Fruit Crops Edition

Seasonal updates on diseases, insects, weeds impacting tree fruit and small fruit (blueberry, cranberry, and wine grape). Fruit Pest Alerts are also available via this category feed.
 
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Application for Cost-Share Grant Funding for Installation of Deer Fencing on UNPRESERVED Farmland – Out NOW

“The NJDA Deer Fencing Program makes cost-sharing funding available for the installation of deer fencing on unpreserved farms. The program is conducted in accordance with N.J.S.A 4:40-6.1.”

Please click here for the full application, eligibility, and other important information

Timing is important if considering this program. NJDA began accepting applications on 5/15/23.

 

Tree Fruit IPM Report for May 10, 2023

Peach:

Bacterial Spot leaf symptoms about 2 weeks old.

Fig. 1 Bacterial Spot leaf symptoms about 2 weeks old.

Bacterial Spot leaf symptoms about a week old.

Fig. 2 Bacterial Spot leaf symptoms about a week old.

Bacterial Spot: Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics such as Mycoshield or Fireline may also be used and may offer slightly more residual activity during long wetting periods. Bacterial Spot leaf symptoms have begun appearing in southern county orchards. These infections probably occurred mostly during the heavy rains that occurred on 4/30-5/1. There is a small amount of older symptoms which probably occurred the previous weekend of 4/27-4/28 (Figs. 1&2.).

Oriental Fruit Moth: A biofix point for OFM was set on 4/10 in both northern and southern counties.  The first of two insecticide timings for first generation Oriental Fruit Moth control fall at 170-200 degree days base 45 after biofix. This timing generally coincides with 100% petal fall in peaches. Timings are updated below. Do not apply insecticides until all bloom is off. No Insecticides for OFM are needed where Mating Disruption is implemented.

OFM 1st Generation Timing
Insecticide Type
County/Region Degree Days by  5/8 base 45 Conventional

170-200, 350-375

Diamide

100-150, 300-350

Gloucester – Southern 345 1st –past

2nd –5/8-5/10

1st –past

2nd –past

Middlesex – Northern 327 1st –past

2nd –5/10-5/11

1st –past

2nd –5/7-5/10

Green Peach Aphid: GPA colonies begin forming sometime during bloom. Examine trees for the presence of colonies from pink to shuck split. Count 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. The best way to scout for aphids during bloom is with a beating tray. Blossoms may also be collected, opened, and examined for the presence of aphids using a hand lens. This is particularly important for nectarine blocks. Check 10 trees per block with the beating tray. Collect 50 blossoms per block and examine for the presence of aphids. If more than 1 colony of aphids are found in nectarines, or 2-3 colonies are found in peaches, an insecticide for aphids will be needed when all petals are off. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Aphid colonies are now visible in southern county orchards.

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: 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. Currently we have accumulated about 320 DD base 50 in southern counties, and 264 DD base 50 in northern counties. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Catfacing insects are starting activity, but will become more of an issue as temperatures warm and mowing and other ground cover activities become more common. Small amounts of catfacing injury are present statewide.

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 the neonicitiniods Actara and Belay (suppression only), and the IGR’s 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.

Apples and Pears:

Diseases: Apple Scab, Rust diseases, and Powdery Mildew are the main targets at this stage. The NEWA apple scab model is estimating about 100% ascospore maturity in southern NJ with 100% of cumulative ascospores discharged as of April 15. Northern counties were at Green tip on or about 4/3. The model estimates about 100% ascosppsore maturity for Northern Counties with 100% ascospores released as of April 30. Between tight cluster and first cover include products effective for powdery mildew and cedar apple rust.

Fire Blight: Infections can still occur post bloom so covers with antibiotics when infection events are forecast using the NEWA fire blight model may be beneficial. Remember to rotate streptomycin and oxytetracycline products. Fire Blight symptoms began appearing in southern county apple and pear orchards this week. Typically it is recommended to cut out infected limbs however this is a practical decision that must be made. This blog post from Michigan State may be helpful to decide whether it is worth cutting out infected tissue.

