Tree Fruit Edition

Seasonal updates on insects, diseases, weeds, maturity dates and cultural practices impacting only tree fruit.
 
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June 4, 2025 and

Fruit IPM Report June 4, 2025

Peach:

Diseases:

Bacterial Spot: Bacterial spot leaf symptoms appeared on highly susceptible varieties in southern counties starting in May. Leaf infections appear water soaked, stay within the leaf veins, and gradually darken (Figure 1). Eventually the chlorotic tissue abscises from the leaf leaving a “shot-hole”. Copper injury appears similar. The main differences are copper injury will often appear at the leaf bottom where the spray collects as it runs off, and the shot-hole will cross over leaf veins. Copper injury often has a red appearance at the shot-hole margins (Figure 2). Fruit injury from bacterial spot results in dark lesions that are often accompanied by gummosis. So far fruit symptoms are very low and only in highly susceptible varieties. Growers should continue to manage using Oxytetracycline and lower rates of copper, especially around rainy periods and severe weather. Fruit will become less susceptible to infection at pit hardening which should occur around the middle of June.

Figure 1. Bacterial spot infection on leaf in peach. Photo by David Schmitt.

Figure 2. Copper injury to peach leaf.

Rusty Spot: Rusty spot infections are appearing on fruit in southern counties and ongoing until pit hardening. Maintain coverage with effective materials such as Rally, Rhyme, or potassium bicarbonate products. Other choices include Flint Extra, Inspire Super, and Luna Sensation.

Peach Scab: Maintain good coverage with captan or other effective fungicides until July where scab was an issue last year.

 

 

Oriental Fruit Moth: A biofix point for OFM was set on 4/2 for southern counties and 4/17 in northern counties. All Treatments for the first generation have past.

OFM 2nd Generation Timing
Insecticide Type
County/Region Degree Days by  6/2 base 45 Conventional

1150-1200

1450-1500

 Intrepid/Rimon

1050-1150

1300-1400

 Diamides/Virus

1075-1150

1375-1450
Gloucester – Southern 912 1st –June 11-13

2nd – too far off

 1st –June 7-10

2nd – too far off

 1st –June 8-10

2nd – too far off
Middlesex – Northern 775 1st – too far off

2nd – too far off

 1st – too far off

2nd – too far off

 1st – too far off

2nd – too far off

Tarnished Plant Bugs; and Other Catfacing Insects: Catfacing insects are active, but very little recent fruit feeding has been observed.

Green Peach Aphid: We are still observing aphid colonies above threshold at some farm sites. If more than 1 colony of aphids are found in nectarines, or 2-3 colonies are found in peaches, an insecticide for aphids is needed. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.

Scale Insects: White peach scale and San Jose scale crawlers began emergence around mid-May in southern counties and San Jose scale crawlers began emergence around May 26 and will continue emergence for up to 6 weeks. Control options during crawler emergence include Neonicotinoids (suppression only), Sivanto, and the IGR’s Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide and the product labels for more information.

Apples and Pears:

Diseases: Now that primary scab is nearing the end, or has ended, the focus turns toward summer diseases such as fruit rots (esp. Bitter rot), and sooty blotch and fly speck. Bitter rot control has been difficult at best in recent years even where management programs have been rigorous. Research has suggested products such as Merivon, Luna Sensation, Inspire Super, Aprovia, and Omega may be effective, and longtime reliable broad spectrum fungicides such as captan and ziram should provide control. Experience has suggested that the addition of phosphorous acid products such as Prophyt or Rampart to captan sprays may improve control. Observations are that these products improve control of other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present. Scab symptoms are appearing in some orchards statewide.

Fire Blight: Fire Blight symptoms began appearing in southern county apple orchards the week of 5/19. Typically it is recommended to cut out infected limbs however this is a practical decision that must be made. This blog post from Michigan State may be helpful to decide whether it is worth cutting out infected tissue. Once the terminal buds set, typically in July, infected wood should be removed to prevent colonization by the bitter rot pathogen.

Codling Moth (CM): A Codling Moth Biofix was set in Southern counties on 4/28 and in Northern counties on 4/30. Codling moth applications for the first generation is due later this week into the weekend. See the chart below for timings based on location and the chemistry being used.

Codling Moth Degree Day Timing
Application and Insecticide Type
County Area Biofix Rimon:

75-100DD + 14-17 days later

 

 Intrepid

150 + 450 DD

Diamides – Altacor, Voliam mixes: (150-200 DD)

 Madex

250 DD + every 7-9 days during brood hatch (later if first spray is an IGR)

 Standard Insecticides –  Delegate, Avaunt, OP’s, carbamates, pyrethroids

250 DD + 550 DD

 
DD 75 100 150 450 250 250 550
Southern April 28 past past past past past past June 5
Northern  April 30 past past past June 4 past past June 8

 

Ambrosia Beetle : Infested trees are showing signs of stress. If you have had a history of this pest in your orchard, now is a good time remove and burn any trees that have been attacked as the flight appears to be declining or is over.

