Menu

Rain, Humidity Amplify Importance of Head Scab Management

Wheat is starting to flower in southern and central Indiana, meaning growers need to assess risk of head scab and prepare management tactics.

Head scab, also known as Fusarium head blight, is caused by the Fusarium graminearum fungus. It infects wheat during flowering, but symptoms including bleached spikelets on the head and small or shriveled grains show up later in the season.

The fungus also produces mycotoxins, which can be toxic to animals and humans when consumed in high concentrations.

“Rainy, warm and humid weather conditions favor disease development,” said Kiersten Wise, Purdue Extension plant pathologist. “We have had ample moisture this spring, but temperatures have fluctuated, and the risk of disease development is variable across the state.”

Wise said growers might want to consider a fungicide application at early flowering to suppress head scab development.

Purdue research in Indiana has shown that applications of certain fungicides are most effective at head scab management at early flowering. While there are many choices of fungicides, not all are effective. For example, Wise said fungicides with a strobilurin mode of action are not labeled for head blight suppression.

“Growers also need to be sure to follow label restrictions on how many days must pass between fungicide application and harvest,” she said.

One tool to help wheat farmers assess the head scab risk in their fields is through the free Fusariam Risk Assessment Tool provided by the Fusarium Head Blight Prediction Center, a partnership of universities and government agencies across the country. The tool can be accessed at http://www.wheatscab.psu.edu/.

The site is a model that uses weather information, including temperature, rainfall and relative humidity, to calculate risk levels for head blight.

While the tool is a good resource, Wise said growers need to remember it isn’t perfect.

“Keep in mind that the model does not provide guaranteed prediction for whether or not scab will occur in individual fields,” she said. “Additional factors, such as the local weather forecast, crop conditions and Extension commentary should be considered when assessing the level of risk.”

The U.S. Wheat and Barley Scab Initiative also has a system in which wheat growers can sign up for alerts that update them on the risk of scab. Sign up at http://scabusa.org/fhb_alert.php.

Source: Purdue University Extension

Recent News

Managing Corn Tar Spot in 2020
6/4/2020

It’s early in the season, but before we know it, corn will be chest high and we will be thinking about if in season management is needed.  Last year I mentioned that you should “avoid the cosmic freakout” around tar spot.  I again emphasize this statement this season.  Tar spot is endemic to the state […]

Prevent Plant 2020
6/3/2020

Some Illinois corn acres are still unplanted due to wet weather. The final plant date for crop insurance has passed for extreme southern Illinois (May 28) and is rapidly approaching for the rest of Illinois (June 5). After the final plant date for corn, farmers who purchased the COMBO crop insurance product can take a […]

Soil Residual Herbicide Options after Corn Emergence
6/2/2020

Application of soil residual herbicides is important because they deliver a few weeks of residual weed control and aid in weed resistance management by incorporating additional site(s) of action in herbicide program. Several residual herbicides can be applied after corn emergence without injury to corn. A Few important factors should be considered when addressing weed […]

Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now