Soybean Disease Loss Estimates From the United States and Ontario, Canada — 2019

Soybean Disease Loss Estimates From the United States and Ontario, Canada — 2019

CPN-1018-19. Published May 31 2021. DOI: doi.org/10.31274/cpn-20210607-1

Each year, soybean diseases reduce yield in the United States and Ontario, Canada. The importance of these diseases varies annually, and many factors influence which diseases significantly 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 due to plant diseases and pathogens in 2019 for the major soybean-producing areas in the United States and Ontario, Canada. Extension, university, USDA plant pathologists and 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 Ontario in 2019. The estimated losses include those caused by foliar diseases, stem diseases, nematodes, seedling blights, and diseases of harvested grain.

Disease loss estimates are gathered through various means including disease surveys; interactions with Extension, university, government, industry, and farmer representatives; and personal experience with disease losses. Estimation methods vary by state or province.

For this publication, the authors determined disease loss values based on yield before estimated losses for each state or province using this formula:

(harvested bushels/[{100 – percent estimated disease loss}/100])

The authors then formulated the total number of bushels lost for each disease ([percent loss/100] x yield before estimated loss) for each 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.

2019 Production

The United States produced nearly 3.6 billion bushels of soybean in 2019, the lowest reported value since 2013. Ontario, Canada, produced 136.3 million bushels.

Figure 1. 2020 soybean production (in millions of bushels) from 29 U.S. states and Ontario, Canada. 

Figure 2. Sclerotinia stem rot (white mold) was estimated to have caused more than 31 million bushels of yield losses in 2019 in the United States and Ontario.

Image: Craig Grau

2019 Disease Losses

In all, 6.1 percent of the potential estimated soybean production (bushels/acre) in 2019 was lost due to disease in the top 29 soybean-producing states, and 10.4 percent of the total estimated soybean production in 2019 was lost due to disease in Ontario, Canada. Table 1 provides yield loss estimates for the specific diseases included in the survey of plant pathologists throughout the soybean production system in the U.S. and Ontario, Canada. Estimated percent losses in 2019 were less than those reported in 2018.

Table 1. Estimated soybean yield losses from diseases in 29 soybean producing states in the United States and Ontario, Canada in 2019, listed in order of most losses to least losses in each disease category.

Disease Total US losses (thousands of bushels) Total Ontario losses (thousands of bushels)
Root Rots and Seedling Blights
Soybean cyst nematode 77,392 5,319
Seedling diseases due to Fusarium, Pythium, Phomopsis, and Rhizoctonia 25,578 2,660
Root-knot nematode 8,681 0
Other nematodes¹ 3,692 76
Taproot decline 1,383 0
Reniform nematode 1,023 0
Leaf and Aboveground Diseases
Frogeye leaf spot 12,399 15
Cercospora leaf blight 7,529 76
Septoria brown spot 5,731 76
Purple seed stain² 1,470 76
Bacterial diseases 810 15
Rhizoctonia aerial blight 516 0
Virus diseases³ 500 2
Target spot 442 0
Soybean rust 56 0
Downy mildew 54 0
Stem Diseases
Sclerotinia stem rot (White mold) 29,556 1,520
Sudden death syndrome 17,622 3,040
Phytophthora root and stem rot 11,203 1,520
Pod and stem blight 7,149 304
Brown stem rot 4,357 76
Stem canker 3,472 152
Fusarium wilt and root rot 3,397 30
Charcoal rot 3,210 0
Diaporthe (Phomopsis) seed decay4 2,516 760
Southern blight 1,352 0
Anthracnose 1,165 15
Other Diseases
Other diseases5 12 0

¹Lance, root lesion, sting, stunt, and stubby root. Only root lesion nematode was reported in Ontario, Canada; ²A portion of the estimated yield loss value for purple seed stain in the U.S. is due to dockage from low quality seed reported from New York; ³Bean pod mottle, soybean mosaic, soybean vein necrosis, tobacco ringspot, and tobacco streak. Only soybean mosaic was reported in Ontario, Canada; 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 from New York. Estimated yield loss values for Diaporthe (Phomopsis) seed decay from Ontario is due to dockage from low quality seed; 5Phymatotrichopsis root rot and red crown rot

Diseases in the Northern United States

The northern states in the U.S., which included Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Nebraska, New York, North Dakota, Ohio, Pennsylvania, South Dakota, and Wisconsin, accounted for 77.7 percent of the total estimated yield losses in 2019. Since more than three-quarters of U.S. soybeans are produced in the northern states, disease losses in these states greatly affect the overall importance of different diseases across the country (see Table 2).

