Location: Cereal Disease LabTitle: Wheat rusts in the United States in 2015
Submitted to: Wheat Newsletter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2016
Publication Date: 9/15/2016
Citation: Kolmer, J.A., Jin, Y., Hughes, M.E., Gale, S.W. 2016. Wheat rusts in the United States in 2015. Wheat Newsletter. 62:73-78.
Interpretive Summary: Wheat is attacked by three different rust fungi, stem rust, leaf rust, and stripe rust. Significant amounts of rainfall and cool temperatures in the spring throughout the southern Great Plains region allowed stripe rust to be widespread in the United States in 2015. Wheat stem rust was very limited and was found in only a few states. Wheat leaf rust was found throughout the wheat growing regions of the southern and northern Great Plains and eastern United States, however at generally low levels due to the widespread incidence of stripe rust and the cool temperatures in the spring that slowed development and spread.
Technical Abstract: In 2015 wheat stripe rust caused by Puccinia striiformis f. sp. graminis was widespread throughout the United States. Cool temperatures and abundant rainfall in the southern Great Plains allowed stripe rust to become widely established and spread throughout the Great Plains and eastern United States. Stripe rust was also common in the Pacific northwest region. Losses due to stripe rust were highest in the Great Plains region. Wheat stem rust caused by Puccinia graminis f. sp. tritici was found in seven states, mostly in plots of susceptible wheat cultivars. Race QFCS was the most common race found, followed by RFCS. Race BBLBB was collected from barberry in California. Wheat leaf rust caused by Puccinia triticina was widespread throughout the Great Plains and eastern United States, however severity was low due to the cool spring temperatures and widespread incidence of stripe rust which prevented infection by leaf rust. Over 50 races of P. triticina were described. Races MBTNB, MBDSD, and TBBGS were the most common races and are highly virulent to leaf rust resistance genes found in the winter and spring wheat cultivars.