Rutgers University | New Jersey Agricultural Experiment Station | Pesticide User Responsibility

December 7, 2020

A Primer on Dormant Oil Applications

Dormant Oil Guidelines:

Dormant oils at 2-4% rates in the late fall & late winter seasons can aid in the control of overwintering insects and insect eggs. Consider treating for such pests as aphids (eggs), southern red mites/eggs, spruce spider mites/eggs, oak spider mites (eggs), eriophyid mites/eggs, spruce gall adelgids, lace bugs (deciduous plants), cankerworms (eggs), leaftiers, psyllids, plant bugs, etc.

Some landscapers have been successful applying both late fall and early spring dormant oil treatments to the same plants on the same properties. This is a reasonable approach since a single dormant oil treatment will not provide 100% control and it gives the field technician another opportunity to monitor the landscape for problems.

Dormant oil sprays require excellent coverage & often repeat applications. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

Japanese maple scale infested branch will likely require multiple dormant oil treatments to suppress. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

 

 

 

 

 

 

 

 

 

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Filed Under: Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab
September 15, 2020

Register for the September Nursery Twilight Meeting (credit-bearing online webinar)

Nursery Twilight MeetingThursday, September 24th, 2020

6:00-7:00 pm

Click here to register for the twilight meeting

Registration password: nursery

Click here to upload your government issued photo ID prior to the meeting

We will NOT be checking photo-IDs within the actual session this time around (to better protect your information). However, you will still need to be visible on screen to acquire recertification credits.

Upload directions: If you click on the photo ID upload link using a smart phone/tablet you will have the option of simply taking a photo of your ID and uploading it directly into the system. Otherwise, you can scan a copy of your photo ID into a computer and follow the directions at the upload link. If you are unable to upload documentation prior to the meeting, don’t worry, we are here to help; Tim Waller will work with you to verify your identity for NJDEP recertification credit purposes using the attendance roster to contact individuals that are seeking credits.

Please note: the file upload goes to a secure Rutgers folder and no one other than the session host (Tim Waller) can view. Also, if you upload your information for the September meeting and plan to attend an October meeting, you will not need to upload your information again (good for 60 days).

September 2020 Nursery Crop Twilight Meeting 

NJ Pesticide License Recertification credits obtained: PP2 (2); 3A (2); 10 (1)

Online Program

5:30pm          Webinar opens and visual attendance check 

                        –Timothy Waller, Rutgers Cooperative Extension Agriculture Agent for Cumberland County

(Recording begins) : Welcome Remarks

6:00pm          Preparing for a successful season; Understanding the factors that contribute to pest  and disease outbreaks– Timothy Waller, Rutgers Cooperative Extension Agriculture Agent for Cumberland County

6:15pm          Emerging pests and diseases of New Jersey nursery crops – Rich Buckley, Rutgers Plant Diagnostic Laboratory and Nematode Detection Service, Director

6:30pm          Cultivating sustainable soils in ornamentals– Bill Errickson, Rutgers Cooperative Extension Agriculture Agent for Monmouth County

6:45pm          Effective nutrient management via fertigation– Raul Cabrera, Rutgers Extension Specialist in Nursery Production & Management

(Recording ends)

7:00pm          Additional questions; Adjourn

 

In cooperation with the NJNLA, NJLCA, and NJCTGA

Instructions:

  • Register for event at the above link
  • Include your pesticide license number and date of birth if you would like recertification credits
  • After registration you will receive a confirmation email with a link to the actual twilight meeting.
  • Upload a copy of your government issued photo ID at the link above
  • Day-of: click the link in the registration confirmation email and select “join by browser-New” around 5:30pm
  • Day-of: Have your video on if you wish to obtain credits

Additional requirements for those seeking credits:

  • Licensed applicators with a recertification period expiring October 31, 2020 will be given an exemption from the NJDEP online credit cap of 25% and are eligible for all credits, otherwise this exemption does not apply.
  • Verification of identity is required prior to or in short duration after the meeting
  • Attendees must be visible throughout the entire session (with live video on) and must stay to the end.
  • Polls can be randomly scheduled, & attendance will be visually monitored by a moderator.
  • Call-ins (audio only) are not eligible for pesticide recertification credits as of now; you need a computer/phone/tablet with *live* video capability.

