May 22, 2026 and

Vegetable IPM Update 5/22/26

Greetings from the Veg IPM team! Here are the most recent pest and disease issues we’re seeing in various vegetable crops.

[Read more…]

Filed Under: Organic Production, vegetable, Vegetable Crops Tagged With: , , , ,
May 19, 2026 , , , , , , , and

Vineyard Management Following Freeze Injury and Reduced Crop Potential 

Vineyard Management Following Freeze Injury and Reduced Crop Potential
What Caused the Widespread Freeze Injury?

The widespread freeze injury observed this spring followed several nights of below-freezing temperatures after unusually warm early-season conditions accelerated bud development throughout much of New Jersey. In many southern New Jersey production regions, temperatures dropped into the mid-20s°F, while in northern areas they were near or below 20°F. Clear skies and calm wind conditions likely intensified injury through radiational cooling and rapid heat loss from actively growing green tissue. Comparable freeze injury has been reported across much of the Northeast and Mid-Atlantic this season, particularly in vineyards.

Damage severity varied substantially across vineyards depending on location, topography, vine developmental stage, and cultivar. Low-lying frost pockets generally sustained more severe damage, while elevated sites and some coastal areas sustained less damage. Vineyards with vines still in earlier developmental stages often escaped damage more successfully than vineyards with actively expanding shoots and flower clusters. Even within the same vineyard block, damage may vary considerably depending on local elevation changes, air drainage, and cold-air movement patterns. Because of this, management decisions should be based on detailed observations and adjusted in light of remaining crop potential and vine recovery. Although crop loss is the immediate concern in many vineyards, freeze injury may also alter canopy development, nutrient demand, disease pressure, and long-term vine productivity.

Evaluating Freeze Injury and Vineyard Recovery

The full extent of freeze injury is not immediately apparent. Injured shoots and flower clusters may continue to deteriorate for several days after freezing temperatures, and growers should avoid making rapid assumptions about final crop loss immediately after injury. In many vineyards, much of the damage only becomes evident as secondary buds begin to emerge and fruit set progresses. Some vines that initially appeared heavily damaged may still yield partial crops through surviving secondary buds, while others may continue showing delayed injury symptoms over the coming weeks.

Fortunately, grapevines recover from freezes through shoot growth from secondary and tertiary buds within count buds, release from inhibition of basal buds, and development of adventitious shoots from latent buds. These features give vines the capacity for recovery after freeze events.

Primary buds are generally the most productive and account for the majority of crop production. When primary shoots are damaged or killed, secondary buds may emerge within days to weeks, depending on weather conditions and vine vigor. Although secondary shoots often produce smaller clusters and reduced yields, they may still contribute meaningfully to crop recovery in some cultivars. Figure 1 provides an example of freeze injury where a frost-killed shoot from the primary bud is accompanied by new development emerging from a surviving secondary bud.

Figure 1. The frost-killed young shoot (right) of Chambourcin and a new bud developing from the secondary bud (left).

Figure 1. The frost-killed young shoot (right) of Chambourcin and a new bud developing from the secondary bud (left). Photo by H. Gohil

 

In many Vitis vinifera cultivars, secondary shoots may support only a fraction of a normal crop. However, several hybrid cultivars may retain greater productivity following freeze injury.

When both primary and secondary buds are damaged, tertiary buds may still produce vegetative shoots. While tertiary growth and adventitious shoots generally contribute little or no fruit, they remain critically important for rebuilding the canopy and maintaining vine productivity for future seasons.

Vineyards may also contain both primary and secondary shoot-derived clusters on the same vine, contributing to uneven crop development and maturity (Figure 2).

Figure 2. Vidal Blanc, a shoot from the primary bud, had a typical cluster; on the same cordon, a shoot from the secondary bud had a smaller cluster.

Figure 2. Vidal Blanc, a shoot from the primary bud, had a typical cluster; on the same cordon, a shoot from the secondary bud had a smaller cluster. Photo by H. Gohil

As recovery continues, vineyards may contain a mixture of surviving primary shoots, secondary regrowth, and delayed vegetative growth. Uneven canopy development may complicate pest management, fungicide timing, canopy management, and harvest timing later in the season.

Growers should continue monitoring:

  • Primary and secondary shoot survival
  • Cluster development on secondary shoots
  • Variability within vineyard blocks
  • Low-lying frost pockets and delayed-growth areas
  • Trunk or cordon vascular injury
  • Sucker emergence and retraining potential
  • Overall vine vigor and canopy development

Management decisions may differ substantially among blocks depending on remaining crop potential.

Avoid Removing Frost-Damaged Shoots Prematurely

Although severely damaged shoots may appear unlikely to recover, removing frost-injured shoots too early often provides little benefit and may unintentionally reduce remaining crop potential.

In many situations, allowing vines time to recover naturally is the best approach, particularly when injury severity is still being assessed. Removal of damaged tissue too soon may eliminate secondary or latent buds capable of producing additional growth. Dead or injured tissues frequently dry and detach naturally over time without intervention.

Growers should therefore avoid making aggressive canopy removal decisions immediately after freeze injury unless tissue viability and recovery potential are clearly understood.

