May 4, 2026 , , and

Fruit IPM Updates Week of 4/27/2026

Tree Fruit Phenology Update

Tree fruit development across New Jersey continued to progress over the past week, and the impacts of the recent freeze event are now becoming more clearly defined. Across much of the state, significant injury to blossoms and young fruit has been confirmed, with many orchards reporting substantial crop loss. The extent of damage remains highly variable by location, elevation, variety, and phenological stage at the time of the freeze, with the most severe injury observed in low-lying areas and blocks that were at full bloom or petal fall.

At this stage, surviving fruitlets are becoming easier to identify, although some additional drop is still expected over the coming week. Growers are encouraged to continue evaluating blocks carefully before making final management decisions, as crop potential may continue to change.

In apples, early varieties such as ‘Pink Lady’ sustained significant injury in many locations. However, some later-developing blooms appear to have escaped the freeze, and limited fruit set is being observed from these later flowers. While this provides some promise in select blocks, overall yield potential remains extremely low across most orchards. Variability remains high even within individual blocks.

In pears, most varieties across the state were at or just past bloom during the freeze, and widespread crop loss has now been confirmed. In many orchards, little to no viable fruit remains, though isolated pockets of surviving fruit may still be present depending on site conditions.

Peach and nectarine varieties in southern counties, which were at petal fall to early shuck split during the freeze, experienced extensive crop loss in many orchards. In northern counties, where bloom was still ongoing at the time of the freeze, damage remains variable but is often substantial in more exposed locations.

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.

Apples
Apple Phenology Update

Apple phenology continued to progress across New Jersey over the past week, with most blocks now moving through bloom into petal fall. The impacts of the recent freeze event are now becoming more apparent, with significant injury observed in many orchards statewide. Early varieties in southern counties, such as ‘Pink Lady,’ sustained substantial damage where they were at full bloom during the freeze.

Later varieties and more northern regions show variable levels of injury depending on bloom stage and site conditions. In some blocks, later-developing blooms appear to have escaped damage and are setting limited fruit. Surviving fruitlets are becoming easier to identify, although some additional drop may still occur over the coming week.

As development continues into petal fall and early fruit set, this remains a critical period for disease management, particularly for fire blight, apple scab, powdery mildew, and cedar apple rust. Even in blocks with reduced crop, maintaining protection of foliage and any surviving fruit is essential for overall tree health and to support return bloom next season. Monitoring for early-season insect pests should also continue, with management decisions adjusted based on crop presence and block-specific conditions.

Phenology Dates by County (earliest varieties)

County Green Tip Tight Cluster Pink Bud Bloom Petal Fall
Cumberland 3/22 3/28 4/3 4/8 4/17
Gloucester 3/22 3/28 4/3 4/8 4/17
Burlington 3/22 3/28 4/2 4/13 4/22
Mercer 3/22 3/28 4/2 4/13 4/22
Middlesex 3/22 4/1 4/4 4/14 4/22
Monmouth 3/22 4/1 4/4 4/14 4/22
Hunterdon 3/22 4/1 4/10 4/17 4/24
Morris 3/26 4/4 4/11 4/17 4/24
Warren 3/30 4/4 4/13 4/17 4/24
Sussex 3/31 4/10 4/14 4/18 4/24
Bergen 3/22 4/1 4/4 4/14 4/24
Apple Scab
Apple scab season is approaching the end of primary ascospore release, with most ascospores now matured and a large proportion already discharged. We are transitioning out of peak primary infection risk; however, recent infection events and any established lesions can continue to drive secondary spread if not controlled.Recent wetting events earlier this week resulted in infection periods, but the upcoming forecast is relatively dry, which should limit additional infection risk in the short term. Growers should continue to monitor conditions closely and maintain coverage, particularly where primary infections may have already occurred. Models are available through NEWA and RIMpro
Current Update using the Upper Deerfield Station
  • ~91–94% ascospore maturity as of April 29–May 1
  • ~62–63% cumulative ascospore discharge to date
  • Forecasted to reach ~95–98% maturity by May 2–6
  • Cumulative ascospore discharge forecasted to increase to ~73% by May 2–6
  • Infection events occurred April 29–30 under sufficient wetting and favorable temperatures
  • Limited infection risk is forecast over the next several days due to dry conditions

While primary scab season is nearing completion, remaining ascospores and recent infection events mean that protection should be maintained until discharge is complete and orchards are scouted for lesions.

Management Considerations

Fungicide programs should be maintained through petal fall and early fruit set, particularly in blocks where infection events occurred this week. However, as primary scab season nears completion and ascospore maturity approaches full discharge, growers should begin planning to wind down intensive scab programs.

One additional well-timed fungicide application over the next week may be sufficient to protect against any remaining ascospore release and recent infection events. Following this, programs can be adjusted based on scouting and the presence or absence of lesions.

Despite widespread freeze injury, protecting foliage remains critical for tree health and return bloom. Programs should continue to prioritize apple scab until primary season is complete, along with powdery mildew and cedar apple rust. Fire blight protection should continue where bloom or trauma blight risk remains.

Recommended Programs

  • Final primary scab spray (next 5–7 days):
    • Mancozeb or Captan + single-site fungicide (use reduced rate when tank mixing)
    • Time this application ahead of any remaining wetting events to protect against final ascospore discharge
  • Primary scab season is nearing completion — begin transitioning out of intensive spray programs
  • One final fungicide application over the next week should be sufficient in most blocks to cover remaining ascospore discharge
  • Recent infection events occurred April 29–30 — ensure coverage was adequate and consider follow-up where needed
  • After this final application, shift to scouting for primary lesions and adjust programs accordingly
  • Do not fully relax programs where foliage health is still a priority, especially in blocks with any remaining crop
  • Powdery mildew remains active under dry conditions
  • Do not tank mix Captan with oil due to phytotoxicity risk

Fireblight

Models

Fire blight risk remains present as we move through the end of bloom and into early post-bloom, particularly in blocks with open blossoms or where freeze injury may have created additional infection sites. Recent conditions included wetting events on April 29–30; however, risk has been relatively low over the past few days.

