Wheat's already beginning to head in Maryland. So it's already prime scouting time in the Northeast. And you need to be ready to move quickly if scab infections are imminent.
One of the best preventive tools is "tuning into" Penn State's wheat_scab website, officially known as the Fusarium Head Blight Prediction Center. Check it daily to assess risk or probability that scab is a danger in your area.
Currently conditions are too dry for significant disease development and fungicides are not required, but may change as thunderstorms and rainfall comes through, notes Arv Grybauskas, University of Maryland plant pathologist.
Check this website as your wheat approaches flowering to determine disease risk and whether or not there is a need for a fungicide application. Note the model this year has a new feature that incorporates varietal susceptibility. It can be changed in the Choose the Model section of the risk map.
If you are unsure of varietal susceptibility go to www.scabsmart.org, click on the variety resistance section, and under SRWW - Southern region and click on the Virginia FHB data. The Maryland 2014 link at this site is observational information under low disease pressure.
Then keep your eye peeled for flag leaf emergence, boot stage, or heading/flowering. Be aware of the stage your wheat is in, and to watch future weather patterns to predict if you should spray.
The fungal infection occurs when wheat is flowering. Read more about wheat growth stages.
To treat or not to treat
If risk is high and wheat is flowering to about 6 days after flowering, a fungicide may be required to reduce toxin development in the grain. The small window for fungicide application requires pre-planning to be able to get effective suppression of the disease and deoxynivalenol (DON) toxin development.
Grybauskas recommends to fungicides: Prosaro and Caramba. Ground application must be made with nozzles facing forward (30 to 45 degrees forward) and traveling at least 6 mph to get adequate head coverage. Similarly for adequate head coverage, aerial applications must be made at labeled volume rates.
For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, click on scab_usa.
