Grain Bins


AFLATOXIN ALERT: SDCGA urges testing before combining corn

Posted on October 26, 2007

Aflatoxin is threatening southeast South Dakota corn fields at a time when producers are in their busiest season harvesting the state’s largest corn crop on record. The South Dakota Corn Growers Association (SDCGA) urges corn producers to take the time to test for aflatoxin, particularly before storing corn as crop insurance will not cover losses in the bin. Insurance ends at harvest.

Counties in South Dakota that aflatoxin has been found include Clay, Lincoln, Turner, Union and Yankton including the towns of Beresford, Canton and Viborg. Growing conditions were ideal for aflatoxin to develop during dry and hot conditions in July followed by the recent multi-day rain received throughout the state. The SDCGA has launched a widespread educational effort to alert corn producers to check for aflatoxin before clearing fields.

“Call your insurance agent today! Testing for aflatoxin before combining may slow producers down a bit but would save them thousands of dollars in losses due to discounted or rejected grain because of aflatoxin contamination,” said Reid Jensen, SDCGA president. “Conditions were prime for this fungus to establish during dry conditions this summer and with a wet fall, the environment was favorable for aflatoxins to grow. Producers must act now to prevent grain losses!”

The first step for producers prior to harvesting their corn is to contact their insurance adjuster. Aflatoxin losses are an insurable cause of loss as long as the grain is tested before being moved into commercial or on-farm storage. According to Robert Berg with the SDSU Southeast Experiment Station in Beresford, S.D., crop insurance groups claim that farmers will automatically lose their crop revenue protection coverage entirely if infected corn is stored in a bin; adjusters can still work with farmers, but only if the grain is still in the field or on the truck.

Aflatoxin cannot be detected by a visual evaluation. Moldy grain doesn’t always test positive for aflatoxin whereas grain that looks clean sometimes does test positive. Blacklight testing is an indicator used for detection, but is not a definitive test for aflatoxin. According to Extension reports, a USDA approved determinative test and/or lab is required to quantify if the load’s aflatoxin levels exceed FDA Advisory Levels.

FDA Advisory levels:

  • Zero to 20 parts per billion (ppb): No advisory levels. Grain accepted.
  • 21-300 ppb: Corn can be fed to finishing feeder pigs at 200 ppb or less; beef in feedlots can tolerate up to 300 ppb. There is zero tolerance for aflatoxin in dairy products.
  • Over 300 ppb: FDA prohibits use. Grain would be recommended destroyed.

Price discounts at grain handling facilities have exceeded $1 per bushel for aflatoxin-contaminated corn.

To test corn for aflatoxin, submit a 2-pound sample less than 18 percent moisture in a paper bag (no plastic bags) to the following address:

Sioux City Inspection and Weighing Service Company

840 Clark Street

Sioux City, Iowa 51101-2037

Producers should include a check for $33.90 per sample and results will be called to the producer within one to two days. Call (712) 255-8033 or email [email protected] for more information.

Aflatoxin can also develop or continue to develop on corn in storage. Factors affecting that growth include moisture content and temperature of stored grain, condition of grain going into storage and length of storage. One strategy for reducing risk of contaminating a bin of corn with aflatoxin is to dry corn out of the field down to 12 or 13 percent as quickly as possible. Aflatoxin grows rapidly at 14 percent moisture; moisture content below 13 percent prevents invasion by the fungus, according to university studies. The fungus also grows rapidly in grain storage temperatures 34 degrees F and above.

Crop insurance coverage ends at harvest, according to the USDA Risk Management Agency (RMA), and since there is the possibility of post-harvest contamination, producers must have insurance agents obtain samples prior to storage.

For more information, contact the SDCGA at 605-334-0100.

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