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Corn Disease Loss Estimates – 2015

Corn Disease Management

Corn Disease Loss Estimates For the United States and Ontario, Canada — 2015

CPN 2007-15-W — published Sep. 2016

 

This figure is a bar graph titled: Figure 1: 2015 corn production (in millions of bushels) in 22 U.S. states and Ontario, Canada. The U.S. states/Ontario, CA are listed in order from greatest to least amount of corn production in 2015, beginning with Iowa at about 2,500 million bushels of corn and ending with Louisiana that produced about 100 million bushels of corn. Each state/ Ontario, CA has its own bar that indicates the amount of corn produced there. The order along the x-axis of the graph reads, in order, Iowa, Illinois, Nebraska, Minnesota, Indiana, South Dakota, Kansas, Ohio, Wisconsin, Missouri, Ontario, Michigan, North Dakota, Texas, Kentucky, Pennsylvania, Colorado, Tennessee, Mississippi, New York, North Carolina, Arkansas, and Louisiana. The top 4 producing states each grew over about 1,400 million bushels of corn. Indiana, South Dakota and Kansas (the 5th, 6th, and 7th biggest producers), each grew between 500 and 1,000 million bushels of corn, and the remaining states grew 500 or fewer million bushels of corn in 2015.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 13.6 billion bushels (97.2 percent) of the total corn produced in the United States and Ontario in 2015 (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 2015. 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 estimate 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.

 

2015 Conditions and Production

Table 1: Estimated corn yield loss (millions of bushels) from diseases in the top 22 U.S. corn-producing states and Ontario, Canada, in 2015. Disease(s) followed by the 2015 Yield Loss (millions of bushels) it/they caused. Group, “Root Rot and Seedling Blights”. Nematodes, 72.2; Root rots, 59.3; Seedling blights, 48.0; Group, “Leaf and Aboveground Diseases”. Northern corn leaf blight, 551.1; Goss’s wilt, 139.8; Gray leaf spot, 258.7; Common rust, 18.2; Physoderma leaf spot, 56.3; Southern rust, 138.8; Eyespot, 68.8; Anthracnose leaf blight, 11.2; Common smut, 7.4; Carbonum leaf spot (previously Northern corn leaf spot), 4.2; Virus (maize dwarf mosaic), 2.4; Other virus & virus-like diseases, 2.4; Other leaf & aboveground diseases, 1.4; Holcus spot, 0.7; Southern corn leaf blight, 6.2; Head smut, 0.2; Crazy top, 0.5; Stewarts’s disease,The United States and Ontario produced more than 13.9 billion bushels of corn in 2015, and many areas reported record yields. Overall, temperatures were very mild across most of the Corn Belt, which contributed to an increase in diseases like northern corn leaf blight. The late summer and fall were hot and dry across much of the United States and Ontario, which facilitated a timely harvest, but led to an increase in stalk rot diseases compared to 2014.

 

 

2015 Disease Losses

In all, 13.5 percent of the total estimated corn bushels were lost in 2015 due to disease in 22 corn-producing states and Ontario, which is up from a 10.8 percent loss in 2014. Table 1 provides yield loss estimates for all diseases. 

 

 

Diseases in the Northern United States and Ontario

Table 2: Disease losses from the 12 nothernmost states and Ontario, Canada, in 2015. 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 2015 Yield Loss (millions of bushels) it caused.  Northern corn leaf blight, 547.7; Anthracnose stalk rot and top dieback, 233.2; Gray leaf spot, 224.4; Goss’s wilt, 139.6; Southern rust, 129.2; Fusarium stalk rot, 116.8; Gibberella stalk rot, 89.3. Northern corn leaf blight was the most damaging disease in the northern United States and Ontario in 2015 — nearly 550 million bushels lost. This is more than twice the number of bushels than the second most damaging disease, anthracnose stalk rot. 

Mild conditions through most of this area favored northern corn leaf blight development. Foliar diseases (such as gray leaf spot) were also prevalent, but Goss’s wilt was less damaging than in previous years. Southern rust and stalk rots caused more yield loss in the Midwest than in past years.

 

Diseases in Southern States

Fusarium stalk rot caused the greatest damage in the southern United States in 2015. Nematodes were second. Gray leaf spot, southern rust, and northern corn leaf blight were the primary foliar diseases present (Table 3). Seedling blights and root rots were more damaging in this area in 2015 compared to previous years.

 

Mycotoxin Losses

Table 3: Disease losses from the 10 southernmost states in 2015. The 10 southernmost states referred to are Missouri, Arkansas, Colorado, Kansas, Kentucky, Louisiana, Mississippi, North Carolina, Tennessee, and Texas. Disease followed by the 2015 Yield Loss (millions of bushels) it caused. Fusarium stalk rot, 57.0; Nematodes, 36.0; Gray leaf spot, 34.3; Southern rust, 9.6; Seedling blights, 4.7; Root rots, 4.3; Northern corn leaf blight, 3.4. In 2015, 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 2015.

 

Summary

Environmental conditions varied across the United States and Ontario in 2015, 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 in 2015, likely due to mild weather. 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. 

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

 

 


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. 

Authors

Daren Mueller, Iowa State University; Adam Sisson, Iowa State University; 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 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  

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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