Fumonisin Mycotoxin Larry Stalcup
If consumed, corn with even 5 ppm can cause severe brain damage and death to horses and other animals. Beef cattle can be in danger if there’s a 60 ppm rate.

Fumonisin mycotoxin hits High Plains corn

Fumonisin is often found in Panhandle area fields, but in amounts far below the minimum of 2 ppm. David Gibson, executive director, Texas Corn Producers Board, said TCPB began receiving calls from farmers whose early harvest loads were being flagged by grain elevators and other handlers.

With hundreds of High Plains combines ready to hit the corn field, many farmers are seeing parts of their crops contaminated with a dangerous mycotoxin that can zero-out a 250-bushel corn field if concentrations, measured in parts per million, are high enough.

Fumonisin is the deadly invader. It’s a mycotoxin produced by Fusarium mold. If consumed, corn with even 5 ppm can cause severe brain damage and death to horses and other animals. Beef cattle can be in danger if there’s a 60 ppm rate.

Fumonisin is often found in Panhandle area fields, but in amounts far below the minimum of 2 ppm. David Gibson, executive director, Texas Corn Producers Board, said TCPB began receiving calls from farmers whose early harvest loads were being flagged by grain elevators and other handlers.

The loads had fumonisin levels that required testing and potential quality adjustments. “Some farmers are seeing a $1 per bushel taken off their price,” noted Tim Ballinger, independent crop consultant in Dumas. “If the elevator price is $3.50, that drops to $2.50 per bushel. That’s quite a hit.”

The seriousness of the situation caused TCPB and Texas A&M AgriLife Extension to call two “emergency meetings” to better inform growers of the problem. Held Sept. 27, the Dimmitt and Dumas meetings attracted more than 700 people.

“These are similar to meetings we’ve seen in central Texas when aflatoxin becomes a problem,” Gibson said. “We try to inform growers of mycotoxin problems and how they should proceed if their corn is contaminated.”

Jourdan Bell, AgriLife Extension Agronomist, Amarillo, said that while fusarium ear molds are not uncommon, under certain environmental conditions, fumonisin is released. “The 2017 growing conditions have made this year’s corn crops more susceptible to higher than expected levels of fumonisin.”

Dr. Tom Isakeit, AgriLife Extension plant pathologist, College Station, said the situation “is a High Plains problem, not a central Texas problem.” He said the fumonisin was likely caused by hot, dry weather that hit the Panhandle-South Plains region this year in parts of June and July, followed by cool, wet weather in August.

“We are seeing more kernel integrity issues; especially silk-cut and damaged kernels,” Bell said. “In addition, hybrid characteristics such as open husks and upright ears make some hybrids more susceptible to fusarium ear rots and consequently fumonisin.

“In the High Plains, most farmers want an open, upright ear to speed up dry down, but in wet years, this can create issues because kernels are exposed.”

In examining several fields in the region, Extension personnel randomly found corn ears that displayed fusarium. Symptoms include moldy kernels clumped at the tip of the ear or randomly dispersed across the ear. Infected kernels may be pink or show a white starburst pattern radiating from the top of the kernel.

Proper sampling/testing vital 

If these symptoms are apparent, there’s no way to determine which mycotoxin or other disease is contaminating the corn other than thorough testing that’s specified by the Texas State Chemist and Texas Feed and Fertilizer Control Service, said Dr. Tim Herrman, Texas state chemist.

Initially, that requires growers to alert their federal crop insurance agent of a potential problem. “It’s up to the grower to examine specific fields and alert his approved Risk Management Agency insurance agent of a possible contamination,” Gibson says.

RMA regulations state:

• Make the insurance provider aware of suspected issue prior to harvest, storage or destruction of the cornfield.

• Adjuster must collect samples of the representative sample area prior to the grain entering storage or the destruction of the field. Only the adjuster is approved to obtain samples from the standing crop.

• An Approved Insurance Provider (AIP)-Approved Testing Facility (i.e. laboratory) must complete analysis of these samples.

Matt Mitchell, RMA loss adjustment specialist, Kansas City, said once the insurance adjuster takes samples, testing must be completed by elevators, grain exchanges, or approved independent laboratory facilities.

“We encourage you to contact your agent or insurance adjuster and file a notice of loss, which in this case is drought,” Mitchell said. “When the sample is taken, the sample must be delivered to the testing facility within four days.”

He added that if farmers use on farm storage for their corn, they must have it sampled before placing it in storage.

Herrman said his agency is working with certified elevators and other grain handlers to assure they have proper personnel conducting the grain tests. He explained how a “One Sample Strategy Plan” would provide a straight path to assuring that “each sample is representative of the entire truckload of corn.”

RMA and end users can use that information to determine whether the corn can be fed or blended to meet specific feed control guidelines, or must be destroyed. “There is a lot of tension concerning fumonisin, but I think we can work though this,” Herrman said.

Mitchell said when tested, “if fumonisin is less than 2 ppm, there is no discount” for that particular fault. “If the test shows 2.1 to 100 ppm, there can be an adjustment.”

PPM for humans, livestock  

The FDA states that fumonisin can test no more than 2 to 4 ppm for corn intended for human consumption. Rates are higher for livestock.

Maximum ppm rates include: 5 ppm for horses and other equine and rabbits; 20 ppm for swine and catfish; 30 ppm for breeding ruminants and breeding poultry; 60 ppm for ruminants raised for slaughter; 100 ppm for poultry raised for slaughter; and 10 ppm for pet animals.

Elevators and other grain handlers will determine if contaminated corn can be blended with clean corn to bring fumonisin readings down to satisfactory levels.

Feedyard operators showed concern for yards that contract directly with farmers for delivery of high moisture corn straight from the field. Testing and potential threat to cattle are issues to consider.

“If the elevator is accepting up to 60 ppm without any docks then there is no adjustment,” Bell said. “Because almost all of our corn is feed corn, some elevators are not docking below 60 ppm because levels are still within USDA limits for beef cattle.” 

If the corn tests high enough, the crop could be zeroed-out for insurance purposes. Actual insurance payment to the farmer would depend on the type of crop insurance policy or the type of farm program in which he is enrolled.

Prevention

Bell and Isakeit said farmers who see contaminated fields should note the type of hybrids that were infected and whether they saw a delay in planting.

Unfortunately, there are no fungicides known to control fumonisin, Isakeit said. He added that Bt corn may help lower the risk of contamination due to reduced insect damage to ears, “but you can’t count on transgenic plants for total control.”

He said fumonisin is more of a problem in the Midwest. There, where on farm storage is common, growers use drying equipment to stop growth of the fungus and reduce contamination.

For more on managing fumonisin or other mycotoxins, contact your local or regional Extension office or go to www.texascorn.org.

                                                 

 

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