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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2009-41

Dates Covered: 
December 22, 2009 - January 11, 2010
Greg LaBarge

Questions and Answers on Moldy Grain and Mycotoxins Part 1-2009 Crop

The 2009 corn crop is providing some challenge to grain users due to various levels of mycotoxins that are being found in individual lots of grain. According to some livestock operations and ethanol plants, levels of (vomitoxin) and zearalenone in 2009 crop are unprecedented. Grain deliveries have been rejected because of excessively high mycotoxin levels. Some ethanol plants are starting to discount grain at 3 ppm (vomitoxin), with rejection above 7 ppm. Although we’ve experienced localized problems with ear rots in Ohio in past years, the incidence and severity of ear rots and associated mycotoxins this year is more severe and widespread.

Q1. How bad was the mold and mycotoxin problem in 2009?

Abnormally cool and wet weather during and after silking provided optimal conditions for the development of Gibberalla ear rot that resulted in high levels of mycotoxins contamination of harvested grain.

The fungus Gibberella zeae causes ear rot of corn and head scab of wheat. The fungus produces mycotoxins, most notably vomitoxin (deoxynivalenol, DON) as it colonizes. In general, high levels of disease severity and moldy grain indicate high levels of toxin in susceptible varieties/hybrids. Once the crop has dried down (<20% moisture), fungal growth and vomitoxin production are reduced substantially. In harvested grain, vomitoxin is heat stable and water soluble and will survive many processing, baking and distilling procedures.

Q2. What is the impact of these ear rot mycotoxins?

The Gibberella ear rot fungus produces mycotoxins that are harmful to both humans and animals. These include deoxynivalenol (Vomitoxin) and zearalenone and T-2 toxin, all of which may cause health problems. Therefore, suspect grain should be tested for these mycotoxins by chemical analysis before being fed to animals. As a general rule do not feed any grain with 5% or more Gibberella moldy kernels. Hogs and young animals are particularly sensitive to these mycotoxins.

Sampling and testing of grain are necessary to determine that vomitoxin (deoxynivalenol or DON) is below advisory levels in products. The FDA has set the advisory levels to insure the safety of the food and feed supply. For bran, flour, and germ intended for human consumption at 1 ppm. For grain and grain by-products destined for ruminating beef and feedlot cattle older than four months and for chickens with the added recommendation that these ingredients not exceed 50% of the diet of cattle or chicken at 10 ppm. For grains and grain by-products destined for swine, and all others animals with the added recommendation that these ingredients not exceed 20% of the diet for swine and 40% of the diet for other animals set at 5 ppm.

Mycotoxins in corn are concentrated about three fold in dry distillers grains, i.e. during ethanol production, removing the starch from corn (the content of which can average about 60 percent) concentrates levels of these mycotoxins.

If growers were not aware of the moldy corn/mycotoxin problem at harvest more than likely the corn could have gone into the bin in poor conditions. If proper storage conditions were not maintained, the corn will come out of the bin in very bad, perhaps unmarketable, condition surprising the grower and affecting his bottom line significantly.

Q3) Procedures to sample grain lots for Vomitoxin.

Before pulling samples for toxin analysis, grain handlers should first protect themselves from dust and toxin exposure by wearing a mask, goggles and gloves. Careful attention to sampling, extraction and testing protocol should be followed to accurately measure vomitoxin accumulation in grain. Guidelines have been written based on research done with wheat and barley and are available at the United States Department of Agriculture Grain Inspection, Packers and Stockyards website at

To collect a representative sample from the bin or truckload of grain, 5-10 subsamples should be randomly collected from multiple locations. Samples taken only from the central or outer portions of the load or from the beginning and end of the grain stream will not provide an accurate estimate of toxin contamination. For end-gate sampling, sample from the entire width and depth of the stream. For probe sampling, use hand or mechanical probes to sample from the entire bin, in an “X”-shaped pattern, for example. The use of suction or air probes is not recommended when sampling grain for mycotoxins. Once subsamples are obtained, bulked, and cleaned, the grain must be ground uniformly, in a clean grinding apparatus, to resemble flour. Finer particle size increases surface area of the grain and allows for more efficient extraction of vomitoxin.