Rust Diseases: The two most common rust diseases that affect pome fruit are Quince Rust and Cedar Apple Rust. In some years these diseases can be troublesome in commercial orchards. Most disease control programs for scab will also control rust. In organically managed blocks in the east options are limited for approved materials that are effective for rust. Potassium Bicarbonate products have shown good efficacy for rust diseases in trials performed in Virginia. Organic growers should seek out and plant rust resistant cultivars. Cultural controls are not practicable due to the widespread presence of alternate host Junipers both wild and cultivated. Rust disease development on junipers should now be producing large spore releases during wetting periods. See this link for pictures of rust on pome fruit and juniper.

Dogwood Borer: Growers who plan to use mating disruption for Dogwood Borer should have ties in place by the end of May. See the Product label and the NJ Commercial Tree Fruit Production Guide for more Information.

Codling Moth (CM): The first codling moth flight has started. A biofix was set for CM on April 17th in both northern and southern counties.

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)

Cyd-X, Carpovirusine

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 17 past 5/7 5/11 Too far off 5/17 5/17 Too far off
Northern  5/7  5/10  5/12 Too far off 5/21 5/21 Too far off

Pear Diseases:  Continue managing for Rust, Fire Blight and Fabrea Leaf Spot through May.

Grapes: The most important diseases to manage at this time are Phomopsis, Black Rot, and Powdery Mildew. More information about early season disease control can be found in this blogpost from Virginia Tech. SLF hatch began in southern counties sometime during the last week of April. There is no need to control SLF at this time.

Tree Fruit Trap Captures – Southern Counties

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/15/2023 433 20 1
4/23/2023 423 1 13 8 0
4/30/2023 417 7 15 4 1 0
5/06/2023 9 2 3 1 0 0

Tree Fruit Trap Captures – Northern Counties

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/8/2023 10
4/15/2023 20 3
4/30/2023 28 11 6
5/06/2023 22 2 19 9

Phenology Table: Based on annual observations made in Gloucester County.

Pest Event or Growth Stage Approximate Date 2023 Observed Date
 Bud Swell (Redhaven)  March 23 +/- 15 Days March 7
1/4″ Green Tip Red Delicious March 31 +/- 13 Days March 27
Pink Peach (Redhaven) April 4 +/- 15 Days March 24
Tight Cluster Red Delicious April 9 +/- 13 Days April 7
Full Bloom Peach (Redhaven) April 9 +/- 14 Days April 4
Pink Apple (Red Delicious) April 14 +/- 12 Days April 11
Full Bloom Apple (Red Delicious) April 22 +/- 11 Days April 16
Petal Fall (Redhaven) April 22 +/- 10 Days April 15
Petal Fall (Red Delicious) April 27 +/- 13 Days  May 3
Shuck Split (Redhaven) April 30 +/- 11 Days April 21
Pit Hardening June 15 +/- 9 Days

 

 

 

Tree Fruit IPM Report for May 4, 2023

Peach:

Bacterial Spot: Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics such as Mycoshield or Fireline may also be used and may offer slightly more residual activity during long wetting periods. No Bacterial Spot symptoms have been observed as of this writing.

Peach Scab: In addition to Rusty Spot and Bacterial Spot, Peach Scab requires protective applications starting at petal fall. Peach scab cankers (Fig. 1) begin to expand at bloom and by shuck split begin to shed spores during wetting periods. Topsin, Topsin/Captan combinations, Flint Extra, Inspire Super, and especially Quadris Top applied at petal fall are the best materials for blocks that had scab last year. Quadris Top, Flint Extra or Topsin should be used at the high rate to suppress overwintering lesions on the wood. Quadris Top contains azoxystrobin which is phytotoxic to many apple varieties. Phytotoxic residues can remain in the tank for long periods after an application is made, even if a tank cleaner is used. Do not use Quadris Top or Abound in the same sprayer used for apples. Bravo (chlorothalonil) is also a good protectant that may be applied no later than shuck split. Captan is also helpful in cover sprays after shuck split where scab was troublesome last year.

Oriental Fruit Moth: A biofix point for OFM was set on 4/10 in both northern and southern counties.  The first of two insecticide timings for first generation Oriental Fruit Moth control fall at 170-200 degree days base 45 after biofix. This timing generally coincides with 100% petal fall in peaches. Timings are updated below. Do not apply insecticides until all bloom is off. No Insecticides for OFM are needed where Mating Disruption is implemented.

