Isakeit says biocontrols have reduced aflatoxin in his tests, but are not slam dunk certainties. “They can fail to sporulate because of drought. A heavy rain can cover them with soil. If the product is applied too early, the fungus produces spores before they are needed. If it’s applied too late, it doesn’t activate in time to compete with the toxic strains of Aspergillus.

“Atoxigenic strains work in small, experiment plots, but we still need to run replicated tests on a larger scale to quantify the economic impact of atoxigenic treatments under commercial conditions.”

Afla-Guard application rates run from 10 pounds to 20 pounds per acre and Isakeit says the 10-pound rate has worked well in his trials. Efficacy at a lower rate is uncertain.  A liquid formulation, which could help farmers with ease of application, has been tested but is still experimental. So far, applying the material on grain seed is the only option.

Early application also would help farmers get the material out efficiently, but Isakeit says some questions remain about proper timing. “At-planting is too early, but we know we can’t wait too late, and we know that uniform application is very important.”

Those are areas he and others are still evaluating. “Overall, we need more research into the different approaches for managing aflatoxin, but there are several things that can be done now.”

More information on this topic can be found at: http://aflatoxin.tamu.edu/aflatoxin.html