Q4) How and where to test for mycotoxins?

The most common test for vomitoxin is an ELISA test, which is based on the ability of toxin in the grain to bind to specific antibodies coating the specially-designed sample cups provided with the ELISA kit. These kits are very specific for the toxin being tested (vomitoxin in this case) and will not provide estimates of other toxins in the sample. There are separate kits for each toxin. ELISA-based tests are generally qualitative, providing a yes/no answer for the presence of DON, or semi-quantitative, giving an estimate of DON above certain levels or within a given range. However, quantitative estimates can also be obtained using some ELISA-based test. A color-change will be indicative of vomitoxin presence in the sample. To quantify toxin concentration an additional step of assessing color quality through a well reader or spectrophotometer is required. There is a relationship between the intensity of color in the sample cup and vomitoxin, as determined by a standard curve included in the kit. ELISA’s are easy, quick and affordable, but must be performed carefully to ensure quantifiable and accurate results. Due to the test’s specificity, you must use an ELISA kit specifically designed to detect vomitoxin. In addition, the ELISA kit must be approved for the substrate to be tested (corn, DDGs, wheat, etc).

Individuals who to know what the status of grain lots they have in storage maybe can work with grain handlers with the test or if they want to do there own analysis they can obtain ELISA kits . GIPSA has approved several different types of test kits that use either fluorescence or enzyme linked immunosorbent assay (ELISA) technology. The commercial testmethods approved by GIPSA for official testing of barley, malted barley, corn, oats, and wheat for DON are:

Biopharm - RidaScreen Fast SC for registered users only
Charm Science - Rosa Don P/N,en/
Diachemix -DON FPA
Diagnostix - EZ- Quant, EZ- Tox
Neogen- 5/5, Agriscreen, Veratox
Romer - Accutox, Fluoroquant
Strategic Diagnostic Inc - Myco,
Vicam - Don FQ

A listing of Laboratories who will test for deoxynivalenol or DON, T-2 which are all terms for the group of toxin of concern can be found at:

Protein and Oil Results added to Soybean Trials

The result of soybean and protein content testing has been added to the Ohio Soybeans Performance Trials which can be found at

Deadline Approaching for Grain Quality Crop Insurance Claims

Corn growers who utilize crop insurance coverage and have a significant portion of their 2009 crop in private storage have a very powerful risk management tool at their disposal if they act quickly. December 25, 2009 is the deadline to initiate a grain quality crop insurance claim for the 2009 corn crop according to Bill Lund, Crop Insurance Agent and partner in Lund and Smith Insurance Services of Huron County, Ohio. Once the deadline passes, producers assume the risk of inferior grain quality even if they purchased crop insurance.

In most marketing years producers have some peace of mind that the grain stored in their bins will maintain reasonable quality under good management. This is not a forgone conclusion this year, because in many cases producers didn’t know the quality of the grain that they placed into storage. Lund suggests that by initiating a grain quality claim prior to December 25, 2009 an insured producer can take up to 60 days to complete the claim. The next 60 days may prove very important in telling how the entire vomitoxin issue plays out during this marketing year.

Here is a scenario that is not so far fetched. A corn producer in Ohio had a record corn crop in 2009. He sold 40% of his crop right out of the field to a terminal that was not testing for vomitoxin when he delivered his corn before Thanksgiving. After New Years Day, that same producer loads his truck to begin filling January contracts. Upon arrival at the terminal, the producer realizes that the buyer is now testing for vomitoxin. His load proves to be above the terminal’s acceptable levels and hence is rejected. Short of finding another buyer, this producer is without good options because he no longer has any grain quality coverage through crop insurance since he had not opened a claim prior to the deadline.