Forecasts indicate increasing risk heading into early next week, with Cougarblight values rising and infection potential (EIP) expected to increase by May 5–6 under warmer conditions. These conditions may support infection if bloom remains or if trauma events occur.

Given the current outlook, one to two additional bactericide applications may be warranted, particularly in blocks with a history of fire blight, open bloom, or high-value varieties. Applications should be timed ahead of forecasted rain events where possible.

Management Considerations

  • Consider 1–2 additional sprays.
    • Particularly important in blocks with open bloom, recent freeze injury, or known fire blight history
    • Time applications ahead of forecasted wetting events
  • Rotate bactericides.
    • Streptomycin, Kasugamycin, and Oxytetracycline should be rotated to reduce resistance risk
    • Kasumin is labeled through bloom/petal fall only
    • Streptomycin and oxytetracycline may be used post-bloom (FireLine 45 allows only one post-bloom application)
  • Monitor models closely.
    • Use Cougarblight and EIP tools to guide timing
    • Enter your last streptomycin application date to improve model accuracy
  • Be aware of trauma blight risk.
    • Freeze injury, wind, or hail can create entry points for infection even after bloom
  • Plan for aggressive sanitation this season.
    • With reduced crop in many blocks, this is an ideal year to focus on removing infected wood
    • Prune out blighted shoots and cankers during dry conditions to reduce inoculum for future seasons

Monitor:

    • NEWA models
    • Weather/wetting events
    • Phenology
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 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.

  • Ambrosia Beetle
    • No new significant flight activity has been observed in recent days
    • Peak flight period appears to have passed, though low-level activity may still occur
    • Continue monitoring traps, particularly in stressed, freeze-damaged, declining, or newly planted blocks
    • Freeze-injured trees may remain attractive, so risk is not fully eliminated
    • No additional insecticide applications are needed in most blocks at this time unless activity resumes or trees are under stress
  • Codling Moth (CM)
    • Biofix has been set for southern New Jersey as of April 20, 2026
    • In blocks with little to no crop, CM management programs can often be reduced or delayed, as the risk of economic injury is low; however, monitoring should continue.
    • Mating disruption should remain in place where already deployed; do not remove dispensers, as they will continue to suppress populations
    • 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 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 5/4 5/5 5/11 Too far off Too far off Too far off Too far off
Northern  NA NA NA NA NA NA NA NA
  • Other Apple Insects
    • In blocks with little to no crop, many early-season fruit-feeding insects will not require treatment at this time. Continue monitoring, and focus management on pests that impact tree health, terminal growth, or future crop potential.
  • 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
  • Mites:
    • Continue to use standard thresholds through June
    • Maintaining healthy foliage is important for return bloom next season
  •  Rosy apple aphid:
    • Manage only in cases of severe infestation to avoid excessive leaf curling and shoot distortion
  • Dogwood borer:
    • Manage as needed in blocks with a history of infestation
Summary
  • The recent freeze has resulted in widespread blossom and fruit loss across many orchards, with damage now becoming more clearly defined at the block level
  • Some late-developing apple blooms have escaped injury and are setting limited fruit
  • Apple scab season is nearing completion, with most ascospores matured and a large portion already discharged; one final well-timed fungicide application should be sufficient in most blocks
  • Fire blight risk remains in blocks with open bloom or recent injury; 1–2 additional bactericide applications may be warranted based on model predictions and weather conditions
  • Insect management programs can be reduced in many blocks due to low crop, but monitoring should continue and management maintained for pests that impact tree health
  • Maintaining healthy foliage and overall tree vigor remains critical to support return bloom and production for the 2027 season

Pears
Pear Phenology Update

Pear development continued to progress across New Jersey over the past week, and the impacts of the recent freeze event are now becoming more clearly defined. Significant injury to blossoms and young fruit has been confirmed across much of the state, with many orchards reporting substantial crop loss.

Most European pear varieties were at full bloom to early petal fall during the freeze and have sustained widespread damage, particularly in low-lying or frost-prone areas. In many blocks, little to no viable fruit remains, though isolated pockets of surviving fruit may still be present depending on site conditions.

Asian pear varieties, which were generally more advanced at the time of the freeze, appear to have experienced even greater levels of injury in some locations. In northern counties, where bloom was still ongoing, damage remains variable but is often still substantial in exposed sites.

At this stage, surviving fruitlets are becoming easier to identify (Figure 2), although some additional drop may still occur over the coming week. Growers should continue to assess blocks carefully before making final management decisions.

Pear fruitlets cut to assess freeze injury—internal tissue appears viable; however, additional drop may occur. Salem County, NJ.

Figure 1. Pear fruitlets cut to assess freeze injury—internal tissue appears viable; however, additional drop may occur. Salem County, NJ.

Despite reduced crop potential, maintaining disease management and overall tree health remains important, particularly to support return bloom and long-term productivity.

Pear Psylla
  • Pear psylla activity remains low across much of southern New Jersey, with limited observations to date
  • Some variability exists by block, though overall pressure remains light at this time
  • Freeze-damaged orchards may be more susceptible to colonization as stressed trees can favor psylla buildup

Regional Observations:

  • Gloucester County: None observed
  • Salem County: Newly emerged Adults observed
  • Burlington County: No activity observed to date
  • Mercer County: No activity observed to date

As orchards move through petal fall and temperatures warm, psylla populations may increase gradually, particularly in blocks where adults are present. However, given the widespread crop loss this season, economic risk is reduced in many orchards.

