Submitted to: Aflatoxin Workshop
Publication Type: Abstract Only
Publication Acceptance Date: October 13, 2003
Publication Date: December 1, 2003
Citation: Hua, S.T. 2003. Biocontrol of aspergillus flavus by saprophytic yeast: progress from laboratory bioassay to field trial [abstract]. Aflatoxin Workshop. p. 75. Technical Abstract: The bioassay developed for screening effective yeast to inhibit both the growth of the Aspergillus flavus and aflatoxin production has been used to select a few species of yeast strains as biocontrol agents. One particular yeast , Pichia anomala WRL-076 was tested for its antagonistic activities to reduce spore production of both toxigenic and atoxigenic strains of A. flavus in pistachio orchard. A field research permit for field test of the yeast has been authorized by the Department of Pesticed Regulation, California Deparatment of Food and Agriculture. Pistachio nut-fruits on the tree were individually wounded with a dental needle and sprayed with aqueous suspension of yeasts at 3x107 cells/ml. Colonization of A. flavus in yeast-sprayed and wounded nut-fruits was 2-3 fold lower than the control. Furthermore the total spore numbers of A. flavus on yeast-sprayed nut-fruits had decreased by 90% in comparison to the control. The results indicated strongly that P. anomala could protect the wounds from the infection and growth of A. flavus.