June 8, 2020

Bagworms will be hatching very soon and need attention

This advisory has three topics: (1) Bagworm hatch, (2) boxwood blight activity, and (3) NJNLA online pesticide credit course availability.

Bagworm hanging from a branch

Photo: Rich Buckley

Bagworms

Photo: Rich Buckley

(1) Bagworms

Bagworms (and many other caterpillars) will be hatching any day now, and should be managed very soon. Bagworms should be targeted during egg hatch through first/second instar caterpillars, typically between 600-900 GDD50 (growing degree-days) prior to their airborne “ballooning” phase. Check that the eggs have hatched prior to application of pesticides as most compounds will not be effective at all if the first instar caterpillars are not present. Lethal pesticide doses are important, as sub-lethal doses can trigger early pupation, making the pest all but invincible.

Growing degree-days as of 6/7 (Using NEWA): (Upper Deerfield: 651 GDD50)(Howell: 502 GDD50)(Pequest: 414.5 GDD50)

Bagworm management: If eggs have not hatched: hand-remove sacs/bags. Typically female/egg filled sacs are higher in the canopy so keep that in mind while scouting.

Bagworm preferred materials: B.t. (Bacillus thuringiensis) and Spinosad containing compounds.

Other bagworm material options: Indoxacarb(Provaunt), chlorantraniliprole (Acelepryne), cyantraniliprole (Ference), growth regulator such as tebufenozide (Mimic), and many other compounds are available. Please contact your extension agent or chemical dealer for more information.

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

Bagworm links / Shade tree insect recommendations:

https://plant-pest-advisory.rutgers.edu/bagworm-caterpillars-have-hatched-throughout-most-of-nj/#more-5610

https://njaes.rutgers.edu/pubs/publication.php?pid=FS1144

https://njaes.rutgers.edu/pubs/publication.php?pid=E334

Photo Credits: Rich Buckley (Plant Diagnostics Laboratory) https://njaes.rutgers.edu/plant-diagnostic-lab/

(2) Boxwood blight

Please continue or initiate protective/preventative applications this week for Boxwood Blight.

Previous Boxwood PPA 6/4/2020: https://plant-pest-advisory.rutgers.edu/immediate-potential-for-boxwood-blight-activity/

Boxwood blight activity as of today (6/8) for the next week (using a Millville, NJ weather station) 

As of now the predicative model found at (https://uspest.org/risk/boxwood_app) indicates that there is a possibility for Boxwood Blight activity Wednesday (10th) and Thursday (11th) of this week. Additionally, I am expecting another round of pathogen activity on Sunday (14th). The tropical storm systems pushing up from the south may bring higher winds and short periods of rain that could easily spread the disease if present. Be mindful of overhead irrigation during this period and only water when leaves will have adequate time to dry.

Please visit and use this webpage for local disease forecasting (select a close-by weather station within the website or application): https://uspest.org/risk/boxwood_app) 

(3) NJNLA online pesticide credit opportunity

NJNLA pesticide credit webinar/course: Invasive Forest Pests: New Threats and Their Management

Sign-up: https://www.njnla.org/events/EventDetails.aspx?id=1383945

Webinar – June 10th, 2020 – 7:00pm to 8:30pm. Invasive Forest Pests: New Threats and Their Management. You must include your email address when registering. Information to join Webinar will be sent just prior to the start. Cost: $35/Member, $50/Non-Member

NJ Pest Credits: 3A (Ornamentals) – 3, PP2 (Private Applicator Category) – 3, Plus: 2 (Forest) – 3, 8C (Campgrounds) – 3, 9 (Regulatory) – 3,. CNLP: Environment – 1.5, LTE/LTCO: 1 CEU, NJUCF: 1 CEU and ISA is still pending.