Management Considerations

  • In most blocks, immediate treatment is not necessary at this time
  • Continue monitoring for adults, eggs, and early nymphs, especially in historically infested blocks
  • Where management is needed, target newly hatched nymphs, which are the most susceptible stage
  • Focus treatments on blocks with high historical pressure, active populations, or significant freeze stress
  • Even with little to no crop, psylla should be managed where populations build to levels that may impact tree health, vigor, or lead to honeydew and sooty mold accumulation

Recommended Options

  • Movento (IRAC 23) – excellent systemic control of psylla, scale, and aphids (apply with a spreading/penetrating adjuvant for best performance)
  • Actara, Assail, Belay (IRAC 4A) – effective options for psylla control
  • Centaur (IRAC 16) – targets immature stages
  • Sivanto Prime (IRAC 4D) – effective, softer option with good activity
  • Agri-Mek (IRAC 6) – strong option when applied with oil/adjuvant, especially for nymph control

With little to no fruit in many blocks, psylla management should be highly targeted rather than routine. Focus on monitoring and only treat where populations threaten tree health or where there is a history of significant infestation.

Pear Diseases
Fire Blight and Early Season Management

As pear orchards move through petal fall and into early post-bloom, the primary bloom infection period is largely complete. However, fire blight remains a concern, particularly in blocks with freeze injury, where damaged tissue and rapid regrowth increase susceptibility.

The recent freeze has created additional risk for trauma blight, as injured blossoms and developing shoots provide entry points for infection during periods of warm temperatures, wind, or rain. At the same time, widespread crop loss reduces the need for fruit-focused disease programs, shifting management emphasis toward protecting tree health and controlling shoot blight.

At Petal Fall and Post-Bloom:

  • Continue monitoring forecasts using NEWA for fire blight risk, especially following storms or warm periods
  • Discontinue streptomycin after petal fall (not labeled beyond this stage)
  • Kasumin may be used up to petal fall only; do not apply afterward
  • Focus on protecting actively growing shoots, particularly during warm, wet, or stormy conditions
  • In high-risk situations, oxytetracycline (e.g., Mycoshield, FireLine) may be used post-bloom for shoot blight suppression

Management Considerations:

  • Monitor closely for trauma events (hail, wind, heavy rain), which can trigger shoot blight infections
  • Maintain heightened awareness in blocks with a history of fire blight or significant freeze injury
  • Rapid shoot growth under warm conditions increases susceptibility—vigorous orchards are at higher risk
  • With little to no crop in many blocks, focus management on tree health and reducing inoculum for future seasons

Fungicide Considerations (Post-Bloom)

  • Maintain protectant fungicides (e.g., Mancozeb, Ziram) for pear scab and Fabraea leaf spot to protect foliage
  • Use FRAC 3, 7, and premix fungicides (e.g., Inspire Super, Merivon, Luna products) where needed for foliar disease control
  • Rotate FRAC groups to manage resistance and maintain program efficacy
  • In blocks with little to no fruit, fungicide programs can often be reduced and focused on maintaining healthy foliage rather than fruit protection
Summary
  • The recent freeze has resulted in widespread blossom and fruit loss across many New Jersey pear orchards, with damage now more clearly defined at the block level.
  • Most orchards are now at petal fall to early post-bloom in southern counties, while northern counties have largely progressed through bloom with variable levels of injury.
  • Asian pear varieties, which were more advanced at the time of the freeze, experienced greater levels of injury in many locations; in most blocks, little to no viable fruit remains.
  • Pear psylla pressure remains low at this time; while populations may increase with warmer temperatures, most blocks do not require immediate treatment, though monitoring should continue—particularly in freeze-stressed or historically infested orchards.
  • Insecticide applications can be reduced in many blocks due to low crop; where needed, target early nymph stages and focus on blocks with active populations or a history of pressure.
  • Pear scab risk peaked during the April 25–27 infection period; current risk is declining, and one additional fungicide application is likely sufficient in most blocks to cover remaining primary infection.
  • Fire blight risk remains a concern in blocks with freeze injury and actively growing shoots; 1–2 additional bactericide applications may be warranted depending on conditions and model predictions.
  • With little to no crop in many orchards, management should shift toward maintaining healthy foliage, reducing inoculum, and supporting return bloom and productivity for the 2027 season.
  • Continued scouting and monitoring of weather conditions, pest activity, and tree response will remain important over the next 7–10 days.

Peaches
Peach Phenology

Peach and nectarine development continued to progress across New Jersey over the past week, and the impacts of the recent freeze event are now becoming more clearly defined. Significant injury to blossoms and young fruit has been confirmed in many orchards, particularly in southern counties.

Most varieties in southern New Jersey were at shuck split during the freeze, a highly sensitive stage, and have sustained substantial crop loss, especially in low-lying or frost-prone areas. In many blocks, little to no viable fruit remains, though isolated pockets of surviving fruit may still be present depending on site conditions.

In northern counties, where bloom was still ongoing at the time of the freeze, damage remains variable but is often still significant in more exposed locations. Some blocks may retain limited crop depending on bloom stage and site protection.

At this stage, surviving fruitlets are becoming easier to identify, although additional drop may still occur over the coming week. Growers should continue to assess crop viability at the block level before making final management decisions.

Despite reduced crop potential, maintaining disease management and overall tree health remains important to support return bloom and long-term productivity for the 2027 season.

