Soybean Disease Loss Estimates from the United States and Ontario, Canada — 2023

Soybean diseases reduce yield in the United States and Ontario, Canada, each year. The importance of these diseases varies annually as many factors influence which diseases affect yield. These factors can include environment, production practices, and a variety’s susceptibility to disease.

The current publication provides the estimated annual soybean yield losses as a result of soybean diseases during the 2023 season for the major soybean-producing areas in the United States and Ontario, Canada. Extension, university, USDA plant pathologists, and/or soybean specialists from each state and province provided the estimates. These reports accounted for 99.9 percent of the total soybean production in the United States and 100 percent of production from Ontario in 2023. The estimated losses include those caused by foliar diseases, stem diseases, nematodes, seedling blights, and diseases of harvested grain.

Disease loss estimates are gathered using several methods that typically include disease surveys; interactions with Extension, university, government, industry, and farmer representatives; and personal experience with disease losses. Estimation methods vary by state or province.

Values for soybean disease losses are based on yield before estimated losses occurred for each state or province and are determined using the formula (harvested bushels/[{100 – percent estimated disease loss}/100]). Next, the formula ([percent loss/100] × yield before estimated loss) is used to determine bushels lost for each participating state or province. Additional information on yield and economic losses due to soybean diseases can be found at the CPN Field Crop Disease Loss Calculator. 

2023 Production

The United States produced nearly 4.2 billion bushels of soybean in 2023, a slight decrease compared to the previous two years of production (Figure 1). Ontario, Canada, produced 148.3 million bushels in 2023.

2023 Disease Losses

In all, an estimate of 4.8 percent of the potential soybean production (bushels/acre) in 2023 was lost due to disease from the 29 soybean-producing U.S. states, and 6.1 percent of the total soybean bushels in 2023 were estimated to be lost due to disease in Ontario, Canada. Table 1 provides yield loss estimates for the specific diseases throughout the soybean production system in the U.S. and Ontario, Canada, and Figure 3 compares the proportion of losses caused by major diseases. The 2023 estimated losses from soybean disease in the U.S. are the second lowest observed out of 28 years of available data, with only 2022 being lower. In Ontario, 2023 percent losses were slightly higher than in 2022, reversing an annual decline beginning after 2018.

Table 1. Estimated soybean yield losses from diseases in 29 soybean-producing states in the United States and Ontario, Canada, in 2023, listed in order of most to least losses in each disease category.

¹Lance, root lesion, sting, and stubby root. Only root lesion nematode was reported in Ontario, Canada; ²Alfalfa mosaic, bean pod mottle, soybean mosaic, soybean vein necrosis, and tobacco streak. Only soybean mosaic was reported in Ontario, Canada; ³A portion of the estimated yield loss value for purple seed stain in the U.S. is due to dockage from low-quality seed reported; ⁴A portion of the estimated yield loss value for Diaporthe (Phomopsis) seed decay in the U.S. is due to dockage from low-quality seed reported.

Diseases in the Northern United States

The northern states in the U.S., which include Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Nebraska, New York, North Dakota, Ohio, Pennsylvania, South Dakota, and Wisconsin, accounted for 76.6 percent of the total estimated U.S. yield losses in 2023. Because more than three-quarters of U.S. soybean production occurs in the northern states, disease losses in these states greatly affect the overall importance of different diseases across the country (see Table 2). However, dry conditions in soybean production areas in 2023, as well as in the previous three years, likely resulted in less disease loss than typically observed in the northern region. There were no foliar diseases among the top yield-reducing diseases in 2023 for the northern region.

Table 2. Estimated soybean yield losses due to the five most significant diseases in the northernmost U.S. states¹ in 2023.

¹Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Nebraska, New York, North Dakota, Ohio, Pennsylvania, South Dakota, and Wisconsin.

Diseases in the Southern United States

Similar to what was observed in 2022, soybean cyst nematode and root-knot nematode caused the most estimated yield losses in 2023 in the southernmost U.S., which includes Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia (see Table 3).

Table 3. Estimated soybean yield losses due to the five most significant diseases in the southernmost U.S. states¹ in 2023.

¹Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia.

Diseases in Ontario, Canada

Soybean cyst nematode caused the greatest estimated yield loss in Ontario, Canada, in 2023, followed by sudden death syndrome and Sclerotinia stem rot (white mold; see Table 4).

Table 4. Estimated soybean yield losses due to the six most significant diseases in Ontario, Canada, in 2023.

Disclaimer

The yield losses estimated in this publication were provided by members of the North Central Research and Extension Activity (NCERA) 137 Soybean Disease Committee and the Southern Soybean Disease Workers. The information contained in the current publication is meant to be used as a guide. The values in this publication are estimates and are not intended to be used as exact measurements of soybean yield losses due to plant diseases. However, these data provide valuable insight into the ranking of importance of a given disease within a production region (north or south), as well as across the entire production system. The most appropriate means available were used to estimate disease losses and no liability resulting from the use of these estimates is assumed.

Additional information on yield and economic losses due to soybean diseases can be found at the CPN Field Crop Disease Loss Calculator. 

Acknowledgements

Data Compilers

Tom Allen, Mississippi State University; Daren Mueller, Iowa State University; and Adam Sisson, Iowa State University 

Authors

Ed Sikora, Auburn University; Travis Faske and Terry Spurlock, University of Arkansas; Alyssa Koehler-Betts, University of Delaware; Zane Grabau and Ian Small, University of Florida; Bob Kemerait, University of Georgia; Santiago Mideros, University of Illinois; Jason Bond, Southern Illinois University; Darcy Telenko, Purdue University; Daren Mueller and Adam Sisson, Iowa State University; Rodrigo Onofre, Kansas State University; Carl Bradley, University of Kentucky; Boyd Padgett, Trey Price, and Tristan Watson, Louisiana State University; Marty Chilvers, Michigan State University; Dean Malvick, University of Minnesota; Tom Allen, Mississippi State University; Mandy Bish, University of Missouri; Dylan Mangel, University of Nebraska; Gary Bergstrom, Cornell University; LeAnn Lux, North Carolina State University; Samuel Markell and Wade Webster, North Dakota State University; Horacio Lopez-Nicora, The Ohio State University; Maira Rodrigues Duffeck, Oklahoma State University; Albert Tenuta, Ontario Ministry of Agriculture, Food and Rural Affairs; Alyssa Collins, Paul Esker, and Greg Roth, Pennsylvania State University; John Mueller and Michael Plumblee, Clemson University; Madalyn Shires, South Dakota State University; Heather Kelly, University of Tennessee; Tom Isakeit, Texas A&M University; David Langston and Yuan Zeng, Virginia Tech; and Damon Smith, University of Wisconsin-Madison. 

Reviewers

Kiersten Wise, University of Kentucky and Alison Robertson, Iowa State University

Production data from the United States Department of Agriculture-National Agriculture Statistics Service, Farm Service Agency, Statistics Canada, and direct state representative communication when data was unavailable elsewhere.  

United States Department of Agriculture National Agricultural Statistics Service. Quick Stats Database. Accessed 27 February 2024.

United States Department of Agriculture Farm Service Agency. 2023 acreage data as of January 2, 2024. Accessed 27 February 2024.

Statistics Canada. Table 32-10-0359-01 Estimated areas, yield, production, average farm price, and total farm value of principal field crops in metric and imperial units. Accessed 14 February 2024.

Sponsors

The authors thank the United Soybean Board and the Grain Farmers of Ontario through the Sustainable Canadian Agricultural Partnership (Sustainable CAP), a federal-provincial territorial initiative, for their support. Support was also provided by State and Federal Funds appropriated to the State Land Grant Institutions of cooperating authors and the United States Department of Agriculture - National Institute of Food and Agriculture (USDA-NIFA).