Authors: Sidrat Abdullah 1, Suzette Arcibal Baldwin 3, Belayneh A. Yimer 4, Yanhong Dong 5, Clayton Balfe 1, Tod Shelman 1, and Juliet M Marshall 1,2
1. University of Idaho, Department of Plant Sciences, Aberdeen Research and Extension Center, Aberdeen, ID
2. University of Idaho, Department of Plant Sciences, Idaho Falls Research and Extension Center, Idaho Falls, ID
3. North Dakota State University, Department of Plant Pathology, Fargo, ND
4. USDA-ARS, Small grains and Potato Germplasm Research Unit, Aberdeen, ID
5. University of Minnesota, Department of Plant Pathology, St. Paul, MN
Corresponding Author: Juliet M. Marshall, jmarshall@uidaho.edu
Presenting Author: Sidrat Abdullah
Abstract
Fusarium
head blight (FHB) impacts wheat in the Pacific Northwest, increasing with
climate change and corn production, elevating the prevalence of Fusarium
graminearum. Disease occurs frequently in spring wheat, where IPM efforts
have focused. Most winter wheat varieties are highly susceptible, resulting in
high levels of deoxynivalenol (DON) when diseased. A five-year (2020-2024)
screening study was conducted at Kimberly, Idaho to evaluate varieties and
advanced lines for susceptibility to F. graminearum. Widely grown
varieties and advanced lines of soft white winter (SWW) and hard winter wheat
(HWW) from public and private breeding programs were tested in two-row, 5-foot
plots with two replications in a randomized complete block design. Plots were
planted with a Hege 1000 head row planter. Secondary mist irrigation systems
fostered conditions for FHB infection, with corn spawn applied at 30 g/m² three
weeks before anthesis. FHB incidence, severity, and index were assessed at the
soft dough (Feekes 11.2). FDK and DON concentrations were measured from
harvested samples. Data were analyzed using PROC GLM in SAS 9.4, with LSD (α =
0.05) for mean comparisons. Disease pressure varied across years, with no
varieties showing resistance to FHB. After multiple years of testing, four
cultivars 'WB4510CLP’ and ‘WB4623CLP’ (HWW) and ‘Sockeye CL+’ and ‘Perrine’
(SWW)) showed moderate susceptibility. Overall, 82.7% of cultivars were rated
as susceptible (S) or very susceptible (VS). In HWW, FHB index ranged from 5.1
in Brundage (check) to 54.7 in UI Bronze Jade, with DON content from 4.4 ppm in
WB4510CLP to 58.7 ppm in MT1642. In SWW, FHB index values ranged from 11.2 in
ORI2190025CL+ to 58.0 in WA8334, while DON levels across entries varied from
5.1 to 56.1 ppm. Eighteen entries in multi-year trials exhibited varied
reactions (MS to VS), with mixed reactions observed in approximately 24.3% of
cases. 70 entries were evaluated only in a single year, with 36 rated S or VS.
In 2024, DON and FDK data for the other 34 single-year entries are pending. A
weighted equation that includes DON, Incidence, Severity and FDK was developed
(DISK value) as [(0.3 * DON) + (0.2 * Incidence) + (0.2 * Severity) + (0.3 *
FDK)] for assessing FHB reaction. Significant positive correlations were
observed between FHB index and DISK in both HWW (r = 0.733) and SWW (r =
0.798), with p < 0.0001. This study offers insights for selecting less
susceptible varieties to reduce DON contamination in grain.