Wooly Apple Aphid (WAA); Green Apple (Spirea) Aphids (GAA): GAA colonies are present in some apple blocks. GAA is generally a pest that can be tolerated since they do little direct damage. Treatment thresholds for GAA are if 50% of the shoots are infested with no beneficial insects present. WAA colonies are also beginning to form in southern counties. In most years these are controlled by beneficials; however, in some years like 2022, serious outbreaks can occur. The best control for WAA is Movento applied before or when the first colonies appear. Diazinon is also effective at knocking down infestations. Movento will also control GAA and should control San Jose scale when applied in mid-May, and suppress scale when applied in late May or early June.  Do not combine diazinon, oil, or oil-based penetrants with Captan.

Pear: Second generation pear psylla began hatching about 5/19. Options for control include spinosyn products such as Delegate and Entrust, and the neonicotinoids (IRAC group 4A). The addition of 0.25-1 gal of summer oil may improve control. Other options include Movento, the IGR’s Esteem and Centaur, and products containing abamectin. Be sure to read and follow the label instructions regarding the addition of penetrants for abamectin products, and Movento. Pear Psylla are still actively laying eggs and nymphs continue to hatch.

Grape: Early blooming native grapes were at trace bloom on 5/16, therefore we have set the Grape Berry Moth biofix at 5/16 for southern counties. Since V. riparia typically blooms with early natives we used Concord to set the biofix. The model works best when growers record their own bloom dates and use the Grape Berry Moth model at NEWA. Applications for GBM using Intrepid or Diamides should be made at 810 DD base 47. Other effective materials can be applied a few days later. Applications have been historically made around the end of June in southern counties. As for diseases, we are seeing low levels of phomopsis and symptoms of downy mildew beginning in some vineyards. Bloom is the critical time to protect against cluster infections from Downy and Powdery Mildew; Black rot; Botrytis; and ripe rot. Dr. Mizuho Nita at Virginia Tech has a comprehensive summary of fungicide choices for bloom.

Phenology Table: Based on annual observations made in Gloucester County.

Pest Event or Growth Stage Approximate Date 2025 Observed Date
 Bud Swell (Redhaven/PF-17)  March 23 +/- 15 Days March 30
1/4″ Green Tip Red Delicious March 31 +/- 13 Days March 30
Pink Peach (Redhaven/PF-17) April 4 +/- 15 Days April 1
Tight Cluster Red Delicious April 9 +/- 13 Days April 5
Full Bloom Peach (Redhaven/PF-17) April 9 +/- 14 Days April 10
Pink Apple (Red Delicious) April 14 +/- 12 Days April 16
Full Bloom Apple (Red Delicious) April 22 +/- 11 Days April 25
Petal Fall (Redhaven) April 22 +/- 10 Days April 19
Petal Fall (Red Delicious) April 27 +/- 13 Days May 2
Shuck Split (Redhaven) April 30 +/- 11 Days April 26
Pit Hardening June 15 +/- 9 Days

 

Tree Fruit Trap Captures – Southern Counties

Week Ending STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/5/2025 0 0 0 0 0 0 0 0 0 0
4/12/2025 0 0 0 0 6 0 0 0 0 0
4/21/2025 0 0 0 0 36 0 1 0 0 0
4/27/2025 25 0 0 0 24 0 5 0 1 0
5/2/2025 517 0 4 0 12 0 6 0 13 0
5/9/2025 159 4 10 0 3 16 5 4 46 0
5/16/2025 91 11 6 0 1 36 2 14 69 0
5/23/2025 299 21 3 0 1 23 1 26 23 0
5/30/2025 399 14 2 0 0 41 1 11 10 3

Tree Fruit Trap Captures – Northern Counties

Week Ending STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB AMBROSIA BEETLE
4/5/2025 387 0 0 0 0 0 0 0 0 0 0
4/21/2025 435 0 0 0 0 0 1.3 0 0 0 0
4/27/2025 26 0 0 0 0 0 25 0 0 0 72
5/2/2025 86 0 0.33 0 72.5 0 47.2 0 0 0 136
5/9/2025 56 0 5.3 0 58.8 0 22.9 0 0 0 145
5/16/2025 13.75 2.6 7.3 0 4 0 5 0 0 0 50.5
5/23/2025 4.8 10.3 10.5 0 0.6 31.25 4.2 0 14.6 1 22.2
5/30/2025 2.2 4.8 1.8 0 0 12.4 9.6 0 9.6 1.9 22.1

 

Filed Under: Fruit, Tree Fruit, Wine Grape
June 2, 2025 , , and

High Temperatures Predicted this Coming Week – Ways to Prevent Heat Stress

OSHA Safe + Sound Header for Heat Illness Prevention

Heat exposure for agricultural laborers should be a consideration when working outside and even in non-airconditioned buildings. When a person’s ability to adapt to heat stress is exceeded, exposure can lead to reduced productivity, mistakes in job performance, increased workplace incidents, and/or heat-related illnesses. Each person’s heat tolerance varies and several factors including type of physical activity, fitness level, underlying health issues, temperature, sun exposure, air movement (wind), and humidity can dramatically impact the potential for heat stress. To determine the level of heat risk, employers should consider the job, the environment, and the worker.