 

We are here to help you connect, please contact Tim Waller (twaller@njaes.rutgers.edu) with any questions or concerns. Thank you very much for your willingness to cooperate within our online space!

Rutgers is dedicated to protecting your privacy and keeping your personal information safe. Your information will be kept strictly confidential; used solely to meet NJDEP ID verification protocol for recertification credit. Any information will be deleted after 60 days.

 

Filed Under: Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab, Turf
July 23, 2020

Differentiating the Common Wood Borers of Ash Trees

It is understandable for arborists and landscapers to assume that Emerald Ash Borers (Agrilus planipennis) are the cause when they observe branch die-back of ash trees (Fraxinus genus). During the 21st century, this invasive Asian tree beetle borer has killed many 100’s of millions of ash tree species as it has spread across much of the eastern half of the United States. However, it is important to remember some of the other wood borer species that cause ash decline, if not death. This blog will discuss the symptoms to distinguish between the Emerald ash beetle borer, the Ash/Lilac Clearwing moth borer (Podosesia syringae), the Banded Ash Clearwing moth borer (Podosesia aureocincta) and Ash Bark Beetle borers (Hylesinus species). Only the ash bark beetle species will have more than a single generation per season.

Symptoms on ash from banded ash clearwing moth borer infestation. (Photo Credit: Steven K. Rettke of RCE)

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Filed Under: Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab
June 25, 2020

Azalea Leafminer: A Commonly Unrecognized Azalea Pest Problem

The Azalea Leafminer (Caloptilia azaleella) produces plant symptoms that are typically subtle & can often be overlooked. Symptoms from this caterpillar can also confuse people by having both leafminer & leafroller stages. The early instar stages are leafminers, while the later instar stages are leafrollers or leaftiers. Commercial nurseries generally have more concerns with this pest, while they often receive little attention in the landscape. Although the Azalea Leafminer has 2+ generations per year, the azalea (Rhododendron genus) is the only known host of this native caterpillar having the unique one-two punch.

Symptom of Azalea Leafminers

Azalea Leafminers: Symptom stages from 3 leafmines & a single leafroller (Photo Credit: Steven Rettke of RCE)

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Filed Under: Commercial Ag Updates, Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab
June 17, 2020

Nursery update; focus on warm season spider mites

This advisory provides; (1) warm season spider mite biology and control options, (2) current growing degree-day information, and (3) a boxwood blight risk update.

Note: Previous spider mite advisories

Steve Rettke, Rutgers IPM, wrote two very good advisory posts pertaining to the different seasonal mites, in addition to symptomology and images of the different mites. He is a wealth of information and has contributed photos and will be assisting in future fact-sheets pertaining to common pests and their control. In light of these advisory posts (below) this current advisory will only cover the basics as it applies to pest control. Contact: rettke@njaes.rutgers.edu

Please review his very informative advisories:

Cool season mites: https://plant-pest-advisory.rutgers.edu/cool-season-mites-wax-as-the-warm-season-mites-wane/

Warm season mites: https://plant-pest-advisory.rutgers.edu/cool-season-mites-have-faded-but-warm-season-mites-now-surge/

Spider mite damaged tree

Cool season: Spruce spider mite damage on an Aberta Dwarf Spruce. Photo: Steven Rettke, RCE.

Plant covered in webs

Warm season: Two spotted spider mite webbing and damage. Photo: Steven Rettke, RCE.

(2) Basic spider mite biology and control options

Cool season mites: The mites affecting horticulture crop production can be broken into two functional groups; cool season and warm season. Cool season mites feed and lay eggs, as the name suggests, in cooler times of the year (late winter-early spring and then again fall-early winter depending on the year). The two most common cool season mites are the Spruce and Southern red spider mites that feed on conifers and broadleaf evergreens, respectively. In many cases the damages caused by these mites are not noticed until well into the growing season. Meaning that if damages are observed mid-season you would be better off waiting until the fall to control cool season mites, i.e. targeting late season egg hatches and developing mites.

