Growers Can Use Online Tool to
Forecast Head Blight in Wheat

Wheat heads with symptoms of Fusarium head blight. Diseased spikelets become bleached or tan in appearance and may have signs of fungal reproduction.

The Fusarium Head Blight Prediction Center is a joint research effort of Penn State, Ohio State University, Purdue University, South Dakota State University, and North Dakota State University, with support from the U.S. Department of Agriculture’s U.S. Wheat and Barley Scab Initiative.

Fusarium head blight, or scab, affects the developing heads of small grains, leading to yield losses that can easily approach or exceed 50 percent during severe outbreaks. The disease also negatively affects grain quality, often resulting in mycotoxin contamination and lower test weights. The presence of mycotoxins, which are produced by fungi, can lead to wheat unsuitable for milling and barley unsuitable for malting.

Grain produced in heads damaged by Fusarium head blight is often shriveled, white, and chalky in appearance.

“Temperature, humidity, and rainfall in the week before flowering influence reproduction of the fungus that causes the disease,” he adds. “The model we developed will forecast scab development with about 80 percent accuracy. But growers also should carefully evaluate other sources of information, such as weather forecasts, grain markets, and local experts, when making disease-management decisions.”

The forecasting system combines National Weather Service readings for temperature and relative humidity, Doppler radar estimates of rainfall, and data collected at local weather-monitoring stations. At the Web site, growers are asked to enter whether they have winter or spring wheat, the expected flowering date (when anthers are exposed on 50 percent of the heads), and information on production practices. Users then can click on a state and location, and the system will indicate whether the risk of disease is low, medium, or high.

There about 120,000 acres of wheat grown in Pennsylvania annually. “Unfortunately, there are no fungicides registered for use in Pennsylvania to combat wheat scab, so to reduce the severity of outbreaks, it’s important for growers to consider management practices such as crop rotation and planting varieties that are less susceptible to the disease,” DeWolf says. “Knowing the likelihood of an outbreak also will help growers make decisions about how best to harvest and market the grain to minimize losses.” A fact sheet on Fusarium head blight is available for download in PDF format.