Survey of Fusarium Species Associated with Fusarium Head Blight of Spring Wheat (Triticum aestivum) in Southeastern Idaho

In Idaho, losses due to Fusarium head blight (FHB) of spring wheat (Triticum aestivum) have been infrequent and have historically been dominated by Fusarium culmorum (Wm. G. Sm.) Sacc. However, the incidence of FHB and deoxynivalenol-contaminated grain has increased in spring wheat in southeastern Idaho since 2009, indicating that other species of Fusarium may be contributing to disease. In 2011 and 2012, 17 spring wheat fields were scouted and sampled for FHB in southern Idaho. Contaminated grains were cultured, and putative Fusarium isolates were identified using species-specific polymerase chain reaction. In 2011, 87% of all recovered isolates were identified as F. graminearum, whereas only 13% were identified as F. culmorum. Of the isolates collected in 2012, 51% were identified as F. graminearum and 49% as F. culmorum. In both years, more F. graminearum isolates were recovered as compared to a survey conducted in 1984. Implementation of effective disease management practices will be necessary to minimize the establishment and spread of F. graminearum–responsible FHB in southeastern Idaho.