Evaluate the Risk of Heat Stress:
Monitoring the environmental conditions during work times to make management decisions for workers is an important part of preventing heat-related illnesses. Temperature is not the only factor in implementing heat stress management. Humidity is another important consideration. The heat index is a measure of how hot it feels when the relative humidity is factored in with the actual air temperature.

An environmental heat assessment should account for the following factors: air temperature, humidity, radiant heat from sunlight or other artificial heat sources, and air movement. OSHA recommends the use of wet bulb globe temperature (WBGT) monitor to measure workplace environmental heat. OSHA provides this link to calculate the WBGT for a specific location. There is also a NIOSH/OSHA Heat App for Android and iPhone devices that uses the Heat Index as a screening tool.

Management Suggestions for Enhancing Heat Tolerance:
Acclimatization (to heat) is a process of adaptation that involves a stepwise adjustment to heat over a week or sometimes longer. An acceptable schedule for achieving acclimatization is to limit occupational heat exposure to one-third of the workday during the first and second days, one-half of the workday during the third and fourth days, and two-thirds of the workday during the fifth and sixth days. The acclimatization procedure should be repeated if a person misses workdays after days off due to illness, vacation, or other reasons for missing one week or more of job duties.

Fluid replacement:
Provide adequate drinking water for all employees. Recommend to employees they drink plenty of water before work shifts, during work, and after work. Simply relying on feeling thirsty will not ensure adequate hydration. To replace the four to eight quarts of sweat that may be produced in hot environments, people require one-half to one cup of water every 20 minutes of the workday. Potable drinking water kept at a temperature of 59°F or less is recommended.

Physical Fitness: Physical fitness is extremely important. The rate of acclimatization is a function of the individual’s physical fitness. The unfit worker takes 50 percent longer to acclimate than one who is fit.

Increasing Safe Work Practices:
To find management and guidance tools for determining whether to implement heat stress management plans refer to the CDC documents on Heat Stress and Work/Rest Schedules.

The following list of management options should be considered to prevent heat stress for workers:

  • Limit exposure time. Schedule as many physical work activities as practical for the coolest part of the day (early morning or late afternoon). Employ additional help or increase mechanical assistance, if possible, to lighten individual workloads.
  • Minimize heat exposure by taking advantage of natural or mechanical ventilation (increased air velocities up to 5 mph increase the rate of evaporation and thus the rate of heat loss from the body) and heat shields/shade when applicable.
  • Take rest breaks at frequent, regular intervals, preferably in a cool environment sheltered from direct sunlight. Anyone experiencing extreme heat discomfort should rest immediately and be provided with first aid for heat stress.
  • Wear clothing that is permeable to air and loose fitting. Generally, less clothing is desirable in hot environments, except when the air temperature is greater than 95°F or a person is standing next to a radiant heat source. In these cases, covering exposed skin can reduce the risk of heat stress.
  • A buddy system may also be helpful. It depends on a fellow worker’s ability to spot the early signs of heat stress, such as irritability, confusion, or clumsiness. A ready means of cooling should be available in work areas where heat illness might occur.
Filed Under: Blueberry, Commercial Ag Updates, Cranberry, Field, Forage & Livestock, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, Strawberry, Tree Fruit, Turf, vegetable, Vegetable Crops, Wine Grape Tagged With: ,
May 28, 2025 and

Fruit IPM Report May 26, 2025

Peach:

Bacterial Spot: Copper formulations should be used starting at petal fall to suppress bacterial spot. Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics containing oxytetracycline may also be used and may offer slightly more residual activity during long wetting periods. We have seen minimal bacterial spot symptoms. We are nearing pit hardening which usually occurs mid-June. Once fruit gets to this stage it develops some resistance to bacterial spot. Infections may still occur but will be less severe.

Oriental Fruit Moth: A biofix point for OFM was set on 4/2 for southern counties and 4/17 in northern counties. All Treatments for the first generation have past.

OFM 2nd Generation Timing
Insecticide Type
County/Region Degree Days by  5/26 base 45 Conventional

1150-1200

1450-1500

 Intrepid/Rimon

1050-1150

1300-1400

 Diamides/Virus

1075-1150

1375-1450
Gloucester – Southern 796 1st –too far off

2nd – too far off

 1st –too far off

2nd – too far off

 1st – too far off

2nd – too far off
Middlesex – Northern 662 1st – too far off

2nd – too far off

 1st – too far off

2nd – too far off

 1st – too far off

2nd – too far off

Green Peach Aphid: We are still observing aphid colonies above threshold at some farm sites. If more than 1 colony of aphids are found in nectarines, or 2-3 colonies are found in peaches, an insecticide for aphids. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.

Tarnished Plant Bugs; and Other Catfacing Insects: Catfacing insects are active, and activity will increase with dry weather and summer temperatures. Very little recent fruit feeding has been observed.

