Flowering Wheat Turns Attention to Head Scab

May 27, 2005

WOOSTER, Ohio — As Ohio wheat enters the flowering stage - a critical time for potential head scab infection — growers are being encouraged to stay on top of the latest predictions from the Fusarium Head Blight Prediction Center.

 

The early warning system (http://www.wheatscab.psu.edu) is a joint project between Ohio State University Extension, Penn State University, Purdue University, North Dakota State University, South Dakota State University and the U.S. Wheat and Barley Scab Initiative. The system uses the flowering dates of wheat and weather data to predict the risk of head scab in wheat fields throughout the growing season for 23 states.

"The head scab system is predicting very low levels of scab as the wheat in southern Ohio enters the flowering stage," said Pat Lipps, an Ohio State University plant pathologist with the Ohio Agricultural Research and Development Center. "That news is especially good for growers who have planted wheat after soybeans. For those growers who plant wheat after corn, there is a moderate risk of head scab in the south west quarter of the state."

Head scab or Fusarium head blight is a very significant disease, not only from yield loss, but also from contaminants associated with the disease called mycotoxins that are toxic to humans and animals. The affects of the disease can impact growers, millers, bakers and consumers. Growers who plant wheat into corn residue are more at risk for head scab infection because the disease can survive in the corn residue and then easily spread to wheat if weather situations are ripe.

Winter wheat is now flowering throughout southern Ohio. In the central part of the state, the crop is now heading.

"The flowering period starts from three to seven days after heads emerge depending on temperatures. When the anthers are exposed on the heads, that's when the crop is most susceptible to Fusarium infection," said Lipps, adding that mild temperatures and moist conditions drive the infection. "Our flowering period in the state will be at least two weeks this year because of the weather and the different wheat varieties that are being grown. That's a bit longer than the usual 10 days."

Lipps said that day and night temperatures in the 70s followed by a few days of misting rain could set the state up for an epidemic. However, current weather forecasts are calling for low nightly temperatures with daily high temperatures in the 60s in the coming days.

"There will probably be some locations where head scab will be a problem, but at this point in time, it doesn't look like it's going to be a widespread problem in the state. We will see what happens to the weather next week," said Lipps.

Overall the wheat is progressing well. According to the Ohio Agricultural Statistics Service, nearly 80 percent of the crop is considered in good to excellent condition. Over 60 percent of the wheat has headed, with little disease issues.

 

Author(s): 
Candace Pollock
Source(s): 
Pat Lipps