Tree Fruit Edition

Seasonal updates on insects, diseases, weeds, maturity dates and cultural practices impacting only tree fruit.
 
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April 12, 2026 , and

Fruit IPM Updates Week of 4/06/2026

Tree Fruit Phenology Update

While tree fruit phenology seemed to advance rapidly late last month into early April across New Jersey, temperatures dropped below freezing overnight early in the week, slowing development and prompting frost warnings, negatively impacting advanced crops and cultivars in bloom. Warmer temperatures are forecast for the weekend and into next week, resuming and accelerating rapid development. It is also important to note that NJ remains under a NJ Department of Environmental Protection Drought Warning, and the entire state is currently in a moderate drought or abnormal dryness according to the US Drought Monitor.

In apples, most varieties have reached pink bud across the state, with early varieties such as Pink Lady now entering bloom in southern counties. In pears, most varieties are at bloom statewide, with Asian pears remaining slightly more advanced. Peach and nectarine varieties have reached full bloom in southern counties and pink in most northern counties, with some early varieties in southern counties beginning to enter petal fall. 

Apples
Apple Phenology Update

Apple phenology continues to progress across New Jersey, with development advancing rapidly under recent warm temperatures. Observations indicate that most varieties statewide are at pink bud, while early varieties in southern counties, such as Pink Lady, have entered bloom. 

This stage marks a critical transition in disease management, particularly for apple scab, powdery mildew, and cedar apple rust, while also representing an important period for early-season insect management and monitoring. 

Phenology Dates by County (earliest varieties)

County Green Tip Tight Cluster Pink Bud Bloom
Cumberland 3/22 3/28 4/3 4/8
Gloucester 3/22 3/28 4/3 4/8
Burlington 3/22 3/28 4/2 TBD
Mercer 3/22 3/28 4/2 TBD
Middlesex 3/22 4/1 4/4 TBD
Monmouth 3/22 TBD 4/4 TBD
Hunterdon 3/22 TBD TBD TBD
Morris 3/26 TBD TBD TBD
Warren 3/30 TBD TBD TBD
Sussex 3/31 TBD TBD TBD
Bergen 3/22 4/1 TBD TBD
Figure 1. Pink Lady apple variety in Gloucester County entering bloom on 04/06/2026. Photo by Katrina DeWitt.

Figure 1. Pink Lady apple variety in Gloucester County entering bloom on 04/06/2026. Photo by Katrina DeWitt.

Apple Scab
Models

Apple scab models are available through NEWA and RIMpro. Current models indicate that ascospore maturity is increasing rapidly, with infection risk expected to rise significantly as we move through bloom. While no major infection events are currently forecast for the next several days, growers should continue to monitor the weather closely and maintain fungicide coverage

Current Update using the Upper Deerfield Station
  • ~40% maturity on April 8  
  • ~42% maturity on April 9  
  • ~28% cumulative ascospore discharge to date 
  • Forecasted to reach ~48–59% by April 10–15 
Management Considerations

As apples progress from pink through bloom, maintaining fungicide coverage is critical, as ascospore maturity and discharge increase rapidly during this period. Growers should select fungicides that protect against apple scab, powdery mildew, and cedar apple rust, particularly in susceptible varieties and southern counties where bloom is underway. 

Keep in mind that powdery mildew favors warm, dry conditions and does not require rainfall for infection, while cedar apple rust management becomes increasingly important from pink through bloom.  

Recommended fungicide programs include: 

  • Mancozeb + single-site fungicide tank mix (use half-rate mancozeb when tank mixing with resistance-risk fungicides)  
  • FRAC 3 fungicides (DMI), including Rally, Procure, Indar, Inspire Super, Topguard, or Cevya for strong activity against scab, powdery mildew, and cedar apple rust  
  • FRAC 7 fungicides, including Fontelis, Miravis, or Sercadis for scab and mildew control, though these provide limited/no cedar apple rust activity  (Aprovia should be saved for bitter rot management later in the season since it is limited to 4 applications per season)
  • FRAC 9 fungicides, including Vangard or Scala for scab suppression, though ineffective on cedar apple rust   
  • FRAC 1 fungicides, including Topsin, though ineffective on cedar apple rust

Important Notes: 

  • Mancozeb remains highly effective for apple scab and cedar apple rust but does not control powdery mildew.  
  • Avoid combining Captan with oil products due to the risk of phytotoxicity.  
  • Consider saving some FRAC 11 materials for summer disease programs to assist with resistance management. 

Monitor:

  • NEWA models
  • Weather/wetting events
  • Phenology

Early control is critical to avoiding season-long pressure.

