The Use of Fungi to Prevent Aflatoxin Contamination of Cottonseed in the Yuma Valley

Abstract

A strain of Aspergillus flavus that does not produce aflatoxins was applied to soils planted with cotton at the Yuma Valley Agricultural Center in order to assess strain ability to competitively exclude aflatoxin producing strains during cotton boll infection and thereby prevent aflatoxin contamination of cottonseed. In both 1989 and 1990, the atoxigenic strain displaced other infecting strains during cotton boll development. Displacement was associated with significant reductions (75% to 82% in 1989, and 99% in 1990) in the quantity of aflatoxins contaminating the crop at maturity. Although frequency of infected locules differed between years, in both years displacement occurred without increases in the amount of developing boll infection. Currently, an Experimental Use Permit is being sought from the EPA for tests on commercial acreage