About the Calculator

A research tool for calculating estimated historical yield loss in corn, soybean, and wheat from diseases and insect pests

The purpose this calculator is to share economically important information on estimated crop losses from diseases or insect pests with those engaged in research, education, and policy formation. This online calculator can query multiple types of production and yield loss data for a variety of user-defined or predetermined factors including geographic area and timeframe. It is important to note the limitations of this tool including the fact that loss values here are expert estimates and not actual loss values. Also, not all data categories are available for all locations and all years, and categories changed slightly over the years. 

How to cite information from this resource: 

Crop Protection Network. 2021. Estimates of corn, soybean, and wheat yield losses due to diseases and insect pests: an online tool. Doi.org/10.31274/cpn-20191121-0

How are loss estimates determined?

The Corn Disease Working Group (CDWG), the North Central Research and Extension Activity (NCERA) 137 Soybean Disease Committee, the Southern Soybean Disease Workers, the North Central Regional Committee on Management of Small Grain Diseases (NCERA 184), and others from land grant universities revise disease loss estimates annually. Methods for estimating disease loss vary by state or province and year. Estimates may be based on statewide disease surveys; feedback from university Extension, industry, government, and farmer representatives; and personal experience with disease losses. Information on soybean insect pests forthcoming.

Loss values are based on production before estimated losses for each state or province:

Bushels or USD harvested / (100 - total percent estimated disease loss) ÷ 100

Then, total bushels or USD lost per disease for each state or province are formulated:  

(percent loss ÷ 100) x yield before estimated losses

Average loss values in USD per acre are determined by dividing economic losses by acres planted. 

Important notes about data

Not all data categories are available for all locations and all years, and disease categories changed slightly over the years.

Corn Diseases:

  • Data is currently available from 2012 onwards.
  • Mycotoxin contamination values are currently not available. 
  • Corn loss data are not available for Alabama from 2012-2018, Georgia from 2012-2019, Missouri in 2013, South Carolina from 2012-2019, and Virginia from 2012-2016. 

Soybean Diseases: 

  • Data is currently available from 1996 onwards.
  • Because data was obtained from differing sources (extension personnel, previously published papers, and government reporting agencies) discrepancies among years and locations exist that cannot be accounted for. Thus, it is important to remember that the data presented here are estimates only. 
  • Most soybean data were back calculated from reported yield reductions to percent losses using production reports from USDA NASS and OMAFRA.
  • Soybean loss data not available for Florida in 2002 and 2003; Minnesota in 1999 and 2000; New York from 1996-2016; Ontario in 1996, 1997, 2003-2005, and 2007-2009; Pennsylvania in 2001; and Texas in 2011
  • Cercospora leaf blight and purple seed stain losses have been combined into one value. 
  • From 1996-2010, losses from root knot nematode and other nematodes (excluding soybean cyst nematode) were contained in a single category; from 2011 onward, root knot nematode data were separated from the other nematodes category; from 2014 onward, Reniform nematode data were separated from the other nematodes category.  
  • Canadian data from 1998 may be representative of all of Canada rather than just Ontario. 
  • Data from Iowa in 2005 was missing. However, since Iowa production is such a high percentage of soybeans grown in the U.S., not reporting estimated disease loss data from Iowa in 2005 would heavily skew queried results. To account for this, disease-related extension articles from 2005 and data from other sources were used to estimate percent losses for this year.

Wheat Diseases:

  • Data is currently available from 2018 onwards.
  • Mycotoxin contamination values or Ergoty seed lot contamination values are not yet available. 
  • Disease loss data for Texas in 2018 is not available.

Soybean Insect Pests:

  • Information forthcoming.


This information is only a guide. The values in this resoure are not intended to be exact values of yield losses due to diseases or insect pests, and some data are missing for certain years and locations. Contributors and data managers used the most appropriate means available to estimate disease and insect pest losses and assume no liability resulting from the use of these estimates. 

References to products in this resource are 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. 

Find out More 

The Crop Protection Network (CPN) is a multi-state and international collaboration of university and provincial extension specialists, and public and private professionals who provide unbiased, research-based information to farmers and agricultural personnel. Our goal is to communicate relevant information that will help professionals identify and manage field crop diseases.