Figure 1. San Jose scale crawlers on peach. Photo by Dave Schmitt.

Scale Insects: White peach scale and San Jose scale crawlers (Figure 1) began emergence this week and will continue emergence for up to 6 weeks. Control options during crawler emergence include neonicotinoids (suppression only), and the IGR’s Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide and the product labels for more information.

Apples and Pears:

Diseases: Now that primary scab is nearing the end, or has ended, the focus turns toward summer diseases such as fruit rots (esp. Bitter rot), and sooty blotch and fly speck. Bitter rot control has been difficult at best in recent years even where management programs have been rigorous. Research has suggested products such as Merivon, Luna Sensation, Inspire Super, Omega, and Aprovia may be effective, and longtime reliable broad spectrum fungicides such as captan and ziram should provide control. Experience has suggested that the addition of phosphorous acid products such as Prophyt or Rampart to captan sprays may improve control. Observations are that these products improve control of other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present. Scab symptoms are appearing in some orchards statewide.

Fire Blight: Fire Blight symptoms began appearing in southern county apple orchards the week of 5/19 (Figure 2). Typically it is recommended to cut out infected limbs however this is a practical decision that must be made. This blog post from Michigan State may be helpful to decide whether it is worth cutting out infected tissue. Once the terminal buds set, typically in July, infected wood should be removed to prevent colonization by the bitter rot pathogen.

Figure 2. Fire blight strike on apple tree branch. Photo by Karlton Neidigh.

Codling Moth: A Codling Moth Biofix was set in Southern counties on 4/28 and in Northern counties on 4/30. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Where Mating Disruption has been employed, supplemental Madex applications should be made at the timings listed below.

Codling Moth Degree Day Timing
Application and Insecticide Type
County Area Biofix Rimon:

75-100DD + 14-17 days later

 

 Intrepid

150 + 450 DD

Diamides – Altacor, Voliam mixes: (150-200 DD)

 Madex

250 DD + every 7-9 days during brood hatch (later if first spray is an IGR)

 Standard Insecticides –  Delegate, Avaunt, OP’s, carbamates, pyrethroids

250 DD + 550 DD

 
DD 75 100 150 450 250 250 550
Southern April 28 past past past May 29 past past too soon to predict
Northern  April 30 past past past too soon to predict past past too soon to predict

 

Ambrosia Beetle : Infested trees are showing signs of stress. If you have had a history of this pest in your orchard, now is a good time remove and burn any trees that have been attacked as the flight appears to be declining or is over.

Wooly Apple Aphid (WAA); Green Apple (Spirea) Aphids (GAA): GAA colonies are beginning to appear in some apple blocks. GAA is generally a pest that can be tolerated since they do little direct damage. Treatment thresholds for GAA are if 50% of the shoots are infested with no beneficial insects present. WAA aerial colonies are also forming in southern counties. This is about a month earlier than usually observed. In most years these are controlled by beneficials however in some years like 2022, serious outbreaks can occur. The best control for WAA is Movento applied before or when the first colonies appear. Diazinon is also effective at knocking down infestations. Movento will also control GAA and should control San Jose scale when applied in mid-May, and suppress scale when applied in late May or early June.  Do not combine diazinon, oil, or oil based penetrants with Captan.

Potato Leafhoppers (PLH): PLH adults began appearing in apples this past week (Figure 3). PLH should not be tolerated in non-bearing orchards because they can stunt the growth of new shoots. Likewise they should not be tolerated in orchards were fire blight is present because they have been demonstrated to spread the disease. PLH appear as light green smallish leafhoppers and are often found on the new leaves in the growing tips. Neonicotinoids are generally recommended for control however there are other broad spectrum materials that are effective. Refer to the NJ Commercial Tree Fruit Production Guide for more information.

Potato Leafhopper Adult & Nymph

Figure 3. Potato Leafhopper Adult & Nymph

Pear: Second generation pear psylla began hatching about 5/19. Options for control include spinosyn products such as Delegate and Entrust, and the neonicotinoids (IRAC group 4A). The addition of 0.25-1 gal of summer oil may improve control. Other options include Movento, the IGR’s Esteem and Centaur, and products containing abamectin. Be sure to read and follow the label instructions regarding the addition of penetrants for abamectin products, and Movento. Pear Psylla are still actively laying eggs and nymphs continue to hatch.

Grape: Early blooming native grapes were at trace bloom on 5/16, therefore we have set the Grape Berry Moth biofix at 5/16 for southern counties. Since V. riparia typically blooms with early natives we used Concord to set the biofix. The model works best when growers record their own bloom dates and use the Grape Berry Moth model at NEWA. Applications for GBM using Intrepid or Diamides should be made at 810 DD base 47. Other effective materials can be applied a few days later. Applications have been historically made around the end of June in southern counties.

Phenology Table: Based on annual observations made in Gloucester County.

