Fruit Crops Edition - Blueberry Section

Seasonal updates on diseases, insects, weeds impacting small fruit (blueberry, cranberry, and wine grape). Fruit Pest Alerts are also available via this category feed.
 
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Fruit IPM Report for Week of 5/25/2026

Following a rainy and cool Memorial Day weekend, temperatures remained mild in the 60s and 70s for the remainder of the week. Temperatures gradually increased to the lower 80s by the weekend.

We are seeing fruitlets beginning to drop, and additional drops are still expected throughout this month. Growers are encouraged to continue evaluating blocks carefully before making management decisions throughout the season.

Despite reduced crop potential, continued monitoring and management remain important, particularly in blocks with surviving fruit or where maintaining tree health and supporting return bloom for the 2027 season are priorities. See the recent post from Rutgers Extension Specialists and Cooperative Extension on Managing orchards with through a season with limited yields.

Apples
Disease Management Considerations

Apple Scab: Primary scab period has ended. Wetting events can support disease spread where primary scab infection occurred, but the upcoming forecast is relatively dry, which should limit additional infection risk at this time. Growers should continue to monitor conditions and maintain coverage with Mancozeb or Captan plus a single-site fungicide, particularly where primary infections may have occurred. Keep in mind that Mancozeb has a 77-day pre-harvest interval (PHI).

Cedar apple rust: We have observed a few instances of cedar apple rust infections spreading into orchards. The period critical to maintaining coverage from infection has ended.

Powdery mildew developing on leaves in apple. Photo by Sophia Solewater.

Figure 1. Powdery mildew developing on leaves in apple. Photo by Sophia Solewater.

Powdery mildew: This week, we have had ideal conditions for powdery mildew infections in orchards, and powdery mildew has been observed on leaves (Figure 1). Mancozeb is not effective. In periods of hot days with high humidity and no rain, sulfur (e.g., Microthiol Disperss at 10 lb./A) can be applied. Powdery mildew needs to be managed through July. Do not tank mix captan and sulfur.

Fire blight: Symptoms began appearing in southern county apple orchards the week of 5/11 and continue to develop throughout the state. It is recommended to cut out infected limbs 6–12 inches below the margin of visible infection. Ideally, infected tissue should be removed from the orchard and burned. However, if pressed for time, prunings can be left in the row middles to dry out and subsequently chopped with a mower. Do not cut out infections during wet weather, as bacteria can spread through water.

Rots: In orchards with fruit, management moving forward will focus on summer diseases, including fruit rots like bitter rot, sooty blotch, and fly speck. Broad-spectrum fungicides captan and ziram are effective, and the addition of single-site products such as Merivon, Luna Sensation, Pristine, Omega, and Aprovia may improve control. The addition of phosphorous acid products such as Prophyt or Rampart to captan sprays can improve control of rots and other summer diseases, such as sooty blotch and flyspeck, and may help suppress scab infections where present.

Marssonina Blotch, Glomerella Leaf Spot, and Frogeye Leaf Spot: These diseases should be managed, as they will cause defoliation and provide a source of inoculum for black rot and bitter rot next season.  Maintain coverage of captan, manzate, or ziram prior to rain events through the growing season according to the cover spray rule of applications every 2” of rain or 14 days, whichever comes first.

 

 

Insect Update

Insect management programs should be adjusted this season based on reduced crop load in many orchards. In blocks with little to no fruit, many insect pests will not require treatment; however, monitoring should continue, and management should be maintained where pests threaten tree health or next year’s crop.

Codling Moth (CM): Biofix has been set for southern counties as of April 20 and in northern counties as of May 5. In blocks with little to no crop, CM management programs can often be reduced or delayed; however, monitoring should continue. Where mating disruption has been employed, or there is a reduced insecticide program, supplemental Madex applications can be made at the timings listed below if the threshold exceeds 5 or more moths per trap per week.

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 20 Past Past Past Past Past Past 6/4
Northern  May 5 Past Past Past 6/4 Past Past 6/8

Tufted Apple Bud Moth (TABM): A biofix for TABM was set in southern county orchards on 4/28. This has been considered a minor pest in recent years; however, we have recorded high trap captures this season. Consider management when pheromone trap counts are high, if injury was noted last year, or if leaf shelters and fruit feeding are easily found. Many materials used for codling moth, including Lannate, Delegate, diamides, and Intrepid, will also control TABM. Timing for management of first generation is best timed for 500-650 DD and 805-850 DD base 45°F.

Woolly Apple Aphid (WAA); Green Apple (Spirea) Aphids (GAA): Aphid colonies are being observed in some apple blocks. WAA and GAA are generally pests that can be tolerated because they cause little direct damage. Treatment thresholds for WAA and GAA are met if 50% of the shoots are infested with no beneficial insects present. Movento will control WAA and GAA and can suppress scale when applied in late May or early June when crawlers are active.

Ambrosia Beetle: Trap captures have decreased, indicating peak flight has ended or is coming to an end. Infested trees should be showing signs of stress or will soon. If trees are showing significant decline, particularly smaller/younger trees in high-density plantings, we recommend removing the trees and inspecting infested trees for signs of other confounding factors that may be causing tree stress (fire blight, Phytophthora).

Leafhoppers: Adult leafhoppers typically begin appearing in apples at this time of year. They appear as small, light-green, soft-bodied insects and are often found on the new leaves at the growing tips. High densities should not be tolerated in non-bearing orchards because they can stunt the growth of new shoots. They should also not be tolerated in orchards where fire blight is present, as they have been shown to spread the disease. Neonicotinoids are generally recommended for control; however, there are other broad-spectrum materials that are effective.

Dogwood borer: Monitoring traps have captured high numbers of male dogwood borer adults, particularly in orchards with a history of the pest. Mating disruption is recommended and effective for this pest. Manage as needed in blocks with a history of infestation. Assail has demonstrated activity when targeting adults to reduce egg laying. See the 2026 Integrated Orchard Management Guide for Commercial Apples in the Southeast.

Traps

Average Trap Captures in Apple – Southern Counties

  Week STLM TABM CM OFM DWB AMBROSIA BEETLE
5/11/2026 18  11  6 3   25   2
5/18/2026 16 21 3 10   54 13
5/25/2026 1.3 23 2 2   71 7

Average Trap Captures in Apple – Northern Counties

  Week STLM TABM CM DWB AMBROSIA BEETLE
5/11/2026 13.7  1.5  1.8   12.8   1.1
5/18/2026 8.3 13.25 2.4 18.5 10.8
5/25/2026 2.2 13.75 1.2 24.5 5.1

 

Pears
Disease Management

Fabraea Leaf Spot: Spots have been observed on leaves in orchards (Figure 2). Infections can result in significant leaf spotting, defoliation, and unmarketable fruit. Foliar diseases should be managed with Mancozeb or Ziram, plus a single-site fungicide, to maintain pressure and inoculum at low levels, protecting fruit and maintaining a healthy orchard going into the next season. See the New Jersey Commercial Tree Fruit Production Guide for more information.

Fabraea leaf spot on foliage in pear. Photo by Katrina DeWitt.

Figure 2. Fabraea leaf spot on foliage in pear. Photo by Katrina DeWitt.