Annual disease loss summaries for selected years can be found here

Find more crop protection resources at the Crop Protection Network


Text and images:

Daren Mueller and Adam Sisson 

Data compilation:

Tom Allen, Carl Bradley, Daren Mueller, Andrew Friskop, Adam Sisson, Fred Musser, Steve Koenning and Allen Wrather 


Tom Allen, Kelsey Anderson-Onofre, Gary Bergstrom, Kaitlyn Bissonnette, Jason Bond, Kira Bowen, Bruce Bosley, Carl Bradley, Kirk Broders, Mary Burrows, Emmanuel Byamukama, Martin Chilvers, Cliff Coker, Alyssa Collins, Christina Cowger, John Damicone, Erick DeWolf, Anne Dorrance, Nicholas Dufault, Paul Esker, Travis Faske, Nicole Fiorellino, Andrew Friskop, Loren Giesler, Arvydas Grybauskas, Austin Hagan, Glen Hartman, Ron Heiniger, Donald Hershman, Clayton Hollier, David Hooker, Bob Hunger, Tom Isakeit, Tamra Jackson-Ziems, Douglas Jardine, Heather Kelly, Robert Kemerait, Kasia Kinzer, Nathan Kleczewski, Alyssa Koehler, Steve Koenning, Robert Kratochvil, James Kurle, David Langston, Dean Malvick, Sam Markell, James Marois, Juliet Marshall, Alfredo Martinez, Febina Mathew, Marcia McMullen, Hillary Mehl, Kelsey Mehl, Ron Meyer, Michelle Mostrom, Daren Mueller, John Mueller, Robert Mulrooney, Tim Murray, Fred Musser, Berlin Nelson, Melvin Newman, Ken Obasa, Rodrigo Onofre, Larry Osborne, Charles Overstreet, Guy Padgett, Pierce Paul, Angie Peltier, Patrick Phipps, Paul Price, Alison Robertson, Gregory Roth, Edward Sikora, Adam Sisson, Ian Small, Damon Smith, Terry Spurlock, Bill Stump, Connie Tande, Darcy Telenko, Albert Tenuta, Lindsey Thiessen, Paul Vincelli, Fred Warner, Stephen Wegulo, Bill Wiebold, Jochum Wiersma, Kiersten Wise, and Allen Wrather. 

Contributors to this publication include members of the Corn Disease Working Group, North Central Research and Extension Activity 137 Soybean Disease Committee, the Southern Soybean Disease Workers, the North Central Regional Committee on Management of Small Grain Diseases (NCERA 184), and others from land grant universities. These university and extension scientists represent many institutions, including: University of Arkansas, Auburn University, Clemson University, Colorado State University, Cornell University, University of Delaware, University of Florida, University of Georgia, University of Guelph, University of Idaho, University of Illinois, Iowa State University, Kansas State University, University of Kentucky, Louisiana State University, Michigan State University, University of Minnesota, Mississippi State University, University of Missouri, Montana State University, University of Nebraska, North Carolina State University, North Dakota State University, The Ohio State University, Oklahoma State University, Ontario Ministry of Agriculture, Food and Rural Affairs, Pennsylvania State University, Purdue University, South Dakota State University, University of Tennessee, Texas A&M University, Virginia Tech, Washington State University, University of Wisconsin-Madison, and University of Wyoming.


Yield and USD production values obtained from: 

United States Department of Agriculture - National Agriculture Statistics Service (USDA-NASS). Quick Stats 2.0. Https://www.nass.usda.gov/Quick_Stats/index.php.

Statistics Canada: Field Crop Reporting Series.Ontario Ministry of Agric., Food, and Rural Affairs, Guelph. Http://www.omafra.gov.on.ca/english/stats/crops/index.html

Personal inquiries with crop specialists when data was unavailable via USDA-NASS

Additional Canadian data from: 

Wrather, J.A., Anderson, T.R., Arsyad, D.M., Tan, Y., Ploper, L.D., Porta-Puglia, A., Ram, H.H., and Yorinori, J.T. 2001. Soybean disease loss estimates for the top ten soybean-producing countries in 1998. Can. J. Plant Pathol. 23: 115-121. 

Wrather, J. A., Koenning, S. R., and Anderson, T. R. 2003. Effect of diseases on soybean yields in the United States and Ontario (1999-2002). Online. Plant Health Progress doi:10.1094/PHP-2003-0325-01-RV.


In addition to support from USDA-NIFA, this project was funded in part through Growing Forward 2 (GF2), a federal-provincial territorial initiative. The Agricultural Adaptation Council assists in the delivery of GF2 in Ontario. 

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