Insect Update

Ambrosia Beetle:

  • The first flight of the ambrosia beetle has been detected in southern New Jersey.  
  • There has been minimal activity observed further north at this time. 
  • Continue monitoring traps closely, particularly in stressed, declining, or newly planted blocks, as beetle activity is expected to increase with continued warming temperatures. 

Mating Disruption Timing:

  • Codling moth (CM) mating disruption should be applied around pink. 
  • Growers should begin preparing materials and planning applications now. 
Summary
  • Apple phenology continues to progress rapidly across New Jersey, with most varieties at tight cluster to pink bud and early southern varieties entering bloom.  
  • This stage marks a critical period for disease management, particularly for apple scab, powdery mildew, and cedar apple rust, as well as key insect monitoring timings.  
  • Apple scab ascospore maturity has increased to approximately 40–42% and is forecasted to reach 48–59% over the next week, increasing overall infection risk as bloom progresses.  
  • No major infection events are currently forecast, but growers should continue to monitor the weather closely and maintain fungicide coverage ahead of rain events.  
  • Fungicide programs should target apple scab, powdery mildew, and cedar apple rust, with materials selected based on orchard phenology and disease pressure.  
  • Southern counties entering bloom should maintain cedar apple rust protection and continue scouting for early-season insect activity.  

Pears
Pear Phenology Update

Pear phenology has advanced rapidly across southern New Jersey over the past week. Observations indicate that most European pear varieties are now in full bloom, with orchards progressing quickly under recent warm temperatures. 

Asian pear varieties remain slightly more advanced, with most blocks also at full bloom or moving toward late bloom in the earliest plantings. 

Figure 2. Bloom. Asian pear variety phenology. Gloucester County, NJ. Photo by Katrina DeWitt.

Figure 2. Bloom. Asian pear variety phenology. Gloucester County, NJ. Photo by Katrina DeWitt.

Pear Psylla

Pear psylla activity has remained variable across southern New Jersey. Observations from April 7 indicate differences by county: 

  • Gloucester County: None observed  
  • Burlington County: No activity observed to date  
  • Mercer County: No activity observed to date  

Overall pressure remains relatively low in many orchards. This is likely due, in part, to recent oil applications, particularly where oil was combined with materials such as Esteem, which can suppress egg laying and early population development. 

At this stage (full bloom): 

  • Continue monitoring for adults, eggs, and the onset of nymph hatch  
  • Use beating trays to assess adult activity  
  • Examine developing shoots and leaves for egg presence 

Management considerations:

  • Do not apply insecticides during bloom due to pollinator protection restrictions.  
  • Continue scouting to monitor psylla population development and identify blocks where pressure may increase rapidly.  
  • Prepare for petal fall applications targeting early nymph hatch, as this timing is critical for effective suppression. 

Recommended post-bloom / petal fall options include: 

  • Movento – excellent activity on pear psylla and aphids  
  • Agri-Mek / Gladiator / Minecto Pro – strong knockdown where higher pressure exists  
  • Delegate / Danitol / Warrior II / Lambda-Cy – additional options where adult populations remain elevated  
  • Centaur / Sivanto Prime – softer alternatives for moderate pressure situations  

Management should focus on targeting newly hatched nymphs shortly after petal fall, when control is most effective. 

Pear Diseases
Fire Blight and Early Season Management

With pear orchards now in full bloom across southern New Jersey, fire blight risk is increasing significantly. Forecasted warm temperatures for next week, combined with moisture, create favorable conditions for bacterial multiplication, spread, and blossom infection. 

During bloom:

  • Monitor weather closely and use forecasting models, such as NEWA, to track infection periods.  
  • Apply bactericides when the first blossoms open, and repeat every 3–7 days during bloom as needed, based on weather/infection risk.  
  • Streptomycin (Agri-Mycin/FireWall/Streptrol) remains a primary option for blossom blight protection.  
  • Kasumin may also be used through petal fall.  
  • Oxytetracycline products (Mycoshield/FireLine) may be rotated to manage resistance.  
  • Rotate chemistries, when possible, to reduce resistance development. 
Pear Scab

RIMpro modeling for pear scab in Upper Deerfield indicates that infection risk has increased, with multiple infection periods observed in recent days and additional ascospores still available. Current modeling suggests that the inoculum remains available and that conditions continue to favor infection during wetting events. 

At bloom:

  • Maintain protective fungicide coverage throughout bloom, especially ahead of forecasted rainfall.  
  • Effective protectant options include Mancozeb, Ziram, or Ferbam.  
  • Effective resistance-risk materials include Procure, Cevya, Flint, Merivon, Luna Sensation, Inspire Super, or Vangard (tank-mixed only).  
  • Applications should be made prior to rainfall/wetting periods, as infections occur during wet conditions.  
  • If 2 inches or more of rainfall occurs following an application, consider a follow-up spray to maintain coverage.  

