Transformation of soil microbial community structure in response to anaerobic soil disinfestation for soil-borne disease control in strawberry

Authors: Mazzola, Mark; MURAMOTO, JOJI - University Of California; SHENNAN, CAROL - University Of California

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2012
Publication Date: 7/1/2012
Citation: Mazzola, M., Muramoto, J., Shennan, C. 2012. Transformation of soil microbial community structure in response to anaerobic soil disinfestation for soil-borne disease control in strawberry. Phytopathology. 102:S4.77-78.

Interpretive Summary:

Technical Abstract: Anaerobic soil disinfestation (ASD) has been used to control soil-borne pathogens and nematodes in various plant production systems including strawberries. Disease control is commonly attributed to the depletion of oxygen and the generation of toxic compounds, including organic acids and volatiles. However, recent evidence suggests that disease control, in part, may be dependent upon specific changes in soil biology that are induced by ASD. Although reported to control disease by depressing targeted microbial populations, ASD and ASD in conjunction with Brassicaceae seed meal or fish emulsion applications increased total bacterial, total fungi, and fluorescent pseudomonad densities in two test strawberry field soils. In certain instances, densities of potential pathogens including Fusarium oxysporum and Pythium ultimum were also elevated in response to ASD. ASD dramatically altered composition of the fungal community resident to these field soils, with the yeast Galactomyces geotrichum becoming dominant at both study sites. The fact that ASD elevates microbial densities but disease control is attained suggests that mechanisms other than oxygen depletion or generation of organic acids, potentially including competitive interactions, may contribute to the observed plant response.