OFM 1st Generation Timing
Insecticide Type
County/Region Degree Days by  4/25 base 45 Conventional

170-200, 350-375

Diamide

100-150, 300-350

Gloucester – Southern 224 1st –past

2nd –5/8-5/10

1st –past

2nd –5/6-5/8

Middlesex – Northern 219 1st –past

2nd –5/10-5/12

1st –past

2nd –5/7-5/10

 

Green Peach Aphid: GPA colonies begin forming sometime during bloom. Examine trees for the presence of colonies from pink to shuck split. Count 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. The best way to scout for aphids during bloom is with a beating tray. Blossoms may also be collected, opened, and examined for the presence of aphids using a hand lens. This is particularly important for nectarine blocks. Check 10 trees per block with the beating tray. Collect 50 blossoms per block and examine for the presence of aphids. If more than 1 colony of aphids are found in nectarines, or 2-3 colonies are found in peaches, an insecticide for aphids will be needed when all petals are off. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Aphid colonies are now visible in southern county orchards.

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: 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. Currently we have accumulated about 285 DD base 50 in southern counties, and 218 DD base 50 in northern counties. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Catfacing insects are starting activity, but will become more of an issue as temperatures warm and mowing and other ground cover activities become more common. Insecticides for catfacing insects are not recommended until after all petals are off.

Scale Insects: Dormant oil applications are standard recommendations for scale control but in some years when conditions are not optimal for oil application scale control may be less than desired. Where oil was not applied or in orchards and where scale is a recurring problem, an application of Movento between petal fall and shuck split should “clean up” problem blocks. Movento should be applied at 6-9 ozs./ac. A penetrant must be included as per the product label. Movento will also control green peach aphid when used at this timing. White peach scale crawlers usually begin emergence around the 3rd week of May while San jose scale crawlers usually begin emergence around the first of June in southern counties. COntrol options once crawlers emerge in clude the neonicitinoids Actara and Belay (suppression); and the growth regulators Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide for other recommended materials and rates.

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.

Apples and Pears:

Diseases: Fire Blight, Apple Scab, Rust diseases, and Powdery Mildew are the main targets at this stage. The NEWA apple scab model is estimating about 100% ascospore maturity as of 5/4 in southern NJ with 100% of cumulative ascospores discharged. Northern counties were at Green tip on or about 4/3. The model estimates about 90% ascopsore maturity for Northern Counties with 87% ascospores released. Primary apple scab spores are released during any substantial infection period. More information can be found in this blogpost from Penn State. Between tight cluster and first cover include products effective for powdery mildew and cedar apple rust. Very little fire blight has been observed to date statewide. Infections can still occur post bloom so covers with antibiotics when infection events are forecast using the NEWA fire blight model may be beneficial. Remember to rotate streptomycin and oxytetracycline products.

Rust Diseases: The two most common rust diseases that affect pome fruit are Quince Rust and Cedar Apple Rust. In some years these diseases can be troublesome in commercial orchards. Most disease control programs for scab will also control rust. In organically managed blocks in the east options are limited for approved materials that are effective for rust. Potassium Bicarbonate products have shown good efficacy for rust diseases in trials performed in Virginia. Organic growers should seek out and plant rust resistant cultivars. Cultural controls are not practicable due to the widespread presence of alternate host Junipers both wild and cultivated. Rust disease development on junipers should now be producing large spore releases during wetting periods. See this link for pictures of rust on pome fruit and juniper.

Codling Moth (CM): The first codling moth flight has started. A biofix was set for CM on April 17th in both northern and southern counties.

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)

Cyd-X, Carpovirusine

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 17 past 5/7 5/10 Too far off 5/17 5/17 Too far off
Northern  5/7  5/9  5/14-5/16 Too far off 5/24 5/24 Too far off

Rosy Apple Aphid:  If a pre-bloom application was not made, monitor for colonies during bloom and use a treatment threshold of 1 colony/tree at petal fall. Some orchards have colonies that require treatment in southern counties.

Pear Diseases:  Continue managing for Rust, Fire Blight and Fabrea Leaf Spot through May.

Dogwood Borer: Growers planning to use mating disruption for Dogwood Borer should have dispensers in place by the end of May.

