers is likely to become active soon. Usually looking at 619-757 accumulated growing degree days. Consult your guide to select crop protection materials for trees where you saw damage last year.

Get ready for apple maggot season as these flies will be emerging from their overwintering habitats soon. Traps for monitoring can be purchased from GreatLakesIPM, Gemplers, Ladd Research Industries. There’s a bit of a philosophical divide over whether or not to use an attractive bait on red sticky sphere traps. Some fear that the odor pulls in more flies, so they opt you use the traps by themselves. However, the odor makes the traps much more sensitive, so you don’t need to put out as many to get a good read of AM activity in your orchard – maybe three per block with the lure. If you are relying on the visual cue alone make sure to use several more traps to read activity through out the orchard.

Peach tree borer is likely starting its flight period around now, expected to start around 448-812 GDD.

We have not yet detected spotted wing drosophila in our traps but areas to the south of us have consistent detection so I expect them to show up in New Hampshire any day now. Protect ripe fruit when flies are present on your farm.

Events:

Equipment Demo Day for Vegetable Producers Wed, 06/26/2019, 4:30pm - 7:30pm UNH Woodman Farm, Spinney Lane, Durham, NH 03824. NHSoilHealth.org or by calling (603) 749-3037.

Addressing Wildlife Concerns for Vegetable and Small Fruit Crops - Farm Twilight Meeting, Mon, 07/01/2019, 5:30pm - 7:30pm, Wilson Farm NH, Charles Bancroft Hwy (Route 3A), Litchfield, NH 03052, Two pesticide credits will be available.

Our Dairy and Livestock Team are hosting a Mid-Season Corn Checkup and Pest Scouting, Tue, 07/02/2019, 11:00am - 1:00pm, Morrill Farm, 43 Rolfe Street, Penacook, NH, Pesticide Applicator Credits & VT Water Quality Credits pending. RSVP Appreciated. For questions, special accommodations, or to rsvp contact: Carl Majewski at (603)352-4550 or carl.majewski@unh.edu.

June 17, 2019

DD accumulation since 1Jan in Durham is (base 43) = 795, (base50) = 386.

This is certainly a challenging year for apple scab. As you’re planning your crop protection approach for secondary infection period, remember that fungicides control disease in different ways. Protectants must be applied before infection occurs, so before infection periods caused by rain or wetness. Some fungicides can suppress production of conidia from recent infections (i.e. those with “kickback”) but those with post-infection activity must be applied within a narrow time after the beginning of an infection event.

Plum curculio is likely still laying eggs in tree fruit but winding down as codling moth is flight and egg laying is likely winding up. The first generation of San Jose scale crawlers are likely being produced. Consult your tree fruit guide for crop protection strategies.

For peach, fruit are susceptible to catfacing insects like tarnished plant bugs and other piercing sucking insects. Lesser peach tree borer is likely flying now. This species of peach tree borer is less a threat to trees as greater peach tree borer, which starts flying a little later in the summer. LPT tends to damage smaller, more distal branches compared to attacking the main trunk, but very high populations might warrant action. Consult your guide.

For strawberry, now might be a good time to release spider mite predators as two-spotted spider mite populations are growing. I’ve heard reports of outbreaks here and there, even though this spring hasn’t been providing what we consider ideal conditions for mites. Once fruit sets, strawberry sap beetle, anthracnose, and botrytis are going to be concerns. Strawberry sap beetle is a little black nocturnal beetle that damages ripe strawberry fruit when it goes after the seeds so the damage might easily be confused with slug damage. Make sure you know who you’re dealing with before acting.

Potato leafhopper might be a problem in small fruit this year – remember that this insect overwinters in the gulf states and migrates here, arriving in the northeast by late June or early July. So even though, we’ve had a slow moving season up here, that doesn’t affect potato leafhopper. Piercing-sucking feeding, and injection of toxic saliva, results in hopperburn on leaves. This looks like discolored, crinkled, sometimes downward curling leaves. Look for these symptoms and check on the underside of leaves for the leafhoppers to confirm. There’s no hard threshold but younger, delayed, or stunted plants are more susceptible, so keep an eye out and consult your small fruit guide to select your plant protection approach.