 

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

Have a plant problem? Contact the Rutgers Plant Diagnostic Laboratory https://njaes.rutgers.edu/plant-diagnostic-lab/

 

 

Timothy J. Waller, Ph.D. @ twaller@njaes.rutgers.edu

 

Filed Under: Disease Forecasting, Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab, Turf
June 4, 2020

Immediate potential for Boxwood Blight activity: Plus a Nursery and Greenhouse growers’ update

 

There is a potential for new boxwood blight infections in the next few days according to 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. According to https://uspest.org/risk/boxwood_app, this is the first legitimate potential for boxwood blight spread and new infections in 2020 for southern NJ. Please continue preventative/protectant fungicide applications utilizing; chlorothalonil (FRAC Group M05), mancozeb (FRAC Group M03), and QoI-fungicides (FRAC Group 11) in a rotation. Please contact Tim Waller at twaller@njaes.rutgers.edu for more information or questions.

UPDATES: 

Growing Degree-days as of 6/4/20 using NEWA

GDD50 = Growing Degree-Day with min. temp. set to 50F

Upper Deerfield = 548.5 GDD50 ; Howell = 407.5 GDD50 ; Pequest = 335.0 GDD50

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/

Pests: The number of accumulated growing degree-days has been rapidly increasing with higher and higher temperatures (approaching normalcy). Throughout New Jersey various adult borers will be emerging, these include; Lilac, Emerald Ash, Banded Ash Clearwing, and Peach Tree borers. Additionally, Ambrosia beetles (multiple species) will be in-flight and actively seeking egg-laying locations. Pyrethroids should be used as preventative sprays but should be targeted to the bases of susceptible hosts such as Magnolias, Yellow bud, Red bud, Japanese maples, Styrax, and Hybrid chestnuts. These Targeted applications are geared towards protecting beneficial insect populations. The eggs of many scale insects are hatching now, leaving their ‘crawler’ stage vulnerable to pesticide applications. Scale insect species to be mindful of; Maskell, Oystershell, Taxus, Euonymus, Prunicola, Oak lecanium, Japanese maple, Cottony maple, Calico, Golden oak, and Juniper scale. Aphids, especially on roses, and mites will be increasing their populations with the warmer weather and should be minded when in high density. Management should utilize an appropriate pesticide rotation when necessary, as these pests are prone to developing pesticide resistance quickly. Four lined plant bugs, basswood lacebug, and multiple leaf and plant hoppers have been reported south of NJ and should be monitored and treated for as appropriate through the coming weeks as many of these insects are capable of vectoring plant viruses. Lilac leafminer, Juniper tip-midge, and Pin oak sawfly may also be an issue in some locations. Red-headed flea beetle will be hatching between 250-480 GDD50, with adults emerging between 500-1000 GDD50. A second generation of larva will then be active between 1,570 to 1860 GDD50, emerging later 1,878 to 2,318 GDD50. Reminder, keep an eye out for the Box tree moth that has been identified approaching the border of US and Canada. This pest has prompted APHIS importation amendments for Boxwood, Euonymus, and Illex. Gypsy moths, Bagworms, Mimosa webworm will be hatching or emerging in many parts of the state very soon, (in some locations they may already have).

Please visit https://njaes.rutgers.edu/pubs/publication.php?pid=E334 for more specific information.

Understanding and approaching plant diseases: The weather as of late has been conducive to plant disease for much of NJ. Higher humidity, increasing temperatures, and prolonged periods of leaf wetness (particularly at night) are considered the factors associated with the ‘sweet spot’ of disease development. Regularly scheduled protectant fungicide applications should be continued if a pathogen or history-thereof is suspected. Compounds should be rotated to guard against pesticide resistance to any one compound (rotating high/medium-risk with low-risk materials). Also, any steps geared towards increasing airflow, reducing wet-feet, limiting mechanical injury, and reducing leaf wetness duration or excessive overhead irrigation during this warm and humid period will benefit disease management efforts.

Please visit: https://njaes.rutgers.edu/pubs/publication.php?pid=E036 for more specific information on individual plant and pathogen species.