Table 2. Estimated soybean yield losses due to the seven most significant diseases in the northernmost U.S. states¹ in 2019.

Rank Disease/Pathogen Total losses (thousands of bushels)
Northern Region Nation
1 1 Soybean cyst nematode 64,245
2 2 Sclerotinia stem rot (White mold) 29,546
3 3 Seedling diseases due to Fusarium, Pythium, Phomopsis, and Rhizoctonia 21,957
4 4 Sudden death syndrome 16,099
5 6 Phytophthora root and stem rot 10,313
6 5 Frogeye leaf spot 9,610
7 9 Pod and stem blight 6,273

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

Diseases in the Southern United States

Soybean cyst nematode, root-knot nematode, and Cercospora leaf blight were the three diseases of greatest importance in 2019 in the southernmost U.S., which included Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia.

Table 3. Estimated soybean yield losses due to the seven most significant diseases in the southernmost U.S. states¹ in 2019.

Rank Disease/Pathogen Total losses (thousands of bushels)
Southern Region Nation
1 1 Soybean cyst nematode 13,147
2 7 Root-knot Nematode  8,652
3 8 Cercospora leaf blight  6,616
4 3 Seedling diseases due to Fusarium, Pythium, Phomopsis, and Rhizoctonia 3,621
5 5 Frogeye leaf spot 2,789
6 10 Septoria brown spot 2,206
7 4 Sudden death syndrome 1,523

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

Figure 3. Root-knot nematode caused more than 8.6 million bushels of yield losses in the southern U.S. in 2019.

Image: Ed Sikora

Diseases in Ontario, Canada

Soybean cyst nematode caused the greatest estimated yield loss in Ontario, Canada, in 2019, followed by sudden death syndrome and seedling diseases (see Table 4). There were no foliar diseases present among the top yield-reducing diseases in Ontario.

Table 4. Estimated soybean yield losses due to the seven most significant diseases in Ontario, Canada in 2019.

Rank Disease/Pathogen Total losses (thousands of bushels)
Ontario, Canada United States
1 1 Soybean cyst nematode 5,319
2 4 Sudden death syndrome 3,040
3 3 Seedling diseases due to Fusarium, Pythium, Phomopsis, and Rhizoctonia 2,660
4a 6 Phytophthora root and stem rot 1,520
4b 2 Sclerotinia stem rot (White mold) 1,520
6 16 Diaporthe (Phomopsis) seed decay 760
7 9 Pod and stem blight 304

 

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

Acknowledgments

Authors

Carl Bradley, University of Kentucky; Tom Allen, Mississippi State University; Albert Tenuta, Ontario Ministry of Agriculture, Food and Rural Affairs; Kelsey Mehl, University of Kentucky; and Adam Sisson, Iowa State University

Contributors

Ed Sikora, Auburn University; Terry Spurlock and Travis Faske, University of Arkansas; Alyssa Koehler, University of Delaware; Nick Dufault, University of Florida; Bob Kemerait, University of Georgia; Nathan Kleczewski, University of Illinois; Darcy Telenko, Purdue University; Daren Mueller, Iowa State University; Doug Jardine, Kansas State University; Carl Bradley, University of Kentucky; Trey Price and Boyd Padgett, Louisiana State University; Marty Chilvers and Fred Warner, Michigan State University; Dean Malvick and James Kurle, University of Minnesota; Tom Allen, Mississippi State University; Kaitlyn Bissonnette, University of Missouri; Loren Giesler, University of Nebraska; Gary Bergstrom, Cornell University; Lindsey Thiessen, North Carolina State University; Samuel Markell and Berlin Nelson, North Dakota State University; Anne Dorrance, The Ohio State University; John Damicone, Oklahoma State University; Albert Tenuta, Ontario Ministry of Agriculture, Food and Rural Affairs; Alyssa Collins, Pennsylvania State University; John Mueller, Clemson University; Emmanuel Byamukama and Connie Tande, South Dakota State University; Heather Kelly, University of Tennessee; Tom Isakeit, Texas A&M University; Hillary Mehl, Virginia Tech; and Damon Smith, University of Wisconsin-Madison.

Sponsors

The authors thank the United Soybean Board and the Grain Farmers of Ontario for their support. Support also was 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).

This publication was developed by the Crop Protection Network, a multi-state and international collaboration of university/provincial extension specialists and public/ private professionals that provides unbiased, research-based information to farmers and agricultural personnel.

This information in this publication is only a guide, and the authors assume no liability for practices implemented based on this information. Reference to products in this publication is not intended to be an endorsement to the exclusion of others that may be similar. Individuals using such products assume responsibility for their use in accordance with current directions of the manufacturer.

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