Events: Equipment Demo Day at Woodman Farm in Durham for Vegetable Producers next Wednesday (6/26) 4:30pm - 7:30pm. Featuring a two-wheel BCS tractor with various implements useful for vegetable growers, a no-till transplanter for planting and optimizing soil health, and tarping and roller crimper techniques for terminating cover crops. I believe some of this equipment can be loaned from your conservation district if you’re interested in adopting no-till practices so come and check it out. More information at NHSoilHealth.org or by calling (603) 749-3037.

There will be a twilight meeting July 1, addressing wildlife concerns for veg and fruit growers in Litchfield NH.

June 11, 2019

DD accumulation since 1Jan in Durham is (base 43) = 684, (base50) = 316.

We’ve been enjoying some lovely weather but it looks like rain is in the forecast this week. Scout for apple scab lesions and keep an eye on those apple scab models, with your risk levels in mind.

Plum curculio is likely laying its eggs in apple orchards now, so continue to scout for fresh oviposition scars to determine whether or not to treat. I heard some reports of first capture of codling moth adults last week, so right on time according to degree day estimates. Ovicides for codling moth should go out now. Treatments for codling moth larvae should be timed for egg hatch, which occurs about 220 DD (base50) after first trap catch.

Reports of SWD first trap capture continue to roll in from areas south of us here in New Hampshire so, if you are monitoring for SWD in crops like strawberry, blueberry, and summer raspberry, you should get those traps out soon.

For those of you with serious winter injury to your blueberries, FSA is considering a disaster relief program so reach out to me or to your county specialist if you think this would be helpful to you.

Grapes: Peak flight of the overwintering generation of grape berry moth normally occurs at 350-400 GDD, this also often coincides with wild grape bloom. So keep an eye out for that if you know you have a

There is a tree fruit twilight meeting scheduled for this Wednesday, June 12th at Meadow Ledge Farm, 612 NH-129 Loudon, 5:30-7:30. Pesticide applicator credits will be available. Special Topics: BMSB Trapping, Apple Processing, USDA Wildlife Service.

June 3, 2019

DD accumulation since 1Jan in Durham is (Base43)= 536, (Base50) = 224. Many apples are at post petal fall. Fruitlets are sizing up quickly and are susceptible to plum curculio so now is a good time to get out and scout for oviposition scars. According to the models, apple scab primary infection period is over in most areas. Now might also be a good time to scout for apple scab lesions on leaves and on fruits. Walk a transect through the orchard and examine the leaves and fruits of at least 10 clusters on at least 10 trees.

First capture of codling moth, or CM “biofix” normally occurs around now 200-300 GDD (base 50), but timing codling moth treatment is best when you have first catch data for your own farm. If you are using an insecticide that needs to be present before egg laying, it should be applied about 50-75 DD after first capture and if you are targeting young larvae, eggs normally hatch after about 220 DD after first capture.

The same goes for San Jose scale, where treatment for crawlers should be timed at roughly 310 GDD after first capture of flying males. That first flight should be happening soon between 300-400 GDD from Jan1, but trapping is the best way to know what’s going on at your farm.

Reports of SWD first trap capture are rolling in from areas south of us here in New Hampshire so, if you are monitoring for SWD in crops like strawberry, blueberry, and summer raspberry, you should get those traps out soon.

For strawberry, keep scouting for tarnished plant bug during bloom. Threshold is reached if 4 or more flower clusters are infested with nymphs out of 30 clusters sampled evenly from across the field…and keep an eye out for thrips as these guys might come out while you’re tapping those flower clusters. Look for spider mites on the undersides of leaves and keep a record of hot spots that might need attention later as conditions warm up and dry up. The action threshold is when 25% (i.e., 15 leaves) or more of a 60 leaf sample is infested.

It sounds like orange rust of brambles could be a problem with the wet spring we’ve had so if you come across this you should cull out affected plants.

Events in the near future: there is a tree fruit twilight meeting scheduled for next week, June 12th at Meadow Ledge Farm in Loudon, 5:30-7:30. Special Topic: BMSB Trapping, Apple Processing, USDA Wildlife Service. Pesticide applicator credits will be available.