Petal Fall / Early Cover Disease Programs

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
  • 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 in peaches and nectarines should be adjusted this season based on 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)

  • OFM biofix has been set for April 7 in southern New Jersey and April 15 in northern counties
  • Degree-day accumulations should continue to be tracked from biofix to time first-generation management
  • In blocks with little to no fruit, OFM pressure will have limited economic impact; however, a well-timed application may still be beneficial to reduce populations, particularly in young blocks or orchards with historically high pressure
  • Where treatment is warranted, first-generation control should be timed around 170–200 DD (base 45°F) after biofix
  • A second treatment can be timed 10-14 days after petal fall where traps capture moths above threshold (>10) at 300-350 DD.
  • Mating disruption should remain in place where already deployed; do not remove dispensers
OFM 1st Generation Timing
  Insecticide Type
County/Region Degree Days

by 5/3 base 45

 Conventional

170-200, 350-375

 Diamide

100-150, 300-350
Gloucester – Southern 288 1st –past

2nd – 5/7-5/9

 1st –past

2nd – 5/4-5/7
Middlesex – Northern 206 1st –4/30-5/2

2nd –

  1st – past

2nd –

Scale

  • Beneficial insects may help suppress populations in many blocks
  • In orchards with a history of infestation, plan to target the crawler stage later in the season
  • In severe infestations, materials such as Esteem or Centaur may be used
  • Where scale is a recurring problem, an application of Centaur at petal fall or Movento between petal fall and shuck split should “clean up” problem blocks. Centaur is recommended at 34.5 ozs./ac and Movento should be applied at 6-9 ozs./ac. A penetrant must be included to Movento as per the product label. Movento will also control green peach aphid when used at this time.
  • Continue monitoring historically infested blocks and planning for crawler management later in the season if populations persist.

Green Peach Aphid

  • Continue scouting as terminals expand and colonies begin to establish
  • Manage populations to prevent leaf curling and shoot distortion
  • Treatment thresholds remain:
    • Nectarines: 1 colony per tree
    • Peaches: 2–3 colonies per tree

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.
  • 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 manage as usual in problem blocks

Other Insects

  • Plum curculio, tarnished plant bug, stink bugs, BMSB, Japanese beetle, TABM, and thrips: In most blocks with little to no fruit, treatment is not necessary

Recommended Options

  • OFM / Leafrollers:
    • Altacor, Asana, Delegate, Besiege, Voliam Flexi
  • Lesser and Greater Peach Tree Borers
    • Asana XL, Pounce 25WG
  • Green Peach Aphid:
    • Assail, Actara, Admire Pro
Summary
  • The recent freeze has resulted in widespread blossom and fruit loss across many peach and nectarine orchards, with damage now clearly defined at the block level
  • Most southern New Jersey orchards have little to no viable fruit remaining, while northern orchards show variable but often significant injury depending on bloom stage and site conditions
  • Surviving fruitlets are becoming easier to identify, though additional drop may still occur over the coming week
  • With minimal crop present, disease management programs can be significantly reduced, with emphasis shifting to maintaining foliage health and reducing inoculum for next season
  • Fruit diseases such as brown rot and rusty spot are not a concern in most blocks this season
  • Insect management programs can also be reduced; most fruit-feeding pests will not require treatment in blocks without crop
  • Oriental fruit moth should still be monitored and may warrant a well-timed application in high-pressure or young blocks to reduce populations
  • Green peach aphid and mites should be managed as needed to protect foliage and support return bloom
  • Maintaining tree health and canopy development remains critical to support productivity for the 2027 season
  • Continued scouting and monitoring of weather, pest activity, and tree response will be important over the next 7–10 days

Blueberries
Blueberry Phenology

Blueberries were observed in bloom throughout Atlantic and Burlington Counties. While the freeze event the week of April 20 had some impact on earlier blooming varieties, later-blooming acreage that did not have significant freeze damage is now hitting peak bloom (Draper, Elliott, etc.).

Insect Update

Scouting activities were conducted across 141 fields in Burlington and Atlantic Counties. Field evaluations focused on the presence of leafrollers, spongy moths, plum curculio, and thrips. There was a minor increase in plum curculio and thrips; however, due to the ongoing pollination period, the application of insecticides is not recommended at this stage.

IPM Data

Leafroller 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

 

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

Grape development across New Jersey has progressed under recent warm conditions, with most vineyards in southern counties moving through early shoot growth stages. 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 2) 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 shoot 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 2. Grapevines with secondary bud break.

Diseases
Insect Update
  • Insect pests to monitor are grape flea beetle, and climbing cutworms. Controls for these insects are rarely needed.
  • The first generation flight of grape berry moth (GBM) was completed in April. Management of GBM will focus on controlling later generations when they migrate into fields after bloom.
  • Spotted lanternfly nymphs have been observed in southern NJ vineyards (Figure 3). There is no need to control SLF at this time.
    Spotted lanternfly nymphs on grapevines.

    Figure 3. Spotted lanternfly nymphs on grapevines.

    It’s also not too late to scout for and destroy SLF egg masses on posts and trunks.

Filed Under: Blueberry, Fruit, Tree Fruit, Uncategorized, Wine Grape Tagged With: , , , , , , , , , , , , , , , , , , , , , ,
April 6, 2023

Alion herbicide received 24(c) Special Local Need label for use on Highbush Blueberry

Thanks to field research conduct by the Rutgers Specialty crops Weed Science lab and funded by Rutgers NJAES, Bayer CropScience, and the NJ Blueberry and Cranberry Research Council, Alion® herbicide received a FIFRA 24(c) Special Local Need label from the EPA and the NJDEP for use ONLY on dormant highbush blueberry in sandy soils containing greater than 1% organic matter. The new  24(c) Special Local Need label can be found on the Agrian website here.

Alion® (indaziflam) is a Weed Science Society of America (WSSA) group 29 cellulose biosynthesis inhibitor in the alkylazine family. The FIFRA Section 3 label of Alion® allows its use on blueberries that have been established for at least one year but prevents its use on soil with ≥ 20% gravel content or on sandy soil, regardless of soil organic matter content. Thus, prior to receiving the new  24(c) Special Local Need label, Alion® could not legally be applied on New Jersey blueberries that are primarily planted on sandy soils.

