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

March 8, 2025

Black Knot Fungus of Prunus: A Common Landscape Disease

Overview:

Black knot is a cankering fungus disease that infects many trees and shrubs within the genus Prunus. It is caused by the native North American fungal pathogen Apiosporina morbosa. Although black knot fungal galls have been found in a couple of dozen Prunus species, not all species are equally susceptible, and it can be most destructive to certain varieties of cherries and plums (Photo 1).

The following species can be highly susceptible to infections: Japanese plums (Prunus salicina), European and American plums (Prunus domestica & Prunus americana), Sweet cherry (Prunus avium), Mahaleb cherry (Prunus mahaleb), and cultivated species of chokecherries.

This blog reviews the symptoms and signs of Black Knot Disease. It’s management by pruning and fungicide treatments is discussed. Finally, a handful of resistant plum varieties is provided.

Photo 1: This Japanese Plum species is highly susceptible to Black Knot Disease.

Photo 1: This Japanese Plum species is highly susceptible to Black Knot Disease. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

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Filed Under: Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab
March 4, 2025

Approaching 2025 Boxwood Blight Season

March weather is always unpredictable, however, if we have sustained periods of increased temperatures and spring rains, boxwood blight (BWB) will become an issue quickly.

New – [pictorial tri-fold] Common Boxwood Pests and Diseases (click-here). This includes Box Tree Moth images. Print the PDF out double-sided, then fold. We are working to have a better resolution print of this material very soon.

If you suspect Boxwood Blight and would like to have this verified – please contact the Rutgers Plant Diagnostic Laboratory (click here) for sample submission instructions

Boxwood Blight Risk Assessment as of 3/4/2025
Region Location CODE 3-March 4-March 5-March 6-March 7-March 8-March
Southern Upper Deerfield NJ50 Very Low  Very Low  Low Minor Risk Very Low  Very Low 
Central Howell / Freehold NJ10 Very Low  Very Low  Low Minor Risk Very Low  Very Low 
Northern High Point NJ59 Very Low  Very Low  Very Low  Minor Risk Very Low  Very Low 
M T W TH F S
 Please check YOUR LOCAL risk (click here)

There is a minor potential for boxwood blight infections this Wednesday & Thursday, throughout ALL of NJ. Incoming rains, coupled with warmer temperatures may initiate boxwood blight infections this week.

  • It is time to begin protective fungicide applications in boxwoods throughout the state if you have not already done so. 

  • If BWB is important to your business – Use the USPEST – PUSH Alerts – (click here) – to setup weekly email alerts. Create an account, watch the tutorial, and then set up your subscriptions. You select which locations (as many as you like), days you want to receive emails, and what you would like to receive alerts about (BWB and a variety of other pests and diseases). Rutgers is not directly affiliated, however this is an incredible tool. 

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Filed Under: Landscape, Nursery, & Turf, Nursery, Turf Tagged With: , , , , , , , , , ,
February 6, 2025

Southern NJ Nursery Round Table : Next Monday & Delaware BTM Updates

Nursery Round Tables – I am hosting these free events at the Cumberland RCE (291 Morton Ave, Millville NJ)

Free RSVP here: https://forms.office.com/r/hJhesNgBxv Or RSVP at: 856-451-2800 ext 1.
February 10th – Hands on Growing Degree-days. We are going to sit down with computers (I have 10+ laptops), our cellphones, and a tablet to see how easy it is to use GDD calculators. We will then compare with the Rutgers Pest Scouting Guides (this is the guide;  https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2023/03/LONT-PSG-DISTRIB-2023.pdf)
  • Like the idea of using growing degree-days, but are unsure how to use the online calculators or other resources – THIS IS FOR YOU. On Monday 2/10 – we will be using laptop computers (I have 12 on-site), tablets, and smart cellphones to access and explore online growing degree-day calculators. We will then use the Rutgers Pest Scouting Guides to line up when to expect these pests and will discuss treatment opportunities with overlapping pest populations.