Other timely diseases to note: Many needle cast diseases of conifers should be well into a fungicide application schedule, utilizing chlorothalonil, azoxystrobin, basic sulfate coppers, mancozeb, and T-methyl in a rotation of materials. Many of these compounds will also control Pine needle rust that may become prevalent in some locations, especially those locations with high levels of goldenrod or aster weeds. Botrytis and powdery mildew are still a concern in many parts of the state, especially those that are experiencing cooler nighttime temperatures. What fungicide used is dependent on the specific host species in many cases. Please refer to the link above for specific information. Fungal and bacterial leaf spots are very common and often only intensively treated if those plants are to enter the market the next season. However, in areas prone to disease or severe cases (defoliation occurs), treatments should be preventative and conducted throughout the season. Sooty mold grows on the honeydew produced by large populations of sap-sucking insect pests (aphids, scales, leaf/plant hoppers). Controlling the insect pests is our best option to reduce this unsightly disease. In severe casts of sooty mold, plants can be washed free of this fungal growth using mild detergents. Phytophthora diseases are ever present at the nursery, however cultural practices such as sterilized potting media, cleaning tools and machinery regularly, efforts to reduce wet-feet or overwatering, and sterilization or treatment of recycled water can have profound impacts on the expression or spread of Phytophthora diseases. When fungicide applications are required, materials like phosphorus acids, fosetyl-Al (Aliette), mefenoxam (Ridomil), and etridiazole + T-methyl (Banrot) are commonly used. Rotation of these compounds and proper disease identification are incredibly important as many root-rotting pathogens have a strong propensity towards developing pesticide resistance.

Please consider the Rutgers Plant Diagnostics Laboratory for pest/pathogen identification concerns: https://njaes.rutgers.edu/plant-diagnostic-lab/

 

Online discussions and credit events

NJNLA pesticide credit webinar/course: Invasive Forest Pests: New Threats and Their Management (6/10/20): https://www.njnla.org/events/EventDetails.aspx?id=1383945

Webinar – June 10th, 2020 – 7:00pm to 8:30pm. Invasive Forest Pests: New Threats and Their Management. You must include your email address when registering. Information to join Webinar will be sent just prior to the start. Cost: $35/Member, $50/Non-Member. NJ Pest Credits: 3A (Ornamentals) – 3, PP2 (Private Applicator Category) – 3, 2 (Forest) – 3, 8C (Campgrounds) – 3, 9 (Regulatory) – 3,. CNLP: Environment – 1.5, LTE/LTCO: 1 CEU, NJUCF: 1 CEU and ISA is still pending. 

EPA information pertaining to online credits for licenses expiring in 2020: https://pestmanagement.rutgers.edu/increased-online-ceus-for-licenses-expiring-2020-act-now/

Ask the Agent (every Wednesday @ 7:00pm): https://go.rutgers.edu/t7wjkit1 . A new online forum has been created where anyone can log-on and speak with Rutgers Cooperative Extension agents (multiple agents from multiple counties)

NJNLA- Wine Down Wednesdays (every first and third Wednesday @ 7:00pm-8:00pm). Email: Lori Jenssen @ njnla.director@gmail.com. This is a great opportunity to speak with other green-industry businesses.

 

Rutgers nursery survey, advisory, and other resources:

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

The new nursery agents have prepared a preliminary survey aimed at understanding the needs of our growers and clientele, i.e. you. Please take a moment to complete the survey, as this type of information really helps the agents secure grant funding to deal with the problems you actually have. Thank you!

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

Filed Under: Disease Forecasting, Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab, Turf Tagged With: ,
May 22, 2020

10 Best Management Practices to Avoid Herbicide Drift 

The last few weeks have been very windy, and we already received numerous calls from specialty crops growers inquiring about the risk of herbicide drift or investigating if observed crop damages may be the result of herbicide drift.

