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

Wheat diseases annually reduce yield in the United States and Canada. Diseases of importance vary from year to year, and diseases that affect yield are based on multiple factors, including environmental conditions, crop production practices, and susceptibility of a given variety to disease.

Plant pathologists representing 28 wheat-producing U.S. states and Ontario, Canada, estimated the percent yield losses from wheat disease in their states or provinces. These reports account for more than 1.7 billion bushels (89.9 percent) of the total wheat produced in the United States and Ontario in 2023 (Figure 1). The yield loss estimates include root, stem, foliar, head, and kernel diseases in the states/province represented in this survey.

This publication documents the impact of major diseases on wheat production during 2023. The North Central Regional Committee on Management of Small Grain Diseases (NCERA 184) and the Western Wheat Workers (WERA 97) revise the wheat disease loss estimates annually. It is important to note that methods for estimating disease loss vary by state or province. The estimates may be based on statewide disease surveys; feedback from university Extension, industry, farmer representatives; and personal experience with disease losses.

Determination of disease loss values is based on yield prior to estimated losses for each state or province using the formula (harvested bushels/[{100 – percent estimated disease loss}/100]). Total bushels lost per disease is determined for each state or province using the formula ([percent loss/100] x yield before estimated loss). This does not include mycotoxin, black point, or black sooty mold contamination or seed lots contaminated by ergot as these would reduce grain quality rather than quantity. Additional information on yield and economic losses due to wheat diseases can be found at the CPN Field Crop Disease and Insect Loss Calculator. 

2023 Conditions and Production

Farmers in the United States and Ontario planted wheat on 50.8 million acres in 2023. This produced more than 1.9 billion bushels of wheat, worth more than 13.5 billion USD. Above average temperatures were observed throughout much of the contiguous U.S. in 2023. Multiple states experienced drought, reducing the risk from many disease-causing pathogens in those locations.

2023 Disease Losses

In 2023, disease reduced harvested wheat bushels by 2.9 percent across the U.S. states included in this survey and by 0.4 percent in Ontario. Table 1 provides yield loss estimates for all diseases. Total estimated yield losses from wheat disease in the U.S. and Ontario was 49.5 million bushels, which was valued at nearly 360 million USD. This does not include the economic costs of disease management practices such as fungicide seed treatment or foliar fungicide application, crop scouting, or development of disease-resistant varieties. Overall reduction in bushels and percent losses in 2023 were less than any previous year of data collection (2018-2022).

Table 1. Estimated wheat yield losses from diseases in 28 wheat producing states in the United States and Ontario, Canada in 2023.

¹Can include needle, root-gall, root-knot, stem and bulb, stubby-root, and stunt nematodes; ²Can include pink snow mold, speckled snow mold, and snow rot; ³Can include Alternaria leaf blight, anthracnose, Ascochyta leaf spot, bacterial mosaic, and downy mildew; ⁴Can include Agropyron mosaic and Brome mosaic.

Disease Losses by Region

To increase the granularity of loss data, wheat-producing states were divided into six regions and the top five yield-limiting diseases for each region (Figure 3) are reported in Tables 2-7.

East North Central U.S. States and Ontario, Canada

This region represents 21.4 percent of the wheat produced in the U.S. and Ontario, Canada and consists of Illinois, Indiana, Kentucky, Michigan, Missouri, New York, Ohio, and Wisconsin. Total losses to plant disease were estimated to be 2.3 million bushels, or 0.6 percent of production in this region.

Table 2. Estimated wheat yield losses due to the five most significant diseases in the U.S. East North Central states¹ and Ontario, Canada in 2023.

¹Illinois, Indiana, Kentucky, Michigan, Missouri, New York, Ohio, and Wisconsin.

Mid-Atlantic U.S. States

This region represents 4.1 percent of the wheat produced in the U.S. and Ontario, Canada and consists of Delaware, Maryland, North Carolina, Pennsylvania, and Virginia. Total losses to plant disease were estimated to be 1.5 million bushels, or 1.9 percent of production in this region.

Table 3. Estimated wheat yield losses due to the five most significant diseases in the U.S. Mid-Atlantic states¹ in 2023.

¹Delaware, Maryland, North Carolina, Pennsylvania, and Virginia.

