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Corn Disease Loss Estimates – 2013

Corn Disease Management

Corn Disease Loss Estimates For the United States and Ontario, Canada — 2013

CPN 2007-13-W — published Nov. 2016

 

Figure 1. 2013 corn production (in millions of bushels) in 21 U.S. states and Ontario, Canada. Figure 1 shows the highest producer as Iowa, in decending order, Illinois, Nebraska, Minnesota, Indiana, South Dakota, Ohio, Kansas, Wisconsin, North Dakota, Ontario, Michigan, Texas, Kentucky, Arkansas, Pennsylvania, Mississippi, Colorado, Tennessee, North Carolina, Louisiana, New York.Each year, corn diseases reduce yields in the United States and Canada. The most important diseases vary from year to year depending on many factors, including weather conditions, crop production practices, hybrid selection, and susceptibility to disease. 

Plant pathologists in each of 21 corn producing U.S. states and Ontario, Canada, estimated the percent yield loss from corn disease in their states (Figures 1 and 3). These reports account for 13.3 billion bushels (93.3 percent) of the total corn produced in the United States and Ontario in 2013. Root rots, seedling blights, aboveground (foliar) diseases, stalk rots, and ear rots are included in the yield loss estimates. 

Although plant pathologists around the North Central region have noted the prominent diseases in their states or provinces for years, there has been no coordinated effort to document disease-related losses in corn yields across the region — until the 2012 growing season. This publication documents the impact of major diseases on corn production during the 2013 growing season — future publications will document the years to come.

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. Northern corn leaf blight is a consistent source of yield loss in cornproducing areas.

Figure 2. Northern corn leaf blight is a consistent source of yield loss in corn-producing areas.

Figure 3. Map of 2013 corn acres and production (in millions of bushels) in the United States. Source: USDA-National Agricultural Statistics Service.

Figure 3. Map of 2013 corn acres and production (in millions of bushels) in the United States. Source: USDA-National Agricultural Statistics Service.

Figure 4. This map shows the intensity of drought conditions in the United States in mid-August, 2013. Source: U.S. Drought Monitor, droughtmonitor. unl.edu.

Figure 4. This map shows the intensity of drought conditions in the United States in mid-August, 2013. Source: U.S. Drought Monitor, drought monitor. unl.edu.

Table 1. Estimated corn yield loss from diseases in the top 21 U.S. corn-producing states and Ontario, Canada, in 2013.2013 Conditions and Production

During the 2013 growing season many corn-producing states experienced dry conditions that followed a wet spring (Figure 4). These conditions can contribute to root rot losses because plants can be infected early in the season, and then limited water and underdeveloped or injured root systems can stress them later in the season. However, the United States and Ontario still produced more than 14.2 billion bushels of corn — a 3 billion bushel increase from 2012.

2014 Disease Losses

In all, 7.5 percent of the total estimated corn bushels were lost in 2013 to disease in 21 corn-producing states and Ontario. In 2012, losses were nearly 11 percent. This means that almost 1.1 billion bushels were lost to disease in 2013. Seedling blights caused the greatest disease-related losses, with more than 149 million bushels lost. Northern corn leaf blight, Goss’s wilt, Fusarium stalk rot, and gray leaf spot followed in total losses. Table 1 provides yield loss estimates for all diseases. 

 

 

Table 2: Disease losses from the top seven corn diseases in Illinois, Iowa, Minnesota, and Nebraska in 2013. Disease followed by the 2013 Yield Loss (millions of bushels). Seedling blights, 126.5; Goss’s wilt, 75.7; Northern corn leaf blight, 72.6; Root rots, 60.3; Southern rust, 54.1; Fusarium stalk rot, 47.3; Fusarium ear rot, 41.0.
Diseases in the most Productive States

Illinois, Iowa, Minnesota, and Nebraska combined to produce 50.3 percent of the total corn production in the United States and Ontario in 2013. Disease losses reported in these states greatly influenced the overall importance of these diseases. Diseases in these four states caused an estimated 691 million bushels yield loss in 2013, which is approximately 8.8 percent of the total corn production from these states (Table 2). 

Table 3. Disease losses in the 12 northernmost U.S. states and Ontario, Canada, in 2013.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). 

Figure 5. Seedling blights were estimated to have reduced yields by nearly 150 million bushels in 2013 — more than any other disease that season.

Figure 5. Seedling blights were estimated to have reduced yields by nearly 150 million bushels in 2013 — more than any other disease that season.

Table 4. Disease losses from the 9 southernmost states in 2013.Diseases in Southern States

In the South, the greatest yield losses were from nematodes that feed on corn, Fusarium stalk rot, and charcoal rot (Table 4). 

Mycotoxin Losses

In 2013, ear rots also caused losses through mycotoxin-contaminated corn grain. Plant pathologists estimate that 12.5 percent of U.S. harvested grain was contaminated in 2013. Most of the contamination was from aflatoxin, which is produced by the fungus that causes Aspergillus ear rot. 

Summary

Seedling blights and foliar diseases caused a great deal of crop loss in 2013. Seedling blights were favored by the wet spring in many states. Foliar diseases (such as northern corn leaf blight and Goss’s wilt) were more problematic because of the susceptibility of certain hybrids. Therefore, the environment was a primary factor in disease prevalence and impact on corn production in 2013.

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 reports 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 
Nebraska..............................Tamra Jackson 
New York............................Gary Bergstrom 
North Carolina.......................Steve Koennig
North Dakota.................Marcia McMullen,
Kasia Kinzer, Michelle Mostrom 
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

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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