Cases of severe leaf rust and stripe rust in wheat were found in multiple locations around College Station, Texas — even in some varieties thought to be resistant to the disease.

According to Kansas State University plant pathologist Erick DeWolf, the varieties affected include Fuller, Santa Fe, Art, Overley, Jagger and Jagalene. Leaf rust also has been reported at low to moderate levels in multiple locations in Texas. Varieties impacted by leaf rust appear to be those previously known to be susceptible, such as Jagger and Jagalene.

Wheat disease specialists and breeders are working to determine if the reports represent an underlying change in the stripe rust population within the region, according to the Kansas Association of Wheat Growers (KAWG).

"There is a possibility that these varieties have some adult plant resistance that will slow the progress of disease, but the severity of disease is cause for concern," DeWolf said. "Cool temperatures and frequent rainfall through the region has favoured the early development of these diseases."

DeWolf said TAM 112 and Endurance varieties, which are known to have intermediate or moderately susceptible reactions to stripe rust, are showing signs of severe disease.

"I believe these reports of stripe rust and leaf rust have important implications for wheat producers in Kansas," he said. "These are the highest severities for stripe rust in recent years, and the severity of the disease on varieties previously thought to be resistant is cause for concern. Fuller, Santa Fe and Art are all widely grown in central Kansas. TAM 112 is widely grown in western Kansas and is known to be moderately susceptible to stripe rust regardless of changes in the pathogen population."

DeWolf said that producers do not need to take immediate management action, but that they should monitor the disease situation carefully.