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Corn Disease Loss Estimates – 2014

Corn Disease Management

Corn Disease Loss Estimates For the United States and Ontario, Canada — 2014

CPN 2007-14-W — published Nov. 2016

 

Figure 1. 2014 corn production (in millions of bushels) in 22 U.S. states and Ontario, Canada. Figure 1 shows the highest producer as Iowa, in decending order, Illinois, Nebraska, Minnesota, Indiana, South Dakota, Missouri, Ohio, Kansas, Wisconsin, Michigan, North Dakota, Ontario, Texas, Kentucky, Pennsylvania, Colorado, Tennessee, North Carolina, New York, Arkansas, Mississippi, Louisiana.

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 in each of 22 corn-producing U.S. states and Ontario, Canada, estimated the percent yield loss from corn disease in their states. These reports account for 14.1 billion bushels (96.9 percent) of the total corn produced in the United States and Ontario in 2014 (Figure 1). Root rots, seedling blights, foliar diseases, crazy top, ear and head smuts, stalk rots, and ear rots are included in the yield loss estimates. 

This publication documents the impact of major diseases on corn production during 2014. The Corn Disease Working Group 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. These percent loss estimates are converted to total bushels lost per disease (percent loss multiplied by total bushels of corn produced) for each state or province.

Figure 2. Goss's wilt is a common foliar disease of corn. It is caused by a bacterial pathogen that survives the winter in infected corn residue.

Figure 2. Goss's wilt is a common foliar disease of corn. It is caused by a bacterial pathogen that survives the winter in infected corn residue.

Figure 3. Northern corn leaf blight was estimated to have reduced yields by more than 350 million bushels in 2014 — more than any other disease that season.

Figure 3. Northern corn leaf blight was estimated to have reduced yields by more than 350 million bushels in 2014 — more than any other disease that season.

Table 1: Estimated corn yield loss (millions of bushels) from diseases in the top 22 U.S. corn-producing states and Ontario, Canada, in 2014. Disease(s) followed by the 2014 Yield Loss (millions of bushels). Group, “Root Rot and Seedling Blights”. Seedling blights, 103.8; Nematodes, 69.9; Root rots, 48.6; Group, “Leaf and Aboveground Diseases”. Northern corn leaf blight, 350.4; Goss’s wilt, 215.9; Gray leaf spot, 143.3; Common rust, 109.9; Physoderma leaf spot, 32.7; Southern rust, 23.7; Eyespot, 14.0; Anthracnose leaf blight, 13.6; Common smut, 12.1; Northern corn leaf spot, 8.1; Virus (maize dwarf mosaic), 3.2; Other virus & virus-like diseases, 2.7; Other leaf & aboveground diseases, 1.3; Holcus spot, 0.9; Southern corn leaf blight, 0.7; Head smut, 0.6; Crazy top, 0.4; Stewarts’s disease,The United States and Ontario produced more than 14.5 billion bushels of corn in 2014, and many areas reported record yields. Some corn-producing areas in the Midwest experienced wet springs, which led to seedling blight diseases. Summer rainfall was frequent in some areas and temperatures were moderate, which contributed to more foliar diseases in these areas. Rainfall late in the season delayed harvest across parts of the United States and Ontario.  

2014 Disease Losses

Figure 3. Northern corn leaf blight was estimated to have reduced yields by more than 350 million bushels in 2014 — more than any other disease that season.

In all, 10.8 percent of the total estimated corn bushels were lost in 2014 due to disease in 22 corn-producing states and Ontario, which is up from a 7.5 percent loss in 2013. Table 1 provides yield loss estimates for all diseases. 

 

Table 2: Disease losses from the 10 southernmost states in 2014. The 10 southernmost states referred to are Missouri, Arkansas, Colorado, Kansas, Kentucky, Louisiana, Mississippi, North Carolina, Tennessee, and Texas. Disease followed by the 2014 Yield Loss (millions of bushels. Fusarium stalk rot, 33.6; Nematodes, 20.3; Anthracnose stalk rot and top dieback, 13.0; Southern rust, 9.3, Charcoal rot, 8.2, Gray leaf spot, 7.3; Goss’s wilt, 6.9.

Diseases in the Northern United States and Ontario

Northern corn leaf blight and Goss’s wilt were the most damaging diseases in the northern United States and Ontario in 2014, resulting in 557 million bushels lost. Mild conditions through most of this area influenced the development of these foliar diseases. Foliar diseases such as gray leaf spot and common rust were also prevalent. 

More than half of the corn production in the United States occurs in Illinois, Iowa, Minnesota, and Nebraska. In 2014, these states combined for 51.7 percent of the total corn production in the United States and Ontario, and the disease losses reported in these states greatly influenced the overall importance of certain diseases. Diseases in these four states caused an estimated 1.1 billion bushel yield loss in 2014, which is approximately 13.3 percent of the total corn production from these states. 

Diseases in Southern States

Fusarium stalk rot caused the greatest damage in the southern United States in 2014, followed by nematodes. Southern rust, gray leaf spot, and Goss’s wilt were the primary foliar diseases present (Table 2). 

 

Table 3: Disease losses from the 12 northernmost states and Ontario, Canada, in 2014. The 12 northernmost states referred to are Illinois, Indiana, Iowa, Minnesota, Nebraska, Ohio, Michigan, New York, North Dakota, Pennsylvania, South Dakota, and Wisconsin. Disease followed by the 2014 Yield Loss (millions of bushels). Northern corn leaf blight, 348.0; Goss’s wilt, 209.0; Gray leaf spot, 136.0; Common rust, 109.8; Fusarium stalk rot, 101.9; Seedling blights, 97.0; Gibberella stalk rot, 86.1.


Diseases in Northern States

In the north, the greatest yield losses were from seedling blights, Goss’s wilt, and northern corn leaf blight (Table 3). 

Mycotoxin Losses

In 2014, ear rots also caused losses through mycotoxin-contaminated corn grain. Plant pathologists estimated that 1.1 percent of the harvested grain in the United States and Ontario was contaminated in 2014.

Summary

Environmental conditions varied across the United States and Ontario in 2014, which affected the presence of and damage from many diseases. 

The foliar disease northern corn leaf blight was most prevalent across northern states and Ontario, Canada, in 2014, likely due to mild weather. Goss’s wilt reduced yield not only in the northern United States and Ontario, Canada, but also in the southern states. Stalk rots and seedling blights 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.  

 Authors

Compiled by Daren Mueller, Iowa State University. Published by Kiersten Wise, Purdue University. 

Contributors

The following individuals contributed to this publication: 

Arkansas...................................Travis Faske 
Colorado.............Bruce Bosley, Ron Meyer 
Illinois.......................................Carl Bradley 
Indiana...................................Kiersten Wise 
Iowa..................................Alison Robertson 
Kansas.....................................Doug Jardine 
Kentucky...................................Paul Vincelli 
Louisiana..............................Clayton Hollier 
Minnesota...............................Dean Malvick 
Michigan...............................Marty Chilvers 
Mississippi....................................Tom Allen 
Missouri...University of Missouri Extension 
Nebraska...............................Tamra Jackson 
New York............................Gary Bergstrom 
North Carolina....................Steve Koenning 
North Dakota.....................Andrew Friskop 
Ohio............................................Pierce Paul 
Ontario....................................Albert Tenuta 
Pennsylvania.......Greg Roth, Alyssa Collins 
South Dakota.......Emmanuel Byamukama 
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

We thank USDA-NIFA and the Grain Farmers of Ontario for their support. 

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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