May 28, 2019

We’ve been enjoying some beautiful weather here in the Durham area. DD accumulation (Base43)= 468, (Base50) = 195. Many apple varieties and blueberry varieties are still blooming.

According to the NEWA model apple scab ascospore maturity is at 99% so primary infection period is wrapping up, but there is rain in the forecast for many areas of the state so not quite out of the woods yet for potential infection periods.

Hopefully you’ve been checking your fireblight risk models regularly while your apple trees are blooming, especially if you had fireblight in your neighborhood last year. It’s supposed to rain in Durham this afternoon so today’s risk for fireblight infection is extremely high here. If I had trees in bloom here, I would want to get an antibiotic on today or tomorrow.

Planning for petal fall, this period is the best time to consider controls for plum curculio, European apple sawfly, obliquebanded leafroller, codling moth, European red mite. Plum curculio is likely already active in your orchard but females will start laying eggs in fruit once they get to be about a quarter of an inch in diameter. Look for fresh oviposition scars to trigger a control measure and consult your guide for selecting crop protection materials. Continue to scout for those fresh scars over the following weeks and consider a border spray for subsequent controls as this is normally sufficient.

For peaches, lesser peach tree borer starts flying around 476-668 (base 43), 250-370 (base 50). So if you are monitoring for borers, your traps should be up by now.

Once strawberry starts blooming, scout for tarnished plant bug by shaking flower trusses over a flat white surface. Alan Eaton always had a white Frisbee to do this but a white piece of paper will do. Tarnished plant bug nymphs are small and bright green. They kind of look like an aphid but they’re a lot more active, meaning they’ll run off that white paper pretty quickly. Threshold is reached if 4 or more flower clusters are infested with nymphs out of 30 clusters sampled evenly from across the field.

As far as events: we have another Tree Fruit Twilight meeting scheduled for June 12 at Meadowledge Farm in Loudon. If you missed our last meeting at Patch Orchard in Lebanon, so did I. George, Jeremy, Heather and I recorded a quick conversation where they caught me up on what we missed. I’m sending out an email with the link to this recording via the NH Vegetable & Fruit newsletter list so look for it later this week. If you’re not signed up for the newsletter, you can find directions for this on the extension website. Let us know if you’d like us to do more stuff like this.

May 21, 2019

We have many apple varieties blooming in the Durham area, as well as early varieties of blueberry. Peaches are still in bloom. Durham (Base43)= 343, (Base50) = 120.

For those who had fireblight in their neighborhood last year, check fireblight risk models on the NEWA website regularly while your apple trees are blooming. Our model for Durham says trees are at moderate to high risk and a bactericide should be considered.

Apple scab ascospore maturity is predicted to be at 91% in Durham so we are nearing the end of primary infection, but there is more rain in the forecast so continue to keep up with apple scab protection.

The same goes for brown rot and bacterial spot in peaches. Brown rot susceptibility starts to decline after shuck fall but considering all this rainy weather this will be a problem for many of you.

For those of you who monitor codling moth, you should have your traps up by now. First trap is anticipated around 200-300 DD(50) and that first capture establishes a biofix. This biofix is important for subsequent degree day accumulation that predicts peak CM flights on your farm through the year.

For many small fruit growers, we’ve been seeing and hearing about lots of winter kill in blueberry and raspberry. There’s a little discussion about whether or not to prune out dead wood in blueberry but you should probably hold off from pruning to wait and see if these dead canes are just delayed. We’ll be providing more detailed guidance for this in a few weeks but for now, hold off on pruning and continue with your normal fertilization plans.

Mummy berry strikes may be showing up in blueberry soon. Consult the small fruit guide for more details on how to manage outbreaks.

Strawberry is also still wait and see as far as winterkill but this wet spring will produce perfect conditions for problems with Phytopthora infections. Red stele is caused by Phytopthora infections and symptoms are numerous and may be easy to confuse with winter injury: wilting; young leaves with a bluish-green tint; and older red, orange or yellow leaves. As plants progress and conditions dry up, severely diseased plants may die or remain stunted, producing few runners and small berries. Plants showing symptoms usually occur in patches where the soil was the wettest. When roots are cut open lengthwise, the core will show a reddish-brown discoloration; however, a reddish core does not guarantee that it’s red stele or Phytopthora – so send in samples to the diagnostic lab if you haven’t had this confirmed. If you know you have a history of red stele, consult your guide for protection recommendations.

