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.

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.

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.

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

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).

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.