Tree Fruit Trap Captures – Southern Counties

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/15/2023 433 20 1
4/23/2023 423 1 13 8 0
4/30/2023 417 7 15 4 1 0

Tree Fruit Trap Captures – Northern Counties

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/8/2023 10
4/15/2023 20 3
4/30/2023 28 11 6

Phenology Table: Based on annual observations made in Gloucester County.

Pest Event or Growth Stage Approximate Date 2023 Observed Date
 Bud Swell (Redhaven)  March 23 +/- 15 Days March 7
1/4″ Green Tip Red Delicious March 31 +/- 13 Days March 27
Pink Peach (Redhaven) April 4 +/- 15 Days March 24
Tight Cluster Red Delicious April 9 +/- 13 Days April 7
Full Bloom Peach (Redhaven) April 9 +/- 14 Days April 4
Pink Apple (Red Delicious) April 14 +/- 12 Days April 11
Full Bloom Apple (Red Delicious) April 22 +/- 11 Days April 16
Petal Fall (Redhaven) April 22 +/- 10 Days April 15
Petal Fall (Red Delicious) April 27 +/- 13 Days  May 3
Shuck Split (Redhaven) April 30 +/- 11 Days April 21
Pit Hardening June 15 +/- 9 Days

 

 

North Jersey Tree Fruit Twilight Meeting I

North Jersey Tree Fruit Twilight Meeting I

May 3, 2023

5:00 PM-7:30 PM

Melicks Town Farm
19 King Street Oldwick, New Jersey 08858

5:00 PM – Registration / Light Refreshments

5:15 PM –Begin to load into wagons for the farm tour and educational talks

5:20 PM –Updates from the Blueberry and Tree Fruit IPM program

Carrie Manuse, Agriculture and Natural Resources Sr. Program Coordinator
Kaitlin Quinn, North Jersey Fruit IPM Program Associate, Rutgers Cooperative Extension of
Hunterdon County

5:40 PM –Apple Fruit Rots

Norm Lalancette PhD, Associate Specialist in Tree Fruit Plant Pathology Rutgers NJAES

6:10 PM –Vegetable Insect Pest and Disease Updates

Kris Holmstrom, IPM Program Associate, Vegetable

6:30 PM – Pesticide Safety, and Compliance

Patricia Hastings, Extension Pesticide Safety Education Program Coordinator for Rutgers NJAES

The following pesticide credits will be awarded

2 CORE   2 CAT 1A   3 CAT 10   2 CAT PP2

Please RSVP to Kim Crommelin at 908.788.1338 or kfrey@co.hunterdon.nj.us by May 2, 2023

Early Season Pests of Cranberries, 2023

By now the winter flood is off from most New Jersey cranberry beds. Once the water is removed, the vines will start to initiate bud break. From now until bloom, growers should scout their beds using sweep net sampling for lepidopteran pests (spongy (=gypsy) moth, blackheaded fireworm, spotted fireworm, Sparganothis fruitworm, and cranberry blossomworm), and blunt-nosed leafhoppers (Figure 1).

variety of bugs

Figure 1. Spongy moth larva (A); Blackheaded fireworm larva (B); Sparganothis fruitworm larva (C), Spotted fireworm larva (D); Cranberry blossomworm larva (E); Blunt-nosed leafhopper nymph (F). Photo Credits: Elvira de Lange & Dan Schiffhauer.

Spongy moth – Although spongy moth numbers should have dropped compared to the last couple of years, we might see larvae still in places where high infestation occurred, particularly in beds near wooded areas. At this time of the year, the larvae are small (early instars). This insect has one generation a year and overwinters as eggs. Eggs hatch at this time of the year and 1st instars “balloon” on silken threads from infested trees onto nearby cranberry beds. Thus, spongy moths tend to be one of the earliest caterpillars to show up in cranberry beds, usually during the first week of May. The larvae are quite easy to detect by means of sweep net sampling and are easy to control with most of the insecticides at our disposal (see recommendations below).

Blackheaded fireworm – Blackheaded fireworm eggs overwinter on the bed and usually hatch by around mid-May. It is important to catch the first generation, if possible, because the second generation occurs during bloom and is typically much more destructive. Blackheaded fireworm larvae can be detected by sweep net sampling and it is a good idea to look along the edges of beds where vines first begin to grow. Remember: blackheaded fireworm is much easier to control if detected during the early part of the season.