Insect Update

Pear psylla: Second generation pear psylla adults are actively laying eggs, and nymphs continue to hatch. Options for control include Actara, Assail, and Belay (IRAC group 4A); Sivanto Prime (IRAC group 4D); Delegate (IRAC Group 5); and products containing abamectin (IRAC group 6). Other options include Movento (IRAC Group 23). The addition of 0.25-1 gal of summer oil may improve control. Be sure to read and follow the label instructions for adding penetrants to these products.

Plum curculio; Stink bug; Tarnished plant bug: Activity during scouting has been low. Where high amounts of injury are observed, and you intend to harvest the crop, consider a well-timed application of an IRAC Group 4A (Actara, Assail, and Belay).

Peaches
Disease Management

Given the widespread crop loss in many orchards, disease management programs should be adjusted accordingly. With little to no fruit present in most blocks, emphasis should shift away from fruit protection and toward maintaining tree health and reducing inoculum for next season.

Peach scab: In orchards without a history of high disease pressure, scab is generally not a concern in the absence of fruit. In blocks with a history of scab, lesions can still develop on current-season shoots and serve as inoculum for next year. In these situations, maintain coverage with captan or other effective fungicides until July, timed to precede significant rainfall events.

Bacterial spot: Maintain low-rate copper programs to protect foliage and reduce inoculum for future seasons, particularly important in blocks with a history of bacterial spot or under warm, wet conditions. 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. Avoid combining copper with captan, especially following extended cloudy or slow-drying conditions.

Rusty spot on peach. Photo by Karlton Raines-Neidigh.

Figure 3. Rusty spot on peach. Photo by Karlton Raines-Neidigh.

Rusty spot: Rusty spot infections are appearing on fruit across the state and are ongoing until pit hardening (Figure 3). Maintain coverage with effective materials such as Rally, Rhyme, or potassium bicarbonate products. Other choices include Flint Extra, Inspire Super, and Luna Sensation.

Brown rot: This disease is not a concern in blocks with little to no fruit. Fungicide applications targeting this disease can be eliminated in most orchards this season unless there is a crop to protect. See the New Jersey Commercial Tree Fruit Production Guide for more information.

Insect Update

Insect management programs for peaches and nectarines should be adjusted this season due to reduced crop load. In blocks with little to no fruit, many fruit-feeding pests will not require treatment; however, monitoring should continue, and management should focus on pests that impact tree health or future production.

Oriental Fruit Moth (OFM): A biofix point for OFM was set on 4/7 for southern counties and 4/15 in northern counties. All treatments for the second generation have passed.

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 865 1st –June 12-14

2nd – too far off

1st –June 9-12

2nd – too far off

1st –June 10-12

2nd – too far off

Middlesex – Northern 762 1st – too far off

2nd – too far off

1st – too far off

2nd – too far off

1st – too far off

2nd – too far off

Scale: Crawler emergence has been observed and will continue for the next 6 weeks (Figure 4). Control options during crawler emergence include Neonicotinoids

San Jose scale crawlers on peach branch. Photo by Dave Schmitt.

Figure 4. San Jose scale crawlers on peach branch. Photo by Dave Schmitt.

(suppression only), Sivanto, Esteem, and Centaur.

Green Peach Aphid: Activity has been low to start this season, but is increasing with warmer temperatures. Examine trees for the presence of aphids by counting the number of colonies on ten trees and using a treatment threshold of 2 colonies/tree at petal fall for peach, and 1 colony/tree for nectarine. Management options include Assail, Actara, Admire Pro, or Sivanto.

Thrips: In dry conditions flower thrips may become an issue in ripening fruit, especially in poorly managed ground covers that contain clover or other flowering weeds. Thrips damage appears as “silvering” and usually appears on fruit close to harvest. If populations are high damage can be extensive. Presence of thrips may be scouted for using a beating tray to detect the presence of adults and nymphs in the tree or by shaking flowers in weeds and shrubs in the orchard onto a beating tray or a sheet of paper. Delegate or Entrust at the highest labeled rate are the usual recommended materials for thrips in stone fruit. Lannate also has activity on thrips. These materials all have short PHI’s and may be applied close to harvest when damage typically appears. Thrips have been seen in southern counties during scouting this past week.

Plum Curculio: Injury to developing peaches and apples has been observed across the state, with high infestation rates in orchards with a history of high pest pressure (Figure 5).

Plum curculio injury on peach.

Figure 5. Plum curculio injury on peach.

Management for PC is not recommended at this time, as adults are typically not active; however, in certain orchards with historically high pressure, we have seen recent activity. If a recent injury is observed, management options include Avaunt and neonicotinoids (Actara, Belay).

Tarnished plant bugs and other catfacing insects: Activity is increasing with dry weather and summer temperatures. Very little recent fruit feeding has been observed. In most blocks with little to no fruit, treatment is not necessary.

Lesser and Greater Peach Tree Borers: Even in orchards with little fruit, borers will need to be managed to maintain healthy tree stands for the next season. If this has been a historical pest in your orchard, mating disruption is recommended. Continue monitoring and managing as usual in problem blocks with mating disruption or trunk sprays.

Traps

Average Trap Captures in Peach – Southern Counties

  Week OFM TABM LPTB PTB
5/11/2026 5 10
5/18/2026 4 20
5/25/2026 2 20 31 1

Average Trap Captures in Peach – Northern Counties

  Week OFM LPTB PTB
5/11/2026 4.4 24 0
5/18/2026 2.4 16.5 0.2
5/25/2026 0.7 8.75 0.1

Blueberries
Insect Update

Scouting activities were conducted last week across 187 commercial and organic blueberry fields in Burlington and Atlantic Counties. Field evaluations focused primarily on inspecting fruit for pest injury and monitoring aphid infestations.

Monitoring of developing fruit indicated a decrease in feeding and/or oviposition by key pests (Table 1), most likely due to recent insecticide applications. Aphid activity has increased since last week; however, colony sizes remain small, averaging 1–5 aphids per shoot (Table 2). For fields with aphid infestations above threshold, management options include Assail, Sivanto, and Movento. When applied for aphid control, these products also have activity on scale. Assail has a 1-day pre-harvest interval (PHI). Sivanto and Movento have a 7-day PHI.

Table 1. Fruit Monitoring Data

% Leafroller Berry Infestation % Plum Curculio Berry Infestation
Date Avg High Avg High
5/9 0.125 1 0.235 2.6
5/16 0.22 1.5 0.67 6.5
5/23 0.04 0.9 0.125 5.8
5/29 0.03 0.8 0.01 0.6

Table 2: Aphid Infestation on new Terminals

Aphids % Terminal Infestation
Date Avg High
5/23 1.5 A 14
5/29 2.83 A 38
Aphid Colony Size: A: 1-5, B: 6-10, C: 11-15, D: >16

 Trap Monitoring

Cranberry fruitworm and cherry fruitworm traps were checked last week, and activity declined for both species (Table 3).

Table 3. Cranberry Fruitworm/Cherry Fruitworm Trap Data

Cranberry Fruitworm (AC) Cherry Fruitworm (AC) Cranberry Fruitworm (BC) Cherry Fruitworm (BC)
Avg High Avg High Avg High Avg High
5/1 0 0 2.5 5 0 0 3.5 7
5/9 0 0 4.4 6 0 0 6.25 10
5/16 0 0 7.7 11 0 0 9 15
5/23 0.14 1 5.14 15 0.25 1 16 29
5/29 0.14 1 1 3 0 0 1.5 6
AC: Atlantic County, BC: Burlington County

Scales: Scale traps have been checked, and crawler activity is increasing in both Terrapin and Putnam traps (Table 4). If scale was observed on sorting lines last year, this would be an appropriate time to consider management options.