Blueberry flowers

Fig.1 Paraquat drift on blueberry flowers

Why does it seem like crops are more affected by herbicide drift in the spring? Well, mostly because this is the time when newly planted crops develop new shoots or reproductive structures that may be very sensitive to herbicide drift (Figure 1). This is also the time of the year when most postemergence herbicide are applied to control emerged weeds and subsequent new flushes. When both events coincide and if weather conditions favor herbicide drift, this could lead to disastrous injury on sensitive non target crops!

Drift is defined as physical movement of an herbicide through air, at the time of application or soon thereafter, to any site other than that intended. It can be particle drift from fine herbicide spray droplets that can travel over long distances during period of high wind. High wind speed, low relative humidity, high temperatures, small droplet size, and spray boom maintained high above the ground are factors that increase the risk of particle drift. Depending on the herbicide, application and weather conditions, fine droplets can travel up to several miles! It can also be vapor drift which results from the ability of an herbicide to vaporize and mix freely with air. Volatility of any herbicidal substance is characterized by its vapor pressure. The higher the vapor pressure of a substance, the greater its tendency to volatilize (Table 1). However, other factors such as herbicide formulation and weather conditions will influence volatility. Some herbicides classified as growth regulators (2,4-D, dicamba, triclopyr or clopyralid) are well known for the higher risk of vapor drift associated with their use when herbicide formulation and/or weather conditions increase volatility (Figure 3).

Herbicide Vapor Pressure (mmHg)
Glyphosate IPA 1.58 x 10-8
Glyphosate Ammonium Salt 6.75 x 10-8
2,4-D DMA <1.0 x 10-7
2,4-D Acid 1.4 x 10-7
Atrazine 2.9 x 10-7
2,4-D BEE 2.4 x 10-6
2,4-D EHE 3.6 x 10-6
Trifluralin 1.1 x 10-4
Clomazone 1.4 x 10-4
Table 1 Vapor Pressures for 2,4-D Formulations and Several Commonly Used Herbicides. Abbreviations: IPA, isopropylamine; DMA, dimethylamine; BEE, butoxyethyl ester; EHE, 2-ethylhexyl ester.

So, there are a few things that you need to consider reducing the risk of potentially expansive damages to sensitive crops:

  1. Select nonvolatile or low volatility herbicides to minimize the risk of vapor drift. Growth regulator herbicides such as 2,4-D, MCPA or triclopyr can be formulated as ester or amine salt. The ester formulation is notorious for its volatility; therefore, always use these herbicides formulated as amine salt to reduce the risk of vapor drift. Other herbicides than growth regulators have high vapor pressure that makes them prone to vapor drift (clomazone, trifluralin, EPTC), but either should be soil incorporated or are formulated in a way (micro-encapsulation) that will limit the risk of vapor drift.

    Beet plant

    Fig. 2 New growth chlorosis on beet. A WSSA group 27 herbicide (“bleacher”) was applied preemergence at planting in a neighboring corn field and drifted to the beet field because of high wind.

  2. Carefully read the herbicide label. The product label will provide information regarding when it is not safe to apply the product based on various parameters such as wind speed, temperature, humidity. You may also find information buffer requirement when spraying near sensitive downwind plants or information on the type of nozzle you must use for a specific herbicide.
  3. Select nozzles that produce the large size droplets while providing adequate coverage at the intended application rate and pressure. You can also select specifically designed drift-reduction nozzles (for example, drift-guard or air induction types) operate at lower pressure (15 to 30 psi) and produce large droplets that will have less potential for drift. A good source of information on droplet characteristics and operating pressure for various nozzle types is the TeeJet nozzle catalog (https://www.teejet.com/CMSImages/TEEJET/documents/catalogs/cat51a_us.pdf).
  4. Use low application pressure and drive at low speed when applying herbicides. Herbicide drift will increase with application pressure and speed…
  5. Keep the boom stable and the nozzles close to the soil as this will minimize herbicide drift but also potential injury to the crop on which herbicide is applied. You may want to consider using a shielded boom when spraying herbicide that are prone to drift or may injure your crop. Keep in mind that postemergence herbicide will provide optimal weed control when applied timely with regards to weed development. If the weeds are too tall (see the maximum weed size for each weed species on the label), then it’s too late to spray!

