Conifer Pest and Disease Update 5/15/2023

In this edition:

  • Insects – Pest Scouting with growing degree-days (250-600 GDD50)
    • Scales
    • Mites
  • Diseases
    • Needle casts (Rhabdocline and Swiss needlecasts – Douglas fir, & Rhizosphaera – spruces)
    • Phytophthora
  • Soil fertility – resources

Please click “read more” below to get updates on pests, diseases, and other important resources for the week of 5/15/2023.

[Read more…]

Updated 2023 Pest Scouting Guides are up – Getting prepared for the season ahead

The updated Pest Scouting Guides are here, and have a few improvements that enable YOU to share what YOU are seeing in the field with RCE.

Please click, download, and print these scouting guides for use at your nursery, landscape, or conifer plantation. Once printed you can scan the QR at the top of document to link back to the digital copy. These are much larger documents than 2022, as they are sorted by GDD, NEW-Insect “Group”, and by NEW-“favored host plants”. 

Nursery and Landscape Pest Scouting Guide – Scouting with Growing Degree-days (GDD) 2023 (click here)

Conifer and Christmas Tree Pest Scouting Guide – Scouting with Growing Degree-days (GDD) 2023 (click here)

Refer to this post “Obtaining your local growing degree-days (GDD)” for additional information (click here)  or contact Tim Waller twaller@njaes.rutgers.edu for help.

It is important to note that the GDD ranges do not replace scouting and that many of these GDD ranges have not been validated in New Jersey and would greatly benefit from local feedback. Therefore you will notice a QR code at the bottom of the cover-page. If you scan this code it will take you to a form that asks for details about pest occurrence, host plants, any observations, and after you submit your comments it allows the user to upload photographs. This is also a great place to leave feedback on what you would like to see in future iterations (such as pictures…).

PLEASE REPORT – pest observations that deviate from the stated GDD ranges in the guides

PLEASE SHARE PICTURES OF PESTSwe are working to develop insect ID pocket guides and other resources for our NJ growers…but we need your help

LONT – Comment and Photo upload REPORTING LINK (click here) 

Conifer – Comment and Photo upload REPORTING LINK (click here) 

If you would like to interact with the raw data yourself or incorporate it more closely into your businesses needs download this data file (click here) (file will download once clicked!). Please note it is a Microsoft Excel file, that is protected / cannot be modified on all but the two sheets labeled “GDD ACCU”. If you would like help with this or a non-protected file please contact twaller@njaes.rutgers.edu.

 

Regular updates will be utilizing this resource throughout the 2023 season. Have a great Spring Season everyone.  

 

Choosing the Perfect Christmas Tree – Tim Waller & Bill Errickson Podcast on Ask the Agent

Just in time for the holiday season! Please listen and SHARE with clientele.

Listen to our NEW “Choosing the Perfect Christmas Tree” podcast by clicking here

Agents Tim Waller (Cumberland) and Bill Errickson (Monmouth) were invited by Rutgers – Ask the Agent – hosts Steve Komar (Sussex), Bill Bamka (Burlington), and Lisa Chiariello (Sussex), to discuss all things Christmas Trees in New Jersey.

The goal of this podcast was to provide the general public with an idea of what it takes to produce a perfect Christmas Tree. We discuss tree production, why Christmas trees cost what they do, variety considerations, complexities of this industry, seasonal offerings, tree care (cut vs choose and cut vs B&B trees), the importance of supporting local communities and traditions, as well as offering some resources for current Christmas tree operators.

Please share this podcast with your clients, and keep an eye for more podcasts to come.

 

Please visit the Ask the Agent Podcast Page for more interesting topics!

Nutrient Management for Christmas Trees

Joseph Heckman, Extension Soil Fertility

Whatever the crop, soil testing and record keeping are guides to sustainable soil fertility and nutrient management.  When soil tests levels are low, Christmas tree growers should attempt to build soil fertility levels into the optimum range.  And once that goal has been achieved, growers should focus on maintaining soil test levels in the optimum range.