Additional Considerations:

  • Continue programs targeting pear scab, Fabraea leaf spot, and powdery mildew during bloom.  
  • Asian pear blocks may require particularly close attention, as they often progress slightly ahead of European pears and may be more susceptible during bloom. 
Summary
  • Most pear varieties across southern New Jersey are now at full bloom, with Asian pears generally slightly more advanced.   
  • Reduced pressure in some blocks is likely due to prior oil applications, particularly where oil was combined with Esteem.  
  • No insecticide applications should be made during bloom to protect pollinators.  
  • Growers should continue scouting for adults, eggs, and early nymph hatch to prepare for post-bloom management decisions.  
  • Recent rainfall and wetting events have increased disease pressure, particularly for pear scab and fire blight.  
  • Protective fungicide programs should be maintained throughout bloom, with reapplication considered following 2 inches or more of rainfall.  
  • Fire blight risk is increasing significantly during bloom, and growers should be prepared to apply antibiotics during infection periods if favorable conditions persist.  
  • Continued scouting and close monitoring of weather conditions will be critical over the next 7–10 days as bloom progresses and disease/insect pressure increases. 

Peaches
Peach Phenology

Peach and nectarine phenology have advanced rapidly across New Jersey over the past week. Most peach and nectarine varieties in southern counties are now in full bloom while northern counties are at pink, with some early varieties in southern New Jersey beginning to enter petal fall. Development is progressing quickly under recent warm temperatures. 

Brown Rot

Blossom infections from the brown rot fungus can occur whenever pistils are exposed, and favorable environmental conditions are present. 

Infections can occur during any wetting period when temperatures are between 41 and 86°F, with optimal infection when wetting periods coincide with mid-70s temperatures. During extended wetting periods, blossoms may become infected regardless of temperature. 

Blossoms and fruitlets remain susceptible until the pistil desiccates, which typically occurs between petal fall and shuck split. 

Management Considerations

  • Maintain fungicide coverage throughout bloom and petal fall, particularly ahead of wetting periods favorable for blossom blight infection.  
  • If favorable weather persists, a third blossom blight spray may be warranted, noting some products are only labeled for two bloom applications.  
  • Fungicides used during bloom should be rotated appropriately for resistance management and should not overly rely on chemistries intended for later pre-harvest brown rot control.  

Recommended Bloom-Stage Materials: 

  • Vangard, Flint Extra, Inspire Super, Luna Sensation, or Rovral  
  • Bravo Weather Stik (through shuck split only)  
  • Fontelis, Indar, Luna Experience, Merivon, Pristine, Cevya, Orius, and Tilt are other rotational options but these should be saved to target brown rot at the pre harvest stage as these products all have a 0-day PHI
  • Rally is also effective but consider saving this product to target rusty spot
  • While Abound and Quadris Top are very effective to control this disease, they are highly phytotoxic to apples and should not be used if you are using the same sprayer on apples and peaches

Petal Fall / Early Cover Considerations: 

  • Where peach scab has historically been problematic, Flint Extra at petal fall is advised for anti-sporulant activity.  
  • For highly susceptible cultivars, warm/wet springs, or blocks with a history of bacterial spot, begin bacterial spot protection at petal fall with materials such as copper or Mycoshield.  
  • Rusty spot programs should begin at petal fall, with Rally commonly used as the first application. 
Insect Update

Oriental Fruit Moth (OFM)

  • OFM traps were deployed this week in southern New Jersey counties.  
  • Biofix for Oriental Fruit Moth was set to April 7, 2026, by Dr. Anne Nielsen.  
  • Growers utilizing degree-day models should begin tracking accumulation from this date to properly time future management applications. 

Scale:

  • Delayed dormant oil timing has now passed for most blocks.  
  • Growers should continue monitoring historically infested blocks and prepare for crawler management later in the season if pressure persists.  

Green Peach Aphid:

  • Continue scouting for green peach aphid colonies as terminals begin developing.  
  • Treatment thresholds remain:  
    • 1 colony per tree in nectarines  
    • 2–3 colonies per tree in peaches  