Table 4. Scale Traps

Putnam Terrapin
Avg High Avg High
5/23 36.85 230 1.8 8
5/29 65.17 352 21.2 41

Traps have been placed for spotted-wing drosophila, blueberry maggot, and Oriental beetle. We will provide data in next week’s Blueberry Bulletin.

Grapes
Grape Phenology

Grape development across New Jersey has progressed, with most vineyards in southern counties in bloom, depending on variety and site conditions.

Diseases

Bloom is the critical time to protect against cluster infections from Downy and Powdery Mildew; Black rot; Botrytis; and ripe rot. More information on fungicide options at bloom can be found in this blog post by Dr. Mizuho Nita at Virginia Tech. Recommended materials can be found in the New Jersey Commercial Grape Production Guide.

Insect Update

Grape berry moth (GBM): Adult GBM captures in pheromone traps has been low in southern counties indicating the first generation flight has ended. Insecticide timings will target control of later generations of grape berry moth in vineyards infesting developing fruit bunches. Concords were at trace bloom on 5/19; a Grape Berry Moth biofix was set at 5/19 for southern counties. The NEWA Grape Berry Moth model works best when growers record their own bloom dates. Applications for GBM using Intrepid or Diamides should be made at 810 DD base 47 F, which for southern counties would be the third week in June. Other effective materials can be applied a few days later. Using January 1st as a biofix, insecticide timing to target second generation will be 1200-1400 DD base 47°F. Refer to the Commercial Grape Pest Control recommendations for New Jersey.

Fruit IPM Report for Week of 5/18/2026

Temperatures early in the week were hot, with highs in the low to mid 90s °F, before cooling later in the week and into the weekend, when temperatures hung in the mid to upper 50s °F. Cooler temperatures over the weekend were accompanied by approximately 1-2 inches of rain.

At this stage, surviving fruitlets are becoming easier to identify, although some additional drop is still expected in the next month. Growers are encouraged to continue evaluating blocks carefully before making management decisions throughout the season.

Despite reduced crop potential, continued monitoring and management remain important, particularly in blocks with surviving fruit or where maintaining tree health and supporting return bloom for the 2027 season are priorities. See the recent post from Rutgers Extension Specialists and Cooperative Extension on Managing orchards with through a season with limited yields.

Apples
Disease Management Considerations

Apple Scab: Primary scab season is approaching the end, or has ended. Any established lesions from the primary scab infection period can continue to drive secondary spread if not controlled. Recent wetting events can support disease spread, but the upcoming forecast is relatively dry, which should limit additional infection risk in the short term. Growers should continue to monitor conditions and maintain coverage with Mancozeb or Captan plus a single-site fungicide, particularly where primary infections may have occurred. Keep in mind that Mancozeb has a 77-day pre-harvest interval (PHI).

Cedar apple rust: Rust is active at this time. Even if you have a low to no apple crop, apple rust and scab still need to be managed. Maintain coverage with mancozeb until the end of May.

Powdery mildew: Leaves with powdery mildew were observed this week, and the risk for infection remains active under dry conditions (Figure 1). Mancozeb is not effective. In periods of hot days with high humidity and no rain, sulfur (e.g., Microthiol Dispers at 10 lb/A) can be applied. PM needs to be managed through July. Do not tank mix captan and sulfur.

Powdery mildew developing on leaves in apple. Photo by Sophia Solewater.

Figure 1. Powdery mildew is developing on the leaves of the apple. Photo by Sophia Solewater.

Fire blight: Symptoms began appearing in southern county apple orchards the week of 5/11. Products such as Apogee or Kudos are highly recommended to help slow the spread of infections. Repeated applications may be necessary to help control shoot blight from previous blossom infections or leftover cankers in the trees. It is recommended to cut out infected limbs 6–12 inches below the margin of visible infection. Ideally, infected tissue should be removed from the orchard and burned. However, if pressed for time, prunings can be left in the row middles to dry out and subsequently chopped with a mower. Do not cut out infections during wet weather, as bacteria can spread through water.

Rots: In orchards with fruit, management moving forward will focus on summer diseases, including fruit rots like bitter rot, sooty blotch, and fly speck. Broad-spectrum fungicides captan and ziram are effective, and adding single-site products such as Merivon, Luna Sensation, Pristine, Omega, and Aprovia may improve control. The addition of phosphorous acid products such as Prophyt or Rampart to captan sprays can improve control of rots and other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present.

Marssonina Blotch, Glomerella Leaf Spot, and Frogeye Leaf Spot: These diseases should be managed, as they will cause defoliation and provide a source of inoculum for black rot and bitter rot next season.  Maintain coverage of captan, manzate, or ziram prior to rain events through the growing season according to the cover spray rule of applications every 2” of rain or 14 days, whichever comes first.

Insect Update

Insect management programs should be adjusted this season to account for reduced crop load in many orchards. In blocks with little to no fruit, many early-season insect pests will not require treatment; however, monitoring should continue, and management should be maintained where pests threaten tree health or next year’s crop.

Rosy apple aphid: Activity has been very low to start this season. RAA can feed extensively on foliage and terminals, causing leaf curling and stunting. This can impact next year’s fruit that will be set this season. Without fruit, the trees may tolerate a higher threshold of these pests, but they should still be managed. Monitor for colonies during bloom and use a treatment threshold of 1 colony/tree at petal fall.

Woolly Apple Aphid (WAA); Green Apple (Spirea) Aphids (GAA): Aphid colonies are being observed in some apple blocks (Figure 2). WAA and GAA are generally pests that can be tolerated because they cause little direct damage. Treatment thresholds for WAA and GAA are met if 50% of the shoots are infested with no beneficial insects present. Movento will control WAA and GAA and should control scale when applied in mid-May, and suppress scale when applied in late May or early June.

Figure 2b. Green apple aphid colonies on younger branches.

Figure 2a. Woolly apple aphid colonizing pruned wood.

Ambrosia Beetle: Trap captures have decreased in southern NJ, indicating peak flight has ended or is coming to an end. In northern NJ counties, trap captures have been increasing with last week’s warm temperatures. Infested trees should be showing signs of stress or will soon. If you have had a history of this pest in your orchard, you should begin scouting for damage and flag any trees that have been attacked for continued monitoring.

Codling Moth (CM): Biofix has been set for southern counties as of April 20 and in northern counties as of 5/5. In blocks with little to no crop, CM management programs can often be reduced or delayed; however, monitoring should continue. Where mating disruption has been employed or there is a reduced insecticide program, supplemental Madex applications can be made at the timings listed below if the threshold exceeds 5 moths per trap per week.

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 20 Past Past Past 5/29 past Past 6/4
Northern  May 5 Past Past Past 6/4 5/21 5/21 Too far off

Leafhoppers: Adult leafhoppers typically begin appearing in apples this time of year. They appear as small, light-green, soft-bodied insects and are often found on the new leaves at the growing tips. High densities should not be tolerated in non-bearing orchards because they can stunt the growth of new shoots. They should also not be tolerated in orchards where fire blight is present, as they have been shown to spread the disease. Neonicotinoids are generally recommended for control; however, other broad-spectrum materials are also effective. 

Dogwood borer: Monitoring traps have captured high numbers of male dogwood borer adults, particularly in orchards with a history of the pest. Mating disruption is recommended and effective for this pest. Manage as needed in blocks with a history of infestation. Assail has demonstrated activity when targeting adults to reduce egg laying. See the 2026 Integrated Orchard Management Guide for Commercial Apples in the Southeast.

Traps

Average Trap Captures in Apple – Southern Counties

  Week STLM TABM CM OFM DWB AMBROSIA BEETLE
5/11/2026 18  11  6 3   25   2
5/18/2026 16 22 3 10   54 13

 

Average Trap Captures in Apple – Northern Counties

  Week STLM TABM CM DWB AMBROSIA BEETLE
5/11/2026 13.7  1.5  1.8   12.8   1.1
5/18/2026 8.3 13.25  2.4   18.5 10.8

Pears
Disease Management

Fabraea Leaf Spot: Spots have been observed on leaves in orchards (Figure 3). Infections can result in significant leaf spotting, defoliation, and unmarketable fruit. Foliar diseases should be managed with Mancozeb or Ziram, plus a single-site fungicide, to maintain pressure and inoculum at low levels, protecting fruit and maintaining a healthy orchard going into the next season. See the New Jersey Commercial Tree Fruit Production Guide for more information.

Fabraea leaf spot on foliage in pear. Photo by Katrina DeWitt.

Figure 3. Fabraea leaf spot on foliage in pear. Photo by Katrina DeWitt.

Insect Update

Pear psylla: Second generation pear psylla adults and eggs have been observed in southern counties. Pear Psylla are still actively laying eggs, and nymphs continue to hatch. Options for control include Actara, Assail, and Belay (IRAC group 4A); Sivanto Prime (IRAC group 4D); Delegate (IRAC Group 5); and products containing abamectin (IRAC group 6). Other options include Movento (IRAC Group 23). The addition of 0.25-1 gal of summer oil may improve control. Be sure to read and follow the label instructions for adding penetrants to these products.

Plum curculio; Stink bug; Tarnished plant bug: While activity during scouting may appear low, injury is being observed and may be more pronounced in orchards where reduced crop load is present. If high amounts of injury are observed and you intend to harvest the crop, consider a well-timed application of an IRAC Group 4A (Actara, Assail, and Belay).

Peaches
Disease Management

Given the widespread crop loss in many orchards, disease management programs should be adjusted accordingly. With little to no fruit present in most blocks, emphasis should shift away from fruit protection and toward maintaining tree health and reducing inoculum for next season.

Peach scab: In orchards without a history of high disease pressure, scab is generally not a concern in the absence of fruit. In blocks with a history of scab, lesions can still develop on current-season shoots and serve as inoculum for next year. In these situations, a reduced program may be warranted, with Captan applications timed ahead of significant rainfall events.

Bacterial spot: Leaf symptoms began appearing in orchards earlier in May. Leaf infections appear water-soaked, stay within the leaf veins, and gradually darken. Eventually, the chlorotic tissue abscises from the leaf, leaving a “shot-hole”. Copper injury appears similar. The main differences are that copper injury often appears at the leaf base, where the spray collects as it runs off, and the shot-hole will cross leaf veins. Copper injury often appears red at the margins of the shot hole. Fruit injury from bacterial spot results in dark lesions that are often accompanied by gummosis. Maintain low-rate copper programs to protect foliage and reduce inoculum for future seasons. Particularly important in blocks with a history of bacterial spot or under warm, wet conditions. Avoid combining copper with captan, especially following extended cloudy or slow-drying conditions.

Rusty spot and brown rot: Not a concern in blocks with little to no fruit. Fungicide applications targeting these diseases can be eliminated in most orchards this season unless there is a crop to protect. See the New Jersey Commercial Tree Fruit Production Guide for more information.

Insect Update

Insect management programs for peaches and nectarines should be adjusted this season due to reduced crop load. In blocks with little to no fruit, many fruit-feeding pests will not require treatment; however, monitoring should continue, and management should focus on pests that impact tree health or future production.

Oriental Fruit Moth (OFM): A biofix point for OFM was set on 4/7 for southern counties and 4/15 in northern counties. All treatments for the second generation have passed. We have seen very little flagging in new leaf tissue where OFM larvae have bored into.

Scale: White peach scale and San Jose scale crawlers begin to emerge at this time and will continue to emerge for up to 6 weeks. Control options during crawler emergence include Neonicotinoids (suppression only), Sivanto, Esteem, and Centaur.

Green Peach Aphid: Activity has been low to start this season, but is increasing with warmer temperatures. Examine trees for the presence of aphids by counting 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. Management options include Assail, Actara, Admire Pro, or Sivanto.

Plum Curculio: Injury to developing peaches and apples has been observed in southern counties, with high infestation rates in orchards with a history of high pest pressure. Management for PC is not recommended at this time since adults are not currently active.

Tarnished plant bugs and other catfacing insects: Activity is increasing with dry weather and summer temperatures. Very little recent fruit feeding has been observed. In most blocks with little to no fruit, treatment is not necessary.

Lesser and Greater Peach Tree Borers: Growers using mating disruption for borer control should have them in place by mid-May. Even in orchards with little fruit, borers will need to be managed to maintain healthy tree stands for the next season. If this has been a historical pest in your orchard, mating disruption is recommended. Continue monitoring and managing as usual in problem blocks with mating disruption or trunk sprays.

Traps

Average Trap Captures in Peach – Southern Counties

  Week OFM TABM LPTB PTB
5/11/2026 5 10
5/18/2026 4 20

 

Average Trap Captures in Peach – Northern Counties

  Week OFM LPTB PTB
5/11/2026 4.4 24 0
5/18/2026 2.4 16.5 0.2

 

Blueberries
Diseases
Infected corolla tissue attached to developing fruit. Photo by Karlton Neidigh.

Figure 4. Infected corolla tissue is attached to the developing fruit. Photo by Karlton Neidigh.

During scouting activities this past week, low levels of Alternaria and Botrytis were observed on corolla tissue (Figure 4). Although disease incidence remained low, both pathogens were present in the field. Moving forward, fungicide programs should include products with activity against Anthracnose, Alternaria, and Botrytis. Anthracnose remains the primary disease concern at this time; however, given the recent weather conditions, an increase in disease development on corolla tissue still attached to the fruit would not be unexpected.

For management recommendations, refer to the Rutgers Commercial Blueberry Guide: https://njaes.rutgers.edu/pubs/publication.php?pid=e265

Insect Update

Scouting activities were conducted last week across 165 commercial and organic blueberry fields in Burlington and Atlantic Counties. Monitoring of leafrollers, spongy moth, plum curculio, and thrips shows an overall decrease in insect activity (Table 1) and corresponding injury to developing fruit (Table 2), most likely due to recent insecticide applications after petal fall.