This practice requires information on balancing fertilizer amendments with crop nutrient removal.  In the case Christmas Trees, this means nutrients associated with harvest of cut trees.  Rutgers NJAES has this type of data already built into an extension fact sheet: Soil Fertility Recommendations for Christmas Trees   https://njaes.rutgers.edu/fs1187/

For nutrient management purposes it is useful to know what a harvested or cut Christmas Tree removes from the soil.  On average, a harvest of 100 cut Christmas Trees contains 29 lb. Nitrogen, 3 lb. Phosphorus, 8 lb. Potassium, 12 lb. Calcium, 2 lb. Magnesium, and 1 lb. Sulfur.

An average fresh cut Christmas Tree that is 92 inches tall may be expected to have a fresh weight of about 48.5 lb.  Water typically makes up about 54% of a fresh cut tree weight.  Thus, on a dry basis a cut tree would have a weight of about 22.4 lb.

Tree recycling and mulch making are now common in many communities.  If the trees are shredded the nutrient content data above can be used to estimate the nutrient density of the resulting wood chips.

Reference:

Zinati, G., J.R. Heckman, and M. Vodak. 2016. Nutrient Removal by Christmas Tree Harvest. Journal Plant Nutrition. 39: 1506-1512.

Welcome to the Christmas Tree PPA – Pest Scouting Guide Resources

Over the coming season we will be adding timely posts about pests, diseases, pesticides, and related agriculture updates that may need to be acted upon urgently. Additionally, we will be adding detailed information about particular issues to facilitate a better understanding moving forward. Please reach out to Tim Waller, Bill Errickson, or your local county agent if there are topics you would like to see covered through this system.

Pest Scouting

We have been working to develop pest scouting guides that utilize growing degree-days to help you better schedule and implement your IPM, scouting, and spray schedules.

If you are unfamiliar with growing degree-days (aka GDD or GDD50) Refer to this post “Obtaining your local growing degree-days” for additional information (click here!) 

Please download or print the Conifer Pest Scouting Guide and supplement below 

 

Thank you all very much for your continued support of Rutgers Cooperative Extension

Bagworm hatch & Boxwood Blight potential now through Friday

Boxwood Blight (BWB) Alert – Infection Potential (Now – FRIDAY) 

There is a potential for new boxwood blight infections throughout much of NJ. The end of week rains coupled with more mild temperatures, cloud cover, and prolonged periods of leaf wetness will contribute to the spread or worsening of boxwood blight infections.

Boxwood Blight Risk Assessment as of 5/24/2022
Region Location CODE 1-June 2-June 3-June 4-June 5-June 6-June
Southern Upper Deerfield NJ50 Very Low  Infection Risk Infection Risk Very Low Very Low  Very Low 
Central Howell / Freehold NJ10 Infection Risk Infection Risk Infection Risk Very Low  Very Low  Very Low 
Northern High Point NJ59 Infection Risk Infection Risk Infection Risk Very Low  Very Low  Very Low 
Check local boxwood blight risk here (CLICK HERE – input your area code – select closest weather station – check 7-14 prediction – click on graph / table)

 

ALSO: Volutella Blight is extremely common and readily mis-diagnosed as boxwood blight or vise-versa.

  • There is a free / open to the public seminar June 23, 2022 about this important disease. Boxwood International Seminar on Biology and Management of Boxwood Volutella Blight by Prof. Tom Hsiang, University of Guelph, Guelph, Ontario, Canada. Registration Link: Click here to register

Pest Scouting – Please refer to these documents for a full listing of insects pests for your area corresponding to growing degree-days (GDDs). 

Bagworm hatch is upon us in Southern NJ and will soon be /already the case throughout NJ. Please be ready to control these insects during the VERY SHORT treatment window.

Days old bagworm sizeBagworm female case with developing juveniles

BAGWORMS (600-900 GDD) (Bagworm hatch prediction as of 6/1/22)
Crop type Common Name Scientific Name GDD Min (50F) GDD Max (95F) Reference Developmental / Target Stage
Conifer mostly, many minor hosts Bagworm Thyridopteryx ephemeraeformis 600 900 RU Larvae (early instars) – ONLY CONTROL WINDOW
Region Location Station Date (600 GDD) Date (900 GDD) Treatment window  Bagworm Hatch – Predictions only, SCOUTING is critical! Treat as soon as larvae detected. 
South Upper Deerfield NJ50 30-May 12-Jun 13 days
Central Howell / Freehold NJ10 3-Jun 18-Jun 15 days
North High Point NJ59 14-Jun 30-Jun 16 days