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United States Department of Agriculture

Agricultural Research Service

Title: Field Tests of a Biocontrol Yeast in Pistachio Orchards

Authors
item Parfitt, Dan - UNIV. OF CA, DAVIS
item Sarreal, Siov
item Almehdi, Ahmed - UNIV. OF CA, DAVIS
item Chan, Helen - UNIV. OF CA, DAVIS
item Hua, Sui Sheng

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 25, 2004
Publication Date: N/A

Technical Abstract: Studies in 2003 were conducted using a replicated experiment with three yeast concentrations (105, 106, and 107 cells/ml) and a water control. Single spray treatments, applied later in the season, were found to be most effective. Highest yeast concentrations were observed just prior to harvest from both earlier and later spray treatments. In 2004, spray treatments of 107, 5 x 107, and 108 cells/ml, and a water control were applied to evaluate possible phytotoxic effects on pistachio. No differences in leaf or nut appearance were observed for any of the treatments when compared to the water control. No differences in nut percent splits or dry weight were observed between any of the treatments. Artificial wounding experiments were also conducted in 2003 and 2004 to simulate the occurrence of early split nuts, the primary repository for A. flavus contamination. Yeast growth was about 103 fold higher on wounded nuts when compared to unwounded controls. A 5x reduction in A. flavus colonization was observed on treated wounded nuts vs. untreated wounded nuts. A 5x reduction in A. flavus sporulation was also observed on treated wounded nuts vs. untreated wounded nuts.

Last Modified: 9/23/2014
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