The new 24(c) Special Local Need label allows directed application to the soil beneath blueberry bushes planted on sandy soils with some important restrictions:

  • Only apply Alion Herbicide to soil as a dormant application in late fall through early spring before bud swell.
  • Do not use Alion® in highbush blueberry crops grown in sand containing <1 % organic matter content.
  • Do not use on soils with 20% or more gravel content.
  • Do not apply more than a total of 10 fl oz product/A (0.13 lb ai/A) per year on sand containing ≥1 % organic matter content in a 12-month period when used in any highbush blueberry.
  • Do not allow spray to contact green stems, foliage, flowers, or berries or unacceptable injury may occur.
  • When making more than one application per year, allow a minimum of 90 days between applications.

Alion® provides excellent and season-long residual control of annual grasses and broadleaf species due to its long soil persistence with half-life greater than 150 days and low water solubility under acidic soil conditions. Results of a 3-years study conducted on three different blueberry cultivars (Duke, Bluecrop, and Elliott) at the Rutgers P.E. Marucci Center  demonstrated that repeated fall or early spring applications of indaziflam at the 5 fl oz/a labeled rate did not cause injury or reduce commercial yield of blueberry grown on sandy acidic soil. Data generated through this research also showed that fall application of indaziflam consistently provided better weed control than spring applications for species such as horseweed, large crabgrass or narrowleaf goldentop. This suggests that Alion®  applications in New Jersey should be restricted to dormant bushes during the fall season in order to maximize weed control effectiveness while maintaining the highest level of crop safety as compared to spring application. Alion® has no activity on sedge species or perennial weeds. Therefore, it is important to consider rotating to different herbicide modes of action after 1 or 2 years of Alion® application to avoid selecting for weeds that are not controlled by Alion® and prevent potential development of herbicide resistance to indaziflam.

Filed Under: Blueberry Tagged With: , ,
March 14, 2023

2023 Weed Control with Residual Herbicides for New Jersey Highbush Blueberry

With T3 stage forecasted for the end of March this year, soil-applied preemergence herbicides should be sprayed before blueberry bud break to minimize the risk of crop injury and allow sufficient time for residual herbicide to be “activated” by rainfall.

Soil-applied preemergence herbicides should be applied prior to weed seed germination. If applied to weeds that are already out of the ground, most of these products will not control them if they are not tank-mixed with a postemergence herbicide. Glufosinate (Rely 280), paraquat (Gramoxone and generic formulations) and carfentrazone (Aim) are postemergence herbicides that may be applied with preemergence herbicides with little risk of crop injury. Keep in mind that at least ½” rainfall or irrigation is needed within 7 days after application to move (“activate”) preemergence herbicides into the soil solution. Delaying activation may reduce overall performance if some weeds continue to germinate under low soil moisture conditions or if herbicide at the surface of the soil is susceptible to sunlight breakdown.

Make sure the herbicides you plan to apply will be effective at controlling the weed species in your field by checking the herbicide label. Usually, residual herbicides will suppress weed for 5 to 8 weeks depending on irrigation as well as soil and weather conditions. After this period, another residual herbicide can be needed to control weeds through harvest and could be mixed with postemergence herbicides to control emerged weeds. To reduce the potential of selecting for herbicide-resistant weeds, it is highly recommended mixing two herbicides that belong to two different WSSA (Weed Science Society of America) groups whenever you apply preemergence herbicides.

Please, refer to the 2022-2023 New Jersey Commercial Blueberry Pest Control Recommendations for more information on herbicide rates and use restrictions. https://njaes.rutgers.edu/pubs/publication.php?pid=E265

WSSA group 0 – Unknown Site of Action

  • Devrinol 50DF-XT or Devrinol 2-XT (napropamide) will provide good control of annual grasses and should therefore be tank mixed with a PSII or a PPO inhibitor for controlling broadleaf weeds. Devrinol is rapidly degraded if left exposed on the soil surface, so it should be applied less than 24 hours before a rain event to incorporate the herbicide in the soil.

WSSA group 2 – Acetolactate Synthase (ALS) Inhibitors

  • Solida 25WDG or Matrix 25SG (rimsulfuron) or Sandea 75DF (halosulfuron) are ALS-inhibiting herbicides that have both preemergence and postemergence activity. They control most annual broadleaves but are weak on common groundsel, common lambsquarters and eastern black nightshade. Sandea is ONLY recommended for postemergence control of yellow nutsedge.
  • However, these two herbicides will NOT control ALS resistant weeds (horseweed, ragweed) already widespread in New Jersey. Thus, these herbicides should always be tank mixed with a partner effective at controlling these weeds.

WSSA group 3 – Mitosis Inhibitors

  • Kerb 50WP or Kerb 3.3SC (pronamide) is effective at controlling many annual grass species for 4 to 6 weeks after application. Surflan should not be applied to soils containing more than 5% organic matter. Kerb also helps controlling perennial quackgrass as well as annual bluegrass. If applied to warm soils, Kerb persistence and weed control can be severely reduced; therefore, keep Kerb for fall/winter application when soil temperature remains under 55°F. Do not use Kerb on blueberries that have not been established for about a year.

WSSA group 5 and 7 – Photosystem II (PS II) Inhibitors

  • PS II inhibitors have a broad spectrum of control and will be effective against many broadleaves and annual grasses when applied in spring. Karmex 80DF (diuron) and Princep 4L or Princep Caliber 90WDG (simazine) have relatively low solubility and have been very safe on blueberries. Sinbar 80WDG (terbacil) has a longer residual life in the soil and also is more soluble, so it should be used infrequently on light, wet soils. These herbicides are effective on many broadleaf weed species, including common chickweed, common lambsquarters, common groundsel, henbit, nightshade, redroot pigweed, pineapple weed, shepherd’s-purse, smartweed, and some mustards.  Princep and Sinbar will also control many annual grasses and help suppressing quackgrass. Do not exceed more than 1 lb/A of Sinbar to minimize the risk of crop injury.
  • Trellis 4.2SC(isoxaben) is registered for bearing and non-bearing blueberry. Trellis will be most useful in new plantings for preemergence control of annual broadleaf weeds such as common lambsquarters, ragweed, black nightshade, horseweed and smartweed. It does not control grasses.
  • Velpar 2L or Velossa 2.4L (hexazinone) is very soluble and should not be used on blueberries grown on sandy soils as the risk of crop injury is high with this herbicide.