 

Table 1. Beating Tray Sampling Data

Leafrollers Spongy Moth Plum Curculio Thrips
Avg High Avg High Avg High Avg High
4/17 0.0649 2 0.0001 0.1 0.0686 2.5 0.5547 9
4/25 0.0801 0.8 0.0001 0.1 0.1156 3 1.0383 26
5/1 0.1 0.8 0.0007 0.1 0.15 3 2.38 39
5/9 0.08 0.7 0 0 0.245 4.5 1.89 37
5/16 0.04 0.7 0.0007 0.1 0.117 3.5 5.02 99
5/23 0.006 0.3 0.0006 0.1 0.016 0.5 3.43 142

 

Table 2. Fruit Sampling Data

% Injury of Fruit by Leafroller % Injury of Fruit by Plum Curculio
Avg High Avg High
5/9 0.125 1 0.235 2.6
5/16 0.22 1.5 0.67 6.5
5/23 0.04 0.9 0.125 5.8

 

Plum Curculio: On average, scouts found 0.125 fruit with plum curculio scars per 10 bushes, with some fields reaching as high as 5.8 injured fruit per 10 bushes.

 

Aphids: Aphid activity has been detected in some scouted fields; however, colony sizes remain small, averaging 1–5 aphids per shoot (Table 3).

 

Table 3: Aphid Infestation on New Terminals

Aphids % Terminal Infestation
Avg High
5/23 1.5 14

 

Cranberry fruitworm and cherry fruitworm: Traps were checked last week. Activity was detected for cranberry fruitworm, while cherry fruitworm activity continues to increase, indicating that adults are still in flight and mating (Table 4).

 

Table 4. Fruitworm Trap Data

Cranberry  Fruitworm (AC) Cherry Fruitworm (AC) Cranberry Fruitworm (BC) Cherry Fruitworm (BC)
Avg High Avg High Avg High Avg High
5/1 0 0 2.5 5 0 0 3.5 7
5/9 0 0 4.4 6 0 0 6.25 10
5/16 0 0 7.7 11 0 0 9 15
5/23 0.14 1 5.14 15 0.25 1 16 29
AC: Atlantic County, BC: Burlington County

 

Scale insects: Traps were set to monitor Putnam scale and terrapin scale. Scales in the crawler stage are beginning to become active (Table 5).

 

Table 5. Scale Insect Trap Data

Putnam Terrapin
Avg High Avg High
5/23 36.85 230 1.8 8

Management recommendations can be found on the current Blueberry Bulletin and Commercial Blueberry Pest Control Recommendations for New Jersey.

Grapes
Grape Phenology

Grape development across New Jersey has progressed, with most vineyards in southern counties moving through to pre-bloom, depending on variety and site conditions.

Damage is most apparent in low-lying or frost-prone sites, where primary shoots may have been injured or killed. In these situations, secondary buds are beginning to push and may help compensate for some crop loss, though overall yield may still be reduced depending on the extent of primary bud injury.

At this stage, vineyards should be assessed for primary and secondary bud viability and uniformity of growth. Blocks with uneven development may require adjustments in management timing over the coming weeks.

Concord grapes were recorded in bloom on 5/19.

Diseases

The most important diseases to manage at this time are Phomopsis, black rot, downy mildew, and powdery mildew. More information on early-season disease control can be found in this blog post by Dr. Mizuho Nita at Virginia Tech. Recommended materials can be found in the New Jersey Commercial Grape Production Guide.

Insect Update

Insect pests to monitor are the grape flea beetle and the climbing cutworms. Controls for these insects are rarely needed. Spotted lanternfly nymphs are emerging in southern counties and will continue to hatch over the next few weeks. Insecticide applications are generally not recommended to control SLF nymphs. Due to the April freeze, the vines are under stress; therefore, a well-timed insecticide application to manage other key pests can knock down nymph populations.

Grape berry moth: Adults continue to be trapped in pheromone traps in vineyards where there is surrounding pressure from wild grapes. Insecticide timings will target control of later generations of grape berry moth in vineyards infesting developing fruit bunches. Using January 1st as a biofix, insecticide timing to target second generation will be 1200-1400 DD base 47°F. Use the NEWA model for grape berry moth to inform management timing for local populations, and refer to the Commercial Grape Pest Control recommendations for New Jersey.

Fruit IPM Report for Week of 5/11/2026

 

Apples
Disease Management Considerations
  • Apple scab symptoms are now appearing in some orchards as secondary infections (Figure 1).

    Early onset of scab symptoms on apple leaves. Photo by Kaitlin Quinn.

    Figure 1. Early onset of scab symptoms on apple leaves. Photo by Kaitlin Quinn.

  • Primary scab season is coming to an end or has ended.
  • Rust and powdery mildew infections are also a risk during this time.
  • These diseases need to be managed, even if you have little to no apple crop, to maintain healthy trees and keep inoculum low going into next season. A conservative spray program can focus on broad-spectrum fungicides, such as mancozeb, captan, ziram, and sulfur. Mancozeb is the only broad-spectrum product to control rust, while sulfur is the only broad-spectrum product to control powdery mildew.

    Fire blight strike in apple. Photo by Karlton Raines-Neidigh.

    Figure 2. Fire blight strike in apple. Photo by Karlton Raines-Neidigh.

  • Marssonina Blotch, Glomerella Leaf Spot, and Frogeye Leaf Spot should be managed, as they will cause defoliation and provide a source of inoculum for black rot and bitter rot next season.  Maintain coverage of captan, manzate, or ziram prior to rain events through the growing season according to the cover spray rule of applications every 2” of rain or 14 days, whichever comes first.
  • For those who have fruit on their trees, there are additional fungicide options to consider, particularly to manage bitter rot, sooty blotch & flyspeck. Products such as Merivon, Luna Sensation, Inspire Super, Omega, and Aprovia are effective and can be combined or rotated with broad-spectrum fungicides such as captan and ziram for sustained control.
  • Fire Blight:
    • Fire blight strikes are developing in orchards statewide (Figure 2).
    • Products such as Apogee or Kudos are highly recommended to help slow the spread of infections. Repeated applications may be necessary to help control shoot blight from previous blossom infections or leftover cankers in the trees.
    • If there is still some bloom, apply antibiotics when infection events are forecasted using the NEWA fire blight model.
    • Remember to rotate streptomycin and oxytetracycline products.
    • If symptoms appear, it is generally recommended to cut out infected limbs and remove them from the orchard when possible; however, this is a practical decision that must be made on a case-by-case basis.
Insect Update

Insect management programs should be adjusted this season to account for reduced crop load in many orchards. In blocks with little to no fruit, many early-season insect pests will not require treatment; however, monitoring should continue, and management should be maintained where pests threaten tree health or next year’s crop.