    Damaged crops

    Fig. 3 Damages to pepper (left), cucumber (center), and eggplant (right) caused by dicamba herbicide applied at 1/1000 of the labeled rate on soybean.

  6. Mix spray additives recommended by the label to reduce the production of fine spray droplets. Avoid tank mix ammonium sulfate with volatile herbicides as ammonium sulfate increases volatility. You can also consider the use of drift retardants that reduce drift by increasing the viscosity or surface tension of a spray solution. However, research shows that while some drift retardants may help under some conditions, the prevention of herbicide drift should primarily rely on nozzle selection, boom height, application pressure, and environmental conditions.
  7. Do not apply herbicides when wind is blowing toward sensitive plants or when wind speed exceeds 10 mph. Ideal spray conditions are when wind speed is between 3 and 10 mph. Low winds (< 3 mph) tend to be unpredictable and variable in direction and may indicate conditions that help the development of a temperature inversion. Applying any herbicide when wind speed exceeds 10 mph may result in catastrophic consequences for neighboring sensitive vegetable or horticultural crops (Figure 2).
  8. Do not apply herbicides when temperature inversion occurs. Inversions occur when warm light air rises upward into the atmosphere and heavy cool air settles near the ground, preventing the mixing of air layers. Temperature inversion will cause small-suspended droplets to form a concentrated cloud that can move long distances (up to several miles). Typically, temperature inversions start at dusk and break up with the sunrise because of vertical air mixing. To confirm the presence of an inversion, air temperature should be measured carefully at two heights out of the direct sun: 6 to 12 inches above the ground or the top of a nearly closed-crop canopy, and at a height of 8 to10 feet above the surface to be sprayed. When the temperature at the higher level is greater than the temperature at the lower level, an inversion exists. The greater the temperature difference between the two levels, the more intense the inversion, and the more stable the lower atmosphere. To test for sure, you can use smoke by burning a small amount of dry vegetation to see if the smoke dissipates or hangs low to the ground. If the smoke hangs in the air together then moves off slowly without dissipating, it indicates that a temperature inversion exists and that you do not want to spray as  long as the temperature inversion persists. Usually, temperature inversion will dissipate when temperature rises 3 degrees or more above the morning low, or when the wind speed increases to more than 3 mph.
  9. Spray when temperatures remain below 80°F to minimize vaporization and droplet evaporation. This will minimize vapor drift but also help with weed control by avoiding that spray droplets evaporate before reaching the target…
  10. Leave a buffer zone between treated fields and sensitive plants. Herbicide labels may specify the width of the buffer zone. The buffer zone will allow larger droplets to settle before reaching sensitive plants. The buffer zone may not be effective in settling small droplets.

Remember that all herbicides are capable of drift, no exception.

When spraying a pesticide, you have a moral and legal responsibility to prevent it from drifting and contaminating or damaging neighboring crops and sensitive areas. Always monitor weather conditions and their evolution carefully when spraying an herbicide. Overall, do not spray if all conditions are not suitable, and stop spraying if conditions change and become unsuitable.

Filed Under: Blueberry, Cranberry, Field, Forage & Livestock, Fruit, Landscape, Nursery, & Turf, Nursery, Strawberry, Tree Fruit, Vegetable Crops, Wine Grape Tagged With: ,
May 19, 2020

NJMVC Further Extends Driver License, Registration, and Inspection Expiration Dates Due to COVID-19

The New Jersey Motor Vehicle Commission Chief Administrator Sue Fulton, on Monday, May 18th, announced additional extensions to driver license, registration, and inspection expiration dates in the continuing efforts to mitigate COVID-19 and safeguard public health.

Effective immediately, the following documents, if expiring between March 13 and May 31, have been extended to July 31. Documents expiring June 30 are extended two months to August 31, and those expiring July 31 are extended to September 30.

• All Standard driver licenses (including permits) and standard non-driver IDs
• Privately owned and commercial vehicle registrations (including Farmer and Farm Use registrations)
• Vehicle inspections
• Purple Heart/Disabled Veteran placards
• Temporary tags

“Get it done online now, if you’re able,” Fulton suggests. “We do anticipate that volumes will spike once we reopen and when we reach the end of these extensions. Our job is to serve customers in the most efficient way possible and one way we can do that is by steering people to our expanded list of online services.”

On March 13, the NJMVC initially announced two-month extensions for licenses, registrations, and inspection stickers expiring in March, April, and May, timelines that have now been pushed back.

The NJMVC encourages customers to utilize online services, which have been expanded during the COVID-19 crisis. In most cases, customers can renew a license, replace a lost license, change an address, renew a registration, and complete other transactions through the NJMVC’s Online Services portal.

Customers also should check NJMVC.gov for the latest information and updates.

Filed Under: Blueberry, Commercial Ag Updates, Cranberry, Field, Forage & Livestock, Food Safety, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, Strawberry, Tree Fruit, Turf, Uncategorized, Vegetable Crops, Wine Grape Tagged With: , , ,
May 12, 2020

Labor Will Be Hot Topic For 7:00PM Wednesday Night Webinar – “Ask the Ag Agent”

This week, the webinar will be concentrated on the topic of farm labor. Since updates are coming to the industry and we have learned of some programs for migrant workers please join us for discussion. Please feel free to bring up other topics.

Ask the Ag Agent – 7:00PM Weekly – Every Wednesday – Farmer Video Conference/Call-In ForumAsk the Ag agent

“Ask the Ag Agent” weekly 1-hour sessions for farmers will be hosted again on Wednesday May 13th and continue each Wednesday until May 27th. The online conferencing/call in events will begin at 7:00PM with an open forum to discuss ag-related questions about production, marketing, regulations and any other topics farmers wish to discuss. All are welcome. Events are hosted by William Bamka, Stephen Komar, Meredith Melendez and Michelle Infante-Casella – Agricultural Agents.

To access via WebEx on a computer go to https://go.rutgers.edu/rc9n3kxt

Or, Join by phone
+1-650-429-3300 USA Toll
Access code: 799 743 872

For additional Rutgers Cooperative Extension educational programs check out https://events.rutgers.edu/njaes/

Filed Under: Blueberry, Commercial Ag Updates, Cranberry, Field, Forage & Livestock, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, Strawberry, Tree Fruit, Turf, Uncategorized, Vegetable Crops, Wine Grape
May 8, 2020

Using Growing Degree-day calculators, nursery pest and pathogen updates, important resource links

Announcements:

NJ Department of Agriculture Issues Burn Permit for Frost Protection –May 7 thru May 11

New Jersey Department of Agriculture has issued a notice concerning open burning due to colder spring overnight temperatures presently forecasted for areas of New Jersey from Thursday, May 7 through Monday, May 11, 2020, which could adversely affect fruit, vegetable, and floriculture crops in bloom or near bloom around the state. For more information: https://plant-pest-advisory.rutgers.edu/nj-department-of-agriculture-issues-burn-permit-for-frost-protection-thru-may-11/

Sourcing PPE for your workers:

If you need PPE for you and your workers, please do not wait to obtain more supplies! When our region re-opens to the masses there will be another wave of high-demand for masks and PPE. https://plant-pest-advisory.rutgers.edu/sourcing-personal-protective-equipment-ppe-for-your-farm-employees/

Recent financial Plant and Pest Advisory Posts:

US Small Business Admin Opens Economic Injury Disaster Loan (EIDL) Programs to Agriculture: https://plant-pest-advisory.rutgers.edu/us-small-business-admin-opens-economic-injury-disaster-loan-eidl-programs-to-agriculture/

SBA resumed accepting Paycheck Protection Program applications: https://plant-pest-advisory.rutgers.edu/sba-resumed-accepting-paycheck-protection-program-applications/

 

Utilizing Growing Degree-day calculators and resources:

(As of 5/7/20 using NEWA, Upper Deerfield = 213.5GDD50 ; Howell = 153.5 GDD50 ; Pequest = 88.0 GDD50) (GDD50 = Growing Degree-Day with min. temp. set to 50F)

Using Growing Degree Day models to plan pest management timing is a proven method for understanding when a pest or pathogen will rear its ugly head. These models utilize temperature min. and max. throughout the day to generate “growing degree day” units that accumulate throughout the year (typically starting on Jan. 1st, with a minimum temperature set to 50F (base-50)). Correlations between degree-day accumulation and vulnerable life stage events, such as egg hatch or adult emergence, allow pest management to be conducted, or scouted for, more efficiently. These models can track or predict insect, mite, weed, and plant pathogen lifecycles as well as those of beneficial insects, allowing us to protect that arm of Integrated Pest Management (IPM).

Within these models the user can set multiple parameters, allowing hyper-localized information for most of the country. Simple models are also available. The temperature min/max, can be manipulated for specific pests, however a minimum temperature of 50F (aka base-50) is most often cited in growing degree-day pest lists. These models are general in nature, as biology occurs over some span of time or set of conditions, and should therefor be ground-truthed at each location if at all possible. Many other types of pest or disease predictive models are available within the resources listed below, and the agents can help you understand what information you need for those calculations.

Note: The nursery agents are working to develop a local, Rutgers centralized, growing degree-day calculator that will provide information on key pests as well as nursery and greenhouse BMPs thereof. Armed with this information, we will be generating charts and other visual aids that target multiple pests per application, thus increasing labor efficiency.

Degree Day Calculators (select a local weather station within the website):

NEWA (Cornell): http://newa.cornell.edu/index.php?page=growing-degree-days

–        Very easy to use

Integrated Plant Protection Center (Oregon State): http://uspest.org/

–        More complicated but has many different modeling options

–        ***Boxwood blight specific risk model: https://uspest.org/risk/boxwood_app  , also available as an iOS or Android app ***

Typically the procedure is as follows: select a close by weather station, select degree-day calculator, select the min. temperature (50F or “base-50”), select max. temperature (arbitrarily high- 110F), click graph or calculate or get report, then locate the date(s) of interest on the computed table. The accumulated growing degree-days of those dates can then be compared to the target GDD50 on the pest lists below. *Tim Waller will help you set up a local degree-day calculation, or understand how to use this information if needed (twaller@njaes.rutgers.edu)

Pest lists with GDD50 targets:

Ohio State: http://cues.cfans.umn.edu/old/Web/049DegreeDays.pdf

University of California: http://ipm.ucanr.edu/MODELS/index.html

University of Maryland: https://extension.umd.edu/node/11155

University of New Hampshire: http://ccetompkins.org/resources/using-growing-degree-days-for-insect-management

*Some discrepancies between degree-day targets; go with what you have observed locally*

 

Pests and diseases to be on the lookout for:

(Upper Deerfield = 213.5GDD50 ; Howell = 153.5 GDD50 ; Pequest = 88.0 GDD50)

Pests: Looking towards our southern neighbor states, several pests are either currently present or will become evident in the near future including: Boxwood leafminer, Allium Leaf miner, Lilac borer, Ambrosia beetles (multiple species), Red-headed flea beetle, Hemlock woolly adelgid, Pine Bark adelgid, Roseslug sawflies, Spruce spider mites, Wooly elm aphids, Spirea aphid, Andromeda lace bug, Azalea lace bug, and Pine needle scale. The warm weather jump-started pest development only to be slowed by the current cool days and cooler nights, providing more wiggle room for protective or systemic pesticide applications. Utilize growing degree-day (GDD50) models to apply protectant applications as well as systemic soil drenches when applicable or allowable for pollinator protection.