WSSA group 12 and 27 – Carotenoid Biosynthesis Inhibitors

  • Solicam 80DF (norflurazon) can be applied in fall or early spring primarily for annual grass control and quackgrass suppression. Solicam may also provide partial control of many broadleaf weeds as well as of yellow nutsedge. Do not use Solicam on blueberries that have not been established for about a year.
  • Callisto 4SC or Motif 4L (mesotrione) will control many annual broadleaf weeds as well as annual sedges. It controls large crabgrass but no other grasses, such as goosegrass. Callisto may be used as a broadcast spray between rows to control broadleaves and crabgrass without injuring the fescue sod. However, Callisto CANNOT be applied after the onset of bloom.

WSSA group 14 – Protoporphyrinogen Oxidase (PP0) Inhibitors

  • Chateau EZ (flumioxazin) and Zeus 4XC or Zeus Prime 3.5XC (sulfentrazone) have activity against many annual broadleaf weeds (pigweeds, common lambsquarters, ladysthumb, mallow, shepherd’s-purse) when applied preemergence in spring. Chateau and Zeus Prime XC also have some postemergence activity on newly emerged seedlings of annual weeds. Herbicides containing sulfentrazone will also provide suppression of yellow nutsedge. Chateau has a 7 days pre-harvest interval (PHI) and Zeus Prime XC has a 3 days PHI, allowing these herbicides to be applied later in the season to extend preemergence broadleaves control into summer. Blueberry plants must have been established at least two years prior to use of these herbicides.

WSSA group 15 – Protoporphyrinogen Oxidase (PP0) Inhibitors

  • Dual Magnum 7.6ec (S-metolachlor) has a 24(c) Special Local Need label for blueberry in New Jersey. This herbicide provides preemergence control of many annual grasses and some small-seeded broadleaf annual weeds such as redroot pigweed, nightshade and common purslane. Dual Magnum also suppresses emergence of yellow nutsedge. Use Dual Magnum only on plants established for more than one year, and lower rates are suggested on 2- to 3-year-old plantings.

WSSA group 29 – Cellulose Synthesis Inhibitors

  • Casoron 4G (dichlobenil) is a cellulose synthesis inhibitor recommended for fall application to control many annual and perennial broadleaves, grasses and yellow nutsedge. If left on the soil surface or if applied to warm soil (> 55°F or 70°F depending on Casoron formulation), Casoron can lose much of its activity.
  • Alion 1.67SC (indaziflam) IS NOT LABELED FOR USE ON HIGHBUSH BLUEBERRY GROWN ON SANDY SOILS AND/OR ON SOILS WITH ≥20% GRAVEL CONTENT. Additionally, Alion requires significant rainfall for being activated which is not guaranteed with spring applications. Field trials at the Marucci Center have consistently shown better weed control efficacy with fall applications than spring applications.
  • Casoron 4G and Alion 1.67SC should be used ONLY for fall/winter applications. Plants must be at least one year old before Casoron 4G or Alion 1.67SC should be used.
Filed Under: Blueberry, Fruit Tagged With: , , ,
March 10, 2022

Tips in Preparation of Herbicide Shortages in 2022 – Tree Fruit and Small Fruit Crops

Thierry E. Besançon, Rutgers University, and Lynn M. Sosnoskie, Cornell University

Many growers in the US have been focused on predicted herbicide shortages in the upcoming field season. While the primary concerns have surrounded glyphosate and glufosinate, there is increasing apprehension that active ingredients of importance to tree fruit and small fruit growers may also be affected. Although the supply change is dynamic, chemical stocks may become, and remain, tight at the local or regional level as growers try to fill gaps in their toolboxes. As spring residual herbicide are soon to be applied, please consider the following when planning for the 2022 season.

Important note: Not all herbicides are available in all crops in both New Jersey and New York. Always review current labels before applying products

 

Successful Weed Identification, Regular Scouting and Detailed Field Records are Crucial for Optimizing Weed Control Success

  • The first step in developing a novel herbicide program is knowing what species are present and determining which combination of products will be the most effective (and affordable) at suppressing them. Not all active ingredients are equally useful against all species and careful consideration needs to be paid to each chemical’s spectrum of control. Please, carefully review herbicide effectiveness tables for various weed species that are available in the 2022 Commercial New Jersey Pest Control Recommendations for blueberry, tree fruits or grape (https://njaes.rutgers.edu/pubs/). Similar tables are available in Cornell’s weed control guides (PMEP Guidelines (cornell.edu))

Familiarize Yourself with Chemical Substitutes before Applying Them over Many Acres

  • Some switches may be intuitive (e.g. using Poast (sethoxydim) or Fusilade (fluazifop) in place of clethodim where allowed) while others may be more complicated (e.g. using a tank-mixture in place of a single product). In addition to knowing a product’s target species, become acquainted with each herbicide’s labeled rate structure and spray volume, use patterns (e.g. application timing), environmental limitations (e.g. soil type or temperature restrictions), adjuvant requirements, and potential interactions with tank-mix partners. Not all chemicals are compatible with each other, and antagonism can reduce weed control efficacy while enhancing crop injury concerns. Contact your Extension Specialists if you have any doubt regarding physical compatibility and efficacy of herbicides mixtures.