Pest Event or Growth Stage Approximate Date 2025 Observed Date
 Bud Swell (Redhaven/PF-17)  March 23 +/- 15 Days March 30
1/4″ Green Tip Red Delicious March 31 +/- 13 Days March 30
Pink Peach (Redhaven/PF-17) April 4 +/- 15 Days April 1
Tight Cluster Red Delicious April 9 +/- 13 Days April 5
Full Bloom Peach (Redhaven/PF-17) April 9 +/- 14 Days April 10
Pink Apple (Red Delicious) April 14 +/- 12 Days April 16
Full Bloom Apple (Red Delicious) April 22 +/- 11 Days April 25
Petal Fall (Redhaven) April 22 +/- 10 Days April 19
Petal Fall (Red Delicious) April 27 +/- 13 Days May 2
Shuck Split (Redhaven) April 30 +/- 11 Days April 26
Pit Hardening June 15 +/- 9 Days

 

Tree Fruit Trap Captures – Southern Counties

Week Ending STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/5/2025 0 0 0 0 0 0 0 0 0 0
4/12/2025 0 0 0 0 6 0 0 0 0 0
4/21/2025 0 0 0 0 36 0 1 0 0 0
4/27/2025 25 0 0 0 24 0 5 0 1 0
5/2/2025 517 0 4 0 12 0 6 0 13 0
5/9/2025 159 4 10 0 3 16 5 4 46 0
5/16/2025 91 11 6 0 1 36 2 14 69 0
5/23/2025 299 21 3 0 1 23 1 26 23 0

 

Tree Fruit Trap Captures – Northern Counties

Week Ending STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB AMBROSIA BEETLE
4/5/2025 387 0 0 0 0 0 0 0 0 0 0
4/21/2025 435 0 0 0 0 0 1.3 0 0 0 0
4/27/2025 26 0 0 0 0 0 25 0 0 0 72
5/2/2025 86 0 0.33 0 72.5 0 47.2 0 0 0 136
5/9/2025 56 0 5.3 0 58.8 0 22.9 0 0 0 145
5/16/2025 13.75 2.6 7.3 0 4 0 5 0 0 0 50.5
5/23/2025 4.8 10.3 10.5 0 0.6 31.25 4.2 0 14.6 1 22.2
Filed Under: Fruit, Tree Fruit, Uncategorized, Wine Grape
May 20, 2025 and

Fruit IPM Report May 20, 2025

Peach:

Bacterial Spot: Copper formulations should be used starting at petal fall to suppress bacterial spot. Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics containing oxytetracycline may also be used and may offer slightly more residual activity during long wetting periods. We have observed bacterial leaf spot symptoms in orchards in southern and northern counties.

Peach Scab: In addition to Rusty Spot and Bacterial Spot, Peach Scab requires protective applications starting at petal fall. Peach scab cankers (Figure 1) begin to expand at bloom and by shuck split begin to shed spores during wetting periods.

Figure 1. Peach Scab lesions on peach twig. Photo by Dave Schmitt.

Topsin, Topsin/Captan combinations, Flint Extra, Inspire Super, and Quadris Top applied at petal fall are the best materials for blocks that had scab last year. Quadris Top, Flint Extra or Topsin should be used at the high rate to suppress overwintering lesions on the wood. Quadris Top contains azoxystrobin which is phytotoxic to many apple varieties. Phytotoxic residues can remain in the tank for long periods after an application is made, even if a tank cleaner is used. Do not use Quadris Top or Abound in the same sprayer used for apples. Bravo (chlorothalonil) is also a good protectant that may be applied no later than shuck split. Captan is also helpful in cover sprays after shuck split where scab was troublesome last year.

Oriental Fruit Moth: We have recorded high OFM trap captures this season throughout the state. A biofix point for OFM was set on 4/2 for southern counties and 4/17 in northern counties. All Treatments for the first generation have past.

OFM 2nd Generation Timing
Insecticide Type
County/Region Degree Days by  5/19 base 45 Conventional

1450-1500

 Diamide

1300-1400
Gloucester – Southern 712 1st –too far off

2nd – too far off

 1st –too far off

2nd – too far off
Middlesex – Northern 586 1st –too far off

2nd – too far off

 1st –too far off

2nd – too far off

Green Peach Aphid: GPA colonies begin forming sometime during bloom. Examine trees for the presence of colonies from pink to shuck split. Count the number of colonies on ten trees and use a treatment threshold of 2 colonies/tree at petal fall for peach, and 1 colony/tree for nectarine. The best way to scout for aphids during bloom is with a beating tray. Blossoms may also be collected, opened, and examined for the presence of aphids using a hand lens. This is particularly important for nectarine blocks. Check 10 trees per block with the beating tray. Collect 50 blossoms per block and examine for the presence of aphids. If more than 1 colony of aphids are found in nectarines, or 2-3 colonies are found in peaches, an insecticide for aphids will be needed when all petals are off. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. We are observing aphid colonies above threshold at some farm sites.