Events: there is nothing from the Veg & Fruit Team in the immediate future but there is a backyard chicken basics workshop tonight, 6 pm at the Nesmith library in Windham, NH, for anyone interested.

May 14, 2019

Here in Durham, apples are at pink and peaches are in bloom. Durham (Base43)=250, (Base50) = 72

Apple Scab: For Boscawen: 61% mature ascospores (southern areas will be ahead, northern areas behind). Although many of the mature ascospores have been discharged, a scab infection period is predicted for the 14th. So, if you did not have a fungicide on prior to the infection, consider a kickback fungicide, especially if you had scab in the orchard last year.

Telial horns on cedar apple rust galls are still active.

Fire blight: With the southern portions of NH reporting some blossoms open on Macs (and earlier varieties), it’s time to monitor NEWA for fire blight. Go to newa.cornell.edu and click on apple diseases under the pest forecast tab. Select fire blight, NH, and the weather station closest to you. The date defaults to the current days date. When the model opens, select your orchard blight history, and enter the date of first blossom open. Hit the calculate button. The model will give you the current risk, and 5-day forecast. The next few days will be too cold for infections, but keep monitoring the situation.

Pink stage is the last time to check for little green pug moth larvae and rosy apple aphid colonies – these can be yellow or powdery blue or pinkish. Act before bloom and before leaves surrounding blossoms curl up and around fruit clusters, thereby providing protection from sprays. Tarnished plant bug is likely moving into orchards soon and you might consider using white sticky traps to assess density. Redbanded leafrollers and spotted tentiform leafminers are flying. Peak flight for RBLR occurs at roughly 105-200 GDD (50), STLM at roughly 124-212. GDD (50).

For peaches: bloomtime is a good time to act for brown rot treatment, especially if you had brown rot problems last year…which is most of us. Consult the tree fruit management guide for product selection.

Raspberry and blackberry: we’ve seen a bit of winter damage on summer fruiting varieties and this may mean variable or delayed shoot growth along the cane.

For blueberry: If you had problems with mummyberry last year, be sure to get 2” of mulch down ASAP (if you have not done so already).

There is a tree fruit twilight meeting this Wednesday on May 15th at Patch Orchard at 40 Patch Rd. in Lebanon, 5:30-7:30pm with an opportunity to earn pesticide applicator credits. For anyone interested in buying a hardcopy of the new Tree Fruit Management guide, you should be able to pick one up at this meeting or contact me at Anna.Wallingford@unh.edu or 603-862-1734. Hardcopies are $25 but the guide is always available online for free. For those of you that volunteer to monitor conservation easements in your area, extension is hosting a workshop this Saturday in New Durham – so check out the website for details.

May 7, 2019

Things are moving along nicely here in Durham. Apples are at tight cluster for the most part, however I’ve seen a little early pink, blueberries are at tight cluster, and peaches are in bloom.

In anticipation of apple bloom, if you had fireblight in your neighborhood last year, consider making sure you have a streptomycin product on hand. As we watch for risk indicators of blossom blight infections to come, it is best to be prepared.

Apple scab ascospore maturity is estimated to be 38% and the recent wet weather has provided prime conditions for infection events. You may want to take advantage of this nice weather and get a protectant fungicide on before the rain predicted for Thursday and Friday or make sure to have materials with some kickback on hand.

Cornell has just launched a new tool on their NEWA website to help with timing your thinning efforts. This tool can be found under the crop management drop down menu – its called “Apple CHO v2019” -and differs from the old model in a few ways. You can enter information about the flowering status of your crop to improve the precision of this decision making tool. Check it out at NEWA.cornell.edu.

For peach, bloom time is a good time to apply a fungicide for brown rot, especially if you had brown rot issues last year and did not take extensive sanitation measures over the dormant period. Tart cherries are also particularly susceptible to brown rot. Consult the tree fruit management guide for more information on selecting a product.

If you are using mating disruption for peach tree and lesser peach tree borers and haven’t put your ties out, they should go out soon.