Bloom/Petal Fall Considerations 

  • Avoid insecticide applications during bloom to protect pollinators.  
  • As blocks move through petal fall, growers should begin preparing for upcoming petal-fall insect management timings based on OFM degree-day accumulation. 
Summary
  • Most peach and nectarine varieties in southern New Jersey are now at full bloom, with some early southern varieties beginning to enter petal fall.  
  • Development has progressed rapidly under recent warm temperatures and will continue advancing quickly with favorable weather.  
  • Brown rot infection risk remains present whenever blossoms are exposed under wet conditions, particularly between 41–86°F.  
  • Blossoms and young fruit remain susceptible until pistil desiccation, typically between petal fall and shuck split.  
  • Fungicide coverage should be maintained through bloom and petal fall, particularly ahead of wetting periods favorable for blossom blight infection.  
  • OFM traps were deployed this week in southern counties, and biofix has been established as April 7, 2026.
  • Growers should begin tracking degree-day accumulation from biofix to prepare for upcoming OFM management timings.  
  • The delayed dormant oil timing has passed for most blocks, and focus should shift to in-season insect monitoring.  
  • Continue scouting for green peach aphid, with treatment thresholds of 1 colony/tree in nectarines and 2–3 colonies/tree in peaches.  
  • Avoid insecticide applications during bloom to protect pollinators.  
  • Continued scouting and timely applications will be critical over the next 7–10 days as phenology and pest pressure continue to progress. 
Filed Under: Commercial Ag Updates, Disease Forecasting, Fruit, Tree Fruit Tagged With: , , , , , , , , , , , , ,
April 10, 2026

Assessing the Severity of Frost Damage to Peach and Apple Flower Buds

Figure 1. The brown and shrunken pistil (L) indicates the flower is dead; a green and upright pistil indicates that the flower is alive. Photo by H. Gohil.

The below-freezing temperatures on Wednesday (4/8/26) and Thursday (4/9/26) early mornings are likely to cause frost damage in several peach and a few apple orchards in New Jersey. It got down to 25°F–28°F in Southern NJ, and 22°F -27°F in Central and Northern NJ, and those temperatures could have killed vulnerable blossoms. The night of April 8th saw wind speeds above 10 mph, which mixed the cold air at the bottom with the warm air above. This prevented cold-air stratification and reduced the heat loss from the soil surface and plant tissues. The night of April 9th was even colder, and the wind dropped below 5 mph, almost coming to a standstill for a few hours. This causes the rapid loss of thermal energy from the soil and plant tissues. Most unprotected peach and a few apple orchards were affected by these conditions on the night of April 9th. In several parts of New Jersey, peach flower buds were at full bloom, the most susceptible stage to frost (Fig. 1). In Apples, though most orchards were in the tight cluster or earlier stages of bud development, and few varieties were in the first pink. The critical temperatures for 90% bud kill at these stages are 21°F for the tight cluster and 24°F for the first pink; hence, only a few apple orchards in South NJ were vulnerable to significant frost damage (Fig. 2).

Figure 2. Frost damage to Apple bloom at first pink

In Peach, not all flowers bloom at the same time, which makes frost-damage assessment a little more difficult. Often, many flowers look damaged, but they still bear fruit. This estimate can be even more difficult in some varieties, simply because they bloom so much that even 90% damage can yield close to the full crop. The natural tendency is to look for open flowers, which can easily lead to overestimating the damage. The developing flower buds will quickly die once damaged by a freeze. You can’t tell what will happen just by looking at the flower. The browning of flower petals doesn’t mean the ovary is dead.

You can do a quick, destructive assessment of loss by randomly opening 10-20 flowers per tree; do this on 5-10 trees across an acre or block for each variety. This can give a relative estimate of bloom loss. If you take a more systemic approach, you may get more accurate results. Due to cold-air stratification, cold air settles to the bottom, so more buds are damaged at the bottom; therefore, you want to sample from both the upper and lower branches. Sometimes, the loss of flower buds could be as good as natural thinning. So, flower bud loss may not result in a crop loss.

After opening the flower, if the pistil is shrunken and brown, consider it dead; and if completely green, consider it alive (Fig 1). The pistil is sticking out, and you see it is brown; it could have been pollinated and is in the senescence stage. It is not brown because of frost, but it’s brown because of the normal progression of development. In another scenario, the pistil is brown because it has frost damage, but it still may have done its job of pollination. It served its purpose and senescence because both frost and pollination are over. After pollination and fertilization, rapid hormonal changes enhance fruit development and make them slightly more cold-hardy. So even the destructive analysis is a close approximation.

Figure 3. Uneven development of peach due to frost injuries, represented by very small ripe fruits in PF Flamin Fury 24 (Left) and Silverglo (right), and a significant number of green unripe fruits in Lady Nancy (middle). Photo by H. Gohil.

If frost occurs at the shuck-split or shuck-off stage, the seed/pit will be damaged. But the fruit looks normal. However, they will not reach full size because the nonviable seed cannot produce the hormones required for fruit growth (Fig. 3). Even if they do grow, they may still face other problems. For example, the pit may have sustained damage, predisposing it to shatter during phase III of fruit growth. If you wait for a week to 10 days, it will be easier and more accurate non-destructive assessment. The live flowers will develop normally, and the dead flowers will be shrunken brown mummies that can be flicked away easily. You will still have plenty of time to adjust fruit thinning to achieve a near-normal crop. You should not be in a hurry to do fruit thinning this year! If you see some fruits that have stopped getting bigger and are distinctly smaller, will you want to thin? Maybe after the June drop.