Sparganothis fruitworm – This insect is a serious pest in most cranberry-growing states.  It completes 2 generations a year and overwinters as an early-instar larva. The larvae from the 1st generation feed on foliage. In New Jersey, first generation adult moths emerge from mid-June through the first weeks in July; pheromone traps are commonly used to monitor adult flight and population size. The 2nd-generation eggs are laid on cranberry leaves, and larvae will feed on fruit.

Spotted fireworm – This insect overwinters as a 2nd instar larva and completes 2 generations a year. The larvae feed between uprights they have webbed together. First-generation larvae injure the foliage causing it to turn brown as if burned. In New Jersey, 1st-generation adult moths emerge the first week of June, followed by a 2nd-generation adult emergence in early August. Eggs are laid in masses on weedy hosts. The larvae from 2nd-generation adults emerge in mid-August and may feed on fruit. Populations of spotted fireworm are regulated by their natural enemies, particularly Trichogramma wasps that parasitize the eggs.

Cranberry blossomworm – Adults lay their eggs in October in cranberry beds. The eggs overwinter and hatch over a period of several weeks. Early instars can be found during the first week of May. Larvae go through 6 instars to complete their development. Because the first instars feed during the day (and at night), scouting can be done during the daytime using sweep nets to estimate larval abundance. Larvae turn nocturnal during the later instars and thus night sweeping (9 pm – 1 am) is recommended for sampling. Larvae complete their development by June-July. Older instars are very voracious and capable of destroying 100 blossoms within a 3-week period. There is a pre-pupal stage that lasts until the end of August and a pupal stage that lasts until October. Adults emerge from the end of August to the end of October.

Lepidopteran Pests Monitoring and Control – Use sweep netting for monitoring early lepidopteran pests (pre-bloom). A sweep set consists of 25 sweeps and 1 sweep set is recommended per acre (this may vary depending on the size of bogs). The action threshold for false armyworm, blossomworm, other cutworms, and spongy moth (we use a combined threshold from adding all these caterpillars per sweep set) is an average of 4.5 caterpillars in sets of 25 sweeps. For brown and green spanworms is an average of 18 per sweep set. The action threshold for blackheaded fireworm and Sparganothis fruitworm is an average of 1.5 per sweep set. We recommend the use of reduced-risk materials such as the insect growth regulator (IGR) Intrepid, the spinosyn insecticide Delegate, or any of the diamide insecticides Altacor, Exirel or Verdepryn if populations exceed action thresholds. These are reduced-risk, softer insecticides that are very effective against lepidopteran pests. Remember to rotate insecticides with different modes of action to prevent onset of insecticide-resistant pest populations.

Leafhoppers –There is continuing concern among New Jersey cranberry growers of a potential increase in leafhopper populations because of changes in pest management strategies (e.g., adoption of new reduced-risk products and decreased applications of broad-spectrum insecticides). The blunt-nosed leafhopper is of particular concern because this insect can transmit cranberry false blossom disease. This leafhopper has one generation a year. The adults are found in the highest numbers during July, although nymphs or adults may be found from the end of May until October. The eggs are laid in August-September and the overwintered eggs hatch in May or June. The nymphs go through 5 instars to complete their development.

Leafhopper Monitoring and Control: Leafhopper nymphs can be sampled using sweep nets (as described above for lepidopteran pests). Nymphs before bloom are small; thus, you may need to freeze the samples (to kill them), and then count the number of nymphs under a microscope or using a magnifying lens. There is no established threshold based on sweep net counts because it varies depending on the age of beds, the variety, and/or with false blossom incidence. These decisions should be made by comparing current numbers with prior infestation history.

In cases of high numbers of blunt-nosed leafhopper nymphs, we recommend application of a broad-spectrum insecticide, such as Sevin, Diazinon (no aerial applications allowed), Fanfare, or Danitol. Broad-spectrum insecticides will disrupt biological control particularly the natural enemies (predators and parasitoids) of Sparganothis fruitworm, so their use should be restricted only to areas of high leafhopper populations.

Tree Fruit IPM Report for April 27, 2023

Tree Fruit Phenology: Tree Fruit Phenology remains advanced in peach. In southern counties all peach orchards are shuck split to shuck off. Redhaven was at approximately full bloom on April 4. Red Delicious is at 90% petal fall. Sweet cherries are at about petal fall to shuck split depending on variety.

