Apple Scab: Primary scab season is approaching the end, or has ended. Any established lesions from the primary scab infection period can continue to drive secondary spread if not controlled. Recent wetting events can support disease spread, but the upcoming forecast is relatively dry, which should limit additional infection risk in the short term. Growers should continue to monitor conditions and maintain coverage with Mancozeb or Captan plus a single-site fungicide, particularly where primary infections may have occurred. Keep in mind that Mancozeb has a 77-day pre-harvest interval (PHI).

Cedar apple rust: Rust is active at this time. Even if you have a low to no apple crop, apple rust and scab still need to be managed. Maintain coverage with mancozeb until the end of May.

Powdery mildew: Leaves with powdery mildew were observed this week, and the risk for infection remains active under dry conditions (Figure 1). Mancozeb is not effective. In periods of hot days with high humidity and no rain, sulfur (e.g., Microthiol Dispers at 10 lb/A) can be applied. PM needs to be managed through July. Do not tank mix captan and sulfur.

Figure 1. Powdery mildew is developing on the leaves of the apple. Photo by Sophia Solewater.

Fire blight: Symptoms began appearing in southern county apple orchards the week of 5/11. 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. It is recommended to cut out infected limbs 6–12 inches below the margin of visible infection. Ideally, infected tissue should be removed from the orchard and burned. However, if pressed for time, prunings can be left in the row middles to dry out and subsequently chopped with a mower. Do not cut out infections during wet weather, as bacteria can spread through water.

Rots: In orchards with fruit, management moving forward will focus on summer diseases, including fruit rots like bitter rot, sooty blotch, and fly speck. Broad-spectrum fungicides captan and ziram are effective, and adding single-site products such as Merivon, Luna Sensation, Pristine, Omega, and Aprovia may improve control. The addition of phosphorous acid products such as Prophyt or Rampart to captan sprays can improve control of rots and other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present.

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

Insect 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.

Woolly Apple Aphid (WAA); Green Apple (Spirea) Aphids (GAA): Aphid colonies are being observed in some apple blocks (Figure 2). WAA and GAA are generally pests that can be tolerated because they cause little direct damage. Treatment thresholds for WAA and GAA are met if 50% of the shoots are infested with no beneficial insects present. Movento will control WAA and GAA and should control scale when applied in mid-May, and suppress scale when applied in late May or early June.

Figure 2b. Green apple aphid colonies on younger branches.

Figure 2a. Woolly apple aphid colonizing pruned wood.

Ambrosia Beetle: Trap captures have decreased in southern NJ, indicating peak flight has ended or is coming to an end. In northern NJ counties, trap captures have been increasing with last week’s warm temperatures. 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): Biofix has been set for southern counties as of April 20 and in northern counties as of 5/5. In blocks with little to no crop, CM management programs can often be reduced or delayed; however, monitoring should continue. Where mating disruption has been employed or there is a reduced insecticide program, supplemental Madex applications can be made at the timings listed below if the threshold exceeds 5 moths per trap per week.

Leafhoppers: Adult leafhoppers typically begin appearing in apples this time of year. They appear as small, light-green, soft-bodied insects and are often found on the new leaves at the growing tips. High densities should not be tolerated in non-bearing orchards because they can stunt the growth of new shoots. They should also not be tolerated in orchards where fire blight is present, as they have been shown to spread the disease. Neonicotinoids are generally recommended for control; however, other broad-spectrum materials are also effective. 

Dogwood borer: Monitoring traps have captured high numbers of male dogwood borer adults, particularly in orchards with a history of the pest. Mating disruption is recommended and effective for this pest. Manage as needed in blocks with a history of infestation. Assail has demonstrated activity when targeting adults to reduce egg laying. See the 2026 Integrated Orchard Management Guide for Commercial Apples in the Southeast.

Average Trap Captures in Apple – Southern Counties

Average Trap Captures in Apple – Northern Counties

Fabraea Leaf Spot: Spots have been observed on leaves in orchards (Figure 3). Infections can result in significant leaf spotting, defoliation, and unmarketable fruit. Foliar diseases should be managed with Mancozeb or Ziram, plus a single-site fungicide, to maintain pressure and inoculum at low levels, protecting fruit and maintaining a healthy orchard going into the next season. See the New Jersey Commercial Tree Fruit Production Guide for more information.

Figure 3. Fabraea leaf spot on foliage in pear. Photo by Katrina DeWitt.

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

Plum curculio; Stink bug; Tarnished plant bug: While activity during scouting may appear low, injury is being observed and may be more pronounced in orchards where reduced crop load is present. If high amounts of injury are observed and you intend to harvest the crop, consider a well-timed application of an IRAC Group 4A (Actara, Assail, and Belay).

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.

Bacterial spot: Leaf symptoms began appearing in orchards earlier in May. Leaf infections appear water-soaked, stay within the leaf veins, and gradually darken. Eventually, the chlorotic tissue abscises from the leaf, leaving a “shot-hole”. Copper injury appears similar. The main differences are that copper injury often appears at the leaf base, where the spray collects as it runs off, and the shot-hole will cross leaf veins. Copper injury often appears red at the margins of the shot hole. Fruit injury from bacterial spot results in dark lesions that are often accompanied by gummosis. 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. See the New Jersey Commercial Tree Fruit Production Guide for more information.

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

Oriental Fruit Moth (OFM): A biofix point for OFM was set on 4/7 for southern counties and 4/15 in northern counties. All treatments for the second generation have passed. We have seen very little flagging in new leaf tissue where OFM larvae have bored into.

Scale: White peach scale and San Jose scale crawlers begin to emerge at this time and will continue to emerge for up to 6 weeks. Control options during crawler emergence include Neonicotinoids (suppression only), Sivanto, Esteem, and Centaur.

Green Peach Aphid: Activity has been low to start this season, but is increasing with warmer temperatures. Examine trees for the presence of aphids by counting the number of colonies on ten trees and use a treatment threshold of 2 colonies/tree at petal fall for peach, and 1 colony/tree for nectarine. Management options include Assail, Actara, Admire Pro, or Sivanto.

Plum Curculio: Injury to developing peaches and apples has been observed in southern counties, with high infestation rates in orchards with a history of high pest pressure. Management for PC is not recommended at this time since adults are not currently active.

Tarnished plant bugs and other catfacing insects: Activity is increasing with dry weather and summer temperatures. Very little recent fruit feeding has been observed. In most blocks with little to no fruit, treatment is not necessary.

Lesser and Greater Peach Tree Borers: 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 with mating disruption or trunk sprays.

Average Trap Captures in Peach – Southern Counties

Average Trap Captures in Peach – Northern Counties

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

  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.
  

  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 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

Average Trap Captures in Apple – Southern Counties

Average Trap Captures in Apple – Northern Counties

• 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.

• 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.

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

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 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.

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

• Activity has been low to start this season, but is starting to increase.
• 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.

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

Average Trap Captures in Peach – Southern Counties

Average Trap Captures in Peach – Northern Counties