Speaking of mating disruption and bouncing back to apple for a moment – we have news that NH registration was approved on CIDETRAK mating disruption products for codling moth and oriental fruit moth CMDA+OFM MESO, OFM-L MESO and DA MEC. So ask your supplier about that if you are interested but ask soon if you want to act this year because mating disruption has to go out before moths start flying.

In strawberry fields where Strawberry Bud Weevil/Clipper were a problem last year, now might be a good time scout fields as flower trusses emerge and expand for sign of this pest. In the pre-bloom to early bloom period female clippers lay an egg in an unopened flower bud and then clip the stem of the bud causing it to flop over or fall off, obviously causing the loss of that fruit. Clipper tends to be a more severe problem along borders of plantings, near woods, hedgerows or stonewalls. Treat for clipper when you find an average of more than 3 highly damaged flower trusses per meter of row. You might consider only treating border rows, especially rows bordering woods, hedgerows and stonewalls. Do not treat during bloom.

For brambles - As leaf tissue expands, watch for orange rust on blackberries and black raspberries and rogue out plants where it is found. Orange rust is systemic and cannot be treated to eliminate it from an infected plant.

Next week there will be a tree fruit twilight meeting on May 15th at Patch Orchard at 40 Patch Rd. in Lebanon, 5:30-7:30pm with an opportunity to earn pesticide applicator credits.

April 30, 2019

There has been quite a bit of variability in fruit tree development depending on where you are in the state and the microclimate on your farm. GDD (base 43): Durham – 172 (last year 105), Hollis – 216 (last year 124)

Our plant pathologist, Cheryl Smith has reported that Jellie horns are out on cedar apple rusts so trees are at risk of infection with rains. In Durham, we estimate 11% apple scab ascospore maturation. This, as well as lots of rain, puts apple orchards at high risk of apple scab infection. Consult your management guide for crop protection materials.

Now until pink would be a good time to scout apple orchards for the presence of winter moth or green pug moth larvae. This can be done by observing fruit buds for caterpillars or by tapping branches with fruit buds onto a white surface. Presence of these sporadic pest species may trigger an insecticide treatment before bloom. Insecticide sprays during bloom are discouraged in order to avoid negative impacts on pollinators in the orchard. However, there are selective insecticides (like Dipel) which have efficacy on caterpillars like winter moth and pug moth but little effect on pollinators.

For blueberry – wet weather means continued risk for mummy berry infection. Cleaning up fallen mummies, or covering them with at least 2” of mulch is a helpful sanitation practice. Consult the guide for effective fungicides. If your blueberry plants are affected by any species of scale insect, a dormant or delayed-dormant oil spray may still be appropriate. If you do have green tissue, make sure the oil product you are using specifically allows for delayed dormant applications.

For strawberry – As foliage expands, now is a good time to start tracking weak areas of the field and check roots for Black Root Rot or signs of Red Steele if you find stunted or sparse growth. Check the extension websites for details on how to submit plant samples to the diagnostic center if you think you have a disease problem, but best management practices call for proper nutrition and proper timing of renovation to allow for good winter preparation in the fall.

Events - It sounds like registration is full for the Women’s Farm Equipment Field day on May 4th but you can contact elaina.enzien@unh.edu or (603) 679-5616 to see if there’s room for you, or to encourage more events like this in the future. Looking well ahead on the calendar there will be another tree fruit twilight meeting on May 15th at Patch Orchard in Lebanon, with opportunity to earn some pesticide applicator credits.

April 22, 2019

Degree day accumulation is 135 in Durham. Depending on the weather conditions at your site, you should be seeing some green tissue in apple orchards and therefore susceptibility to apple scab infection. Ascopore maturity is moderate – 4% - however rain events, temperature, and leaf wetness hours over the weekend provided ideal conditions for ascospore infection events. If you were not able to apply a preventative product, you might consider a fungicide with some kickback. Unless you are sure your risk is very low - meaning you had little scab last year and passed a PAD count last fall. Consult the NE Tree Fruit guide for help selecting a product.

