Efficacy of water-dispersible formulations of biological control strains of Aspergillus flavus for aflatoxin management in corn

ABSTRACT

Field experiments were conducted in 2011 and 2012 to evaluate the efficacy of water-dispersible granule (WDG) formulations of biocontrol strains of Aspergillus flavus in controlling aflatoxin contamination of corn. In 2011, when aflatoxin was present at very high levels, there was no WDG treatment that could provide significant protection against aflatoxin contamination. The following year a new WDG formulation was tested that resulted in 100% reduction in aflatoxin in one field experiment and ≥ 49% reduction in all five WDG treatments with biocontrol strain 21882. Large sampling error, however, limited the resolution of various treatment effects. Corn samples were also subjected to microbial analysis to understand better the mechanisms of successful biocontrol. In the samples examined here, the size of the A. flavus population on the grain was associated with the amount of aflatoxin, but the toxigenic status of that population was a poor predictor of aflatoxin concentration.

KEYWORDS:

• Mycotoxin
• biological control
• spray application
• maize (Zea mays L.)
• formulation

Acknowledgements

The authors are grateful for assistance and support from Alemah Butler, Jaime Hardin, Jeremy Kotowicz, Randy Luttrell, Carol Morris, Rodrick Patterson and Robert Zablotowicz. Mention of trade or commercial names is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture (USDA).

ORCID

Mark A. Weaver http://orcid.org/0000-0001-9020-7264

Additional information

Funding

Portions of this work were supported by Syngenta [cooperative research agreement number 58-3K95-0-1434].