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: We continue to see an increase of percent injury on fruit from plum curculio with an average 1.5% injury reported on developing apples in southern counties. Plum Curculio start to move into orchards at about 88-100 degree days base 50 after January 1. Applications for PC should be initiated once all petals are off, with a second application made with ovicidal materials at 379-402 DD. We are currently past this treatment window as southern counties have accumulated about 664 DD base 50 and northern counties have accumulated 584 DD base 50. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Catfacing insects are active now and can cause injury. Greater than 1 to 2% fresh catfacing injury on the fruit means that adjustments have to be made in the spray program.

Scale Insects: White peach scale crawlers will begin to emerge in southern counties and should continue emergence until about the middle of June. San Jose scale crawlers typically begin emergence about late May or Early June and continue emergence for up to 6 weeks. Control options during crawler emergence include Neonicotinoids (suppression only), and the IGR’s Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide and the product labels for more information.

Apples and Pears:

Diseases: Now that primary scab is nearing the end, or has ended, the focus turns toward summer diseases such as fruit rots (esp. Bitter rot), and sooty blotch and fly speck. Bitter rot control has been difficult at best in recent years even where management programs have been rigorous. Research has suggested products such as Merivon, Luna Sensation, Inspire Super, and Aprovia may be effective, and longtime reliable broad spectrum fungicides such as omega, captan and ziram should provide control. Experience has suggested that the addition of phosphorous acid products such as Prophyt or Rampart to captan sprays may improve control. Observations are that these products improve control of other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present. Scab symptoms are appearing in some orchards statewide.

Fire Blight: Infections can still occur post bloom so covers with antibiotics when infection events are forecast using the NEWA fire blight model may be beneficial. Remember to rotate streptomycin and oxytetracycline products. Where symptoms occur (Figure 2) it is recommended to cut out infected limbs; however, this is a practical decision that must be made.

Figure 2. Fire Blight strike on limb in apple.

This blog post from Michigan State may be helpful to decide whether it is worth cutting out infected tissue. Once the terminal buds set, typically in July, infected wood should be removed to prevent colonization by the bitter rot pathogen.

 

 

 

 

 

 

 

Codling Moth: A Codling Moth Biofix was set in Southern counties on 4/28 and in Northern counties on 4/30. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Where Mating Disruption has been employed, supplemental Madex applications should be made at the timings listed below.

Codling Moth Degree Day Timing
Application and Insecticide Type
County Area Biofix Rimon:

75-100DD + 14-17 days later

 

 Intrepid

150 + 450 DD

Diamides – Altacor, Voliam mixes: (150-200 DD)

 Madex

250 DD + every 7-9 days during brood hatch (later if first spray is an IGR)

 Standard Insecticides –  Delegate, Avaunt, OP’s, carbamates, pyrethroids

250 DD + 550 DD

 
DD 75 100 150 450 250 250 550
Southern April 28 past past past too soon to predict past past too soon to predict
Northern  April 30 past past past too soon to predict past past too soon to predict

Scale Insects: Dormant oil applications are standard recommendations for scale control but in some years when conditions are not optimal for oil application scale control may be less than desired. Where oil was not applied or in orchards where scale is a recurring problem, an application of Centaur at petal fall or Movento between petal fall and first cover should “clean up” problem blocks. Centaur is recommended at 34.5 oz/A and Movento should be applied at 6-9 oz/A. A penetrant must be included to Movento as per the product label. Movento will also control apple aphids, including Wooly Aphid, when used at this timing. In pears Movento may also control aphids and 2nd generation pear psylla (if eggs are present) when applied at first cover.

Wooly Apple Aphid (WAA); Green Apple (Spirea) Aphids (GAA): GAA colonies are present in some apple blocks. GAA is generally a pest that can be tolerated since they do little direct damage. Treatment thresholds for GAA are if 50% of the shoots are infested with no beneficial insects present. WAA aerial colonies are also beginning to form in southern counties. This is about a month earlier than usual. In most years these are controlled by beneficials; however, in some years like 2022, serious outbreaks can occur. The best control for WAA is Movento applied before or when the first colonies appear. Diazinon is also effective at knocking down infestations. Movento will also control GAA and should control San Jose scale when applied in mid-May, and suppress scale when applied in late May or early June.  Do not combine Diazinon with Captan.

Ambrosia Beetle : Trap captures continue to decline. Infested trees should be showing signs of stress or will be soon. Once these beetles bore into the trunk, they will form a gallery in the heartwood of the tree to lay their eggs and farm the ambrosia fungus to feed themselves and their larvae. Once the female lays her eggs, it will take about 30 days for them to become adults and emerge from their host tree to begin the second flight. If you have had a history of this pest in your orchard, you should begin scouting for damage and remove any trees that have been attacked. It may be beneficial to leave attacked trees in the orchard for a few weeks before removal so they can act as trap trees to reduce populations. Beetles generally do not leave the host tree once they’ve attacked it. They will attract other beetles to the stressed tree and adjacent trees so they tend to stay in one area rather than spread throughout the orchard.

Pear Psylla: Second generation pear psylla adults are present and laying eggs in southern counties (Figure 3).

Pear Psylla eggs along midrib

Figure 3. Pear Psylla eggs along midrib.