Warm season mites: As the season progresses towards summer, the warm season mites including Two-spotted, Maple, Oak, Honey locust, European, and other host specific spider mites become active (typically June – September). The Two-spotted spider mite is known as a “cosmopolitan” pest because of its ability to colonize, and damage, a wide variety of horticulture crops (but are rarely observed on conifers). Sentinel plants would include rose, euonymus, and forsythia, as they are favorites of these mites. In contrast to the cool season mites, warm season mite damages are often visible while the pest is actively feeding and multiplying, as up to 10-15 generations per growing season can impact your crop. Warm season mites evade suffocation by dormant oil sprays and other miticide applications by leaving their feeding locations on plants once temperatures begin to drop, and overwinter in the soil horizon or leaf litter under the host plant. As warm season mites are preparing to go into dormancy they begin to change their color to an orange hue, meaning they are not feeding as readily and will not be as affected by miticides because of this.

Two spotted spider mites

Multiple life stages of Two spotted spider mites. Photo: Steven Rettke, RCE.

Two spotted spider mites

Two spotted spider mite females going into dormancy (orange coloration). Photo: Steven Rettke, RCE.

Conditions favoring spider mites: Full sun and dry, dusty conditions are often associated with increasing mite populations as low relative humidity often stimulates mite reproduction. Additionally, during periods of rain (and resulting leaf wetness-periods), certain fungi are able to attack and reduce mite populations (called entomopathogenic fungi). Meaning in frequently wet seasons mite numbers, damage, and miticide applications should be lowered due to increased fungal activity. However, this situation can certainly lead to increased plant pathogenic fungi activity as well, therefor a balance between the two is most desirable. Excessive nitrogen fertilizer has also been linked to explosive mite populations; therefor a well-planned nutritional regiment should be strictly followed.

IPM is important when suppressing spider mite populations!

Beneficials: In addition to entomopathogenic fungi (like Beauveria bassiana), numerous beneficial organisms can also manage mite populations including predacious mites (Phytoseiidae family), spider mite destroyer (Stethorus punctillim), ladybug larvae, midge larvae (Feltiella acarisuga), and minute pirate bugs. Given this complex, and many times free, natural defense system, applications of certain insecticides can actually cause mite populations to resurge by killing the mite-feeding beneficials (see note below). Therefor, all applications should be thoughtfully considered with economic (or cosmetic) thresholds in mind.

Compounds that can cause spider mite resurgence:

  • Carbaryl (Sevin)
  • Cyfluthrin containing compounds (Tempo, Decathalon, Scimitar)
  • Permethrin (Astro)
  • Imdacloprid (Merit, Marathon)

Warm season spider mite treatment options:

ROTATE between Insecticide Resistance Action Committee (IRAC #)

Format: [IRAC Group #]: Chemical name (Trade names)

  • [3A]: Pyrethrins (Tersus)
  • [5]: Spinosad (Conserve, Entrust)
  • [6]: Abamectin (Avid, Lucid, Aracinate TM)
  • [20D]: Bifenazate (Floramite SC)
  • [10A]: Hexythiazox (Hexygon)
  • [21A]: Pyridaben (Sanmite, Sanmite SC)
  • [21A]: Fenazaquin (Magus)
  • [23]: Spiromesifen (Forbid 4F, Judo)

“Softer” spider mite materials

  • Agitator (forces mites out of hiding): Captiva
  • Azadirachtin from the Neem plant: (Azatrol EC)
  • Beauveria bassiana: (Naturalis-L)
  • Horticulture oil: (@ 1-2% vol:vol summer applications)
  • Insecticidal soaps: (M-Pede)

Always refer to the label for allowable host crops, use-restrictions, application rates, reapplication intervals, REI times, and mix compatibility information.

NOTE: Production and pesticide information on this site are for commercial operators only and are NOT for home gardener use. Provided materials represent examples and do not cover all possible control scenarios. Please contact your local agent or chemical sales representative for more information.   

(2) Growing Degree-days as of 6/16/2020 (if you need help please contact me at twaller@njaes.rutgers.edu)

Upper Deerfield (NJ50)= 809 GDD50 Howell/Freehold (NJ10) = 628 GDD50 Pequest (NJ58) = 525 GDD50

Growing degree day map for our area: (courtesy of Cornell University; Fore Cast)

Growing degree-day map for Northeastern US

Growing degree-day map for our area. Cornell, Fore Cast.