  • Rosy apple aphid activity has been very low to start this season. RAA can feed extensively on foliage and terminals, causing leaf curling and stunting. This can impact next year’s fruit that will be set this season. Without fruit, the trees may tolerate a higher threshold of these pests, but they should still be managed.
    • Monitor for colonies during bloom and use a treatment threshold of 1 colony/tree at petal fall.
  • Green Apple (Spirea) Aphids (GAA) colonies are being observed in some apple blocks. GAA is generally a pest that can be tolerated because it causes little direct damage.
    • Treatment thresholds for GAA are met if 50% of the shoots are infested with no beneficial insects present.
    • Movento will control GAA and should control scale when applied in mid-May, and suppress scale when applied in late May or early June.
  • Ambrosia Beetle
    • Trap captures have decreased across NJ, indicating peak flight has ended or is coming to an end.
    • Infested trees should be showing signs of stress or will soon.
    • If you have had a history of this pest in your orchard, you should begin scouting for damage and flag any trees that have been attacked for continued monitoring.
  • Codling Moth (CM)
    • A codling moth biofix was set in Southern counties on 4/20 and in Northern counties on 5/5. 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 + 7-10 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 20 Past Past Past 6/1 5/18 5/18 Too far off
      Northern  May 5 5/12 5/14 5/17 Too far off 5/21 5/21 Too far off
  • Plum curculio, tarnished plant bug, stink bugs, BMSB, TABM, and OBLR:
    • In most blocks, treatment is not necessary where little to no fruit is present
    • The timing to treat plum curculio has passed.
  • Mites:
    • Continue to use standard thresholds through June
    • Maintaining healthy foliage is important for return bloom next season
Traps

Average Trap Captures in Apple – Southern Counties

  Week STLM TABM CM OFM DWB AMBROSIA BEETLE
5/11/2026 18  11  6 3   25   2

 

Average Trap Captures in Apple – Northern Counties

  Week STLM TABM CM DWB AMBROSIA BEETLE
5/11/2026 13.7  1.5  1.8   12.8   1.1

Pears
Disease Management
  • Fire blight remains a concern during warm and wet periods. Continue to protect actively growing shoots, particularly during warm, wet, or stormy conditions. In high-risk situations, oxytetracycline (e.g., Mycoshield, FireLine) may be used post-bloom to suppress shoot blight.
  • Maintain protectant fungicides (e.g., Mancozeb, Ziram) to control rust, scab, and Fabraea leaf spot, protecting foliage.
    • Use FRAC 3 and 7, and premix fungicides (e.g., Inspire Super, Merivon, Luna products) as needed for foliar disease control.
    • In blocks with little to no fruit, fungicide programs can often be reduced and focused on maintaining healthy foliage rather than fruit protection.
Insect Update
  • Second generation pear psylla adults and eggs have been observed in southern counties. Options for control include Actara, Assail, and Belay (IRAC group 4A); Sivanto Prime (IRAC group 4D); Delegate (IRAC Group 5); and products containing abamectin (IRAC group 6). Other options include Movento (IRAC Group 23). The addition of 0.25-1 gal of summer oil may improve control. Be sure to read and follow the label instructions for adding penetrants to these products.

Peaches
Disease Management

Given the widespread crop loss in many orchards, disease management programs should be adjusted accordingly. With little to no fruit present in most blocks, emphasis should

Bacterial leaf spot on peach

Figure 3. Bacterial leaf spot on peach

shift away from fruit protection and toward maintaining tree health and reducing inoculum for next season.

  • Peach scab:
    • In orchards without a history of high disease pressure, scab is generally not a concern in the absence of fruit
    • In blocks with a history of scab, lesions can still develop on current-season shoots and serve as inoculum for next year
    • In these situations, a reduced program may be warranted, with Captan applications timed ahead of significant rainfall events (e.g., ~2.5 lb/A)
  • Bacterial spot:
    • Leaf symptoms are showing in orchards (Figure 3).
    • Maintain low-rate copper programs to protect foliage and reduce inoculum for future seasons
    • Particularly important in blocks with a history of bacterial spot or under warm, wet conditions
    • Avoid combining copper with captan, especially following extended cloudy or slow-drying conditions
  • Rusty spot and brown rot:
    • Not a concern in blocks with little to no fruit
    • Fungicide applications targeting these diseases can be eliminated in most orchards this season unless there is a crop to protect.
Insect Update

Insect management programs for peaches and nectarines should be adjusted this season due to reduced crop load. In blocks with little to no fruit, many fruit-feeding pests will not require treatment; however, monitoring should continue, and management should focus on pests that impact tree health or future production.

Terminal flagging due to Oriental fruit moth.

Figure 4. Terminal flagging due to Oriental fruit moth.

Oriental Fruit Moth (OFM)

    • A biofix point for OFM was set on 4/7 for southern counties and 4/15 in northern counties.
    • The second insecticide timings for the first generation Oriental Fruit Moth have passed.
    • No insecticides are needed for OFM when mating disruption is implemented.
    • We have seen very few flagging in new leaf tissue where OFM larvae have bored into (Figure 4).
    OFM 1st Generation Timing
    Insecticide Type
    County/Region Degree Days by 5/18 base 45 Conventional

    170-200, 350-375

    Diamide

    100-150, 300-350

    Gloucester – Southern 556 1st –past

    2nd – past

    1st –past

    2nd –past

    Middlesex – Northern 456 1st –past

    2nd –5/13-5/15

     1st – past

    2nd –5/10-5/13

Scale

  • Beneficial insects may help suppress populations in many blocks
  • In orchards with a history of infestation, plan to target the crawler stage starting the third week of May and continue emergence until about the middle of June
  • Control options include materials such as Esteem or Centaur
  • Where scale is a recurring problem, Movento should be applied between petal fall and shuck split. A penetrant must be included with Movento as per the product label. Applications should be made at optimal temperature conditions. Movento will also control green peach aphid when used at this time.
  • Continue monitoring historically infested blocks and plan crawler management for later in the season if populations persist.

Green Peach Aphid

Plum Curculio

  • Injury to fruit has been observed on developing peaches and apples in southern counties.
  • Management in NJ typically requires weekly sprays for 3-4 weeks, beginning at petal-fall and continuing through approximately 300 DD50 after petal-fall.
  • Materials that cover PC and other key pests encountered at this time include Asana, Avaunt, Imidan, and Voliam Flexi.

Tarnished plant bugs and other catfacing insects

  • Activity has been low and is considered a low priority for management, where fruit is not present. If you plan to retain a crop, you must continue to manage insect pests intensively as you would in a normal season.

Lesser and Greater Peach Tree Borers

  • Growers using mating disruption for borer control should have them in place by mid-May.
  • Even in orchards with little fruit, borers will need to be managed to maintain healthy tree stands for the next season. If this has been a historical pest in your orchard, mating disruption is recommended.
  • Continue monitoring and managing as usual in problem blocks
Traps

Average Trap Captures in Peach – Southern Counties

  Week OFM TABM LPTB PTB
5/11/2026 5 10

 

Average Trap Captures in Peach – Northern Counties

  Week OFM LPTB PTB
5/11/2026 4.4 24 0

Blueberries
Blueberry Phenology

Early varieties are in the green fruit stage – the flowers have been pollinated, the petals are off, and the tiny green fruit are expanding.

Insect Update

Scouting activities were conducted last week across 139 commercial blueberry fields in Burlington and Atlantic Counties. Field evaluations focused on monitoring pest activity and crop development, including assessments of leafrollers, spongy moth, plum curculio, and thrips using beating tray samples, as well as fruit inspections for pest injury and developmental progress. All target pests were detected during scouting activities (Table 1).

Plum curculio numbers of adults on bushes has decreased over the past week, but some adults are still present. The average count was 0.117 per bush with a high of 3.5 adults per bush.

Thrips numbers increased from previous weeks. The main concern comes from the potential for thrips injury to flowers and developing fruit. After bloom, thrips can feed on young blueberry foliage causing curling of leaves; however, the risk of injury to developing leaves and fruit from thrips is low at this point.

In addition, monitoring of developing fruit indicated increasing feeding and/or oviposition activity by these pests (Table 2).