Hatch should begin soon. Options for control include spinosyn products such as Delegate and Entrust, and the neonicotinoids (IRAC group 4A). The addition of 0.25-1 gal of summer oil may improve control. Other options include Movento, and products containing abamectin. If you are planning to use Movento for the second generation it should be applied just before hatch or as soon as newly hatched nymphs appear as it takes about a week for the material to move throughout the tree. Be sure to read and follow the label instructions regarding the addition of penetrants for these products.

 

Grapes

Early blooming native grapes were at trace bloom on 5/16, therefore we have set the Grape Berry Moth (GBM) biofix at 5/16 for southern counties. Since V. riparia typically blooms with early natives we used Concord and Ives to set the biofix. The model works best when growers record their own bloom dates and use the Grape Berry Moth model at NEWA. Applications for GBM using Intrepid or Diamides should be made at 810 DD base 47 from the biofix date. Other effective materials can be applied a few days later. Applications have been historically made around the end of June in southern counties. SLF nymphs were observed emerging the week of 4/28 in southern counties and will continue to hatch over several weeks. Management for SLF nymphs is not recommended at this time. The most important diseases to manage at this time are Phomopsis, Powdery Mildew, and Black Rot. More information about early season disease control can be found in this blogpost from Virginia Tech.

Phenology Table: Based on annual observations made in Gloucester County.

Pest Event or Growth Stage Approximate Date 2025 Observed Date
 Bud Swell (Redhaven/PF-17)  March 23 +/- 15 Days March 30
1/4″ Green Tip Red Delicious March 31 +/- 13 Days March 30
Pink Peach (Redhaven/PF-17) April 4 +/- 15 Days April 1
Tight Cluster Red Delicious April 9 +/- 13 Days April 5
Full Bloom Peach (Redhaven/PF-17) April 9 +/- 14 Days April 10
Pink Apple (Red Delicious) April 14 +/- 12 Days April 16
Full Bloom Apple (Red Delicious) April 22 +/- 11 Days April 25
Petal Fall (Redhaven) April 22 +/- 10 Days April 19
Petal Fall (Red Delicious) April 27 +/- 13 Days May 2
Shuck Split (Redhaven) April 30 +/- 11 Days April 26
Pit Hardening June 15 +/- 9 Days

 

Tree Fruit Trap Captures – Southern Counties

Week Ending STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/5/2025 0 0 0 0 0 0 0 0 0 0
4/12/2025 0 0 0 0 6 0 0 0 0 0
4/21/2025 0 0 0 0 36 0 1 0 0 0
4/27/2025 25 0 0 0 24 0 5 0 1 0
5/2/2025 517 0 4 0 12 0 6 0 13 0
5/9/2025 159 4 10 0 3 16 5 4 46 0
5/16/2025 91 11 6 0 1 36 2 14 69 0

 

Tree Fruit Trap Captures – Northern Counties

Week Ending STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB AMBROSIA BEETLE
4/5/2025 387 0 0 0 0 0 0 0 0 0 0
4/21/2025 435 0 0 0 0 0 1.3 0 0 0 0
4/27/2025 26 0 0 0 0 0 25 0 0 0 72
5/2/2025 86 0 0.33 0 72.5 0 47.2 0 0 0 136
5/9/2025 56 0 5.3 0 58.8 0 22.9 0 0 0 145
5/16/2025 13.75 2.6 7.3 0 4 0 5 0 0 0 50.5
Filed Under: Fruit, Tree Fruit, Wine Grape
May 16, 2025 and

Deer Damage Control in the Vineyard

New Jersey’s high deer population significantly threatens vineyards, particularly those near wooded areas. Deer are a pest, especially on young vines and in the early growing season when food sources are scarce, and tender shoots are emerging. If the vineyard is close to the deer population, management is needed for the long-term productivity of the vineyards.

Identifying the deer damage: Deer browse on leaves and tender shoots using the lower front teeth. Deer do not have upper incisors, so the leaves browsed by deer have a rough, torn, and shredded appearance but no tooth marks (Figure 1). This can cause substantial crop loss and even compromise the health of the vines, specifically if the same vine is damaged over the years (Figure 1). Fortunately, secondary buds of grapevines can grow and produce replacement shoots when the actively growing shoot tip from the primary bud is damaged. A new shoot from a basal bud may not be as productive, however, it will ensure new vegetative growth, sustaining the canopy of the grapevine. [Read more…]

Filed Under: Blueberry, Cranberry, Fruit, Organic Production, Strawberry, Tree Fruit, Uncategorized, vegetable, Wine Grape Tagged With: , , , ,
May 15, 2025 and

Crown Gall in Grapevines – Early Symptoms and Management.

What is Crown Gall?

Figure 1. Early symptoms. Young soft galls developing on the graft union during early spring (L) and cracking of bark by growing crown galls (C and R).

