Immediate potential for Boxwood Blight 3/24 and 3/25 – First infection potentials

There is a potential for new boxwood blight infections this FRIDAY and SATURDAY throughout much of NJ – especially central regions. Increased temperatures and prolonged periods of leaf wetness will contribute to the spread of boxwood blight infections.

  • It is time to begin protective fungicide applications in high value areas if you have not already done so! 

  • Protective fungicide applications should remain in effect or be initiated immediately for Boxwood Blight in “Infection risk or High Risk areas”. 
  • If your area is not listed (throughout all of NJ please visit the USPEST.ORG Boxwood Blight Risk Model – CLICK HERE TO CHECK YOUR LOCAL PREDICTIONS

Boxwood Blight risk-model information, considerations, and links:

Boxwood Blight Risk Assessment as of 3/22/2023
Region Location CODE 22-Mar 23-Mar 24-Mar 25-Mar 26-Mar 27-Mar NOTES
Southern Upper Deerfield NJ50 Very Low  Low Low  Infection Risk Very Low  Very Low 
Central Howell / Freehold NJ10 Very Low  Low HIGH Risk HIGH Risk Very Low  Very Low  High prob. of first BWB infections
Northern High Point NJ59 Very Low  Very Low   Infection Risk Very Low Very Low  Very Low 
 Please check YOUR LOCAL risk (click here)

(input your area code – select closest weather station – check 7-14 prediction – click on graph / table)

These advisories are general in nature, change rapidly over time, are site-specific…therefore  Someone from your business should be using this risk model daily if boxwood is important to your financial stability– In 30 seconds you can have a better idea of boxwood blight (and other pathogen) activity in your immediate area! Please contact Tim Waller if you need help using this service (twaller@njaes.rutgers.edu), we want to help! 

Fungicides; 

  1. You very well may have these materials already applied as ‘cover-sprays’ – But – be mindful that protectant fungicides loose efficacy the more rain (or overhead irrigation) they are subjected to, and reapplication may be warranted.
  2. ROTATE between Fungicide Resistance Action Committee (FRAC codes) to avoid this pathogen becoming resistant to specific chemicals

Format: [FRAC code]: Chemical name (Trade names * no endorsement implied, other options exist)  

  • [M05]: Chlorothalonil (Daconil WS)
  • [M05 + 1] Chlorothalonil + Thiophanate methyl (Spectro 90WDG)
  • [11] Trifloxystrobin + [7] Fluopyram  (Broadform)
  • [11] Trifloxystrobin + [3] Triadimefon (Armada 50WDG)
  • [M03] Mancozeb
  • [12] Fludioxonil (Medallion WDG)
  • [3] Tebuconazole (Torque)BW

DISCLAIMER: The label is the law, always refer to it for allowable host crops, use-restrictions, application rates, reapplication intervals, re-entry intervals (REI), and mix compatibility information. Production and pesticide information on this site are for private/commercial pesticide applicators and landscape professionals only, and are NOT for home gardener use. Provided materials represent examples and do not cover all possible control scenarios. Trade-names listed do not imply endorsement and are used as examples only. Please contact your local agent or chemical sales representative for more information or to discuss additional pest management options.

Resources 

Background on the pathogen: