Madison Kessler
Kansas State University
Manhattan, KS, USA
Nabin K. Dangal
Postdoc
Iowa State University
Ames, IA, USA
Richard Wade Webster, n/a
Assistant Professor and Extension Soybean Pathologist
North Dakota State University
Fargo, North Dakota, United States
Daren S. Mueller, n/a
Professor
Iowa State University
Ames, Iowa, United States
Rodrigo B. Onofre, n/a
Assistant Professor, Row Crops Pathology
Kansas State University
Manhattan, Kansas, United States
Martin I. Chilvers, n/a
Professor
Michigan State University
EAST LANSING, Michigan, United States
Aqeel Ahmad
Bayer Crop Science
Ballwin, Missouri, United States
Horacio D. Lopez-Nicora, Dr.
Assistant Professor
The Ohio State University
Columbus, Ohio, United States
Febina Mathew, PhD
Associate Professor
Department of Plant Pathology, North Dakota State University, Fargo, ND 58102
Fargo, North Dakota, United States
Dean Malvick
Professor
University of Minnesota
St Paul, Minnesota, United States
Damon L. Smith, n/a
Professor
University of Wisconsin–Madison
Madison, Wisconsin, United States
Darcy Telenko, n/a
Associate professor
Purdue University
West Lafayette, Indiana, United States
Albert Tenuta, n/a
Extension Plant Pathologist
Ontario Ministry of Agriculture, Food and Agribusiness
Ridgetown, Ontario, United States
Timothy Todd
Instructor and Research Scientist
Kansas State University
Manhattan, Kansas, United States
Stith Wiggs
Iowa State University
Ames, Iowa, United States
Sudden death syndrome (SDS), primarily caused by Fusarium virguliforme, threatens soybean production across 16 U.S. states and Ontario, Canada. SDS thrives in cool, wet soils, with post-planting rainfall exacerbating disease, making pre-planting management strategies like resistant cultivars and seed treatments crucial. This study evaluated biological and chemical seed treatments on resistant and susceptible soybean cultivars across 15 locations in 2022 and 16 in 2023. Data collection included stand counts, root rot severity, foliar SDS severity index (FDX), and yield. Trials were categorized into high (FDX ≥ 10%) or low (FDX < 10%) disease locations based on the non-treated control (NTC). In high disease locations, cultivar and seed treatment significantly (P ≤ 0.01) influenced FDX, root rot, and yield. The base+fluopyram+natamycin treatment reduced FDX by 6.7% and increased yield by 288.5 kg/ha over the NTC. The resistant cultivar further reduced FDX by 9.7% and root rot by 2.1%, while increasing yield by 247.7 kg/ha relative to the susceptible cultivar. Under low disease pressure, cultivar selection remained significant, with resistance reducing FDX by 2.4% and root rot by 0.8%, and improving yield by 445.5 kg/ha. In contrast, the effects of seed treatment were not significant. No seed treatments lowered FDX or root rot and only base+fluopyram and base+fluopyram+natamycin increased yield (+254.1-301.2) compared to the NTC. Cultivar resistance remains the most effective SDS management strategy, with seed treatments statistically supported under high disease pressure.