Filed Under: Blueberry, Cranberry, Fruit, Strawberry, Tree Fruit, Wine Grape Tagged With: , , ,
April 8, 2026 and

North Jersey Tree Fruit and Vegetable Twilight Meeting

North Jersey Tree Fruit and Vegetable Twilight Meeting 

Supported by

New Jersey Vegetable Growers Association

 

April 30, 202

4:30 PM-7:30 PM

Ort Farms

25 Bartley Rd.

Long Valley, NJ 07853

 

4:15 PM – Registration and Tour of Farmers Market

4:30 PM – Wagon Tour of the Farm

5:00 PM – Light Dinner (Sponsored by NJ Vegetable Growers Association)

5:30 PM – Proper Pesticide Handling, Personal Protective Equipment and Record Keeping

Janine Spies PhD, State Fruit IPM Program Leader, Rutgers NJAES

6:00 PM – Tree Fruit Insect and Disease Update

Kaitlin Quinn, North Jersey Tree Fruit IPM Program Associate, Rutgers NJAES    

6:30 PM – Key Management Decisions to Minimize Disease, and Pest Pressure while Enhancing Yield in Strawberry Production

Peter Nitzsche, Agriculture and Natural Resources Agent I, Rutgers NJAES

7:00 PM – Managing Thrips in Vegetable Crops

Amanda Quadrel, North Jersey Vegetable IPM Senior Program Coordinator, Rutgers NJAES

The following pesticide recertification credits will be awarded 

1 Unit CORE    3 Units 1A    3 Units 10    3 Units PP2

Please RSVP for the meeting by April 27 with a call to:

Kim Crommelin at 908.788.1338 or kfrey@co.hunterdon.nj.us

Filed Under: Commercial Ag Updates, Fruit, pesticide credits, Strawberry, Tree Fruit, vegetable, Vegetable Crops
April 6, 2026 , and

Frost Protection for Orchards and Perennial Fruit Crops

The forecast for New Jersey statewide is expected to drop below freezing Tuesday and Wednesday overnight into early morning this week. Fruit crops are most vulnerable in the full bloom to petal fall stages.

Peach bud development stages and corresponding critical temperatures. Adapted from MSU Fruit Extension. Photos by H. Gohil.

Figure 1. Peach bud development stages and corresponding critical temperatures. Adapted from MSU Fruit Extension. Photos by H. Gohil.

Temperatures beginning at 28°F can kill 10% of the flowers when in full bloom and 90% of the flowers when temperatures drop to 24°F or below for more than 30 minutes (Figure 1). Please refer to your local forecast at nearby weather stations to receive the most accurate temperatures during this time period at www.njweather.org/ or https://newa.cornell.edu/.

Management Options for Frost Protection

  • Cloth coverings – This can be an effective tool to protect a small number of trees. Sheets, burlap, or frost blankets can provide some protection. Avoid plastic tarps which do not provide efficient insulation and can increase freeze damage on plant tissue. Ensure the covering reaches the ground.
  • Irrigation – Irrigate the soil under the trees the day before so any heat will be absorbed. Overhead irrigation is an option if available. The irrigation must stay on until ice starts to melt.
  • Heaters – Heat can be sourced through burning propane, natural gas, or oil burning Smudge pots. This could be a valuable investment for a commercial orchard that experiences frost events at critical bloom times; however, it is expensive and highly inefficient as heat produced dissipates quickly.
  • Wind machines & helicopters – These devices can be used in conjunction with heat or alone to mix warm air from higher elevation with cold air in the orchard.
  • Frost Rescue Sprays – Plant growth regulators such as Promalin can be applied to apples and pears following a frost event to help increase fruit set. The application must be made within 24 hours of the frost event and the trees must be thawed. Follow the label for use restrictions.

References

Gohil, H., Muehlabuer, M., Polanin, N, and Crassweller, R. (2020). Active Frost Protection Methods for Your Orchard. Rutgers Cooperative Extension Bulletin E363. https://njaes.rutgers.edu/e363/

Gohil, H., Muehlbauer, M., Besancon, T., and Ward, D. (2025). Preparing Orchards Against the Frost – Low Tech Strategies. Plant & Pest Advisory Rutgers Cooperative Extension Preparing Orchards Against the Frost – Low Tech Strategies — Plant & Pest Advisory

Demchak, K. (2020). Frost and Freeze Damage on Berry Crops. PennState Extension https://extension.psu.edu/frost-and-freeze-damage-on-berry-crops

 

 

Filed Under: Blueberry, Fruit, Strawberry, Tree Fruit, Uncategorized
April 4, 2026 , and

Fruit IPM Updates Week of 3/30/2026

Tree Fruit Phenology Update

Tree fruit phenology is progressing across New Jersey, with development in southern counties remaining slightly advanced and northern regions beginning to catch up. Overall, the 2026 season is showing a more compressed phenology window than typical. Warm temperatures this week significantly advanced phenology.