Red-headed flea beetle larva will be hatching between 250-480 GDD50, with adults emerging between 500-1000 GDD50. A second generation of larva will then be active between 1,570 to 1860 GDD50, emerging later 1,878 to 2,318 GDD50. Brian Kunkel, entomologist at the University of Delaware, has determined that up to three, overlapping, generations can be present in container grown ornamentals. Ambrosia beetles, particularly Xylosandrus crassiusculus (granulate ambrosia beetle), and Xylosandrus germanus (black stem borer), should begin flights soon, or have already done so to some degree. These small beetles begin flight when temperatures hover around 60-70F and are attracted to alcohol produced by woody ornamentals in the spring. The cooler nighttime temperatures and daily averages have kept much of this activity low but scouting should be vigilant during this time. Another invasive pest, the Box tree moth, has been identified approaching the border of US and Canada. This pest has prompted APHIS importation amendments for Boxwood, Euonymus, and Illex. (https://content.govdelivery.com/accounts/USDAAPHIS/bulletins/27f467d)

Diseases: The current temperatures coupled with long wetness-periods, provide optimal pathogen conditions for diseases such as Botrytis, Sclerotinia sclerotiorum, Black spot on roses, multiple Needle cast diseases of conifers, root rots, and bacterial diseases. Once temperatures begin to increase again, pathogen numbers could explode. Efforts towards protectant applications are critical, especially in situations where plants are being held longer than previously anticipated due to COVID-19 related disruptions. Any steps geared towards increasing airflow, reducing wet-feet, and limiting mechanical injury during this wet and cool period will benefit disease management approaches. Please consult your agents for specific disease control recommendations.

Beach Leaf Disease, caused by an exotic nematode, is affecting beeches in the Great Lakes region  and into Pennsylvania. Little is known about the disease, other than the nematodes distort beech leaves by forming sunken lesions, which eventually turn the leaf yellow and drop off. Please contact your local agent if you suspect this disease to be anywhere in New Jersey (forest, farm, etc.). https://www.state.nj.us/dep/parksandforests/forest/docs/Pest_Alert-Beech_Leaf_Disease.pdf .USDA-ARS (more info on the nematode): https://tellus.ars.usda.gov/stories/articles/what-s-killing-beech-trees/

Please advise what pests/pathogens you are seeing in the field so we can be better informed on their management!

 

Online events and resources:

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

A new online forum has been created where anyone can log-on and speak with Rutgers Cooperative Extension agents (multiple agents from multiple counties).

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

Our Rutgers Nursery Working group will be uploading many more instructional videos to the NJAES YouTube page in the near future. This webpage has numerous pest/pathogen/ID educational videos, especially from the Plant Diagnostics Lab here at Rutgers.

Tim Waller has posted an introduction video to the newly created “Commercial Nursery and Greenhouse Production” playlist https://youtu.be/RQbXmc5Uug8.

(Please email twaller@njaes.rutgers.edu or william.errickson@njaes.rutgers.edu with ideas for videos!)

 2020 Nursery Industry Survey: https://forms.gle/dUjLxaiu6qDQYYsRA

The new nursery agents have prepared a preliminary survey aimed at understanding the needs of our growers and clientele, i.e. you. Please take a moment to complete the survey, as this type of information really helps the agents secure grant funding to deal with the problems you actually have. Thank you! Please share with other growers that may not have access.

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

 

Thank you.

Contact information for the new nursery agents:

 Timothy J. Waller

County Agent
Specialty areas: Commercial nursery production, plant health, and phytopathology   

Rutgers Cooperative Extension of Cumberland County
291 Morton Ave. Millville, NJ 08332
856-451-2800
twaller@njaes.rutgers.edu

Bill Errickson

County Agent
Specialty areas: Nursery and turfgrass production, agricultural innovation, and soil fertility
Rutgers Cooperative Extension of Monmouth Count
4000 Kozloski Rd., P.O. Box 5033. Freehold, NJ 07728
732-431-7260, ext. 7273
william.errickson@njaes.rutgers.edu

Filed Under: Disease Forecasting, Landscape, Nursery, & Turf, Nursery, Turf