Update on the distribution and intensity stripe rust
Reports from K-State Extension specialists and agents this week indicate that stripe rust is now common on the upper leaves of wheat in southeast and south central Kansas. In central Kansas, stripe rust appears to be primarily on the lower and middle canopy as of May 1, but there are a few reports of the disease on the flag leaves or leaves just below the flag.
This week also brought the first reports of stripe rust in north central and western Kansas. The disease is at low levels in many fields but there were a few locations in the north central region with moderate levels of disease on the lower leaves. Dryland fields with good yield potential and irrigated fields should be a top scouting priority.
Preliminary indications are that stripe rust is more severe on varieties known to be susceptible to the disease based on disease reactions gathered since 2012. Popular varieties known to be susceptible include Everest, Armour, TAM 111, and TAM 112. Stripe rust is also being reported on varieties with intermediate or moderately resistant reactions to the disease, including WB4458, WB-Cedar, and 1863. The populations of fungi that cause rust diseases are notorious for their ability to shift to overcome genetic resistance. Therefore, all fields should be monitored for potential signs of disease.
Erick DeWolf, Extension Plant Pathology