Scab returns to Upper Midwest
An old enemy to Upper Midwest grain farmers is returning in force this growing season.
Scab, also known as Fusarium Head Blight, presents a "high" or "medium" risk in big chunks of central and eastern North Dakota, eastern South Dakota and central and southern Minnesota, according to the website of the Fusarium Head Blight Prediction Center.
"Growers in the high-risk areas should consult with local extension specialists or other advisors regarding the need for fungicide applications to protect the crop," the website says.
The website, using research from a number of universities, has models that predict the risk of a major epidemic based on observed weather patterns.
Scab is a fungal disease that can hurt quality and yields in cereal grains, including wheat and barley. It's occurred in at least 18 states, doing at least $3 billion in damage since 1990, according to the U.S. Wheat and Barley Scab Initiative, which combats the disease.
Substantial rains and high temperatures have hit much of the Upper Midwest recently, boosting the risk of scab. Small grains are most susceptible to scab during the flowering and early grain-fill stages. High humidity and rainfall before and during flowering contribute to the disease, while cool, dry conditions work against it.
Andrew Friskop, North Dakota State University Extension plant pathologist for cereal grains, says farmers need to be aware of the potential threat from scab.
Action against the disease is determined, in large part, by the growth stage the crop has reached, complicating generalizations about what some be done, he says.
Friskop says that farmers should continue to monitor growth stages, particularly for later-planted small grains that may be heading or flowering this week.
Scab was a major challenge to Upper Midwest grain farmers during the wet cycle that began in 1993 and ended a few years ago. Farmers who farmed then are familiar with scab, while younger farmers and ag professionals may not have that first-hand experience, Friskop says.
Much of the Upper Midwest was hit with drought in 2017. The risk of scab this crop season is lessened but not eliminated in those formerly drought-stricken areas, Friskop says.
More information from the Fusarium Head Blight Prediction Center: www.wheatscab.psu.edu.
More information from U.S. Wheat and Barley Scab Initiative: https://scabusa.org/.