(3) Boxwood blight risk update

Boxwood Blight Risk Model
Date Upper Deerfield (NJ50) Howell (NJ10) Pequest (NJ58)
6/14/20 Sun Very low risk Very low risk Very low risk
6/15/20 M Very low risk Very low risk Very low risk
6/16/20 T Very low risk Very low risk Very low risk
6/17/20 W Very low risk Very low risk Very low risk
6/18/20 Th Low risk Low risk Low risk
6/19/20 F Infection potential Infection potential Low risk
6/20/20 S Low risk Infection potential Low risk
6/21/20 Sun Very low risk Low risk Very low risk
Risk of infection
adapted from: https://uspest.org/risk/boxwood_app

Please visit this website (there is a mobile app as well): https://uspest.org/risk/boxwood_app

Protective fungicide applications should remain in effect or be initiated immediately for Boxwood Blight. The disease may be sporulating and spreading amongst plantings if present (or may come into your nursery via shipments) within the next few days. Please continue preventative/protectant fungicide applications utilizing; chlorothalonil (FRAC Group M05), mancozeb (FRAC Group M03), and QoI-fungicides (FRAC Group 11) in a rotation (other materials available as well).

NJAES; Plant Diagnostic Lab https://njaes.rutgers.edu/plant-diagnostic-lab/

 

*Additional links and resources*

Please take the 2020 Nursery Industry Survey: https://forms.gle/dUjLxaiu6qDQYYsRA

Ask the Agent (every Wednesday @ 7:00pm): : https://go.rutgers.edu/t7wjkit1

NJNLA- Wine Down Wednesdays (every first and third Wednesday @ 7:00pm-8:00pm).

Email: Lori Jenssen @ njnla.director@gmail.com

Subscribe to the NJAES YouTube webpage: https://www.youtube.com/user/RutgersNJAES/

RU Sustainable Nursery Production website: https://njaes.rutgers.edu/nursery/

March meeting PDF: https://njaes.rutgers.edu/nursery/documents/2020%20SJ%20Nursery%20Meeting%20Proceedings.pdf

How to use growing degree-day resources: https://plant-pest-advisory.rutgers.edu/using-growing-degree-day-calculators-nursery-pest-and-pathogen-updates-important-resource-links/

2017 Southeastern U.S. Pest Control Guide for Nursery Crops and Landscape Plantings: https://content.ces.ncsu.edu/southeastern-us-pest-control-guide-for-nursery-crops-and-landscape-plantings 

Rutgers Insect Control Recs. for Shade Trees and Commercial Nursery Crops: https://njaes.rutgers.edu/pubs/publication.php?pid=E334

NJAES; Soil Testing Lab: https://njaes.rutgers.edu/soil-testing-lab/

 

Thank you,
Cumberland County Extension: Timothy J. Waller, Ph.D. @ twaller@njaes.rutgers.edu

Filed Under: Disease Forecasting, Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab, Turf
June 11, 2020

Scale insect crawler activity and summer treatment options

Basic Scale Biology

There are two types of scale insects; armored and soft scales. Scale insects hatch from eggs and typically develop through 2 nymphal instar growth stages known as “crawlers”. During this “crawler stage” (many cases mid-May through July) the insects are vulnerable to insecticides and other biological enemies. Once the “crawlers” settle on a feeding location and begin to develop waxy or hard outer coverings, the insects are no longer susceptible to most insecticides.

Targeting the “crawler” stage is imperative to successful pest management.

One slight difference between armored and soft scales is how many generations they can have per year; armored (several), soft (typically only 1). Also, once settled armored scales are stationary whereas soft scales can move (albeit slowly). Many scale insect “crawlers” head towards growing vegetative tips, making this location suitable for scouting. Various sticky traps, including double sided tape wrapped around branches are utilized to determine the presence of scale “crawlers”. As noted prior, the presence of “crawlers” should be first visually confirmed if at all possible as pesticide applications made too early are not effective. Programs that utilized cool season dormant/horticultural oils, proper pruning, and the use of summertime contact or systemic insecticides are most successful.(A detailed scale insect fact-sheet is forthcoming!)  

