Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/11/2008
Publication Date: 6/1/2008
Citation: Pratt, R.G. 2008. Occurrence, survival, and production levels of Trichoderma virens in soils of animal waste application sites in Mississippi [abstract]. Phytopathology. 98(Supplement:S-127
Technical Abstract: Population levels of T. virens, a plant disease biocontrol species, were assayed in soils from three farms in Mississippi where swine waste was applied to pastures, and from two farms where poultry litter was applied as a fertilizer to cotton. Assays of soil from each site with and without applied waste or litter were performed by dilution plating on Sabouraud's medium plus chloramphenicol. Soils were assayed shortly after collection and after storage for up to 5 years in sealed bags. T. virens was detected from fresh or stored soil from all sites at mean population levels of 0.07-1 x 104 cfu/g soil in positive samples. These represented 8-100% of total Trichoderma populations. Population levels of T. virens differed between sites and waste application treatments in some soil samples. T. virens was detected frequently in soils stored for up to 2 years, and it survived for 5 years in soil from one site. Results indicate that T. virens is widely distributed in Mississippi soils, and that population levels may differ between sites and in response to animal waste application treatments.