Soil-Applied Preemergence Herbicides are Critical Tools

  • Soil-applied preemergence herbicides are very useful tools for suppressing weeds that emerge with the crop; these plants are the most injurious as early season competitors are very likely to reduce yields. Like postemergence products, soil-applied herbicides must be carefully selected to balance crop safety with weed control needs. Pay attention to rate requirements according to soil type, as this can influence both efficacy and injury. Preemergence herbicides need to be moved (aka activation) into the soil solution (via either rainfall or irrigation) where they are taken-up by emerging weed seedlings; delays in activation can reduce overall performance if some weeds continue to germinate and emerge under low soil moisture conditions. Delays may also facilitate the degradation of some products susceptible to breakdown in sunlight (i.e. photolysis). Be aware that trickle irrigation may cause less effective and less consistent weed control by washing off residual herbicides from top soil where weeds germinate, thus increasing herbicide application costs. When possible, use overlapping residual products to suppress weed emergence throughout the season. Some active ingredients may have both preemergence and postemergence activity (e.g. flumioxazin (Chateau) or simazine (Princep)).

Timing Matters

  • Postemergence (i.e. foliar) weed control should be undertaken when weeds are small and succulent. Herbicide labels will have specific recommendations regarding the optimal size for treatment. For instance, clethodim (Select Max) and sethoxydim (Poast) have a maximum height or lateral growth requirement of 6 inches for effective control of goosegrass or crabgrass. Weeds are more sensitive to control measures when they are small and succulent, so rapid identification and management will improve control success. Because many foliar-applied herbicides can also damage crops, as well, always follow label guidance to reduce risk of injury.

Optimize Herbicide Application Rate for Postemergence Applications

  • Target using the lowest effective herbicide rate to stretch your herbicide supply. For example, instead of applying 32 or 44 oz/acre of a glyphosate brand product, consider using the standard rate on the label such as 22 oz/acre for Roundup PowerMax. Again, timing of application with regards to weed size will be critical to optimize your herbicide supply. The smaller the weeds, the less herbicide you will have to apply to control it! Therefore, frequent scouting as highlighted above will be very important to optimize your herbicide application and stretch your herbicide supply.

Don’t Skimp on Adjuvants

  • If herbicides are going to be in short supply, then there may be fewer shots to control weeds. If there are fewer shots available, make every shot count as much as possible. Follow label recommendations regarding the inclusion of water conditioners, surfactants, etc…, to maximize product efficacy. Refer to point number two about potential compatibility concerns when tank-mix partners are involved.

Get Perennial Weeds under Control

  • Perennial species such as Canada thistle, goldenrods, bindweed or quackgrass are frequent and troublesome weeds of tree fruit and small fruit crops. Because control of these weeds requires the use of systemic herbicides that may be in short supply (i.e. glyphosate), appropriate timing of application will be critical to maximize herbicide efficacy. For example, Canada thistle should be sprayed with a systemic herbicide in late spring after flower buds started to develop whereas Virginia creeper or poison ivy should be targeted in mid- to late summer after vines flowers but before fall color appears in the foliage. Use effective alternatives such as clopyralid (Stinger) for control of leguminous and composite (e.g. Canada thistle) weeds or soil-applied pronamide (Kerb) for control of perennial grasses where authorized. This may help you to reserve the use of glyphosate for perennial weeds that cannot be efficiently controlled by other products.

Consider Non-Chemical Weed Control Strategies When and Where Appropriate

  • This includes hand weeding, cultivation, and mowing practices. Like herbicides, these practices are not effective against all species at all times. For example, while cultivation can control many weed seedlings, particularly at the white-thread stage, soil disturbance is less effective against well-developed plants. In the case of some perennials (for instance, field bindweed or Canada thistle), cultivation contributes to break up and disperse root fragments within and across fields, facilitating dispersal. Ultimately, plan for hand-weeding escapes prior to the weeds setting seeds as this will help reducing the weed seedbank for future growing seasons.

Plan Ahead Now!

  • 2022 could be a difficult year if many crop production and protection chemicals are limited. Herbicide shortages could impact weed control success in the coming growing season…and beyond. Weeds that are not controlled in 2022 will set seed that will cause problems in the future. Planning now can help with weed management in both the short and long term.
Filed Under: Blueberry, Cranberry, Fruit, Strawberry, Tree Fruit, Vegetable Crops, Wine Grape Tagged With: , , , , , , ,
March 10, 2022

2022 Update on Weed Control with Preemergence Herbicides for Highbush Blueberry

With a looming shortage of some postemergence herbicides, effective use of soil-applied preemergence herbicides becomes increasingly important in 2022. As the T3 stage is forecasted for early April, soil-applied preemergence herbicides should be sprayed before blueberry bud break.

Soil-applied preemergence herbicides should be applied prior to weed seed germination. If applied to weeds that are already out of the ground, most of these products will not control them if they are not mixed with a postemergence herbicide. Glufosinate (Rely 280), paraquat (Gramoxone) and carfentrazone (Aim) are postemergence herbicides that may be applied with preemergence herbicides with little risk for crop injury. Keep in mind that at least ½” rainfall or irrigation is needed within 7 days after application to move (“activate”) preemergence herbicides into the soil solution. Delaying activation may reduce overall performance if some weeds continue to germinate under low soil moisture conditions or if herbicide at the surface of the soil is susceptible to sunlight breakdown.

Make sure the herbicides you plan to apply will be effective at controlling the weed species in your field by checking the herbicide label. Usually, residual herbicides will suppress weed for 5 to 8 weeks depending on irrigation as well as soil and weather conditions. After this period, another residual herbicide can be needed to control weeds through harvest and could be mixed with postemergence herbicides to control emerged weeds. In order to reduce the potential of selecting for herbicide-resistant weeds, it is highly recommended mixing two herbicides that belong to two different WSSA (Weed Science Society of America) groups whenever you apply preemergence herbicides.

