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Corn Disease Loss Estimates – 2016

Corn Disease Management

Corn Disease Loss Estimates For the United States and Ontario, Canada — 2016

CPN 2007-16-W — published April 2017

 

Figure1

Figure 1. 2016 corn production (in millions of bushels) in 24 U.S. states and Ontario, Canada.

Corn 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 hybrid selection and susceptibility to disease.

Plant pathologists representing 24 corn-producing U.S. states and Ontario, Canada, estimated the percent yield loss from corn disease in their states. These reports account for 15.1 billion bushels (97.7 percent) of the total corn produced in the United States and Ontario in 2016 (Figure 1). The yield loss estimates include root rots, seedling blights, foliar diseases, crazy top, ear and head smuts, stalk rots, and ear rots.

This publication documents the impact of major diseases on corn production during 2016. The Corn Disease Working Group (CDWG) 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.

The CDWG determined disease loss values based on yield before estimated losses for each state or province:
[(100 - percent estimated disease loss) ÷ 100]/bushels harvested
The CDWG then formulated total bushels lost per disease (percent loss x yield before estimated losses) for each state or province

Gray leaf spot is a common foliar disease of corn.

Figure 2. Gray leaf spot is a common foliar disease of corn. It was estimated to have reduced yields by more than 235 million bushels in 2016 — more than any other disease that season.

Estimated corn yield losses (millions of bushels) due to diseases in 24 U.S. corn-producing states and Ontario, Canada, in the 2016 growing season.

2016 Conditions and Predictions

The United States and Ontario produced nearly 15.5 billion bushels of corn in 2016, and many areas reported record yields. Overall, temperatures were very warm across most of the Corn Belt, which contributed to an increase in diseases like gray leaf spot and southern rust.

2016 Disease Losses

In all, 10.8 percent of the total estimated corn bushels were lost in 2016 due to disease in 24 corn-producing states and Ontario, which is down from a 13.5 percent loss in 2015, but similar to what was experienced in 2014. Table 1 provides yield loss estimates for all diseases.

Anthracnose stalk rot was the second greatest cause of estimated yield loss due to disease in 2016.

Figure 3. Anthracnose stalk rot was the second greatest cause of estimated yield loss due to disease in 2016.


 

Diseases in the Northern United States and Ontario

Estimated disease losses in the 12 northernmost states* and Ontario, Canada, in 2016. 

Gray leaf spot was the most damaging disease in the northern United States and Ontario in 2016 — nearly 214 million bushels lost. Anthracnose stalk rot was the second most damaging disease.

Warmer conditions through most of this area favored gray leaf spot development. Foliar diseases (such as southern rust and northern corn leaf blight) were also prevalent, but Goss’s wilt was less damaging than in previous years. A new bacterial disease (bacterial leaf streak) was identified in several states, but yield losses to this disease are unknown.

 

 

 

Diseases in Southern States

Estimated disease losses in the 12 southernmost states* in 2016.

Fusarium stalk rot caused the greatest damage in the southern United States in 2016, while nematodes were second, which is similar to 2015. Southern rust, gray leaf spot, and Goss’s wilt were the primary foliar diseases present (Table 3). 

 

Mycotoxin Losses

In 2016, ear rots also caused minor losses through mycotoxin-contaminated corn grain. Plant pathologists estimated that 0.9 percent of the harvested grain in the United States and Ontario was contaminated in 2016.

Summary

Environmental conditions varied across the United States and Ontario in 2016, which affected the presence of and damage from many diseases.

The foliar disease gray leaf spot was most prevalent across northern states and Ontario in 2016, likely due to the warmer weather. Stalk rots continue to be important diseases across the United States and Ontario.

 

Disclaimer

The disease loss estimates in this publication were provided by members of the Corn Disease Working Group (CDWG). This information is only a guide. The values in this publication are not intended to be exact estimates of corn yield losses due to diseases. The members of the CDWG used the most appropriate means available to estimate disease losses and assume no liability resulting from the use of these estimates.

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.

Previous annual editions of this document were published as Purdue Extension publication BP-96.

 

 Authors

Daren Mueller......Iowa State University
Kiersten Wise............Purdue University
Adam Sisson........Iowa State University

Contributors

The following individuals contributed to this publication: 

Arkansas............................Travis Faske
Colorado.......Bruce Bosley, Ron Meyer
Delaware.................Nathan Kleczewski
Illinois................................Angie Peltier
Indiana.............................Kiersten Wise
Iowa............................Alison Robertson
Kansas...............................Doug Jardine
Kentucky.............................Carl Bradley
Louisiana........................Clayton Hollier
Maryland.................Nathan Kleczewski
Michigan..........................Marty Chilvers
Minnesota.........................Dean Malvick
Mississippi..............................Tom Allen
Missouri...............................Bill Wiebold
Nebraska........................Tamra Jackson
New York......................Gary Bergstrom
North Carolina............... Steve Koennig
North Dakota...............Andrew Friskop
Ohio.......................................Pierce Paul
Ontario..............................Albert Tenuta
Pennsylvania:Greg Roth, Alyssa Collins
South Dakota.................. Connie Tande
Tennessee.........................Heather Kelly
Texas.....................................Tom Isakeit
Wisconsin.........................Damon Smith

 

 

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. 

Find more crop disease resources at CropProtectionNetwork.org.

Acknowledgements

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.

Design and production by Purdue Agricultural Communication.

Corn Disease Working Group

Members of the Corn Disease Working Group are university scientists from many institutions, including: University of Arkansas, Colorado State University, Cornell University, University of Guelph, 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, University of Nebraska, North Carolina Sate University, North Dakota State University, Penn State University, Purdue University, South Dakota State University, Texas A&M University, University of Wisconsin 

 

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