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Poster: Biology & Disease Mgmt: Integrated Pest Mgmt


Comparison of carbon quantity in anaerobic soil disinfestation
J. HONG (1), F. Di Gioia (2), M. Ozores-Hampton (2), E. Rosskopf (1) (1) USDA ARS, U.S.A.; (2) University of Florida, Institute of Food and Agricultural Sciences, South West Florida Research and Education Center, U.S.A.

Anaerobic soil disinfestation (ASD) is a pre-plant alternative to chemical fumigation, used to manage soil plant pathogens, nematodes, and weeds. Compared to chemical fumigation, ASD was as effective for controlling these pests, and fruit yield often exceeded. Application of ASD in Florida includes incorporating composted broiler litter, 22 Mg ha-1, and molasses, 13.9 m3 ha-1, tarping the soil, and saturating to capacity. The environment under the tarp becomes anaerobic during the treatment, allowing anaerobic microbes, which contribute to pathogen management, to thrive. The objective of this study was to compare various rates of molasses, 0-4 times the standard rate (SR), in greenhouse conditions. Treatments were compared using the following variables: soil conditions, plant vigor, soil microbiome, and weed count. Soil microbiome was investigated by extracting microbial DNA from the soil, taken periodically during the treatment, and using length-heterogeneity PCR. Shifts in the microbiome correlated to changes in soil pH and reduction potential. The microbiome fluctuated slightly in the no molasses treatment, while the microbiome of the SR changed throughout the treatment, and the pH temporarily decreased. Bacterial diversity decreased 7 day post treatment (dpt) for the treatments with molasses rates greater than the SR. The soil pH for these treatments dropped from pretreatment levels and remained acidic; pH for 4 times the SR was 1 dpt = 6.9 and 21 dpt = 5.3.