MANHATTAN, Kan. – Kansas is hosting an unwanted guest. Wheat fields in south central Kansas are exhibiting signs of stripe rust, which a Kansas State University scientist says has likely blown in from Texas.

"We’re seeing stripe rust on the leaf below the flag leaf, and it could pose a threat to the flag leaf," said Bob Bowden, plant pathologist with K-State Research and Extension. The flag leaf is the key contributor to a wheat plant’s yield.

Bowden said that stripe rust looks much like the orange-colored leaf rust more typically found in Kansas, but that the pustules are arranged in stripes and are a lighter shade of orange.

This year’s crop is suffering from maladies primarily linked to last fall’s dry conditions in some areas, including poor seed germination and a lack of fall tillering, but disease pressure has generally not been a problem, Bowden said. Tan spot has been reported in some continuous wheat fields.

The stripe rust was visible on numerous varieties at the variety performance test field at Hutchinson, including 2137, 2163, 7853, Custer, Hondo, Lakin, Oro Blanco, Trego, Venango, and TAM 302.

"On 2137, one of our most popular varieties, the incidence was almost 100 percent," Bowden added. "However, Jagger – our most popular variety – is resistant."

Stripe rust is not common in Kansas, but Texas had an epidemic earlier this year, he added. Strong winds from the south swept through Kansas in April and likely carried the fungus into the state.

"What happens from here on out depends on the environment," he said. "Several days in the 80s would stop the disease. If we have cooler days and a lot of moisture, the rust fungus will continue to develop."

"The rain is good for the wheat, but it’s good for the fungus too," he added.

For growers who find stripe rust as they scout their fields, spraying with a fungicide is an option.

"With the price of wheat what it is, however, and with this year’s lower yield potential, it would probably not be cost effective for the average grain producer to spray," he said. "But for seed producers, spraying a fungicide is much more likely to be profitable."

For further information, interested persons can contact their county Extension office or visit http://www.oznet.ksu.edu/wheatpage/pests&diseases.htm, scroll to "diseases" and click on "stripe rust."