    -Each person will use all three technology methods to obtain their local growing degree-days. – By the end of the training you will be able to access and utilize this powerful tool anywhere.
February 24th – 2025 Playbook: We will be discussing emerging threats like Box Tree Moth and numerous plant diseases we need to be prepared for. The session will conclude with a 30-minute CORE credit session. 1 unit – CORE obtained-only.
Note you don’t HAVE to be from southern NJ, however I would appreciate you being with a nursery or other commercial ornamental operation. I just want to facilitate thoughtful communication. Registration greatly appreciated.

____________________________________________________

ALL DELAWARE NOW QUARANTINED (DA-2024-47)(as of 12/4/24)

Subject:           APHIS Establishes Box Tree Moth (Cydalima perspectalis) Quarantines in Delaware and Pennsylvania

To:                   State, Tribal, and Territory Agricultural Regulatory Officials

Effective immediately, the Animal and Plant Health Inspection Service (APHIS), in cooperation with the Delaware Department of Agriculture and the Pennsylvania Department of Agriculture (PDA), is adding the entire State of Delaware and Erie County, Pennsylvania to the box tree moth (BTM; Cydalima perspectalis) quarantined area. APHIS is taking this action in response to the confirmed detections of BTM in a residence in Little Creek, Delaware, on July 11 and in Lakeside Cemetery in Erie, Erie County, Pennsylvania, on August 29. PDA has established an intrastate quarantine area for BTM that parallels the Federal quarantine. This Federal Order supersedes Federal Order DA-2024-17.

The attached Federal Order (click here) and additional information about BTM are located on the APHIS box tree moth webpage. For additional information, you may contact:

Matthew Travis
National Policy Manager
580-240-5394
matthew.a.travis@usda.gov

If you see, or think you see this pest, or its damages in New Jersey please contact:

  • RCE -Cumberland Co. Nursery Agent: Tim Waller – twaller@njaes.rutgers.edu
  • Nursery Inspection Program Manager: Sarah Katzenbach –  sarah.katzenbach@ag.nj.gov  (609) 406-6939

Please educate yourself about this in-bound pest here – Resources:

Filed Under: Christmas Trees, Landscape, Nursery, & Turf, Nursery, Turf Tagged With: , , , , , , , , , , , , , ,
January 14, 2025 and

REGISTER TODAY – NJ Ag Convention Coming Soon

We are only days away from the start of the 2025 NJ Agricultural Convention and Trade Show at Harrah’s in Atlantic City starting on February 3rd to February 6th. The convention has evolved over the years to include much more than vegetable topics. See the graphic below or the VGANJ website convention program for a list of expanded topics.

Nursery growers – we have a full day for you. Do you raise livestock? We have a new session for you. Want to learn about agricultural policies? Come to the session on Tuesday morning hosted by Rutgers Cooperative Extension Director, Brian Schilling and colleagues from the State Agricultural Development Committee. Need to learn about Food Safety Regulations, we have both a session and a workshop for you. USDA will be hosting sessions on Tuesday to promote programs for farmers. There are too many more topics to put into text so please check out the program on the VGANJ website. 

Need pesticide recertification credits? This year the workshops and sessions will help you fulfill the obligation to obtain those credits. Monday afternoon hosts a 6-CORE credit workshop that requires a separate special registration. Check out the program and how to register on the VGANJ website.

Have you registered for your hotel rooms yet? If not please use the room block and register online at https://book.passkey.com/GO/SHVEG5 or call to make Room Reservations on the phone at 1-888-516-2215 (8:00am-2:00am EST, 7 days a week), Group Name: New Jersey Vegetable Growers. Group Code: SHVEG5. There are plenty of rooms left in the room block, but the pre-registration ends soon, so reserve your rooms today. Please reserve your rooms through the group block to help us meet our obligations for the convention contract. 