In apples, most varieties have reached tight cluster across the state, with early varieties in southern counties at pink bud. In pears, most varieties are at early white bud to popcorn, with Asian pears more advanced and approaching bloom. Peach varieties have reached pink bud across New Jersey, with nectarines near or in bloom in South Jersey.

Apples
Apple Phenology Update

Apple phenology continues to progress across New Jersey. Observations indicate that northern counties are primarily at tight cluster, while southern counties are at pink bud in early varieties.

This stage marks a critical transition in disease management, particularly for apple scab, powdery mildew, and cedar apple rust, as well as key insect management timings.

Phenology Dates by County (earliest varieties)

County Green Tip Tight Cluster Pink Bud
Cumberland 3/22 3/28 4/3
Gloucester 3/22 3/28 4/3
Burlington 3/22 3/28 4/2
Mercer 3/22 3/28 4/2
Middlesex 3/22 4/1 TBD
Monmouth 3/22 TBD TBD
Hunterdon 3/22 TBD TBD
Morris 3/26 TBD TBD
Warren 3/30 TBD TBD
Sussex 3/31 TBD TBD
Bergen 3/22 4/1 TBD
Pink Lady apple variety in pink bud. Gloucester County, NJ. Photo by Katrina DeWitt

Figure 1: Pink Lady apple variety in pink bud. Gloucester County, NJ. Photo by Katrina DeWitt

Apple Scab
Models

Apple scab models are available through NEWA and RIMpro. These models currently indicate that ascospore maturity is increasing and will continue to rise rapidly over the next several days. Apply fungicides before infection events.

Current Update using the Upper Deerfield Station
  • ~13% maturity on April 1
  • ~15% on April 2
  • Forecasted to reach 25–40% by April 4–8
Management Considerations

Now that we have reached the tight cluster stage, it is important to select fungicides that target both apple scab and powdery mildew. Manzate is ineffective against powdery mildew. Keep in mind that powdery mildew prefers warm, dry conditions and does not require rainfall to infect. For farms in southern counties that have reached pink stage, it is important to begin targeting cedar apple rust. Manzate is effective against cedar apple rust.

  • Manzate + single-site fungicide
  • DMI (FRAC 3) for high pressure
  • Vangard (FRAC 9; not effective on cedar apple rust)
  • FRAC 7 (save Aprovia for summer; not effective on cedar apple rust)
  • Axios (great for scab and powdery mildew; novel FRAC 52)
  • FRAC 11 (save for summer)
  • Topsin (limited uses; consider saving for summer; FRAC 1; not effective on cedar apple rust)

Monitor:

  • NEWA models
  • Weather/wetting events
  • Phenology

Early control is critical to avoiding season-long pressure.

Insect Update

Ambrosia Beetle:

  • Ambrosia beetles have been detected in Burlington, Salem, Gloucester, and Middlesex counties
  • Activity has not yet been observed further north at this time
  • Observed activity is low and is not a concern

Continue monitoring traps, particularly in stressed or newly planted blocks, as activity may increase with warming temperatures.

Mating Disruption Timing:

  • Codling moth (CM) mating disruption should be applied around pink
  • Growers should begin preparing materials and planning applications now
Summary
  • Apple phenology is progressing across New Jersey, with northern counties at tight cluster and southern counties at pink bud in early varieties
  • This stage marks a critical period for apple scab and powdery mildew management, as well as key insect timings
  • Apple scab ascospore maturity is increasing (~13–15%) and is forecasted to reach 25–40% over the next several days, increasing infection risk
  • Fungicide applications should be applied prior to infection events, with materials selected to target both scab and powdery mildew
  • In southern counties at pink, begin targeting cedar apple rust

Pears
Pear Phenology Update

Pear phenology has advanced rapidly across southern New Jersey over the past week. Observations made on April 2 indicate that most European pear varieties are now at early white bud, following cluster separation but prior to petal show, with some blocks progressing into popcorn stage.

Asian pear varieties are more advanced, with many blocks at popcorn stage and approaching bloom.

White bud/popcorn. Asian pear variety phenology. Salem County, NJ.