Vineyard Recovery Scenarios and Canopy Management Considerations

Primary Bud Loss with Secondary Regrowth

In vineyards where primary shoots were largely lost, growers should allow time for secondary buds to push before making major management decisions. Depending on temperatures and vine vigor, secondary shoots may emerge within days to weeks following injury.

Although crop potential will often be reduced, canopy development may still recover relatively uniformly. Delayed development should be expected, and management programs may need to be adjusted according to new growth stages rather than original seasonal timelines.

Dead tissues often fall naturally and may not require immediate removal unless they interfere with vineyard operations or pose a disease risk.

Partial Shoot Injury

Freeze injury is often uneven, even on the same vine. Some shoots may experience leaf injury while retaining healthy shoot tips and continue to grow normally. In these situations, little intervention may be necessary.

Figure 3. Epical meristem is actively growing (left) in Marquette and completely frost-damaged in Chardonnay (Right)

Figure 3. Epical meristem is actively growing (left) in Marquette and completely frost-damaged in Chardonnay (Right). Photos by H. Gohil

However, when shoot tips are killed, continued development may stop, and secondary buds near the base of shoots may begin to grow instead. Vineyard managers should carefully monitor which shoots remain viable and adjust canopy management accordingly. Careful evaluation of shoot tip survival can help determine whether shoots are likely to continue growing or whether regrowth from secondary buds should be expected (Figure 3).

Because vineyards frequently contain both surviving and injured shoots after freeze events, variability within rows and blocks should be expected.

Severe Injury and Cordon or Trunk Damage

In some vineyards, no primary, secondary, or tertiary growth may emerge from portions of the vine, indicating more substantial injury to cordons or vascular tissues. In these situations, strong suckers emerging from the trunk may offer opportunities for retraining vines for future production. Although current-season yields may be lost, maintaining healthy vegetative growth remains critical for long-term vineyard recovery and productivity.

Shoot Thinning Requires a Different Approach This Year

Canopy management recommendations following freeze injury may differ substantially from those of a normal season. Under normal conditions, shoot thinning improves airflow, reduces canopy density, and enhances fruit quality. However, in freeze-damaged vineyards, excessive shoot removal too early may unintentionally increase vine vigor and promote overly vegetative “bull cane” growth with limited fruitfulness. Retaining additional shoots may reduce excess vigor, help balance vine growth, and preserve vine structure for next season. Decisions regarding thinning should therefore be adjusted according to cultivar, remaining crop potential, pruning system, vine vigor, and recovery patterns.

Nitrogen Management Following Freeze Injury

One of the key management questions following widespread freeze injury is whether vineyard nitrogen (N) programs should be adjusted under reduced crop conditions.

In many New Jersey vineyards, nitrogen applications are not made annually and are often applied only every 3 to 5 years. Excessive vine vigor is frequently a greater concern than nitrogen deficiency, particularly in seasons with abundant precipitation. In addition, vineyard soils with moderate to high organic matter often provide substantial nitrogen through natural mineralization. As a general guideline, approximately 20 pounds of nitrogen per acre may become available annually for each 1% soil organic matter.

Following freeze injury, nitrogen demand may be substantially altered due to reduced fruit load. In vineyards where primary buds were lost and crop potential has been significantly reduced, nitrogen requirements are also likely lower than in a typical production year.

Excess nitrogen application under low-crop conditions may unintentionally stimulate excessive vegetative growth, resulting in overly vigorous canopies and increased management challenges later in the season. Excessive vigor may also reduce winter hardiness and negatively affect vine acclimation as vines enter dormancy.

Growers should therefore avoid making automatic nitrogen applications before crop potential becomes clearer.

Where petiole analysis from previous seasons indicated nitrogen deficiency, some nitrogen inputs may still be warranted. However, management decisions should be adjusted according to expected yield, vine vigor, and vineyard history.

It is also important to remember that much of the nitrogen supporting early-season growth from bud break through bloom originates from reserves already stored within the vine. Because of this, immediate nitrogen applications following freeze injury are generally unlikely to improve short-term recovery.

Nitrogen applications are typically timed from approximately two weeks before bloom through two weeks after bloom. In freeze-affected vineyards this season, delaying nitrogen decisions until bloom may allow growers to better evaluate secondary bud survival, crop recovery, and overall fruit potential before making fertility adjustments.

Reduced fruit load means reduced nitrogen demand. In many vineyards affected by freeze injury, a conservative nitrogen management approach may help avoid excessive vigor while supporting long-term vine health and winter hardiness.

Weed Management Following Freeze Injury 

The goal during a low- or no-crop year is not to maintain a completely weed-free vineyard floor, but to reduce perennial weed populations, prevent annual weed seed production, manage excessive vine vigor, and prepare for the following season. 

Low crop years provide a unique opportunity to address persistent weed problems that are often difficult to manage during seasons with normal fruit production. With reduced concerns about immediate crop losses, vineyard managers can shift their focus from protecting current yield to improving long-term vineyard floor management and reducing future weed pressure. 

