Rutgers Cooperative Extension
“WASHINGTON, May 4, 2021 – The U.S. Department of Agriculture (USDA) today announced a virtual listening session for beginning farmers and ranchers to learn how COVID-19 impacted their farming operations and to get their feedback on USDA assistance. The listening session will take place on May 6, 2021, from 1:30 to 3:30 p.m., Eastern time.”
For more information, visit https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/newsroom/releases/?cid=NRCSEPRD1772035
Peach:
Oriental Fruit Moth: First generation timings are updated below: Growers that have utilized mating disruption for OFM can focus on PC; GPA; and catfacing insect pests as described below. If you have not placed mating disruption dispensers yet they can still be deployed for later generations, but this generation must be treated with insecticides at the first generation timings.
| OFM 1st Generation Timing | |||
| Insecticide Type | |||
| County/Region | Degree Days by 5/4 base 45 | Conventional
170-200, 350-375 |
Diamide
100-150, 300-350 |
| Gloucester – Southern | 312 | 1st – past
2nd – May 7-9 |
1st – past
2nd – May 4-7 |
| Hunterdon – Northern | 261 | 1st – past
2nd – May 12-14 |
1st – past
2nd – May 9-12 |
Plum Curculio (PC): PC adults usually begin egg laying once the fruit is out of the shuck. Preferred materials that offer PC control now are Avaunt, and Imidan. If using high rates of a neonicotinoid (i.e. Actara, Belay, Assail), be aware that there is a synergistic effect when used in tank mixes with DMI materials (i.e. Rally) with regard to bee toxicity. Neonicotinoids should not be used if there are any flowering weeds in your orchard. Those flowering weeds will attract bees, which will be killed by the insecticide. The use of most of these products when bees are present is off label and therefore not legal. If pyrethroids are being used, then high rates are advisable, since low rates often do not control PC, especially in hot weather. Where PC is a problem, growers should rotate away from pyrethroid insecticides if possible. Actara and Belay will also control PC (and GPA), but not OFM.
Green Peach Aphids (GPA): Green Peach Aphid: GPA colonies typically begin forming at bloom, however in southern counties aphids are present at very low levels, and well below treatment thresholds. If aphids are at treatment level, you have and your ground cover is clean of blooming weeds, a good choice that will cover catfacing insects, aphids, and plum curculio is Thiamethoxam (Actara and in VoliamFlexi). Actara will not control OFM. Examine trees for the presence of colonies by standing back and looking at the entire tree. Clusters of curled leaves will define a single colony. Count the number of colonies on ten trees and use a treatment threshold of 2 colonies/tree at petal fall to shuck split for peach, and 1 colony/tree for nectarine. If treating aphids alone then Movento @ 6 oz/A is a good non-neonicotinoid choice. Movento must be combined with a spreader/penetrant spray adjuvant. Used later during late May to early June this will also control scale. Movento will not control PC or catfacing insects. Lannate can also be used, but is not quite as effective and is a weak PC material. To date no aphids have been observed in southern county orchards.
Tarnished Plant Bugs and Other Catfacing Insects: This is the other key insect complex at this time of year. Stink bugs have been found at low levels in beating tray samples. Tarnished plant bugs will become more of an issue as temperatures warm and mowing and other ground cover activities become more common. General spray timing at this time of year should still be targeted for Oriental Fruit Moth and/or Plum Curculio (PC). Most materials, except the diamides (Altacor, Belt, Tourismo) used for these pests will have some efficacy for plant bugs.
Lesser Peach Tree Borer and Peach Tree Borer: Growers that wish to use mating disruption for borer control should place them in the orchard before the lesser borer flight begins, which should be sometime in the next few weeks.
Bacterial Spot: Maintain tight covers with antibiotics until pit hardening. Typical antibiotics used include various copper and oxytetracyclene formulations. Full covers with at least 100 gpa are recommended around wetting periods or severe weather. No bacterial spot cankers or leaf symptoms have been observed in southern county orchards as of yet.
Peach Scab: In addition to Rusty Spot and Bacterial Spot, peach scab requires protective applications starting at petal fall. Peach scab cankers 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 and 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.
Rusty Spot: Rusty spot infections are ongoing until pit hardening. If you are using Flint Extra, Inspire Super, or Quadris Top for scab, these materials will also control rusty spot. After petal fall, maintain coverage with effective materials such as Rally, Rhyme, or potassium bicarbonate products.