Don’t miss the great Tuesday events. There is a FREE “Lunch and Learn” on Tuesday (sign up for tickets at registration on Tuesday, limited to 100 participants) in the back area of the trade show hall with time to meet with vendors and also discussion with the new NJ Secretary of Agriculture, Ed Wengryn. Tuesday night hosts a charity auction and if you attended last year, you know how great this event is with food, drink, and time to catch up with old friends and make new friends in farming. Thanks to VGANJ Secretary, Darcy Perehinys the Tuesday events will once again have amazing food! Lots of prizes from our sponsors will be available for bid at the Charity Auction. If you haven’t attended this event in the past, don’t miss it this year as it is much improved from years past. Tuesday is a big day and with the Lunch and Learn and Charity Auction Happy Hour – if you attend both these events you can eat for free!!!!

One more event you won’t want to miss is the annual awards banquet on Wednesday night. Tickets can now be purchased online on the VGANJ website. This year’s NJ Vegetable Grower of the Year award goes to Brian Porch, of Porch Farms in Salem County, NJ. The award will be presented by VGANJ President, Jim Abma. Come help us celebrate Brian and all the other award winners who will be honored by the NJ Department of Agriculture. 




Filed Under: Agrivoltaics, Blueberry, Christmas Trees, Commercial Ag Updates, Field, Forage & Livestock, Food Safety, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, pesticide credits, Strawberry, Tree Fruit, vegetable, Vegetable Crops, Wine Grape, work shop Tagged With: ,
January 13, 2025

Horned Oak Galls & Gouty Oak Galls: Two Exceptions to the Rule

Curiosity of Plant Galls:

Explaining the unusual gall growths or deformities in plants can be challenging. Different galls can be found on virtually any plant part, including leaves, flowers, twigs, bark, or buds of trees and shrubs. Galls caused by insects or mites can typically be identified by the characteristic size, shape, color, and structure that develops.

Insect/mite galls are produced by the interaction of plant hormones with strong plant-regulating chemicals released by the gall maker as they feed. The immature larvae live their entire lives within an individual gall, which provides excellent protection for the larvae as they feed and mature.

This blog contains information on horned and gouty oak galls. When the number of galls infesting an oak is few, tree damage is insignificant. However, tree injuries become more severe when gall numbers reach high levels.   

Maple Bladder Gall Mites

Curious & colorful leaf galls created by maple bladder galls mites may cause alarm to some people but they are mostly harmless. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

Maple Bladder Gall Mites

An extreme infestation of horned oak galls on branches of pin oak tree. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

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Filed Under: Landscape, Nursery, & Turf, Nursery, Plant Diagnostic Lab
December 18, 2024

Register Before December 31 for Bonuses at the 2025 NJ Ag Convention

Have you signed up for the 2025 New Jersey Agricultural Convention and Trade Show yet?
Visit the VGANJ Convention Website and register today!

It’s incredibly simple! Here’s a pro tip: Become a member of the Vegetable Growers Association to enjoy all the benefits, even if you don’t grow vegetables, and save on convention registration fees by becoming a member. Everyone must register to enter the trade show and participate in educational sessions and other events sponsored by the VGANJ. 

Make sure to register by December 31st to receive two complimentary drink tickets (per registered individual) for use at the trade show bars after 2 PM on Tuesday and Wednesday. Plus, you’ll be entered to win a $100 gift card for meals during your time in Atlantic City!

Don’t forget to check the VGANJ website for the exciting new educational sessions for 2025.

Also, on Tuesday there will be a special free “Lunch and Learn” program to engage with vendors and participate in a Q&A session with the new Secretary of Agriculture, Ed Wengryn.
*FREE lunch tickets only for the first 100 farmers Tuesday who sign up for the “Lunch and Learn” at the registration desk on Tuesday morning. Lunch starts at 12:00.

On Wednesday, February 5th the VGANJ will be honoring the NJ Vegetable Grower of the Year. For 2025 the honoree is Brian Porch from Salem County, NJ. Come help us celebrate our awardee and the NJDA awardees at the banquet. Tickets are now available online through VGANJ. See the VGANJ Convention Website to sign up for the banquet and other special events.

Filed Under: Agrivoltaics, Blueberry, Christmas Trees, Commercial Ag Updates, Cranberry, Field, Forage & Livestock, Food Safety, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, pesticide credits, Strawberry, Tree Fruit, vegetable, Vegetable Crops, Wine Grape, work shop Tagged With: