Wheat Disease Loss Estimates from the United States and Ontario, Canada — 2022

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 many factors, including weather conditions, crop production practices, and variety selection and susceptibility to disease.

Plant pathologists representing 29 wheat-producing U.S. states and Ontario, Canada, estimated the percent yield loss from wheat disease in their states or province. These reports account for more than 1.5 billion bushels (87.1 percent) of the total wheat produced in the United States and Ontario in 2022 (Figure 1). The yield loss estimates include foliar, root, stem, head, and kernel diseases in the states/province represented in this survey.

This publication documents the impact of major diseases on wheat production during 2022. The North Central Regional Committee on Management of Small Grain Diseases (NCERA 184) and the Western Wheat Workers (WERA 97) revises 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, and 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/ergoty seed lots/black point/black sooty mold contamination as this reduces quality rather than quantity of grain. Additional information on yield and economic losses due to wheat diseases can be found at the CPN Field Crop Disease and Insect Loss Calculator. 

2022 Conditions and Production

Farmers in the United States and Ontario planted wheat on 46.8 million acres in 2022. This produced more than 1.7 billion bushels of wheat, worth more than 15.4 billion USD. Above average temperatures were observed throughout much of the contiguous U.S. in 2022, with near average temperatures observed in several north central states such as North Dakota and Minnesota. Multiple states such as Nebraska and Kansas experienced drought, reducing the risk from many disease-causing pathogens in those locations.

2022 Disease Losses

In 2022, disease reduced wheat bushels by 3.6 percent across the U.S. states included in this survey and by 1.9 percent in Ontario. Table 1 provides yield loss estimates for all diseases. Total estimated yield loss from wheat disease in the U.S. and Ontario was 55.7 million bushels, and was valued at nearly 500 million USD. This does not include the economic costs of disease management practices such as fungicide seed treatment or foliar application, crop scouting, and development of disease-resistant varieties. Overall reduction in bushels in 2022 was less than half that of any other year of data collection (2018-2021), and percent losses were also much lower than previous years.

Table 1. Estimated wheat yield losses from diseases in 29 wheat producing states in the United States and Ontario, Canada in 2022.

¹Can include needle, root-gall, root-knot, stem, 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.

Diseases in the Northern United States

Bacterial leaf streak and black chaff were the most damaging diseases in the northern United States in 2022 — 7.1 million bushels lost (Table 2). High Plains disease, Triticum mosaic, and wheat streak mosaic caused the second greatest losses, followed by root-lesion nematodes, Fusarium head blight, and common root and foot rot. Overall, 44.6 million bushels of wheat (3.7 percent) were estimated to have been lost due to diseases in the northern United States in 2022.

Table 2. Estimated wheat yield losses due to the five most significant diseases in the northernmost U.S. states¹ in 2022.

¹U.S. States include Colorado, Idaho, Illinois, Indiana, Kansas, Michigan, Minnesota, Montana, Nebraska, New York, North Dakota, Ohio, Pennsylvania, South Dakota, and Wisconsin.

Diseases in Southern States

High Plains disease, Triticum mosaic, and wheat streak mosaic caused the greatest estimated wheat yield losses in the southernmost U.S. states in 2022 (Table 3). Stripe rust, which was the greatest cause of yield loss in 2021, ranked second in 2022, and was followed by barley yellow dwarf, leaf rust, and powdery mildew in descending order. Overall, 9.4 million bushels of wheat (3.4 percent) of yield loss occurred in the southernmost United States due to disease.  

Table 3. Estimated wheat yield losses due to the five most significant diseases in the southernmost U.S. states¹ in 2022.

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

Diseases in Ontario, Canada

Septoria tritici blotch caused twice as much estimated yield loss compared to any other disease of wheat in Ontario, Canada in 2022 (Table 4). The next greatest cause of yield loss was Stagonospora leaf and glume blotch, followed by Fusarium root, crown, and foot rot, and Pythium root rot.

Table 4. Estimated wheat yield losses due to the six¹ most significant diseases in Ontario, Canada in 2022.

¹Six diseases were included as multiple diseases share rankings in terms of yield losses.

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. 

Acknowledgments

Authors

Andrew Friskop; North Dakota State University and Adam Sisson, Iowa State University.

Contributors

Kira Bowen, Auburn University; Travis Faske, University of Arkansas; Ron Meyer, Colorado State University; Alyssa Koehler, University of Delaware; Alfredo Martinez Espinoza, University of Georgia; Juliet Marshall, University of Idaho; Nathan Kleczewski, University of Illinois; 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; Andrew Friskop, North Dakota 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, Texas A&M University; David Langston, Virginia Tech; and Damon Smith, University of Wisconsin-Madison.

Reviewers

Daren Mueller, Iowa State University

Production data from the United States Department of Agriculture-National Agriculture 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 7-8 March 2023.

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 8 March 2023.

Sponsors

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.