Apple:
Codling Moth (CM): Biofixes for Codling moth have been set. See the chart below. Timings for codling moth treatments by chemistry are 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) + 14-21 days later |
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 | May 2 | May 6 | May 9 | May 14 | Too far off | Too far off | Too far off | Too far off |
| Northern | April 28 | May 4 | May 8 | May 13 | Too far off | Too far off | Too far off | Too far off |
Spotted Tentiform Leafminer (STLM): Adults are flying, but are not considered a pest target at this time. This is one of the most highly parasitized insects in the orchard. We have not seen economic damage from this pest in recent years. However in recent summers we have observed a slight increase in trap counts and injury in a few orchards in southern counties. Monitor your orchard for damage.
European Apple Sawfly (EAS): This insect is active through bloom and into petal fall and first cover. Adult females lay eggs just under the skin of freshly set fruit, and the young larvae mine just under the skin. Where this insect is active, it is a primary target at petal fall. In orchards of mixed variety plantings, the petal fall spray for the entire planting is prolonged. This enables EAS to start damaging the first varieties where petals fell earlier before a petal fall spray could be applied to the entire block.
Tufted Apple Budmoth (TABM): A biofix was set statewide on May 3. Predictions for insecticides timings are too far out at this time. More on this in later reports.
Diseases: Apple Scab, Powdery Mildew, Cedar Apple Rust, are diseases of concern at this time. The NEWA scab models are predicting about 100% ascospore maturity during this period in southern NJ. Primary apple scab spores are released during any substantial wetting and infection period, and since all ascospores are predicted to be mature primary scab season is nearing the end in southern counties. Growers should continue to manage for primary scab through May since microclimates may affect spore maturity and because it has been dry the next significant wetting may still result in a primary scab infection. Ascopore maturity will be slightly less in northern counties. Cedar apple rust infections can occur anytime between pink and 3rd cover.
Fire Blight: Continue rotations of Streptomycin, Mycoshield or Firewall through 1st cover for shoot blight. If using apogee or Kudos for shoot blight suppression follow label instructions.
Grapes:
Diseases: Grape diseases active at this growth stage are phomopsis, powdery mildew and black rot. Disease infection periods can be monitored using the NEWA models. Choose the weather station closest to your vineyard.
Insects: At this growth stage monitor for climbing cutworms and grape flea beetle. Both of these are considered minor pests.
Scouting Calendar Tree Fruit Southern Counties
The following table is intended as an aid for orchard scouting. I t should not be used to time pesticide applications. Median dates for pest events and crop phenology are displayed. These dates are compiled from observations made since 1995 in Gloucester County. Events in northern New Jersey should occur 7-10 days later.
Pest Event or Growth Stage |
Approximate Date | 2019 Observed Date |
| Bud Swell (Redhaven) | March 23 +/- 15 Days | March 29 |
1/4″ Green Tip Red Delicious |
March 31 +/- 13 Days | March 27 |
Pink Peach (Redhaven) |
April 4 +/- 15 Days | April 4 |
Tight Cluster Red Delicious |
April 9 +/- 13 Days | April 6 |
Oriental Fruit Moth Biofix |
April 9 +/- 13 Days | April 8 |
Full Bloom Peach (Redhaven) |
April 9 +/- 14 Days | April 10 |
Pink Apple (Red Delicious) |
April 14 +/- 12 Days | April 11 |
Codling Moth Biofix |
April 27 +/- 13 Days | May 2 |
Green Peach Aphid Observed |
April 16 +/- 16 Days | April 26 |
Full Bloom Apple (Red Delicious) |
April 22 +/- 11 Days | April 20 |
Petal Fall (Redhaven) |
April 22 +/- 10 Days | April 24 |
Petal Fall (Red Delicious) |
April 27 +/- 14 Days | Not yet observed |
Shuck Split (Redhaven) |
April 30+/- 11 Days | April 29 |
First PC Oviposition Scars Observed |
May 3 +/- 18 Days | Not yet observed |
Tufted Apple Bud Moth Biofix |
May 4 +/- 10 Days | May 3 |
San Jose Scale Crawlers |
June 2 +/- 8 Days | Not yet observed |
Pit Hardening Peach |
June 16 +/- 8 Days | Not yet observed |
Tree Fruit Trap Counts – Southern Counties
| Weekending | STLM | TABM-A | CM | AM | OFM-A | DWB | OFM-P | TABM-P | LPTB | PTB |
| 4/17/21 | 7 | 0 | 8 | 1 | ||||||
| 4/24/21 | 12 | 0 | 34 | 2 | ||||||
| 5/1/21 | 7 | 0 | 11 | 1 | 0 | 0 |
There is a potential for new boxwood blight infections today and tomorrow with the rain/humidity and higher temperatures
– Protective fungicide applications should remain in effect or be initiated immediately for Boxwood Blight (nursery and landscape settings) –
Boxwood Blight risk-model information, considerations, and links:
| Boxwood Blight Risk Assessment as of 5/4/2021 | ||||||||
| Region | Location | CODE | 3-May | 4-May | 5-May | 6-May | 7-May | 8-May |
| Southern | Upper Deerfield | NJ50 | Very Low | Infection Risk | Infection Risk | Very Low | Very Low | Very Low |
| Central | Howell / Freehold | NJ10 | Very Low | Low | Low | Very Low | Very Low | Very Low |
| Northern | High Point | NJ59 | Very Low | Very Low | Low | Very Low | Very Low | Very Low |
| Please check your local boxwood blight risk here (click here and type in your area code – select closest station) | ||||||||
Fungicides;
Format: [FRAC code]: Chemical name (Trade names)
DISCLAIMER: The label is the law, always refer to it for allowable host crops, use-restrictions, application rates, reapplication intervals, re-entry intervals (REI), and mix compatibility information. Production and pesticide information on this site are for private/commercial pesticide applicators and landscape professionals only, and are NOT for home gardener use. Provided materials represent examples and do not cover all possible control scenarios. Trade-names listed do not imply endorsement and are used as examples only. Please contact your local agent or chemical sales representative for more information or to discuss additional pest management options.
Resources
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 (blackheaded fireworm, spotted fireworm, Sparganothis fruitworm, and cranberry blossomworm), and blunt-nosed leafhoppers.
Blackheaded fireworm – Blackheaded fireworm eggs overwinter on the bed and usually hatch by around mid-May. It is important to catch
Figure 1. Blackheaded Fireworm Larva
the first generation, if possible, because the second generation occurs during bloom and is typically much more destructive. Blackheaded fireworm larvae (Figure 1) 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.
Spotted fireworm – This insect overwinters as a 2nd instar larva. They complete two generations a year. Larvae (Figure 2) feed between uprights they have webbed together. First-generation larvae injure the foliage causing it to turn brown as if burned. In New Jersey, first generation adult moths emerge the first week of June, followed by a second-generation of adult emergence in early August. Eggs are laid in masses on weedy hosts. Larvae from second-generation adults emerge in mid-August and may feed on fruit. Populations of spotted fireworm are regulated by their natural enemies, in particular Trichogramma wasps that parasitize the eggs.
Sparganothis fruitworm – This insect is a serious pest in most cranberry-growing states. Sparganothis fruitworm completes two generations a year and overwinters as an early-instar larva. Larvae (Figure 3) 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. Second-generation eggs are laid on
Figure 2. Spotted Fireworm Larva
cranberry leaves, and larvae will feed on fruit.
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 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 (Figure 4). At this time, 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.
Figure 3. Sparganothis Fruitworm Larva
Lepidopteran Pests Monitoring and Control – Use sweep netting for monitoring early lepidopteran pests (pre-bloom) (Figure 5). 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 gypsy moth (we use a combined threshold from adding all these caterpillars per sweep) 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
Figure 4. Cranberry Blossomworm Larva
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). Blunt-nosed leafhopper is of particular concern because they can transmit cranberry false blossom disease. This leafhopper has one generation a year. The adults are found in highest numbers during July, although nymphs or adults may be found from the end of May until October. Eggs are laid in August-September. The eggs overwinter and hatch in May or June. The nymphs (Figure 6) go through 5 instars to complete development.
Leafhopper Monitoring and Control: Leafhopper nymphs can be sampled using sweep nets (as described above for lepidopteran pests)
Figure 5. Monitoring Insect Pests of Cranberries
(Figure 5). 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. Although there is no established threshold based on sweep net counts, we propose the following tentative thresholds: 20 nymphs per sweep set in young beds, new varieties, and/or with false blossom incidence; and 40 nymphs per sweep set in older beds, older varieties, and no incidence of false blossom. These decisions should be made also 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) or Lorsban (only pre-bloom applications allowed for Ocean Spray growers) (Figure 7). 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. Alternatively, growers can use Closer (sulfoxaflor). In our insecticide trials, Closer has shown good-to-excellent leafhopper control. This insecticide cannot be used when bees are active (i.e., between 3 days prior to bloom and until after
Figure 6. Blunt-nosed Leafhopper Nymph
petal fall).
Figure 7. Leafhopper Control Options
Phomopsis disease of cane and leaf are prevalent throughout Northeastern and Mid-Atlantic region, including New Jersey. Most Vitis vinifera, and interspecific varieties are susceptible to this pathogen. The inoculum is carried in spring from over wintering sites by water onto susceptible tissues. In wet spring, grapevines staying wet for the longer duration following the bud break, is the right condition for the infection. Fruit and rachis infections can be severe if not controlled. Rachis susceptibility reduces few days after bloom. Berry infections remain inactive until preharvest, after which they colonize the fruit. [Read more…]