This situation can be avoided. If there is any doubt about the quality of the grain stored on your farm, contact your crop insurance agent immediately and initiate a grain quality claim. Should your grain prove to be of good quality you can release the claim without a detrimental effect to your crop history. This strategy keeps your options as a seller open as long as possible.

Forage Performance Trials Report

The 2009 Forage Performance Trials Report is now available online at

The report is a summary of performance data collected from forage variety trials in Ohio during 2009, including commercial varieties of alfalfa, orchardgrass, tall fescue, annual ryegrass and teff, in tests planted in 2006 to 2009 across three sites in Ohio: South Charleston, Wooster, and North Baltimore.

A pdf file easy for printing is available, as are downloadable excel files of all the trials.

Links to other states forage performance trials are included as usual on the website, including the link to the University of Wisconsin interactive website to compare alfalfa varieties across many locations (including Ohio data).

Please distribute this information.

If you have any questions, feel free to contact Dr Mark Sulc or John McCormick


January Regional Agronomic Topic Meetings

Other agronomy program are planned for around the state with the following events scheduled in January. If you would like to find out more about these events got to

January 11
West Ohio Agronomy Day
Start Time: 9am
Sidney American Legion Hall
1265 Fourth Avenue
Sidney, 45365

Janaury 11
West Ohio Agronomy Day-Evening Program
Start Time: 6 pm
Sidney American Legion Hall
1265 Fourth Avenue
Sidney, 45365

January 12
Agronomy Day
Start Time: 9:00 AM
Fairfield County Ag Center
831 College Avenue
Lancaster, OH 43130

January 19
Conservation Tillage Breakfast Program Series
Start Time: 7:30 a.m.
Plaza Inn in Mt. Victory
491 S. Main Street
Mt. Victory, Ohio 43340

January 21
Corn/Soybean Day
Start Time: 8:30 am
Founder’s Hall at Sauder Farm and Craft Village
22611 St Rt 2

Janaury 21
2010 Putnam County Agronomy Night
Start Time: 6:30 PM
Kalida Knights of Columbus Hall
718 Napoleon RD
Kalida, OH 45853

January 28
Clark Agronomy Day
Start Time: 8:00
Clark State Community College - LRC Building
570 East Leffel Lane
Springfield, OH 45505

Certified Crop Advisor, Pre-Exam Training Seminar

A Certified Crop Adviser (CCA) Exam Training Session, sponsored by OSU Extension Champaign, Logan and Shelby Counties and the OSU Extension Agronomic Crops Team will be offered at the Shelby County Extension Office, 810 Fair Rd, Sidney, Ohio 45365 on Jan. 19 - 20, 2010 beginning at 9:00 a.m.
on the 19th and adjourn by 3:30 p.m. on the 20th.

This training session is designed to help participants understand the principles necessary to become a certified crop advisor and to assist in preparation for the state and international CCA exams. It is not a crash course designed to cover all specific information necessary to pass the CCA exam. However, it will cover some of the performance objectives and will assist students by giving better direction for independent study.

Registration is on a first-come, first-serve basis. The fee is $195.00 per person, which covers the cost of instruction, lunches, handouts and other costs associated with the course over the two days. Pre-registration by Jan. 13th is requested for meal planning and handouts must be ordered and/or printed in sufficient quantities. Registrations after the Jan. 13th deadline will be subject to materials on hand and we cannot guarantee handout availability.

To register:
* make checks payable to OSU Extension.
* Include your name
* company affiliation
* address
* daytime phone number
* email address

Send registration information and check to Wesley Haun, payable to: OSU Extension ­ Logan County, 120 E. Sandusky Ave. Suite #1, Bellefontaine OH 43311. For more information please contact Wes Haun at 937-599-4227 or Harold Watters at 937-484-1526


Archive Issue Contributors: 

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.