Table 1. Beating Tray Sampling Data

Leafrollers Spongy Moth Plum Curculio Thrips
Avg High Avg High Avg High Avg High
4/17 0.0649 2 0.0001 0.1 0.0686 2.5 0.5547 9
4/25 0.0801 0.8 0.0001 0.1 0.1156 3 1.0383 26
5/1 0.1 0.8 0.0007 0.1 0.15 3 2.38 39
5/9 0.08 0.7 0 0 0.245 4.5 1.89 37
5/16 0.04 0.7 0.0007 0.1 0.117 3.5 5.02 99

Table 2. Fruit Sampling Data

% Leafroller Berry Infestation % Plum Curculio Berry Infestation
Avg High Avg High
5/9 0.125 1 0.235 2.6
5/16 0.22 1.5 0.67 6.5

Trap Monitoring

Scale traps targeting Putnam and terrapin scale were monitored last week and captured very low numbers; therefore, no treatment is recommended at this time.

Cranberry and cherry fruitworm traps were also checked last week. No cranberry fruitworm activity was detected; however, captures of cherry fruitworm increased, indicating that adults are actively flying and mating (Table 3).

Table 3. Trap Sampling Data

Cranberry  Fruitworm (AC) Cherry Fruitworm (AC) Cranberry Fruitworm (BC) Cherry Fruitworm (BC)
Avg High Avg High Avg High Avg High
5/1 0 0 2.5 5 0 0 3.5 7
5/9 0 0 4.4 6 0 0 6.25 10
5/16 0 0 7.7 11 0 0 9 15
AC: Atlantic County, BC: Burlington County

Management recommendations can be found on the current Blueberry Bulletin and Commercial Blueberry Pest Control Recommendations for New Jersey.

Grapes
Grape Phenology

Grape development across New Jersey has progressed, with most vineyards in southern counties moving through to pre-bloom. In many areas, shoots are now between 1–6 inches, depending on variety and site conditions.

Damage is most apparent in low-lying or frost-prone sites, where primary shoots may have been injured or killed. In these situations, secondary buds are beginning to push (Figure 5) and may help compensate for some crop loss, though overall yield may still be reduced depending on the extent of primary bud injury.

At this stage, vineyards should be assessed for primary and secondary bud viability and uniformity of growth. Blocks with uneven development may require adjustments in management timing over the coming weeks.

Grapevines with secondary bud break.

Figure 5. Grapevines with secondary bud break.

Diseases
  • The most important diseases to manage at this time are Phomopsis, black rot, and powdery mildew.
  • More information on early-season disease control can be found in this blog post by Dr. Mizuho Nita at Virginia Tech.
Insect Update
  • Insect pests to monitor are the grape flea beetle and the climbing cutworms. Controls for these insects are rarely needed.
  • Spotted lanternfly nymphs are emerging in southern counties and will continue to hatch over the next few weeks (Figure 6).
    • Insecticide applications are generally not recommended to control SLF nymphs. Due to the April freeze, the vines are under stress; therefore, a well-timed insecticide application to manage other key pests can knock down nymph populations.

      Spotted lanternfly nymphs on grapevines.

      Figure 6. Spotted lanternfly nymphs on grapevines.

  • Grape berry moth adults continue to be trapped in pheromone traps in vineyards where there is surrounding pressure from wild grapes.

April 2026 Frost Damage in Fruit Crops Survey

We invite you to participate in a brief survey to better understand how April frost events have affected crop production, economic impact, and how growers are managing this risk. The information collected will help us assess the overall severity of the frost and compile broad, aggregated data to effectively communicate its impact to legislative offices and Farm Service Agency, and others.  Your input will help also inform research and Extension programs to support fruit growers in New Jersey better.

Please note that your responses are strictly confidential and will only be reported in aggregate. You should be 18 years or older and involved in fruit production to respond to this survey. Approximate time – 10-12 min.

Ready to start? Please click the link below:

https://rutgers.ca1.qualtrics.com/jfe/form/SV_6zliIMszIABIRjU

If you have any questions or concerns, please contact Seowoo Sophie Lee (seowoo.lee@rutgers.edu) or Hemant Gohil gohil@njaes.rutgers.edu

Thank you for your valuable time.

Sincerely,

This document was approved by the Rutgers University Institutional Review Board for the Protection of Human Subjects on May 13, 2026.

NJDA Survey for 250+ Year Old NJ Farms

The New Jersey Department of Agriculture needs your help! The Department is gathering information on New Jersey farms that are 250 years old or older, as USDA and NASDA are recognizing farms marking 250+ years as part of the national Freedom250 celebration.

If your farm or a farm you know qualifies, please complete NJDA’s short form by clicking here — the submission deadline is this coming Monday, 5/18.

Fruit IPM Report 5/11/2026

 

Apples

Disease Management Considerations

Primary scab season is coming to an end or has ended. While the majority of mature ascospores have been released, there is still a risk of infection. An apple scab infection period occurred over the weekend (5/9-5/11), and currently the forecast indicates an apple scab infection period for May 13-14. Rust infection is also a risk during this time. These diseases need to be managed even if you have little to no apple crop in order to maintain healthy trees and keep inoculum low going into next season. A conservative spray program can focus on broad-spectrum fungicides, such as mancozeb, captan, ziram, and sulfur. Mancozeb is the only broad-spectrum product to control rust, while sulfur is the only broad-spectrum product to control powdery mildew.

Marssonina Blotch, Glomerella Leaf Spot, and Frogeye Leaf Spot (Figure 1) should be managed as these diseases will cause defoliation and provide a source of inoculum for black rot and bitter rot next season. Maintain coverage of captan, manzate, or ziram prior to rain events through the growing season according to the cover spray rule of applications every 2” of rain or 14 days, whichever comes first.

Frogeye leaf spot on apple.


Figure 1. Frogeye leaf spot on apple.

For those who have fruit on their trees, there are additional fungicide options to consider, particularly to manage bitter rot, sooty blotch & flyspeck. Products such as Merivon, Luna Sensation, Inspire Super, Omega, and Aprovia are effective and can be combined or rotated with broad-spectrum fungicides such as captan and ziram for sustained control.

Fireblight
Infections can still occur post bloom. Products such as Apogee or Kudos, combined with plant defense inducers such as Actigard, should be used to manage shoot blight. If there is still some bloom, apply antibiotics when infection events are forecasted using the NEWA fire blight model. A potential infection period is predicted for May 13-14. Remember to rotate streptomycin and oxytetracycline products. If symptoms appear, it is generally recommended to cut out infected limbs and remove them from the orchard when possible; however, this is a practical decision that must be made on a case-by-case basis. Applications of Prohexadione calcium (Kudos or Apogee) are highly recommended to help slow infections. Repeated applications may be necessary to help control shoot blight from previous blossom infections or leftover cankers in the trees.

Insect Update

Codling Moth: A Codling Moth Biofix was set in Southern counties on 4/20 and in Northern counties on 5/5. 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 20 Past Past 5/9 Too far off 5/19 5/19 Too far off
Northern  May 5 5/12 5/14 5/19 Too far off Too far off Too far off Too far off

Rosy Apple Aphid: Aphid activity has been very low to start this season. RAA can feed extensively on foliage and terminals, causing leaf curling and stunting. This can impact next year’s fruit that will be set this season. Without fruit, the trees may tolerate a higher threshold of these pests, but they should still be managed. Monitor for colonies during bloom and use a treatment threshold of 1 colony/tree at petal fall.

