Poster # 113

Isaack Kikway ¹, Alyssa Collins ², Alyssa Koehler ³, Andrew Friskop ⁴, Carl Bradley ⁵, Christina Cowger ⁶, Damon Smith ⁷, Darcy Telenko ⁸, Douglas Higgins ⁹, Guy Padgett ¹⁰, Heather Darby ¹¹, Heather Kelly ¹², Juliet M. Marshall ¹³, Kelsey Andersen Onofre ¹⁴, Madalyn Shires ¹⁵, Mandy Bish ¹⁶, Martin Chilvers ¹⁷, Nidhi Rawat ¹⁸, Paul Esker ¹⁹, Santiago Mideros ²⁰, Stephen Wegulo ²¹, Pierce A Paul ¹
1. The Ohio State University/OARDC, Wooster 44691
2. The Pennsylvania State University, Manheim, PA 17545
3. The University of Delaware, Georgetown, DE 19947
4. North Dakota State University, Fargo, ND 58102
5. University of Kentucky, Princeton, KY 42445
6. North Carolina State University/USDA-ARS, Raleigh, NC 27695
7. University of Wisconsin-Madison, Madison, WI 53706
8. Purdue University, West Lafayette, IN 47907
9. Virginia Tech, Suffolk, VA 23437
10. Louisiana State University Ag Center, Baton Rouge, LA 70803
11. University of Vermont and State Agricultural College, St. Albans, VT 05478
12. The University of Tennessee at Knoxville, Jackson, TN 38301
13. University of Idaho, Aberdeen, ID 83210;
14. Kansas State University, Manhattan, KS 66506
15. South Dakota State University, Brookings, SD 57007
16. University of Missouri, Columbia, MO 65211
17. Michigan State University, East Lansing, MI 48824
18. University of Maryland, College Park, MD 20742
19. The Pennsylvania State University, University Park, PA 16802
20. University of Illinois, Urbana, IL 61801
21. University of Nebraska-Lincoln, Lincoln, NE 68588
Corresponding Author: Pierce Paul, paul.661@osu.edu

Kikway, Isaack

kikway.1@osu.edu

The integration of two or more strategies such as a timely fungicide application in combination with genetic resistance is the most effective approach for reducing the impact of Fusarium head blight (FHB) and deoxynivalenol (DON) contamination on wheat grain yield and quality. As new fungicides such as Prosaro Pro, Miravis Ace, and Sphaerex become available on the market for FHB/DON management and new FHB resistant varieties are released, studies such as this becomes necessary to (re)evaluate the efficacy, cost, and benefit of integrating the two strategies for managing this disease-toxin complex across a range of environments and grain market classes. During the 2025 growing season, separate replicated plots of susceptible (S), moderately susceptible (MS), or moderately resistant (MR) cultivars were established in 21 US states, treated with Prosaro, Miravis Ace, Prosaro Pro, or Sphaerex at Feekes 10.5.1 or left untreated, and subsequently inoculated with spores of Fusarium graminearum between 24 and 36 hours after treatment application. Mean FHB index (IND) and DON contamination of grain in the non-treated susceptible check (S_CK) ranged from 0 to 55% and 0.1 to 5.2 ppm, respectively. Relative to S_CK, all fungicide x cultivar treatment combinations resulted in significantly lower (P < 0.001) mean IND and DON. Across all environments for which data were available at the time of this report, combining a moderately resistant cultivar with one of the tested fungicide treatments resulted in significantly lower mean IND and DON compared to when those same treatments were applied to a susceptible cultivar. The efficacy of each management combination was estimated as percent control (C) for IND and DON relative to S_CK. Across environments, the combination of an MR cultivar and a fungicide treatment resulted in higher C values for IND and DON than treatments applied to a S cultivar. For instance, across the tested fungicide treatments, C for IND and DON ranged from 81.5 to 90.9% on MR cultivars and 48.5 to 91.8% on MS cultivars, compared to 54 to 73% on S cultivars. Relative to S_CK, fungicide alone (S_I-IV) reduced mean IND by 55.4 to 73.2% and mean DON 54.1 to 67.9%, whereas MR alone (MR_CK) and MS alone (MS_CK) reduced mean IND by 67.5% and 58.9%, respectively, and mean DON by 59.1% and 1.2%, respectively. The outcomes from this study, conducted under diverse environmental and agronomic conditions, provide valuable insights into the efficacy of the new fungicides relative to the industry standard Prosaro when used in combination with genetic resistance to manage FHB and DON.

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