Prioritizing Perennial Weed Management 

Perennial weeds should be the primary target during low-production years. Effective suppression of species such as mugwort (Artemisia vulgaris), field bindweed (Convolvulus arvensis), poison ivy (Toxicodendron radicans), multiflora rose (Rosa multiflora), Canada thistle (Cirsium arvense), or goldenrod (Solidago spp.) typically requires a multi-year management approach. A season with little or no crop presents an ideal opportunity to target these species when they are actively growing and most susceptible to control measures. Directed applications of systemic herbicides or repeated mowing may help reduce underground reserves and limit re-establishment in subsequent years. 

Rethinking Annual Weed Management 

Unlike perennial weeds, annual weeds may not require complete season-long suppression during a low crop year. Moderate levels of annual weed growth within the row can provide some competition for water and nutrients, potentially helping to moderate excessive vine vigor that frequently develops when crop load is substantially reduced or absent. Excessive vegetative growth can increase canopy management requirements, reduce spray penetration, and create favorable conditions for disease development. For this reason, vineyard managers may be able to tolerate greater annual weed presence than would normally be acceptable in a full-crop season, provided weeds are prevented from producing seed. Mowing and mechanical suppression may therefore become more important management tools than repeated postemergence herbicide applications, particularly where annual weed populations are not interfering with vineyard operations. 

Preparing for the Following Season 

Although some annual weed competition may be acceptable during the growing season, vineyard floors should be as free of weeds as possible by late summer and early fall. Clean vineyard rows improve the effectiveness of fall weed management programs and allow timely application of residual herbicides where appropriate. Reducing existing vegetation before fall applications can improve soil coverage and help establish a cleaner vineyard floor entering the 2027 growing season. 

Scouting and Mapping Problem Areas 

Low crop years also provide an excellent opportunity to scout vineyards and document the location of troublesome perennial weed infestations. Mapping species composition and problem areas can improve future management decisions, facilitate site-specific applications, and help prioritize areas requiring more intensive intervention in subsequent seasons. Investments made in weed management during a low-production year can provide benefits that extend well beyond a single season.

Disease Management Following Freeze Injury

Although immediate concerns following freeze events often focus on crop loss, freeze injury can substantially alter disease risk throughout the growing season. Damaged shoots and leaves are more vulnerable to infection once warm, wet conditions return, while wounds in shoots and permanent wood may provide entry points for pathogens such as Botrytis and grapevine trunk diseases.

Even when crop potential is limited, disease management remains important. Maintaining healthy foliage supports carbohydrate storage, winter hardiness, and next year’s productivity. Disease priorities may shift away from fruit protection and toward preserving canopy health and minimizing inoculum for future seasons.

Remember, long-term vineyard health is the goal this season. Managing diseases that cause defoliation and negatively affect grapevine health remains critical, even in vineyards with little or no harvestable crop.

Key diseases to continue monitoring include:

  • Downy mildew
  • Powdery mildew
  • Black rot
  • Botrytis bunch rot
  • Phomopsis cane and leaf spot
  • Anthracnose in susceptible cultivars

Dense regrowth following freeze injury may increase canopy humidity and prolong leaf wetness periods, creating favorable conditions for disease development. Good canopy airflow and spray penetration remain important, and practices such as shoot positioning and, if needed, selective thinning may help improve canopy conditions. Management decisions should continue to be guided by vineyard history, weather conditions, canopy density, and ongoing regrowth patterns rather than calendar timing alone.

Insect Management Considerations Following Freeze Injury

Although freeze injury may substantially reduce crop potential, insect management should not be abandoned entirely. Reduced fruit load does not necessarily reduce insect pressure, and some pests may still negatively affect vine health, vegetative growth, or future productivity.

In vineyards with limited or no crop, management priorities may shift away from fruit protection and toward preserving canopy health, minimizing vine stress, and maintaining productive vines for future seasons. Continued scouting remains essential, particularly as secondary and tertiary growth emerges following freeze injury.

Growers should continue monitoring for key vineyard pests, including:

  • Grape berry moth
  • Japanese beetle
  • Spotted lanternfly
  • Phylloxera in susceptible vineyards
  • Leafhoppers and other sap-feeding insects
  • Mites during hot, dry periods
  • Grape flea beetle and climbing cutworms where injury is present

Secondary shoots and delayed regrowth may remain susceptible to feeding injury throughout the season, particularly when vines are already stressed from freeze damage. Insect feeding on recovering canopies may further reduce photosynthetic capacity and negatively affect carbohydrate storage needed for winter survival and next season’s productivity.

At the same time, reduced crop potential may allow greater flexibility in treatment thresholds in some situations. Vineyard managers should continue making management decisions based on scouting observations, pest pressure, remaining crop potential, and overall vine recovery rather than relying solely on calendar-based schedules.

Spotted lanternfly (SLF) deserves particular attention in freeze-affected vineyards. Heavy feeding by large populations can place additional stress on vines already recovering from freeze injury. Vineyards with a history of SLF pressure should continue monitoring and management efforts where warranted.

Even in vineyards with little or no fruit, maintaining healthy foliage remains important. Protecting functional canopy growth throughout the season will help support carbohydrate storage, winter hardiness, and productive growth in future years.