Armored and soft scales can be controlled using the same chemicals if targeting “crawlers”.

 

Growing Degree-days as of 6/10/2020 (Weather station selected for each location. Ex: NJ50 = Upper Deerfield)

Upper Deerfield (NJ50)= 686 GDD50 Howell/Freehold (NJ10) = 536 GDD50 Pequest (NJ58) = 441 GDD50

Scale insects target growing degree-days

(Egg hatch + crawler emergence = scout and treat as needed)

Pine needle scale – (448)

Maskell scale – (470)

Oystershell scale – (486)

Cottony camellia/taxus scale – (520)

Euonymus scale – (522)

European elm scale – (542)

White prunicola (Peach) scale – (594)

Cryptomeria scale – (600-800)

Golden oak scale (680)

Juniper scale – (694)

Hemlock ‘fioriniae’ scale – (300-799)

Spruce bud scale – (700)

Fletcher Scale – (730)

Azalea bark scale – (737)

Oak lecanium scale – (789)

Beech scale – (800)

Japanese maple scale – (829)

Calico scale – (834)

Cottony maple scale – (850)

European fruit lecanium scale – (940 DD)

 

Summertime scale treatment options

ROTATE between Insecticide Resistance Action Committee (IRAC #)

Format: [IRAC Group #]: Chemical name (Trade names)

  • [1A]: Carbaryl (Sevin SL)
  • [1B]: Acephate (Orthene, Leptitect, Precise GN)
  • [1B]: Chlorpyrifos (Dursban 50W, DuraGuard ME)
  • [1B]: Malathion (Malathion 5 EC)
  • [3A]: Cyfluthrin (Decathlon)
  • [3A]: Bifenthrin (Talstar S Select, Onyx)
  • [3A]: lambda-cyhalothrin (Scimitar GC)
  • [3A + 4A] Imidacloprid + Bifenthrin (Allectus SC)
  • [3A + 4A] Imidaclopird + cyfluthrin (Discuss NG)
  • [4A]: Acetamiprid (TriStar 8.5 SL)
  • [16]: Buprofezin (Talus 70DF)
  • [7C]: Pyriproxifen (Distance IGR)
  • Insecticidal soaps (M-Pede)
  • Azadirachtin from the Neem plant: (Aza-Direct, Azatin O or XL, Azatrol EC)

Please read the label. The label will provide allowable plant species, use rates, restrictions (phytotoxicity or pollinator concerns), and re-application intervals.

Some useful scale resources: (bare in mind there is variability amongst models and GDD depending on the source, but generally the information will help you make better pest management choices)

 

Southeastern U.S. Pest Control Guide for Nursery Crops and Landscape Plantings: https://content.ces.ncsu.edu/southeastern-us-pest-control-guide-for-nursery-crops-and-landscape-plantings

Rutgers Insect Control Recommendations for Shade Trees and Commercial Nursery Crops: https://njaes.rutgers.edu/pubs/publication.php?pid=E334

 

Online events and Rutgers Resources:

Ask the Agent (every Wednesday @ 7:00pm): Join: https://go.rutgers.edu/t7wjkit1

NJNLA- Wine Down Wednesdays (every first and third Wednesday @ 7:00pm-8:00pm). Email: Lori Jenssen @ njnla.director@gmail.com

Please take the 2020 Nursery Industry Survey: https://forms.gle/dUjLxaiu6qDQYYsRA

Subscribe to the NJAES YouTube webpage: https://www.youtube.com/user/RutgersNJAES/

RU Sustainable Nursery Production website: https://njaes.rutgers.edu/nursery/

How to use growing degree-day resources: https://plant-pest-advisory.rutgers.edu/using-growing-degree-day-calculators-nursery-pest-and-pathogen-updates-important-resource-links/

NJAES; Plant Diagnostic Lab: https://njaes.rutgers.edu/plant-diagnostic-lab/

NJAES; Soil Testing Lab: https://njaes.rutgers.edu/soil-testing-lab/

 

Contact: Timothy Waller, Ph.D. at:      twaller@njaes.rutgers.edu

Filed Under: Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab, Turf