The Impact Of DON

Before 1993, wheat growers hadn’t paid much attention to such terms as vomitoxin. But that year marked the first time producers, grain elevators, and millers noticeably felt the blow of the devastating mycotoxin deoxynivalenol (DON), with widespread incidence in eastern North Dakota and western Minnesota. Since then, the industry has taken notice of these more commonly used names for deoxynivalenol that has hit nearly every U.S. wheat-growing region.

Marcia McMullen, Extension plant pathologist at North Dakota State Uni­ver­sity (NDSU), has been studying diseases in cereal species for more than 25 years. She and other land-grant university plant pathologists have experienced the across-the-board impact vomitoxin has on the wheat industry with three different DON epidemics — in soft red winter wheat in 2003-04, hard red spring wheat in 2005, and hard red winter wheat in 2006-07.

The U.S. wheat industry needs high quality for both domestic and export markets. When a DON epidemic hits, growers’ crops become unmarketable or deeply devalued. Elevators face more difficulty marketing their supply. The profit margins of elevators and millers diminish as they test more loads, apply various technologies to sort out infected kernels, and reach out of their traditional buying radiuses to accommodate their customers by remaining below maximum DON tolerances.

Deoxynivalenol is a toxic substance produced by the fungus that causes a disease in wheat and barley known as Fusarium head blight, or “scab.” Because DON could pose a health risk to humans if consumed in high amounts, the Food and Drug Adminstration (FDA) has set guidelines for maximum DON levels allowed in finished wheat products. Any flour, bran, germ, or other wheat product entering the food industry should not exceed a DON concentration of 1 part per million (ppm). FDA has also set various advisory levels for wheat used in livestock feed. Because various technologies and processes are available to reduce DON levels in the finished wheat product vs. the raw grain, millers can set their own inbound ppm requirements — as long as the product they sell satisfies FDA guidelines.

As vice president of grain supply for Siemer Milling in Teutopolis, IL, Carl Schwinke takes on wheat quality as a priority. He explains that the milling industry’s standard for acceptable DON levels in raw grain is 2 ppm. In general, a grain supply with 2 ppm DON can become a wheat product (such as flour) with 1 ppm DON through the mill’s cleaning and blending processes. Depending on the crop’s end-use, though, different grain elevators or millers may make standards more stringent. Grain for a whole wheat end-use has a 1 ppm industry-set standard at delivery, and grain for a bran end-use usually has the criterion of 0.5 ppm at delivery.

Schwinke says that his company may accept grain with DON measures greater than 2 ppm, but only if the company believes that it can achieve the 1 ppm advisory level with the total grain supply it purchases. The grain seller will receive discounts, though, based on the DON measurement and other quality factors like test weight and amount of kernel damage.

“We process all the wheat we purchase into flour for human consumption — cookies, pastries, pancakes, all kinds of batters,” says Schwinke. “Our interest is providing that food-grade product. Frankly, we eat, too. We want the safest food products reaching the end-user, so we want those DON levels to be as low as possible.”

The Cost Of DON

“DON affects everyone in the wheat value chain,” says Schwinke. “In effect, scab stops kernel development and growth. So if scab infects the plant in earlier stages of grain development, the kernel may be smaller, shrunken, or have lighter test weight than quality wheat. The disease stops any intake of nutrients, too.”

Schwinke says that this loss is felt across the wheat industry. Producers’ yields decrease, and they see more discounts for quality and grain damage. Marketing grain becomes a bit more of a struggle for grain elevators as they try to sell what the market can absorb. Elevators might need to bin grain separately according to different levels of DON stored in their facilities. Milling yields fall, as well as millers’ profit margins. And the end-user faces a higher cost for flour.

“From the miller’s perspective, we face the problem in epidemic years of paying for higher-priced grain that originates from our normal supply territory and additional cleaning of grain that we receive from our regular suppliers,” adds Schwinke. “We conduct more testing, which requires special equipment and personnel training. Maintaining state-of-the-art wheat cleaning equipment is a large expense. DON adds a tremendous amount to our operational costs.”

Screening, airflow, and gravity tables help separate the smaller, under-developed scabby kernels from the rest of the grain, but at an expense and slow pace. Adding the cleaning step to the milling process or at the elevator, though, won’t eliminate DON from the grain supply. Late scab infections might show no visible damage but could still cause elevated DON levels.

Schwinke stresses that millers are responsible for supplying bakers and the food industry with flour that meets FDA standards, and there are no effective methods of sorting out these late-infected kernels. Thus, millers need to source wheat from other regions when DON is not properly managed in their normal buying regions.

Buying out-of-area grain adds additional transportation and freight costs to the operation. Railcar availability may be limited, potentially causing grain supply insufficiencies. Matching flour consistency becomes more difficult because the imported wheat may not have the same milling characteristics as the regional wheat normally used. All these extra expenses add to the discounts growers receive when they sell scabby wheat.