Final Considerations

As vineyard recovery continues over the coming weeks, management programs will likely need to remain flexible. The full extent of freeze injury may not become apparent until secondary growth progresses and crop potential becomes clearer.

Management decisions should therefore be adjusted based on remaining crop potential, canopy recovery, vine vigor, and vineyard-specific conditions rather than standard seasonal assumptions. Different blocks within the same vineyard may require substantially different approaches depending on injury severity and remaining productivity.

Even in vineyards with severely reduced crop potential, maintaining healthy foliage and vine structure remains critical for long-term productivity. Continued attention to canopy management, nutrient decisions, disease prevention, and insect scouting will help support carbohydrate storage, winter hardiness, and productive growth in future seasons.

Growers are encouraged to continue closely monitoring vineyard recovery and adjust management programs as the season progresses.

Filed Under: Fruit, Wine Grape Tagged With: , , , , , , , , , , ,
May 19, 2026 , , and

Fruit IPM Report for Week of 5/11/2026

 

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

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

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

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

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

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

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

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

  • Rosy apple aphid activity has been very low to start this season. RAA can feed extensively on foliage and terminals, causing leaf curling and stunting. This can impact next year’s fruit that will be set this season. Without fruit, the trees may tolerate a higher threshold of these pests, but they should still be managed.
    • Monitor for colonies during bloom and use a treatment threshold of 1 colony/tree at petal fall.
  • Green Apple (Spirea) Aphids (GAA) colonies are being observed in some apple blocks. GAA is generally a pest that can be tolerated because it causes little direct damage.
    • Treatment thresholds for GAA are met if 50% of the shoots are infested with no beneficial insects present.
    • Movento will control GAA and should control scale when applied in mid-May, and suppress scale when applied in late May or early June.
  • Ambrosia Beetle
    • Trap captures have decreased across NJ, indicating peak flight has ended or is coming to an end.
    • Infested trees should be showing signs of stress or will soon.
    • If you have had a history of this pest in your orchard, you should begin scouting for damage and flag any trees that have been attacked for continued monitoring.
  • Codling Moth (CM)
    • A codling moth biofix was set in Southern counties on 4/20 and in Northern counties on 5/5. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Where Mating Disruption has been employed, supplemental Madex applications should be made at the timings listed below.
    • Codling Moth Degree Day Timing
      Application and Insecticide Type
      County Area Biofix Rimon:

      75-100DD + 14-17 days later

       

      		 Intrepid

      150 + 450 DD

      Diamides – Altacor, Voliam mixes: (150-200 DD)

      		 Madex

      250 DD + 7-10 days during brood hatch (later if first spray is an IGR)

      		 Standard Insecticides –  Delegate, Avaunt, OP’s, carbamates, pyrethroids

      250 DD + 550 DD

       
      DD 75 100 150 450 250 250 550
      Southern April 20 Past Past Past 6/1 5/18 5/18 Too far off
      Northern  May 5 5/12 5/14 5/17 Too far off 5/21 5/21 Too far off
  • Plum curculio, tarnished plant bug, stink bugs, BMSB, TABM, and OBLR:
    • In most blocks, treatment is not necessary where little to no fruit is present
    • The timing to treat plum curculio has passed.
  • Mites:
    • Continue to use standard thresholds through June
    • Maintaining healthy foliage is important for return bloom next season
Traps

Average Trap Captures in Apple – Southern Counties

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

 

Average Trap Captures in Apple – Northern Counties

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

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

Peaches
Disease Management

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

Bacterial leaf spot on peach

Figure 3. Bacterial leaf spot on peach

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

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

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

Terminal flagging due to Oriental fruit moth.

Figure 4. Terminal flagging due to Oriental fruit moth.

Oriental Fruit Moth (OFM)

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

    170-200, 350-375

    		 Diamide

    100-150, 300-350
    Gloucester – Southern 556 1st –past

    2nd – past

    		 1st –past

    2nd –past
    Middlesex – Northern 456 1st –past

    2nd –5/13-5/15

    		  1st – past

    2nd –5/10-5/13

Scale

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

Green Peach Aphid

Plum Curculio

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

Tarnished plant bugs and other catfacing insects

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

Lesser and Greater Peach Tree Borers

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

Average Trap Captures in Peach – Southern Counties

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

 

Average Trap Captures in Peach – Northern Counties

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

Blueberries
Blueberry Phenology

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

Insect Update

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

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

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

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

Table 1. Beating Tray Sampling Data

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

Table 2. Fruit Sampling Data

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

Trap Monitoring

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

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

Table 3. Trap Sampling Data

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

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

Grapes
Grape Phenology

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

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

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

Grapevines with secondary bud break.

Figure 5. Grapevines with secondary bud break.

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

      Spotted lanternfly nymphs on grapevines.

      Figure 6. Spotted lanternfly nymphs on grapevines.

  • Grape berry moth adults continue to be trapped in pheromone traps in vineyards where there is surrounding pressure from wild grapes.
Filed Under: Blueberry, Fruit, Tree Fruit, Uncategorized, Wine Grape Tagged With: , , , , , , , , , , , , , , , , , , , , , ,
May 12, 2026 , , and

Fruit IPM Report 5/11/2026

 

Apples

Disease Management Considerations

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

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

Frogeye leaf spot on apple.


