The 2012 growing season brought many challenges in relation to the drought, including high levels of aflatoxin, a byproduct of mold growth and a carcinogen that is harmful to humans and animals at high levels. With more grain elevators testing corn for aflatoxin, reports from farmers and dealers in dryland areas of the southern Midwest indicated the use of hybrids containing the Agrisure Viptera trait have played a role in successfully reducing aflatoxin levels in corn.
“Last year aflatoxin was noticeably higher in some areas and keeping it out is crucial,” said Spencer McIntosh, Syngenta agronomic service representative, Kansas. “We saw a definite correlation of lower aflatoxin levels in hybrids containing insect control traits like Agrisure Viptera because of its superb ear protection.”
Fungal spores, resulting in aflatoxin, can enter grain through injured, exposed areas that are often caused by insect feeding. The Agrisure Viptera trait provides breakthrough protection from ear-feeding insect pests, helping prevent the damage and stress to the corn ear that would otherwise provide a gateway for disease.
Tom Pauly, a farmer from Sumner, Kan., noticed insect feeding that led to fungal infections in his corn in 2011. In 2012, Pauly chose to plant hybrids containing the Agrisure Viptera trait and said he reaped the benefits at the elevator. “The corn I harvested without the Agrisure Viptera trait contained aflatoxin levels so high that it was rejected by the elevator,” said Pauly. “The aflatoxin levels in the corn containing the Agrisure Viptera trait were very low. Elevators are scrambling for low aflatoxin level corn because of this widespread problem.”
Toxin levels became such an issue that the U.S. Food and Drug Administration (FDA) approved requests to allow Iowa, Illinois and Nebraska, the top three U.S. corn states, to blend corn containing aflatoxin with other grain to make animal feed. The FDA has established aflatoxin action feed levels as low as 20 parts per billion (ppb) for immature or dairy animals. Human foods must contain less than 20 ppb, and milk must contain less than 0.5 ppb (aflatoxin M1, found in milk).
Aflatoxins also can develop in fields with minimal insect damage, as a result of fungal spores entering through cracked or damaged kernels from heat or other environmental factors. Managing aflatoxins that are not a result of insect damage may require additional strategies.
Afla-Guard, a naturally occurring biocontrol agent, may be applied within the growing season prior to aflatoxins being established to help further reduce a grower’s overall risk. Recent field trials showed significant reduction in aflatoxin levels from either Afla-Guard or the Agrisure Viptera trait, but the greatest reductions occurred when applying Afla-Guard to hybrids with the Agrisure Viptera trait.
Ryan Britton, a farmer from Villa Ridge, Ill., utilized Afla-Guard on one of his fields where he had planted a hybrid containing the Agrisure Viptera trait and reduced aflatoxins to an almost undetectable level.
“Aflatoxin levels were great. We came off the farm with clean corn while the neighboring farms within a quarter to a half mile of one another had aflatoxin problems,” said Britton. “The combination of the two products is very good and was very effective. All of the corn tested clean.”
Afla-Guard complements hybrids containing the Agrisure Viptera trait by providing a more comprehensive approach to aflatoxin management. Afla-Guard also provides another means for managing risk in areas planted as insect trait refuge or fields planted with an insect-traited hybrid that does not offer as high a level of insect control as the Agrisure Viptera trait.