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. Cooler weather this weekend should help slow development.
In apples, green tip for Pink Lady was observed around March 22 across both southern and some northern regions, with Honeycrisp following around March 26. In pears, swollen buds were observed around March 11, with green clusters reaching by March 26 in southern New Jersey. Peach varieties in southern New Jersey were observed at the swollen bud stage this week.
Apples
Green Tip Dates by County
| County | Green Tip Date (earliest varieties) |
| Cumberland | 3/22 |
| Gloucester | 3/22 |
| Burlington | 3/22 |
| Mercer | 3/22 |
| Middlesex | 3/22 |
| Monmouth | 3/22 |
| Hunterdon | 3/22 |
| Morris | TBD |
| Warren | TBD |
| Sussex | TBD |
| Bergen | TBD |
Apple Scab
Models
Apple scab models are available through NEWA and RIMpro. Apply fungicides before infection events when discharge exceeds thresholds (10–20%).
Current Update
- ~2% ascospore maturity (March 25)
- ~7% by March 31
- ~10% by April 1
- Low cumulative discharge (~1–4%)
Management Considerations
Copper can be applied now but avoid after ½” green.
- Manzate + single-site fungicide
- DMI (FRAC 3) for high pressure
- Vangard (FRAC 9)
- FRAC 7 (save Aprovia)
- Axios (save for later)
- Syllit (avoid if resistance)
- FRAC 11 (save for summer)
- Topsin (limited uses)
As we move toward tight cluster:
- Rapid ascospore increase
- Higher infection risk with rain
Monitor:
- NEWA models
- Weather/wetting events
- Phenology
Early control is critical to avoid season-long pressure.
Scouting Calendar
Use as a scouting guide only (not for spray timing).
- Green tip: March 22–26
- Ascospore maturity: 2–7% increasing
Key Points
- Minimal difference between North and South Jersey
- Green tip ~March 22
- Prepare for scab infection events
- Build fungicide rotation now
Pears
Pear Phenology Update
Pear phenology is progressing, with swollen buds observed around March 11 and green clusters observed on March 26 in southern New Jersey.
Pear Psylla
Pear psylla activity has begun in southern New Jersey, with variability across counties:
- Salem County: adults and eggs observed
- Gloucester County: eggs observed
- Burlington County: no activity observed to date
These observations indicate that egg laying is underway in the southernmost regions and will likely progress north with warming temperatures. Reports from surrounding regions also suggest psylla activity is increasing.
At this stage:
- Continue monitoring for eggs and early nymphs
- Use beating trays to assess adult activity
- Examine buds and developing shoots for egg presence
Dormant oil applications should be applied where possible to deter psylla egg laying and suppress early populations. Timely applications are especially important in areas where activity has already been observed.
At green cluster:
- Oil is often combined with an insecticide to target migrating adults
- In lieu of oil, particle films such as Surround may be used starting at swollen bud and continuing through bloom
Materials such as Esteem, Centaur, and Sivanto Prime may also be incorporated, depending on timing and pressure.
Figure 1. Adult pear psylla laying eggs at swollen bud. Photo by Janine Spies.
Pear Diseases
Fire Blight and Early Season Management
Dormant copper applications should be applied for fire blight and pear scab suppression, but no later than green tip if fruit russet is a concern. Where copper has already been applied, early-season risk is likely reduced.
As bloom approaches:
- Begin planning for antibiotic applications
- Kasumin may be used at bloom and petal fall
- Other options include streptomycin and oxytetracycline for post-bloom use
Rotating chemistries is important for resistance management.
Pear Scab
RIMpro modeling for pear scab in Upper Deerfield indicates low infection risk at this time, with infection values remaining below threshold levels. Despite recent wetting events, limited ascospore maturity is restricting infection potential.
Growers who have applied dormant copper are likely adequately protected under current conditions. Protective fungicide programs should begin at the cluster bud stage, particularly as we approach tighter cluster and bloom, when risk will increase.
Materials such as Ziram or EBDC formulations provide effective protection. At white bud, include materials effective against pear scab, rust diseases, and Fabraea leaf spot. Particular attention should be paid to rust on Asian pear varieties.
Dormant urea applications may also be used, where appropriate, to help reduce overwintering inoculum.
Summary
- Pear psylla activity has begun in southern New Jersey, with adults and eggs observed in Salem County and eggs in Gloucester County
- Dormant oil applications should be applied to suppress egg laying and early populations
- Copper applications should be completed by green tip where russet is a concern
- Pear scab risk is currently low based on RIMpro modeling
- Fungicide programs for pear scab should begin at cluster bud as risk increases
- Dormant urea may be used to reduce overwintering inoculum
Continued scouting will be important over the next 1–2 weeks as both insect and disease pressure increase with advancing phenology.
Peaches
Peach Phenology
Peach varieties in southern New Jersey were observed at the swollen bud stage this week. Development is progressing steadily and will advance with warming temperatures.
Figure 2. Peach Swollen Bud. Photo by Janine Spies.
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.
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.
Scale Insects
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.