Green Apple (Spirea) Aphids (GAA): GAA colonies are being observed in some apple blocks. GAA is generally a pest that can be tolerated because it causes little direct damage. Treatment thresholds for GAA are met if 50% of the shoots are infested with no beneficial insects present. Movento will also control GAA and should control scale when applied in mid-May, and suppress scale when applied in late May or early June.

Ambrosia Beetle: Trap captures have decreased from previous weeks in South Jersey, indicating peak flight has ended. However, in some of the northernmost New Jersey counties, trap captures are increasing, which indicates we are entering peak flight. 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 the eggs to hatch and the adults to 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 flag any trees that have been attacked for continued monitoring.

Pears
Pear Diseases

Although the primary bloom infection period is largely over, fire blight remains a concern during warm, wet periods. Continue to protect actively growing shoots, particularly during warm, wet, or stormy conditions. In high-risk situations, oxytetracycline (e.g., Mycoshield, FireLine) may be used post-bloom to suppress shoot blight. Maintain protectant fungicides (e.g., Mancozeb, Ziram) to control rust, scab, and Fabraea leaf spot, protecting foliage. Use FRAC 3 and 7, and premix fungicides (e.g., Inspire Super, Merivon, Luna products) as needed for foliar disease control. In blocks with little to no fruit, fungicide programs can often be reduced and focused on maintaining healthy foliage rather than fruit protection.

Pear Psylla

Second-generation pear psylla adults and eggs have been observed in southern counties. Options for control include Actara, Assail, and Belay (IRAC group 4A); Sivanto Prime (IRAC group 4D); Delegate (IRAC Group 5); and products containing abamectin (IRAC group 6). Other options include Movento (IRAC Group 23). The addition of 0.25-1 gal of summer oil may improve control. Be sure to read and follow the label instructions for adding penetrants to these products.

Peaches
Peach Diseases

Given the widespread crop loss in many orchards, disease management programs should be adjusted accordingly. With little to no fruit present in most blocks, emphasis should shift away from fruit protection and toward maintaining tree health and reducing inoculum for next season.

  • Peach scab:
    • In orchards without a history of high disease pressure, scab is generally not a concern in the absence of fruit
    • In blocks with a history of scab, lesions can still develop on current-season shoots and serve as inoculum for next year
    • In these situations, a reduced program may be warranted, with Captan applications timed ahead of significant rainfall events (e.g., ~2.5 lb/A)
  • Bacterial spot:
    • Maintain low-rate copper programs to protect foliage and reduce inoculum for future seasons
    • Particularly important in blocks with a history of bacterial spot or under warm, wet conditions
    • Avoid combining copper with captan, especially following extended cloudy or slow-drying conditions
    • Antibiotics containing oxytetracycline may also be used and may offer more residual activity during long wetting periods.

      Bacterial leaf spot on peach.

      Figure 2. Bacterial leaf spot on peach.

    • We have observed bacterial leaf spot symptoms in the field starting in early May (Figure 2).
  • Rusty spot and brown rot:
    • Not a concern in blocks with little to no fruit
    • Fungicide applications targeting these diseases can be eliminated in most orchards this season.

 

 

Insect Update

Insect management programs for peaches and nectarines should be adjusted this season due to reduced crop load. In blocks with little to no fruit, many fruit-feeding pests will not require treatment; however, monitoring should continue, and management should focus on pests that impact tree health or future production.

Oriental Fruit Moth (OFM)

A biofix point for OFM was set on 4/7 for southern counties and 4/15 in northern counties. The second insecticide timings for first generation Oriental Fruit Moth control fall at 350-375 degree days base 45 after biofix. No Insecticides for OFM are needed where mating disruption is implemented.

OFM 1st Generation Timing
Insecticide Type
County/Region Degree Days by 5/10 base 45 Conventional

170-200, 350-375

Diamide

100-150, 300-350

Gloucester – Southern 434 1st –past

2nd – past

1st –past

2nd –past

Middlesex – Northern 325 1st –past

2nd –5/12-514

 1st – past

2nd –5/9-5/12

Green Peach Aphid: Aphid activity has been very low to start this season. GPA colonies usually begin forming sometime during bloom. Examine trees for the presence of aphids by counting 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. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Aphid colonies curling leaves was noted in southern counties starting the week of 5/4.

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: Injury on fruit from plum curculio has been observed on developing peaches and apples in southern counties (Figure 3). 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 508 DD base 50, and northern counties have accumulated 457 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. Tarnished plant bug and catfacing insect activity has been low and is considered a low priority for management where fruit is not present. If you are planning to retain a crop, you must continue to intensively manage insect pests as you would in a normal season.

Plum curculio feeding in apple fruitlets.

Figure 3. Plum curculio feeding in apple fruitlets.

Scale Insects: White peach scale crawlers have not yet emerged, but usually begin emergence about the third week of May and 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 Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide and the product labels for more information.

Lesser and Greater Peach Tree Borers: Growers using mating disruption for borer control can begin placing dispensers around the end of April and should have them in place by mid-May.

 

 

Blueberries
Insect Update

Scouting activities were conducted across 139 fields in Burlington and Atlantic Counties. Field evaluations focused on the presence of leafrollers, spongy moths, plum curculio, and thrips. Insect activity remains low in beating tray samples and observations on developing fruit of feeding and oviposition injury.

Table 1. Beating Tray Data

Leafrollers Spongy Moth Plum Curculio Thrips
Avg High Avg High Avg High Avg High
4/17 0.0649 2 0.0001 0.1 0.0686 2.5 0.5547 9
4/25 0.0801 0.8 0.0001 0.1 0.1156 3 1.0383 26
5/1 0.1 0.8 0.0007 0.1 0.15 3 2.38 39
5/9 0.08 0.7 0 0 0.245 4.5 1.89 37

 

Table 2. Fruit Monitoring Data

% Leafroller Berry Infestation % Plum Curculio Berry Infestation
Avg High Avg High
5/9 0.125 1 0.235 2.6

 

Trap Monitoring: Cranberry and cherry fruitworm traps were deployed and will be monitored on a weekly basis.

Cherry fruitworm activity is increasing, indicating that adults are in flight and mating (Table 3).

Table 3. Trap Data

Cranberry Fruitworm

(AC)

Cherry Fruitworm (AC) Cranberry Fruitworm (BC) Cherry Fruitworm (BC)
Avg High Avg High Avg High Avg High
5/1 0 0 2.5 5 0 0 3.5 7
5/9 0 0 4.4 6 0 0 6.25 10
AC: Atlantic County, BC: Burlington County

 

Scale traps targeting Putnam and terrapin scale will be set up in the coming week to monitor for first-generation crawler emergence and to assist in optimizing treatment timing.

Grapes
Diseases

We are prebloom in vineyards in southern counties. The most important diseases to manage at this time are Phomopsis and Powdery Mildew. Starting at 3″ growth start managing for Black Rot. More information about early-season disease control can be found in this blog post from Virginia Tech.

Insect Update

We are catching the first generation of grape berry moth in pheromone traps in vineyards; however, a biofix will not be set until early native varieties are at trace bloom. Insecticide timings will target control of later generations of grape berry moth in vineyards infesting developing fruit bunches. Spotted lanternfly nymphs have been observed in southern NJ vineyards (Figure 4). There is no need to control SLF at this time.

Spotted lanternfly nymphs on grapevines.

Figure 4. Spotted lanternfly nymphs on grapevines.