Peach:

Bacterial Spot: Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics such as Mycoshield or Fireline may also be used and may offer slightly more residual activity during long wetting periods.

Peach Scab: In addition to Rusty Spot and Bacterial Spot, Peach Scab requires protective applications starting at petal fall. Peach scab cankers (Fig. 1) begin to expand at bloom and by shuck split begin to shed spores during wetting periods. Topsin, Topsin/Captan combinations, Flint Extra, Inspire Super, and especially Quadris Top applied at petal fall are the best materials for blocks that had scab last year. Quadris Top, Flint Extra or Topsin should be used at the high rate to suppress overwintering lesions on the wood. Quadris Top contains azoxystrobin which is phytotoxic to many apple varieties. Phytotoxic residues can remain in the tank for long periods after an application is made, even if a tank cleaner is used. Do not use Quadris Top or Abound in the same sprayer used for apples. Bravo (chlorothalonil) is also a good protectant that may be applied no later than shuck split. Captan is also helpful in cover sprays after shuck split where scab was troublesome last year.

Peach Scab lesions on peach twig

Fig. 1 Peach Scab lesions on peach twig.

Oriental Fruit Moth: A biofix point for OFM was set on 4/10 in both northern and southern counties.  The first of two insecticide timings for first generation Oriental Fruit Moth control fall at 170-200 degree days base 45 after biofix. This timing generally coincides with 100% petal fall in peaches. Timings are updated below. Do not apply insecticides until all bloom is off. No Insecticides for OFM are needed where Mating Disruption is implemented.

OFM 1st Generation Timing
Insecticide Type
County/Region Degree Days by  4/25 base 45 Conventional

170-200, 350-375

Diamide

100-150, 300-350

Gloucester – Southern 224 1st –4/20-4/22

2nd –5/8-5/10

1st –4/15-4/19

2nd –5/3-5/8

Middlesex – Northern 219 1st –4/20-4/22

2nd –5/8-5/10

1st –4/15-4/18

2nd –5/3-5/8

Green Peach Aphid: GPA colonies begin forming sometime during bloom. Examine trees for the presence of colonies from pink to shuck split. Count 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. The best way to scout for aphids during bloom is with a beating tray. Blossoms may also be collected, opened, and examined for the presence of aphids using a hand lens. This is particularly important for nectarine blocks. Check 10 trees per block with the beating tray. Collect 50 blossoms per block and examine for the presence of aphids. If more than 1 colony of aphids are found in nectarines, or 2-3 colonies are found in peaches, an insecticide for aphids will be needed when all petals are off. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. Aphid colonies are now visible in southern county orchards.

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: 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. Currently we have accumulated about 258 DD base 50 in southern counties, and 208 DD base 50 in northern counties. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Catfacing insects are starting activity, but will become more of an issue as temperatures warm and mowing and other ground cover activities become more common. Insecticides for catfacing insects are not recommended until after all petals are off.

Scale Insects: Dormant oil applications are standard recommendations for scale control but in some years when conditions are not optimal for oil application scale control may be less than desired. Where oil was not applied or in orchards and where scale is a recurring problem, an application of Movento between petal fall and shuck split should “clean up” problem blocks. Movento should be applied at 6-9 ozs./ac. A penetrant must be included as per the product label. Movento will also control green peach aphid when used at this timing.

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.

Apples and Pears:

Diseases: Fire Blight, Apple Scab, Rust diseases, and Powdery Mildew are the main targets at this stage. The NEWA apple scab model is estimating about 93% ascospore maturity as of 4/25 in southern NJ with 81% of cumulative ascospores discharged. Northern counties were at Green tip on or about 4/3. The model estimates about 64% ascopsore maturity for Northern Counties with 52% ascospores released. Primary apple scab spores are released during any substantial infection period. More information can be found in this blogpost from Penn State. Between tight cluster and first cover include products effective  for powdery mildew and cedar apple rust. To manage Fire Blight in both apples and pears, consider using Kasumin at bloom. Kasumin is an antibiotic like Streptomycin and Oxytetratracycline. It contains Kasugamycin which is a different chemistry. Kasumin is only labeled for bloom and petal fall applications while strep and oxytet are labeled for post bloom use. Using 3 different chemistries in rotation allows for resistance management while extending the protection into the post bloom period when late blossoms typically appear which ever material you use, the addition of Actigard or other plant defense elicitors may improve control.