The Fight Back

Many local grain elevators, regional mills, and Extension specialists have played an integral role in educating wheat growers on DON and the fungus associated with the mycotoxin since the first scab outbreaks. They have stressed that a combination of technology and smart growing practices can reduce the potential for high DON levels and help protect wheat quality. NDSU’s McMullen suggests:

â–  Plan good crop rotation systems that plant wheat after broadleaf crops such as soybeans, canola, and flax.
â–  Avoid following corn and minimize wheat-on-wheat rotations.
â–  Choose wheat varieties with improved scab resistance.
â–  Assess the region’s scab risk using tools such as or check to see if your own state has a risk outlook tool.
â–  Apply fungicides proactively to control and avoid diseases.

Randy Myers, Bayer Crop Science fungicide product manager, says a growing number of U.S. wheat and barley producers are relying on annual fungicide use as a proactive measure for overall crop protection.

“Annual, proactive approaches to disease management are the most effective because scab on cereals cannot be cured,” explains Myers. “If warm, humid climate conditions and moist soil are present as grain heading approaches — and the Fusarium pathogen is present — disease will develop. You don’t want to wait until you can see signs of the disease to spray, because then it’s too late to get the most out of your fungicide applications.”

Mark Huso is a retailer and crop advisor with Lake Region Grain in northeastern North Dakota. “When I discuss my crop protection strategy with my growers, I tell them that it’s just as efficient to use fungicides as it is to use herbicides,” says Huso. “I recommend fungicide use every year, and my customers see better yields and quality consistently.”

In 2008, Huso administered a strip field trial comparing the new Prosaro fungicide from Bayer CropScience with another fungicide. Although the season was virtually disease-free, the gains in yield, protein levels, and test weight gave the wheat treated with Prosaro an economic advantage over non-treatment and the other fungicide.

Across all kinds of conditions, Pro­saro has been proven to reduce mycotoxins by 50% to 60%. According to Bayer CropScience, no other fungicide reduces DON levels better on wheat and barley than Prosaro.

“In years of heavy scab pressure, this level of reduction could mean preserving the marketability of a crop,” says Myers. “In years of lighter pressure, it means producing an even better crop than expected and helping to secure premiums for high grades. With the industry’s best activity on scab while controlling a broad range of important foliar diseases, Prosaro is a hedge against quality discounts and yield losses and a weapon against scab and DON.”

The Bayer CropScience recommended application rates for Prosaro are 6.5 ounces per acre under normal conditions and 8.2 ounces per acre under high disease pressure. For optimal activity vs. scab in wheat, Prosaro should be applied at Feekes growth stage 10.51 (early flowering). The appropriate Feekes growth stage for scab suppression on barley is 10.5. In areas not threatened with scab infections, Prosaro may be applied at earlier growth stages for control of yield-limiting foliar diseases on wheat including leaf rust, stem rust, Septoria leaf blight and glume blotch, tan spot, and powdery mildew.