You might consider putting out white sticky traps to monitor for tarnished plant bugs entering the orchard. Hang them about knee height on the south side of trunks and above grass rather than bare ground as they will be moving from grass into trees. These piercing-sucking feeders will feed on developing fruit buds early in the season and cause cosmetic damage to fruit later in the season.

Now until pink would be a good time to scout apple orchards for the presence of winter moth or green pug moth larvae. This can be done by observing fruit buds for caterpillars or by tapping branches with fruit buds onto a white surface. Caterpillars will be knocked off and easier to see on the white surface of say – a white Frisbee? Presence of these sporadic pest species may trigger an insecticide treatment before bloom.

For blueberry – the recent wet weather means that any green tissue that may have emerged this week may be susceptible to mummy berry infection. If your blueberry plants are affected by any species of scale insect, a dormant or delayed-dormant oil spray may be appropriate. If you do have green tissue, make sure the oil product you are using specifically allows for delayed dormant applications.

It sounds like registration is full for the Tree Fruit Grafting workshop in Goffstown on Wednesday but you can contact Mary West at 796-2151 to see if there is room for you. There are pruning demonstration workshops coming up soon. Blueberries and raspberries this Saturday afternoon at Pratt Berry Farm in Lancaster NH. Ornamental trees and shrubs this Saturday at UNH’s Woodman farm in Durham. Looking well ahead on the calendar there will be another tree fruit twilight meeting on May 15th at Patch Orchard in Lebanon, with opportunity to earn some pesticide applicator credits.

April 18, 2019

Reports of green tip have been coming in from southern regions of the state. With rainshowers predicted in this weekend’s forecast, those apple growers with green tissue showing may want to apply a protectant fungicide due to high risk of apple scab infection.

April 15, 2019

Growing degree day accumulation for Durham 68, Hollis 82. We’re seeing swelling buds but no green tissue yet.

Risk models for primary infection period for apple scab begin when 50% of macs are at green tip so that’s when we start looking at risk for infection events.

It’s pretty muddy out there but you should be thinking about getting in an application of dormant oil between green tip through tight cluster for smothering overwintered mite eggs and overwintered San Jose scale. Large spray volumes are recommended for getting really good coverage and the standard rate is 2 gallons per 100 gallons of water until half-inch green or 1 gallon per 100 gallons of water at tight cluster. The lower concentration lowers risk for phytotoxicity as more new growth emerges. Applying dormant oils with 48 h of freezing temperatures should also be avoided, or you could use a lower concentration, and it looks like that won’t be an issue in the upcoming weeks, but you never know these days, so keep an eye on your forecast.

There is a Tree Fruit twilight meeting at Butternut Farm on Wednesday April 17 from 5:30-7:30 pm, 195 Meaderborough Road, Farmington, NH. That will come with 2 pesticide credits.

Other opportunities for earning pesticides credits, and for brushing up on your pruning techniques: There are pruning demos and grafting workshops coming up with Saturday April 20 in Tuftonboro and next Tuesday April 23 in Hillsboro. Check out extension.unh.edu for more information.

April 8, 2019

Still not too much to report. Degree days accumulation as of today is 40 at Durham, 49 at Hollis.

The wet weather this week will make getting into the orchard a challenge but you may still have time to apply a dormant fungicide in peaches that were affected by peach leaf curl last year if you did not spray for it before leafdrop last fall.

For blueberry growers with a history of mummy berry, it might be a good time to rake mulch in blueberry plantings. A 2” layer of new mulch is enough to burry the mummies on the ground. Those mummies sources of fungus spores and new infections this year.

There will be a twilight meeting for commercial tree fruit growers next Wednesday the 17th at Butternut Farm in Farmington at 5 pm. For more information, visit extension.unh.edu

April 1, 2019

Not much to report yet, we’ve accumulated roughly 33 degree days here in Durham, 35 in Hollis.

But this is a good time to consider delayed-dormant sprays of petroleum/dormant oil (green tip through tight cluster). Large spray volumes help with good coverage, which is particularly important for smothering overwintered mite eggs and the nymphs, or “crawlers”, of San Jose scale and Comstock mealybug, which start moving around this time of year.

UNH pesticide safety training will be offered in Dover for prospective private and commercial applicators starting next week. Find more information at our website: extension.unh.edu.

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