Crown gall is a serious disease affecting grapevines, particularly in cool-climate viticulture. It is caused by the soil- and plant-borne bacterium Agrobacterium vitis (A. vitis). This pathogen induces tumor-like growths (galls) that disrupt the grapevine’s vascular system, reducing the flow of water and nutrients from roots to shoots. If left unmanaged, crown gall can stunt vine growth and eventually kill the plant.

Diseases Symptoms

The earliest and most distinctive symptoms are abnormal, soft, whitish swellings (see Figure 1, Left). As these galls grow, they cause the bark to crack and peel due to pressure from underneath (Figure 1, Center and Right). Galls can initially be mistaken for benign growth, and therefore, detection requires careful inspection.

Figure 2. Crown gall on the graft union and trunk of the grapevine.

As the disease progresses, galls may become woody, rough, and brown, growing to several inches in diameter (Figure 2). They most often appear at the graft union or sites of mechanical injury on the lower trunk. The graft union is especially susceptible due to: (i) its irregular shape, which is prone to cracking, and (ii) potential contamination by A. vitis during the grafting process. Galls may also form on cordons and canes. Early scouting and removal of affected trunks can help limit the spread of infection. If the gall encircles the vine’s vascular system, the entire plant may collapse and especially in young vines, which have thinner trunks.

Another indicator of severe infection is the emergence of multiple new suckers from the vine base (Figure 1, Left). Additionally, leaves of affected vines may show green wilting and reddening due to restricted water and nutrient flow (Figure 3). However, similar symptoms can also result from viruses or nutrient deficiencies, making diagnosis challenging. In such cases, inspect the trunk visually for physical signs of gall formation or vascular disruption.

 

Why does wounding cause gall formation?

Figure 3. Leaf of crown gall-affected grapevine showing green wilting and reddening.

Wounding is a key point of infection in crown gall development. In early spring, grapevines attempt to heal sites of winter injury by producing callus tissue. These masses of undifferentiated cells with soft cell walls are particularly vulnerable to infection. A. vitis, which may already be present in the vine, exploits these wounds to inject its DNA into the callus cells. This bacterial DNA contains a tumor-inducing gene that integrates into the plant’s genome, leading to uncontrolled cell division, resulting in the characteristic gall.

Management of Crown Gall

An integrated pest management (IPM) approach is essential for effective crown gall control. Strategies include:

1, Avoidance
Site selection is the best decision to avoid cold injury. Avoid planting in low-lying areas where cold air settles. Gentle slopes are preferable for air drainage but beware that cold air may still collect at the lower end of a slope. Avoid planting in such spots unless you have excellent air drainage practices.

Figure 4. Grapevine in a year after hilling and damaging winter. Notice the graft union and trunk a few inches above it, unaffected by winter damage due to hilling-up, while the unprotected trunk shows crown gall.

2. Exclusion
Start with clean, certified planting material to reduce the chance of introducing A. vitis into your vineyard. Ideally, use 2010 Protocol-certified stock, which is propagated using advanced screening techniques to minimize bacterial contamination.

3. Resistance
Different grapevine species vary in susceptibility. Vitis vinifera cultivars are generally more susceptible. Hybrids and some vinifera varieties show moderate tolerance. Native species and certain hybrids tend to have better resistance. Consider planting more resistant varieties in areas prone to cold injury.

4. Protection
Hilling up soil around the base of vines during winter is highly effective. The soil acts as insulation, protecting the graft union and lower trunk. While this won’t shield unburied parts of the vine, it can preserve enough tissue to allow regrowth from protected suckers (Figure 4). Training these suckers as new trunks and using multiple trunks per vine can reduce the risk of total vine loss. For detailed guidance, refer to Rutgers NJAES Factsheet FS1264.

5. Eradication
Remove and destroy infected vine sections (Figure 5). This is the most effective post-infection strategy. Scout during early spring or winter pruning. Any removed vine parts should be taken out of the vineyard entirely. If removing an entire vine, extract it with the root system, as A. vitis can persist in root debris for years.

6. Chemical Control Options

Figure 5. New trunks and cordons were developed after removing the old, infected cordon.

A few commercial treatments are available, including:

  • Galltrol-A (AgBioChem, Inc., Provo, UT)
  • Gallex (AgBioChem, Inc., Provo, UT)
  • Copper-based compounds
  • Antibiotics

However, their effectiveness varies. Once the bacteria establish themselves systemically, eradication becomes extremely difficult. Always follow label instructions and integrate chemical treatments with cultural practices for best results.

References
Burr T. and Martinson T. 2015. Start Clean, Stay Clean Grape Crown Gall. National Clean Plant Network. Factsheet.

Moyer M. 2013. Grapevine Crown Gall. – Disease Management White Paper. Wine.wsu.edu/research-extension/

Gohil H., Nitzsche P., and Ward D. 2017. Hilling up to Prevent Winter Injuries in Vineyard. Rutgers NJAES Factsheet 1264. https://njaes.rutgers.edu/fs1264/

Todaro T. and Longstroth M. Managing Grapevine Crown Gall. Michigan State University Extension.

Filed Under: Blueberry, Fruit, Strawberry, Tree Fruit, Wine Grape Tagged With: , , , ,