Figure 2. White bud/popcorn. Asian pear variety phenology. Salem County, NJ. Photo by Katrina DeWitt.

Pear Psylla

Pear psylla activity has been variable across southern New Jersey. Observations from April 2 indicate differences by county:

  • Salem County: adults and eggs observed
  • Gloucester County: none observed
  • Burlington County: no activity observed to date
  • Mercer County: no activity observed to date

Overall pressure remains relatively low in many orchards. This is likely due, in part, to recent oil applications, particularly where oil was combined with materials such as Esteem, which can suppress egg laying and early population development.

At this stage (white bud to popcorn):

  • Continue monitoring for adults, eggs, and the onset of nymph hatch
  • Use beating trays to assess adult activity
  • Examine developing shoots and leaves for egg presence

Management considerations:

  • In blocks without prior applications, or where psylla is present, consider a pre-bloom insecticide application
  • Consider applying particle films such as dormant oil or Surround to deter egg laying
  • With pre-bloom insecticide applications, softer materials should be used to avoid harming pollinator or beneficial insect populations
  • In blocks where adults are present at low pressure, insecticide options include Esteem (up to 2 applications 14 days apart), Centaur, or Aza-Direct
  • In blocks where adults are present at high pressure (more than 4 adults per beating tray), insecticide options include Apta, Assail, or AgriMek
  • Insecticides should be applied prior to bloom, as use during bloom is restricted due to pollinator protection

As bloom approaches (particularly in Asian pears):

  • Avoid applications that may impact pollinators
  • Management focus will shift to early nymph control post-bloom
Pear Diseases
Fire Blight and Early Season Management

As pears approach bloom, fire blight risk will increase significantly, especially given the recent wet conditions and continued rainfall through the weekend. These conditions are favorable for bacterial spread and infection.

As bloom approaches:

  • Begin planning for antibiotic applications, particularly if warm and wet conditions persist
  • Kasumin may be used at bloom and petal fall
  • Streptomycin and oxytetracycline remain key options, particularly post-bloom
  • Rotate chemistries to support resistance management
Pear Scab

RIMpro modeling for pear scab in Upper Deerfield has indicated low infection risk to date, but conditions are rapidly becoming more favorable for infection.

The primary infection model shows maturing ascospores present and available, with multiple wetting events occurring from late March through early April. These rain events are driving spore release and infection potential, with additional infection periods forecasted in the coming days.

From white bud to popcorn:

  • Protective fungicide programs should now be in place and maintained, particularly ahead of rain events
  • Applications of mancozeb or ziram tank-mixed with Procure, Cevya, or Vangard are effective options for scab control
  • Applications should be made prior to rainfall events, as infections occur during wetting periods
  • If 2 inches or more of rainfall occur following an application, a follow-up spray should be considered to maintain protection

As we move toward bloom:

  • Continue programs targeting pear scab, rust diseases, and Fabraea leaf spot
  • Particular attention should be paid to Asian pear varieties, which are further advanced and at greater risk
Summary
  • Observations from April 2 indicate most European pears are at early white bud, with some at popcorn stage
  • Asian pears are at popcorn and approaching bloom
  • Pear psylla activity remains variable across counties, with adults and eggs observed in Salem County
  • Reduced pressure in some blocks is likely due to oil applications, with or without Esteem
  • Where oil was not applied, or psylla is present, pre-bloom insecticide applications should be considered
  • Insecticide applications must be completed prior to bloom to protect pollinators
  • Recent and continued rainfall is increasing disease pressure, particularly for pear scab and fire blight
  • Fungicide programs should be actively maintained, with reapplication needed after significant rainfall (2 inches or more)
  • Fire blight risk will increase rapidly as bloom approaches, so antibiotic programs should be prepared

Continued scouting is critical over the next 7–10 days as phenology and pest pressure accelerate.

Peaches
Peach Phenology

Peach varieties across New Jersey were observed at the pink bud stage this week. Nectarines are more advanced, with the majority observed near or in bloom in South Jersey. Development is progressing steadily and will continue as temperatures warm.

Brown Rot

Blossom infections from the brown rot fungus can occur whenever pistils are exposed, and favorable environmental conditions are present.

Infections can occur during any wetting period when temperatures are between 41 and 86°F. Optimum conditions occur with wetting and temperatures in the mid-70s. During extended wetting periods (several days or more), blossoms can be infected regardless of temperature. Infections under suboptimal conditions are generally less severe.

Blossoms and fruitlets remain susceptible until the pistil desiccates, which occurs sometime between petal fall and shuck split.

