Symbiosis Control

Aspergillus flavus is a common soil microbe. Certain strains of A. flavus produce aflatoxin, a known carcinogen. Aflatoxin contamination is a problem in corn, peanut, and cotton seed production when cotton seed is used as a feed for cattle. Symbiotic control of aflatoxin was created by the simple process of searching for a strain of A. flavus that does not produce aflatoxin and working out a mechanism for treating agricultural fields. AF36 is a new label for the resulting product. This material is developed from the 36th strain of A. flavus that was found by Peter Cotty of the USDA-ARS in Tucson, AZ. AF36 is made at the research facilities of the Arizona Cotton Growers and is applied to fields at $5.00 an acre and has lasting benefits. The principle of this example of symbiotic control is competitive displacement.

NON-TOXIN STRAINS OF ASPERGILLUS TO FIGHT OFF TOXIC RELATIVES A set of non-toxin producing (atoxigenic) strains of Aspergillus flavus was recently assembled by scientists at the International Institute ofTropical Agriculture (IITA) to radically reduce aflatoxin in maize using the biological control approach. The team, led by Dr Ranajit Bandyopadhyay, used the highly competitive atoxigenic strains of Aspergillus to eliminate their highly toxic relatives. „The atoxigeni strains were able to reduce aflatoxin contamination by up to 99.8% in field trials“, says Ranajit. In addition, the most effective atoxigenic strain could out-compete toxigenic strains in grains by 99% after field release. The next step now is to test the efficacy of biocontrol after releasing multiple strains in large-scale field trials in several sites in Nigeria. 

To read more, visit http://www.iita.org/cms/details/news_feature_details.aspx?articleid=1105&zon

Contact

Cotty, Peter J.

(520) 626-5049

pjcotty@srrc.ars.usda.gov

Research Plant Pathologist

USDA-ARS

New Orleans, but seconded to Tucson, AZ 

Little is available in publication at this time. The USDA description of the project can be found at:

http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=404685