Rust Diseases: The two most common rust diseases that affect pome fruit are Quince Rust and Cedar Apple Rust. In some years these diseases can be troublesome in commercial orchards. Most disease control programs for scab will also control rust. In organically managed blocks in the east options are limited for approved materials that are effective for rust. Potassium Bicarbonate products have shown good efficacy for rust diseases in trials performed in Virginia. Organic growers should seek out and plant rust resistant cultivars. Cultural controls are not practicable due to the widespread presence of alternate host Junipers both wild and cultivated. Rust disease development on junipers should now be producing large spore releases during wetting periods. See this link for pictures of rust on pome fruit and juniper.

Codling Moth (CM): The first codling moth flight has started. A biofix was set for CM on April 17th in southern counties. No biofix has yet been set for northern counties.

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)

Cyd-X, Carpovirusine

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 17 4/29 5/2 5/7 Too far off 5/17 5/17 Too far off
Northern

Rosy Apple Aphid:  If a pre-bloom application was not made, monitor for colonies during bloom and use a treatment threshold of 1 colony/tree at petal fall. Some orchards have colonies that require treatment in southern counties.

Pear Psylla:  Dormant oil applications should have already been started to deter psylla egg laying. At the green cluster stage a pyrethroid is generally included with oil to knock down adults migrating into the orchard.  In lieu of oil, Surround may also be applied starting at swollen bud and continued through petal fall. If using Surround through the bloom period stop at petal fall and switch to applications of 1% summer oil @ 1gal/ac in no less than 150 gals/ac. these should be made at no more than 2 week intervals. At petal fall insecticide options for Psylla control include Actara, Assail, Belay, Movento, Sivanto Prime, and Agri-mek. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.

Pear Diseases:  Include effective materials such as Ziram or EBDC formulations for Pear Scab and Rust diseases beginning at the cluster bud stage. At white bud use products effective for pear scab, rusts, and fabrea leaf spot. For both apples and pears, consider using Kasumin at bloom. Kasumin is an antibiotic like Streptomycin and Oxytetratracycline. It contains Kasugamycin which is a different chemistry. Kasumin is only labeled for bloom and petal fall applications while strep and oxytet are labeled for post bloom use. Using 3 different chemistries in rotation allows for resistance management while extending the protection into the post bloom period when late blossoms typically appear. which ever material you use, the addition of Actigard or other plant defense elicitors may improve control.

SLF Nymph on grape leaf

Fig2 . SLF Nymph on grape leaf.

Grapes: The most important diseases to manage at this time are Phomopsis and Powdery Mildew. At 3″ growth start managing for Black Rot. More information about early season disease control can be found in this blogpost from Virginia Tech. Insect pests to monitor are Grape Flea Beetle, and Climbing Cutworms. Controls for these insects are rarely needed. If control is determined to be necessary, use one of the materials recommended in the New Jersey Commercial Grape Production Guide. SLF hatch began in southern counties sometime last week. (Fig. 2). There is no need to control SLF at this time.

 

 

 

 

 

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/15/2023 433 20 1
4/23/2023 423 1 13 8 0

Tree Fruit Trap Captures – Northern Counties

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/8/2023 10
4/15/2023 20 3

Phenology Table: Based on annual observations made in Gloucester County.

Pest Event or Growth Stage Approximate Date 2023 Observed Date
 Bud Swell (Redhaven)  March 23 +/- 15 Days March 7
1/4″ Green Tip Red Delicious March 31 +/- 13 Days March 27
Pink Peach (Redhaven) April 4 +/- 15 Days March 24
Tight Cluster Red Delicious April 9 +/- 13 Days April 7
Full Bloom Peach (Redhaven) April 9 +/- 14 Days April 4
Pink Apple (Red Delicious) April 14 +/- 12 Days April 11
Full Bloom Apple (Red Delicious) April 22 +/- 11 Days April 16
Petal Fall (Redhaven) April 22 +/- 10 Days April 15
Petal Fall (Red Delicious) April 27 +/- 13 Days
Shuck Split (Redhaven) April 30 +/- 11 Days April 21
Pit Hardening June 15 +/- 9 Days