Management Considerations

  • Fungicides used for control at the blossom blight stage should not overlap with fungicides used in the pre-harvest stage of brown rot
  • Try to save fungicide options with low pre-harvest intervals for later in the season
  • Bravo Weather Stik + single-site fungicide
  • Vangard (applied at pink stage)
  • Rovral (applied at full bloom)
  • Flint Extra (applied at petal fall)

Initiate coverage for blossom blight starting at pink for short-petaled varieties and at 5–10% bloom for showy flowers. Refer to the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.

Insect Update

Mating Disruption Timing:

  • Oriental fruit moth mating disruption should be applied at pink
  • Growers should begin preparing materials and planning applications now

Scale:

  • Oil applications may be safely applied up to pink on peach
  • Oil can be applied alone or in combination with insecticides, including Centaur, Sivanto Prime, and Esteem

Green Peach Aphid:

  • Scouting should begin at pink stage
  • Thresholds for treatment are 1 colony/tree in nectarines or 2–3 colonies/tree in peaches
Summary
  • Observations indicate peaches are at pink bud across New Jersey, with nectarines more advanced and approaching or in bloom in South Jersey
  • Development is progressing steadily and will accelerate with warming temperatures
  • Brown rot infection risk is present whenever blossoms are exposed under wet conditions, particularly between 41–86°F
  • Blossoms remain susceptible through petal fall to shuck split
  • Fungicide programs should be initiated at pink to early bloom, depending on flower type, while avoiding overlap with pre-harvest materials
  • Oriental fruit moth mating disruption should be applied at pink; growers should prepare materials now
  • Oil applications for scale can be made up to pink and may be tank-mixed with labeled insecticides
  • Green peach aphid scouting should begin at pink, with treatment thresholds of 1 colony/tree in nectarines and 2–3 colonies/tree in peaches

Continued scouting and timely applications will be critical over the next 7–10 days as phenology advances.

Filed Under: Commercial Ag Updates, Disease Forecasting, Fruit, Tree Fruit Tagged With: , , , , , , , , , , , , ,
March 30, 2026 , and

Apple Scab Update

Apple Scab Update  

Apple scab models are currently forecasting potential infection periods from March 31st-April 2nd. This is based on a green tip date of March 22nd which was observed across the state aside from the most northern counties. Conditions may be optimal for further scab infection events on April 5th-6th. Model outputs are most accurate within 48-72 hours of the date in question,which should be kept in mind when making management decisions. It will be critical for growers to keep an eye on the models to make timely management decisions for optimal disease control. If you have recently applied copper, you will be covered for this infection period. Other effective options include Manzate at 3 lb/A + Syllit at 1.5 pt/A or Manzate at 3 lb/A + Vangardat 3-5 oz/A.  

NEWA   

The Network for Environment and Weather Applications (NEWA) offers forecasting models for numerous disease and insect pests on a variety of crops including apple scab. This model allows you to select your own weather station or one closest to your farm to get real time information on when apple scab infections may occur. This allows you to make informed management decisions and apply effective fungicides prior to an infection event, which is the ideal timing for optimal disease control. Once you have selected your weather station, you can enter the date you noted green tip on your earliest variety (this will be 3/22 for the majority of NJ this year).  

First, you will see the ‘Ascospore Maturity Summary’ chart. This will give you information on ascospore maturity, daily ascospore discharge, and cumulative ascospore discharge. Right now, the most important number to pay attention to is the daily ascospore discharge. The higher the daily ascospore discharge, the more severe the infection event will be. If the daily ascospore discharge is greater than 10%, there will be a significant scab infection event and fungicides should be applied prior to this event for management. If the daily discharge is above 20%, there will be an extreme infection event, and the most efficacious fungicides (DMI + Manzate) should be applied before the infection for control.   

The next chart will be the ‘Infection Events Summary’. This will tell you if the weather conditions are optimal for apple scab infection. It includes weather data and tells you if there will be an infection event with the readouts ‘Yes’, ‘Combined’, or ‘No’. This information should be compared with the daily ascospore discharge to determine what efficacy of fungicide should be used for a given infection period.  

 

Apple Scab Management Considerations 

  • If you have not applied copper yet, it should be applied before this upcoming potential infection period March 31st-April 2nd  
  • Copper applied after ½” green can cause phytotoxicity and fruit finish concerns  
  • If you have already applied copper, since this is a low-risk infection period, Manzate at 3 lb/A + Syllit at 1.5 pt/A or Manzate at 3 lb/A plus Vangard at 3-5 oz/A would be sufficient management options  
  • Keep in mind, powdery mildew control begins at tight cluster and cedar apple rust control begins at pink 
  • The DMI fungicides should be saved for tight cluster and later timings since they are some of the best options for powdery mildew and cedar apple rust 
Filed Under: Commercial Ag Updates, Disease Forecasting, Fruit, Tree Fruit Tagged With: , , , , , ,