Please, refer to the 2022 New Jersey Commercial Blueberry Pest Control Recommendations for more information on herbicide rates and use restrictions. https://njaes.rutgers.edu/pubs/publication.php?pid=E265

 

WSSA group 0 – Unknown Site of Action

  • Devrinol (napropamide) will provide good control of annual grasses and should therefore be tank mixed with a PSII or a PPO inhibitor for controlling broadleaf weeds. Devrinol is rapidly degraded if left exposed on the soil surface, so it should be applied less than 24 hours before a rain event to incorporate the herbicide in the soil.

WSSA group 2 – Acetolactate Synthase (ALS) Inhibitors

  • Solida, Matrix SG (rimsulfuron) and Sandea (halosulfuron) are ALS-inhibiting herbicides that have both preemergence and postemergence activity. They control most annual broadleaves but are weak on common groundsel, common lambsquarters and eastern black nightshade. Sandea is ONLY recommended for postemergence control of yellow nutsedge.
  • However, these two herbicides will NOT control ALS resistant weeds (horseweed, ragweed) already widespread in New Jersey. Thus, these herbicides should always be tank mixed with a partner effective at controlling these weeds.

WSSA group 3 – Mitosis Inhibitors

  • Kerb (pronamide) and Surflan (oryzalin) are effective at controlling many annual grass species for 4 to 6 weeks after application. Surflan should not be applied to soils containing more than 5% organic matter
  • Kerb also helps controlling perennial quackgrass as well as annual bluegrass. If applied to warm soils, Kerb persistence and weed control can be severely reduced; therefore, keep Kerb for fall/winter application when soil temperature remains under 55°F. Do not use Kerb on blueberries that have not been established for about a year.

WSSA group 5 and 7 – Photosystem II (PS II) Inhibitors

  • PS II inhibitors have a broad spectrum of control and will be effective against many broadleaves and annual grasses when applied in spring. Karmex (diuron) and Princep (simazine) have relatively low solubility and have been very safe on blueberries. Sinbar (terbacil) has a longer residual life in the soil and also is more soluble, so it should be used infrequently on light, wet soils. Velpar (hexazinone) is very soluble and should not be used on New Jersey sandy soils. These herbicides are effective on many broadleaf weed species, including common chickweed, common lambsquarters, common groundsel, henbit, nightshade, redroot pigweed, pineapple weed, shepherd’s-purse, smartweed, and some mustards.  Princep and Sinbar will also control many annual grasses and help suppressing quackgrass.
  • Trellis (isoxaben) is registered for bearing and non-bearing blueberry. Trellis will be most useful in new plantings for preemergence control of annual broadleaf weeds such as common lambsquarters, ragweed, black nightshade, horseweed and smartweed. It does not control grasses.

WSSA group 12 and 27 – Carotenoid Biosynthesis Inhibitors

  • Solicam (norflurazon) can be applied in fall or early spring primarily for annual grass control and quackgrass suppression. Solicam may also provide partial control of many broadleaf weeds as well as of yellow nutsedge. Do not use Solicam on blueberries that have not been established for about a year.
  • Callisto or Motif (mesotrione) will control many annual broadleaf weeds as well as annual sedges. It controls large crabgrass but no other grasses, such as goosegrass. Callisto may be used as a broadcast spray between rows to control broadleaves and crabgrass without injuring the fescue sod. However, Callisto CANNOT be applied after the onset of bloom.

WSSA group 14 – Protoporphyrinogen Oxidase (PP0) Inhibitors

  • Chateau (flumioxazin) and Zeus XC or Zeus Prime XC (sulfentrazone) have activity against many annual broadleaf weeds (pigweeds, common lambsquarters, ladysthumb, mallow, shepherd’s-purse) when applied preemergence in spring.
  • Chateau and Zeus Prime XC also have some postemergence activity on newly emerged seedlings of annual weeds. Herbicides containing sulfentrazone will also provide suppression of yellow nutsedge.
  • Chateau has a 7 days pre-harvest interval (PHI) and Zeus Prime XC has a 3 days PHI, allowing these herbicides to be applied later in the season to extend preemergence broadleaves control into summer. Blueberry plants must have been established at least two years prior to use of these herbicides.

WSSA group 15 – Protoporphyrinogen Oxidase (PP0) Inhibitors

  • Dual Magnum (S-metolachlor) has a 24(c) Special Local Need label for blueberry in New Jersey. This herbicide provides preemergence control of many annual grasses and some small-seeded broadleaf annual weeds such as redroot pigweed, nightshade and common purslane. Dual Magnum also suppresses emergence of yellow nutsedge. Use Dual Magnum only on plants established for more than one year, and lower rates are suggested on 2- to 3-year-old plantings.

WSSA group 20 – Cellulose Synthesis Inhibitors

  • Casoron (dichlobenil) is a cellulose synthesis inhibitor recommended for fall application to control many annual and perennial broadleaves, grasses and yellow nutsedge. If left on the soil surface or if applied to warm soil (> 55°F or 70°F depending on Casoron formulation), Casoron can lose much of its activity. So, keep this herbicide ONLY for fall/winter applications. Plants must be at least one year old before Casoron should be used.
Filed Under: Blueberry, Uncategorized Tagged With: , ,
May 26, 2021

Cicadas Are Here and Fruit IPM for 5/26/21

Cicadas are Here, There and Everywhere (Depending where you are): 17 year cicadas began emergence last week. These insects while a marvel in the insect world, are also capable of doing considerable damage to young fruit trees, grape vines, and blueberry bushes. After mating they begin to deposit their eggs in slits along small diameter branches. Thin branches which are loaded with fruit weight and damaged by egg laying can break. Some growers have asked about damage and what they can do to prevent it. Most egg laying is starting this week.

[Read more…]

Filed Under: Blueberry, Fruit, Landscape, Nursery, & Turf, Nursery, Tree Fruit, Wine Grape Tagged With: , , , , , , , , , , , , , ,