Leave a Reply

Fungicides Stories

Soybean Closeup
FungicidesFMC Begins Registration Process For New Fungicide Active Ingredient
October 19, 2016
FMC Agricultural Solutions has begun the joint U.S. EPA and Canadian Pest Management Regulatory Agency registration process for bixafen, a new Read More
Soybean Field
FungicidesSyngenta Launches Interactive Tools For Vibrance Seed Treatment Fungicide
August 30, 2016
As part of the ongoing commitment to provide growers and retailers with the most current crop protection products and agronomic Read More
Frog eye leaf spot on soybean
FungicidesNew FMC Website Provides Season-Long Updates On Fungicide Plots
July 7, 2016
Grow Forward with FMC Fungicides is a plot initiative in key corn and soybean producing regions showcasing fungicides from FMC. Read More
Wheat Field North Dakota
Crop InputsTrivapro Fungicide Yield Results Elevate 2016 Crop Outlook
May 10, 2016
As growers evaluate business models and consider their 2016 management plans, strong first-year trial results for Trivapro fungicide from Syngenta Read More
Trending Articles
Matt Hopkins15 Twitter Accounts Every Ag Professional Must Follow
October 13, 2016
What do singer Katy Perry and the President of the United States have in common? They are two of the Read More
AGCO RG700 cab
OpinionRoadblocks To Precision Ag Innovation
October 5, 2016
On August 29, I got to preside over the PrecisionAg Innovation Series event, “Game-Changing Advances in Precision Farming Technology,” developed Read More
J.C. Ramsdell containment system
EquipmentClear Opportunity In The Tank Market
October 4, 2016
Crop prices may be down, but steel prices are too — and that’s good news for retailers looking to add some Read More
WinField booth Farm Progress
Special ReportsTalking Weed Management Strategies At Farm Progress 2016
October 2, 2016
The annual Farm Progress Show — this year staged in Boone, IA — is always a great place to catch Read More
Corn Field
Eric SfiligojFacing Ag Industry Challenges
September 26, 2016
At the 2016 annual Mid America CropLife Association (MACA) meeting in September, a pair of crop protection company representatives discussed Read More
Bayer Monsanto
Crop InputsBayer-Monsanto Mega-Merger: 6 Things You Need To Know
September 14, 2016
Mega mergers have become almost routine in the agricultural industry. Right on the heels of Monday’s news that fertilizer giants Potash Read More
Latest News
Crop InputsOhio State Researchers Announce Progress on ‘Phos…
October 27, 2016
Researchers at The Ohio State University are investigating new techniques to detect organic phosphorus compounds in water samples from the Read More
Stewardship4R Nutrient Stewardship Certification Program To Launch…
October 26, 2016
The 4R Nutrient Stewardship Certification Program will expand the voluntary retailer program to the full state of Ohio, allowing nutrient Read More
AGCO RG700 at the 2015 National Farm Machinery Show
EquipmentAGCO Parts Rolls Out No-Interest, No-Payments Offer Via…
October 26, 2016
AGCO Corp. is now offering an innovative financing solution on qualifying Parts and Service transactions. Now through December 31, 2016, Read More
Soybean field
Crop InputsIncotec Invests In North America
October 25, 2016
Leading seed enhancement company Incotec, part of Croda, has announced an investment in their North America business. The total investment of Read More
Patriot 25th anniversary
SprayersCase IH Celebrates 25 Years Of Patriot Sprayers At Bens…
October 24, 2016
Case IH executives, employees and special guests celebrated 25 years of production of Case IH Patriot sprayers in a special Read More
4r Nutrient stewardship
StewardshipNominations For The 4R Advocate Program Due October 31
October 24, 2016
Nominations for the 4R Advocate program are due to The Fertilizer Institute by October 31, 2016. The program recognizes agricultural Read More
Corn close up
Eric SfiligojProtecting Agriculture’s Ability To Feed The World
October 24, 2016
The rate of change coming to agriculture is growing, and will continue to do so for the foreseeable future. This Read More
Student Young Worker CHS
CropLife 100CHS Supports #FirstJob Compact
October 24, 2016
CHS joins the White House and many of the country’s largest employers in signing a new initiative centered on helping Read More
Kennebec Grain terminal
CropLife 100Wheat Growers Kennebec Facility Loads First Rail Cars
October 21, 2016
In a season of firsts for Wheat Growers’ Kennebec Grain Terminal, the first 115-car unit train was loaded with soybeans Read More
ManagementThe Latest Dow-DuPont Rumor, Product of the Year Voting…
October 20, 2016
CropLife Editor Eric Sfiligoj shares a new rumor about the Dow-DuPont merger and updates on two CropLife-driven programs, the CropLife Read More
Soybean Closeup
FungicidesFMC Begins Registration Process For New Fungicide Activ…
October 19, 2016
FMC Agricultural Solutions has begun the joint U.S. EPA and Canadian Pest Management Regulatory Agency registration process for bixafen, a new Read More
Soil Young Corn
Industry NewsAgribusiness Search Firm Appoints New Managing Partner
October 18, 2016
Morris Bixby Group, a leading agribusiness search firm providing the highest quality professional recruiting and career advancement services since 2000, Read More
Wheat Field North Dakota
FertilizerUnited Suppliers Acquires Kansas Fertilizer Business
October 17, 2016
United Suppliers, Inc. has purchased the assets of Evans Enterprises, LLC, an ammonium chloride fertilizer business based in Olathe, KS. Read More
Corn Field
Industry NewsFMC Launches New Operations In Argentina, Exits Joint V…
October 17, 2016
FMC Corp. has exited its joint venture with Ruralco Soluciones S.A. FMC has launched new commercial operations, FMC Quimica S.A., Read More
Dow AgroSciences
InsecticidesRenewed Registration Issued For Products Containing Sul…
October 17, 2016
On October 14, 2016, the U.S. EPA re-established the registration of products containing sulfoxaflor (Isoclast Active), including Transform WG, Closer Read More
Eric SfiligojThe Whys Of Agriculture
October 17, 2016
During 2016, there have been myriad challenges facing the whole agricultural industry. Such wide ranging issues as water protection, sustainable Read More
Young Corn Field
FertilizerImproved Phosphorus Management Essential To Feeding Wor…
October 14, 2016
With a global population expected to reach 9 billion people by 2050, improved management of key essential nutrients such as Read More
ManagementHarvest and Crop Price Updates; EPA and Crop Protection…
October 13, 2016
Glyphosate and atrazine get public comment support from ARA as each is reviewed by EPA, and the latest on the Read More