Mountain West U.S. States

This region represents 18.3 percent of the wheat produced in the U.S. and Ontario, Canada and consists of Colorado, Idaho, and Montana. Total losses to plant disease were estimated to be 19.3 million bushels, or 5.2 percent of production in this region.

Table 4. Estimated wheat yield losses due to the five most significant diseases in U.S. Mountain West states¹ in 2023.

¹Colorado, Idaho, and Montana.

Southeast U.S. States

This region represents 2.8 percent of the wheat produced in the U.S. and Ontario, Canada and consists of Arkansas, Georgia, Louisiana, Mississippi, and Tennessee. Total losses to plant disease were estimated to be 0.5 million bushels, or 1.0 percent of production in this region.

Table 5. Estimated wheat yield losses due to the five most significant diseases in the U.S. Southeast states¹ in 2023.

¹Arkansas, Georgia, Louisiana, Mississippi, and Tennessee.

Northern Great Plains U.S. States

This region represents 23.3 percent of the wheat produced in the U.S. and Ontario, Canada and consists of Minnesota, North Dakota, and South Dakota. Total losses to plant disease were estimated to be 16.3 million bushels, or 3.5 percent of production in this region.

Table 6. Estimated wheat yield losses due to the five most significant diseases in the U.S. Northern Great Plains states¹ in 2023.

¹Minnesota, North Dakota, and South Dakota.

Southern Great Plains U.S. States

This region represents 20.1 percent of the wheat produced in the U.S. and Ontario, Canada and consists of Kansas, Nebraska, Oklahoma, and Texas. Total losses to plant disease were estimated to be 9.5 million bushels, or 2.4 percent of production in this region.

Table 7. Estimated wheat yield losses due to the five most significant diseases in the U.S. Southern Plains states¹ in 2023.

¹Kansas, Nebraska, Oklahoma, and Texas.

Disclaimer

The disease loss estimates in this publication were provided by members of the North Central Regional Committee on Management of Small Grain Diseases (NCERA 184) and the Western Wheat Workers (WERA 97). This information is only a guide. The values in this publication are not intended to be exact estimates of wheat yield losses due to diseases. The members of NCERA 184 used the most appropriate means available to estimate disease losses and assume no liability resulting from the use of these estimates.

Values reported in this document were accurate as of publication date and do not reflect corrections or updates occurring since that time. For the most up-to-date values and additional information on yield and economic losses due to diseases, see the Field Crop Disease and Insect Loss Calculator at https://loss.cropprotectionnetwork.org/.

Acknowledgements

Authors

Andrew Friskop; North Dakota State University; Adam Sisson, Iowa State University; Travis Faske, University of Arkansas; Ron Meyer, Colorado State University; Alyssa Betts, University of Delaware; Alfredo Martinez Espinoza, University of Georgia; Juliet Marshall, University of Idaho; Boris Camiletti, University of Illinois Urbana-Champaign; Darcy Telenko, Purdue University; Kelsey Anderson-Onofre, Kansas State University; Carl Bradley, University of Kentucky;  Paul “Trey” Price III, Louisiana State University; Martin Chilvers, Michigan State University; Jochum Wiersma, University of Minnesota; Tom Allen, Mississippi State University; Mandy Bish, University of Missouri; Uta McKelvy, Montana State University; Stephen Wegulo, University of Nebraska-Lincoln; Gary Bergstrom, Cornell University; Christina Cowger, North Carolina State University; Pierce Paul, Ohio State University; Meriem Aoun, Oklahoma State University; Albert Tenuta, Ontario Ministry of Agriculture, Food, and Rural Affairs; Alyssa Collins, Pennsylvania State University; Madalyn Shires, South Dakota State University; Heather Kelly, University of Tennessee; Ken Obasa and Nolan Anderson, Texas A&M University; David Langston and Doug Higgins, Virginia Tech; and Damon Smith, University of Wisconsin-Madison.

Reviewers

Daren Mueller, Iowa State University and Damon Smith, University of Madison-Wisconsin.

Production data from the United States Department of Agriculture-National Agricultural Statistics Service and the Statistics Canada. Climate information from the National Oceanic and Atmospheric Administration-National Center for Environmental Information.

United States Department of Agriculture National Agricultural Statistics Service. Quick Stats Database. Accessed 27-28 March 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 28 March 2024.

In addition to support from United States Department of Agriculture - National Institute of Food and Agriculture, this project was funded in part through the Grain Farmers of Ontario.