Wheat rusts in the United States in 2016

Authors: Kolmer, James; Jin, Yue; Hughes, Mark

Submitted to: Wheat Newsletter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2017
Publication Date: 7/30/2017
Citation: Kolmer, J.A., Jin, Y., Hughes, M.E. 2017. Wheat rusts in the United States in 2016. Wheat Newsletter. 63:74.

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 2016. 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 2016, 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. Wheat stem rust caused by Puccinia graminis f. sp. tritici was found in eight states, mostly in plots of susceptible wheat cultivars. Race QFCS was the only stem rust race found. 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.