Texas farmers have tried two products, Afla-Guard, a recently-labeled Syngenta product, and AF-36, a product from an Arizona farmers cooperative labeled for cotton but not yet corn. Both have shown promise in reducing aflatoxin levels in corn.

“But they can fail,” Isakeit said. “They both need moisture to sporulate and may fail because of drought. The material also may wash out of the soil in heavy rain.”

He said the materials are applied to the soil surface. “We are working to see how early we can apply the material. If we put it out too early, it uses up all available nutrients and if we put it out too late, it’s not competitive.”

Both products are applied on grain, either wheat or barley.

Recent experiments bear out Isakeit’s point that conditions and timing are critical factors. A trial at Weslaco “significantly reduced the amount of aflatoxin,” he said. “Another test showed no significant difference. We applied that one too late.”

He said applying the material before tasselling is relatively easy and works well.

Growers and researchers have wondered if the material will persist in the soil from one season to the next. “We don’t know yet,” Isakeit said.

“This product is not the whole answer but combined with cultural practices and the right genetics it will help,” said David Ross, Syngenta. Company tests have been reassuring, he said.

“Trials show an average of 89 percent reduction in aflatoxin levels,” he said. “That’s across multiple states. In Texas, with 58 test sites, we saw an 80 percent average reduction.”

Ross said reducing aflatoxin contamination will improve marketability and provide better access to premium markets.

Isakeit said application rate is about 10 pounds per acre. “That’s about $10 per acre,” Ross said.