Rutgers Cooperative Extension
In this edition:
Please click “read more” below to get updates on pests, diseases, and other important resources for the week of 5/15/2023.
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”.
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 PESTS – we 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.
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!
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.
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.
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!)
Thank you all very much for your continued support of Rutgers Cooperative Extension
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.
Pest Scouting – Please refer to these documents for a full listing of insects pests for your area corresponding to growing degree-days (GDDs).
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| 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 | |