Figure 1. Frogeye leaf spot on apple.

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

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

Insect Update

Codling Moth: A Codling Moth Biofix was set in Southern counties on 4/20 and in Northern counties on 5/5. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Where Mating Disruption has been employed, supplemental Madex applications should be made at the timings listed below.

Codling Moth Degree Day Timing
Application and Insecticide Type
County Area Biofix Rimon:

75-100DD + 14-17 days later

 

 Intrepid

150 + 450 DD

Diamides – Altacor, Voliam mixes: (150-200 DD)

 Madex

250 DD + every 7-9 days during brood hatch (later if first spray is an IGR)

 Standard Insecticides –  Delegate, Avaunt, OP’s, carbamates, pyrethroids

250 DD + 550 DD

 
DD 75 100 150 450 250 250 550
Southern April 20 Past Past 5/9 Too far off 5/19 5/19 Too far off
Northern  May 5 5/12 5/14 5/19 Too far off Too far off Too far off Too far off

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

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

Ambrosia Beetle: Trap captures have decreased from previous weeks in South Jersey, indicating peak flight has ended. However, in some of the northernmost New Jersey counties, trap captures are increasing, which indicates we are entering peak flight. Infested trees should be showing signs of stress or will be soon. Once these beetles bore into the trunk, they will form a gallery in the heartwood of the tree to lay their eggs and farm the ambrosia fungus to feed themselves and their larvae. Once the female lays her eggs, it will take about 30 days for the eggs to hatch and the adults to emerge from their host tree to begin the second flight. If you have had a history of this pest in your orchard, you should begin scouting for damage and flag any trees that have been attacked for continued monitoring.

Pears
Pear Diseases

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

Pear Psylla

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

Peaches
Peach Diseases

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

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

      Bacterial leaf spot on peach.

      Figure 2. Bacterial leaf spot on peach.

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

 

 

Insect Update

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

Oriental Fruit Moth (OFM)

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

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

170-200, 350-375

 Diamide

100-150, 300-350
Gloucester – Southern 434 1st –past

2nd – past

 1st –past

2nd –past
Middlesex – Northern 325 1st –past

2nd –5/12-514

  1st – past

2nd –5/9-5/12

Green Peach Aphid: Aphid activity has been very low to start this season. GPA colonies usually begin forming sometime during bloom. Examine trees for the presence of aphids by counting the number of colonies on ten trees and use a treatment threshold of 2 colonies/tree at petal fall for peach, and 1 colony/tree for nectarine. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Aphid colonies curling leaves was noted in southern counties starting the week of 5/4.

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: Injury on fruit from plum curculio has been observed on developing peaches and apples in southern counties (Figure 3). Plum curculio start to move into orchards at about 88-100 degree days base 50 after January 1. Applications for PC should be initiated once all petals are off, with a second application made with ovicidal materials at 379-402 DD. We are currently past this treatment window, as southern counties have accumulated about 508 DD base 50, and northern counties have accumulated 457 DD base 50. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Tarnished plant bug and catfacing insect activity has been low and is considered a low priority for management where fruit is not present. If you are planning to retain a crop, you must continue to intensively manage insect pests as you would in a normal season.

Plum curculio feeding in apple fruitlets.

Figure 3. Plum curculio feeding in apple fruitlets.

Scale Insects: White peach scale crawlers have not yet emerged, but usually begin emergence about the third week of May and continue emergence until about the middle of June. San Jose scale crawlers typically begin emergence about late May or Early June and continue emergence for up to 6 weeks. Control options during crawler emergence include Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide and the product labels for more information.

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

 

 

Blueberries
Insect Update

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

Table 1. Beating Tray Data

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

 

Table 2. Fruit Monitoring Data

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

 

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

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

Table 3. Trap Data

Cranberry Fruitworm

(AC)

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

 

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

Grapes
Diseases

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

Insect Update

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

Spotted lanternfly nymphs on grapevines.

Figure 4. Spotted lanternfly nymphs on grapevines.

 

Filed Under: Blueberry, Fruit, Tree Fruit, Uncategorized, Wine Grape Tagged With: , , , , , , , , , , , , , , , , , , , , ,
May 8, 2026 , , , , , , , , and

Managing Orchards Through a Season With Limited Yields 

The recent freeze event April 20-21, 2026, has had wide ranging impacts on fruit crops statewide, including but not limited to peaches, nectarines, cherries, apples, pears, and plums. Across 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, crop, cultivar, and ultimately phenological stage at the time of the freeze, with the most severe injury observed in low-lying areas and orchard blocks that were at full bloom or petal fall.  

Despite the reduced crop potential, continued pest monitoring and management remain important, particularly in blocks producing some fruit. Even where no fruit will be harvested, we need to adjust our approach to insect and disease management with a focus on maintaining healthy orchards for the next crop. Promoting tree health, maintaining low pest and disease inoculum, and supporting return bloom for the next season should be priorities for the remainder of this season. 

Orchard Tree Care 

Managing Crop Load in Apples 

  • If fruitlets are expanding, there is a good chance they will set fruit.   
  • Assessing internal browning of fruitlets shortly after a frost typically results in over estimation of damage; more time will be needed to determine both cropload and whether thinners will be warranted. 
  • If you saw damage to the fruitlets but they are holding on and growing you will likely have misshapen fruit. 
  • The most precise way to measure crop load THIS YEAR is to measure fruitlet diameter and input that data into the Cornell growth model (Malusim app). 
  • The best way to assess how many fruits you will have per tree is by using the fruit growth rate model (measuring diameters twice over a 5-day period). 
  • You should wait until fruits are 7mm before making the first measurement and then make a second measurement 5 days later and the model will predict what percentage of fruitlets are growing.   
  • When you make the first measurement, tag 15 spurs on each of 5 trees for a total of 75 spurs.   
  • When you enter the data in the Malusism app enter numbers for 5 fruits per spur even if the spur only has 1 or 2 fruits.  For the missing fruits enter a value of 0.1.   
  • The result after the second measurement will be a % fruit set.  To estimate how many actual fruits will be on the tree you need to do whole tree counts of flower clusters on 5 trees. 
  • If most of the spur flowers are killed and not growing, the bloom on one-year-wood should be preserved.  This is accomplished by waiting to apply thinners until the king fruit of those clusters is at least 12mm.  (By that time the fruits on spurs will be rather large, 16mm).  When the king fruits on the clusters from one-year-wood are 12mm, they are set well and will not thin off easily, but the lateral fruitlets on those clusters can still be thinned off.   
  • If by the time fruits are 16mm on spurs and 12mm on lateral bloom you determine that thinning is needed, you should thin according to the carbohydrate balance at that point in time.  Damaged fruits set with Promalin can be just as hard to thin off as undamaged fruits in a normal year. However, it is likely you will apply a reduced dose to make sure you do not overthin and then finish the thinning job with hand thinning in June and early July. 
  • There may be many fruits that have frost ring or russet or are misshapen.  These do not thin off easily. They can only be removed by hand thinning. 
  • Another Plant and Pest Advisory post with more in depth thinning and return bloom spray recommendations will be coming in the next few weeks so keep an eye out!  

Managing Foliar Growth in Trees with Little to no Crop Load 

  • If your crop was significantly damaged do not apply anymore nitrogen to your orchard this year. 
  • In a normal year a portion of the nitrogen fertilizer is applied for fruit trees pre-bloom and a second portion applied post-bloom or after the level of fruit set is known 
  • The 2026 season is not a typical year.  With fruit set in some orchards ranging from a normal load or towards a near total fruit loss due to frost damage, growers should reassess on a case-by-case basis to apply the normal amount or a reduced amount of recommended nitrogen fertilizer. 
  • For orchards where some nitrogen fertilizer was already applied pre-bloom and where there has been a total crop fruit loss due to frost, no further nitrogen fertilizer is recommended for the 2026 growing season. 
  • For orchards with good fruit set, apply nitrogen fertilizer as one would in a normal growing season. 
  • Perform leaf tissue analysis in July to assess nutrient levels (specifically nitrogen status), though do not apply anymore until 2027. 
  • The information provided by the analysis will be useful for guiding nutrient applications in the 2027 fruit growing season.   
  • There is likely to be significant shoot vigor this growing season if there is little to no crop load.  
  •  In apples, Kudos/Apogee (Prohexadione-calcium) can be applied to suppress excessive shoot growth.  Beginning at 1-3 inches of growth apply 8 oz/100 gal once a week for three consecutive weeks. This can also help manage insects like aphids that feed on succulent new growth and diseases like the shoot blight phase of fire blight.  
  • In peaches, consider summer pruning this year to help maintain tree shape and prevent excessive growth.  

Orchard Disease Management 

  • As development continues into petal fall and early fruit set, this remains a critical period for disease management, particularly for diseases like fire blight, bacterial spot, scab, powdery mildew, and cedar apple rust. 
  • Diseases that negatively impact and damage fruit, including rusty spot, brown rot, white rot, sooty blotch and flyspeck should not be a priority this season. However, diseases that can cause severe defoliation still need to be managed effectively. Orchards with low to no crop can use conservative spray programs with focus on using broad spectrum fungicides. 
  • For fire blight, infection can still occur through blossoms even if they are freeze damaged. 
    • Keep an eye on disease prediction models and apply antibiotics prior to infection periods when bloom is present
    • Actigard and Apogee/Kudos can be included for additional defense against shoot blight, especially in young blocks    
  • For bacterial spot, maintain coverage with low levels of copper to reduce inoculum building up on leaves and reduce the risk for infections for the following season.
    • Avoid combining copper with captan especially if it has been overcast for several days.
    • Refer to this guide published by Dr. Norm Lalancette for copper applications in early covers. 
  • Apple scab infections can persist on leaves in the orchards even without fruit, so it could be a good opportunity to knock down inoculum
    • To manage apple scab continue applications of Manzate at 6 lb/A or Microthiol Disperss at 10 lb/A prior to predicted infection periods to lower inoculum for the next season
    • If both powdery mildew and cedar apple rust are a concern, Manzate at 3 lb/A should be tank mixed with Microthiol Disperss at 10 lb/A. Manzate is effective on apple scab and cedar apple rust but not powdery mildew. Microthiol Disperss is effective on apple scab and powdery mildew but not cedar apple rust.
  • Peach scab should not be a concern unless there is a history of high disease pressure – lesions can form on this year’s fruiting shoots which will provide a source of inoculum next season. In this situation management is necessary, and Captan should be applied before a heavy rainfall event at 2.5 lb/A.
    • Management of fungal diseases is still needed to prevent a buildup of rot and leaf pathogens for next season.
  • Pear Scab and Fabraea Leaf Spot should be managed through applications of Manzate or Ziram through may and early summer to prevent defoliation and inoculum build up. Severe infections can weaken trees and impact return bloom.
  • Marssonina Blotch, Glomerella Leaf Spot, and Frogeye Leaf Spot should be managed as these diseases will cause defoliation and provide a source of inoculum for black rot and bitter rot next season.  Maintain coverage of Captan, Manzate, or Ziram prior to rain events through the growing season according to the cover spray rule of applications every 2” of rain or 14 days, whichever comes first.
  • Cedar apple rust and powdery mildew should be managed in orchards with a history of disease as severe infestations can cause stunted growth and stress.
    • For cedar apple rust, continue applying Manzate at 6 lb/A until the end of May
    • If conditions are optimal for cedar apple rust and powdery mildew, apply Manzate at 3 lb/A and Microthiol Disperss at 10 lb/A through July 
    • The pathogen causing powdery mildew of apple also causes rusty spot on peaches so it is especially important to control this disease to keep inoculum levels down for next year if apples are grown next to peaches

Orchard Insect Management 

  • Any fruit remaining on trees will attract insects which will cause damage and continue to maintain populations in the orchards. 
  • Due to the reduced crop load, there may be more insects competing for individual fruit to complete their lifecycle so there may be more damage on a fruit by fruit basis 
  • If you are planning to retain a crop, you must continue to intensively manage insect pests as you would in a normal season  
  • In the event you choose not to harvest fruit this season, there are several insects that will only be targeting the developing fruit and therefore do not need to be managed including plum curculio, tarnished plant bug, brown marmorated stinkbug, native stink bugs, tufted apple bud moth, oblique banded leafroller, and thrips. 
  • Aphids, leafhoppers, and mites can feed extensively on foliage and terminals, causing leaf curling and stunting. This can impact next year’s fruit that will be set in this season. Without fruit, the trees may tolerate a higher threshold of these pests, but they should still be managed.
    • Beneficial insects may help reduce populations of these pests this season, making insecticides targeting them unnecessary.  
  • Pear Psylla can feed extensively on foliage and terminals causing defoliation. In heavy infestations this pest can cause stunting of the tree referred to as “psylla shock” which can reduce next season’s fruit set.
    • Intensive management should be continued in orchards with a history of this pest.  
  • Scale insects are generally controlled with a dormant oil or delayed dormant application; however, in severe infestations you can monitor using double-sided sticky tape on trunks and apply Esteem or Centaur at the crawler stage.
    • Beneficial insects including lady beetles and parasitoid wasps may control pest populations better in reduced spray programs.
  • Oriental fruit moth larvae do not require fruit to cause damage and should be managed in orchards without a crop. The first- and second-generation moths will lay their eggs in terminals and as the larvae develop, they will cause noticeable “flagging” damage.  This “flagging” damage can be particularly detrimental in young orchards.
    • This pest can be managed via mating disruption or well-timed insecticides for the first and second generations to knock populations down particularly in young blocks if there are high trap counts. If you have a history of high OFM pressure, mating disruption may be a more cost-effective option at ~$100/A versus a rotational insecticide program for the first- and second-generation degree day timings averaging ~$150-$200/A. If your orchard typically has low OFM pressure and you have not applied your mating disruption dispensers, it may be more cost effective to save your mating disruption in the freezer for next year and monitor populations. If your populations become higher than normal, one well timed insecticide application to target this pest can range from ~$8-$50/A.
    • Refer to this Plant & Pest Advisory post from Dr. Anne Nielsen on targeted pest management considerations for OFM and other key pests.
  • Codling moth require fruit to complete their lifecycle so it is possible that a season without fruit may be detrimental to their populations. However, this pest may be able to find fruit in the surrounding woodlot and then move back into the orchard the following season.
    • It will be important to monitor this pest via pheromone traps and apply a well-timed insecticide if populations are getting higher than usual.
    • If you have had trouble with this pest in the past, it may be a good year to reduce populations via mating disruption.
  • Borers such as dogwood borer (DWB), lesser peach tree borer (LPTB), greater peach tree borer (GPTB), and ambrosia beetle are indirect pests of tree fruit and will attack the tree regardless of the fruit load.
    • Continue monitoring with pheromone traps to determine if populations are present and time applications around peak flight activity.
    • Mating disruption is an effective strategy for managing DWB, LPTB, and GPTB.
    • Trunk sprays can be applied at well-timed intervals throughout the year.  

