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United States Department of Agriculture

Agricultural Research Service

Title: Surface Charge Properties and Soil Mobilities of Mycoherbicidal Spores

Authors
item Daigle, Donald
item Johnson, Richard - TEXAS TECH UNIVERSITY
item Sands, D - MONTANA STATE UNIVERSITY
item Connick Jr, William

Submitted to: Soil Biology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 19, 2000
Publication Date: N/A

Interpretive Summary: In the laboratory, a white rot fungus breaks down numerous organic pollutants. A method to deliver this white rot fungus to toxic waste sites has been developed. This method allows the fungus to not only remain alive for several months; it also provides slow release of the fungus and a food supply for greater efficiency in breaking down toxic wastes. A system of standardized toxicity testing was also developed.

Technical Abstract: The surface charge properties and soil mobilities of several fungi used as mycohoherbicides were investigated. The surface charge of spores of Fusarium oxysporum, Colletotrichum truncatum, and Alternaria cassiae was characterized by electrostatic interaction chromatography (EIC) and their hydrophobic nature by hydrophobic interaction chromatography (HIC). F. oxysporum spores were expected to be the most mobile spores in soil because of their smaller size and lower hydrobicity. Addition of the non- ionic surfactant Tween 20, resulted in a significant increase in mobility of F. oxysporum spores (5-60%) in hydrophobic resins. Prior to soil column studies the extractability of the F. oxysporum spores from sand and soil was determined. Complete recovery of inoculated spores was obtained from control samples. Decreased numbers of spores were recovered from sand (38%) and from a Gilman sandy loam soil (3.5%). There was a slight influence of formulation on recovery, with a charcoal-based formulation yielding slightly greater recoveries than one with charcoal. The mobility of F. oxysporum spores was studied in sand columns and in Gilman sandy loam soil columns. Spores were relatively immobile in sand columns, with <1% leached. In soil, the mobility was further decreased. Spores from the formulations containing carbon were slightly more mobile than formulations without carbon. The majority (99%) of the applied spores were retained in the surface layers of both sand and soil columns.

Last Modified: 9/23/2014
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