Orchard Weed Management During a Low Crop Year

Low crop production years in tree fruit present a different set of weed management priorities compared to typical seasons. While reduced yield may lessen immediate concerns about weed–crop competition, these seasons offer an important opportunity to reset weed pressure and improve long-term orchard floor management. 

Shift in Management Objectives 

In a low crop year, the focus should shift from protecting current yield to reducing weed populations and preventing future infestations. With fewer fruit sinks, trees often allocate more resources to vegetative growth, which can influence both competitive dynamics with weeds and crop sensitivity to herbicide injury. This is also an ideal time to scout and map weed populations across the orchard, documenting dominant species and problem areas. These records directly inform preemergence (PRE)  herbicide selection and placement in the following season. 

Strengthening Residual Programs 

PRE herbicides should play a central role in weed management during low production years. Maintaining a clean herbicide strip beneath the tree canopy throughout the season helps reduce weed seed production, limits early-season competition, and improves control consistency going into the following year. Where appropriate, consider using full labeled rates and tank mixtures of PRE herbicides with different sites of action to extend residual activity and manage resistance. Always read and follow the full label before use. 

Postemergence Applications and Crop Safety 

Timely postemergence (POST) applications remain important to prevent escapes and seed production, even in low crop years. Registered POST options include glyphosate and glufosinate for directed applications, and clethodim for grass control. However, caution is warranted: 

  • Trees may exhibit altered physiological responses due to reduced crop load 
  • Stone fruits (peach, sweet cherry, tart cherry) are generally more sensitive to herbicide contact and root uptake of certain residuals than pome fruits (apple, pear) 
  • Young plantings and thin-barked trees are at greater risk of injury from bark contact 
  • Directed or shielded applications are strongly recommended to minimize contact with trunks, scaffold branches, and foliage 

Resistance Management 

Herbicide-resistant weed populations are an increasing concern in Mid-Atlantic and Northeastern orchards. Glyphosate- and paraquat-resistant horseweed (Erigeron canadensis) is well-documented in the region, and common lambsquarters (Chenopodium album) has shown reduced sensitivity to certain herbicide classes. To reduce selection pressure, rotate herbicide sites of action across seasons, not only within a single season, and avoid exclusive reliance on any single POST chemistry for escapes and patch control. 

Opportunities for Targeting Perennial Weeds 

Perennial species should be prioritized during low crop years. With reduced concern about fruit loss, growers can target optimal application timing for systemic postemergence herbicides when weeds are actively growing and most susceptible. Key perennial species of concern in NJ and NY orchards include: 

  • Mugwort (Artemisia vulgaris) 
  • Japanese knotweed (Reynoutria japonica) 
  • Multiflora rose (Rosa multiflora) 
  • Poison ivy (Toxicodendron radicans) 
  • Field bindweed (Convolvulus arvensis) 
  • Yellow nutsedge (Cyperus esculentus) 
  • Goldenrod (Solidago spp.) 
  • Canada thistle (Cirsium arvense) 

Sequential applications or integration with mechanical tactics may be necessary to effectively reduce belowground reserves. Note that many of these species may require multi-year management programs and, in some cases, mechanical removal prior to herbicide application. 

Managing Tree Vigor 

Reduced crop load commonly results in increased vegetative growth. A clean orchard floor combined with reduced weed competition can further enhance vigor, which is not always desirable. Excessive shoot growth can complicate canopy management and increase disease pressure. Growers should monitor nitrogen inputs carefully, adjust irrigation to avoid overstimulating growth, and manage watersprouts and excessive shoot development through summer pruning as needed. Competitive cover crops in the alleyway can serve a dual role: suppressing weeds while moderating overall tree vigor through resource competition. 

Environmental and Regulatory Considerations 

Applicators should be familiar with required buffer zones and consult the NJDEP Pesticide Control Program  as well as Registrant database for current restrictions and state-specific requirements. Herbicide applications should always be timed to avoid bloom periods when pollinators are active in the orchard. 

Looking Ahead 

Effective weed management during a low crop year can significantly improve conditions for the following season. Reducing the weed seedbank, targeting difficult perennial species, and scouting to map problem areas positions growers to enter the next production cycle with lower pressure and potentially reduced input needs. 

Bottom line: Low production years should be viewed as an opportunity—not a setback—for improving weed management. Strategic use of residual herbicides, targeted control of perennial species, integration of alternative tactics, and thorough scouting can provide lasting benefits for orchard productivity and long-term sustainability. 

Always read and follow pesticide label directions. The label is the law. Herbicide registrations are subject to change; verify current registration status in New Jersey and New York before use. 

Filed Under: Commercial Ag Updates, Fruit, Tree Fruit, Uncategorized Tagged With: , , , , , , , , , , , , ,
May 7, 2026 and

Vegetable IPM Update 5/08/26

Greetings from the Veg IPM team! We hope everyone is doing alright despite the tough spring weather. In this post, we’ll discuss what we’ve been seeing as we’ve begun scouting cole crops and high tunnel tomatoes.

[Read more…]

Filed Under: Organic Production, vegetable, Vegetable Crops Tagged With: , , , ,