Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 6/26/2006
Publication Date: 6/26/2006
Citation: Mazzola, M., Hoagland, L., Carpenter-Boggs, L., Abi-Ghanem, R., Cohen, M. F. 2006. Contribution of resident soil microorganisms to brassicaceae seed meal-induced disease and weed suppression. Proceedings, 2nd International Biofumigation Conference, Moscow, ID. June 26-28. P.57.
Technical Abstract: Brassicaceae seed meal (BSM) amendments effectively control Rhizoctonia root rot of apple and suppress weed growth in orchard soils. Pasteurization of BSM-amended soils prior to pathogen introduction eliminated disease control, suggesting the functional role of a resident biological factor. When BSM amendment, infestation with R. solani and planting were conducted simultaneously, application of the nitrification inhibitor nitrapyrin suppressed NO emission and disease control. However, nitrapyrin had no impact on disease control when pathogen infestation and planting of apple were delayed until after peak NO emission. Amplification of resident Streptomyces populations was repeatedly observed n response to BSm amendment. Incoluclation of pasteurized BSM-amended soils with individual Streptomyces isolates restored disease control, and did so via the induction of plant resistance in a manner similar to that of BSM. Brassica napus and Sinapis alba, but not B. juncea, stimulate resident Pythium spp. populations and suppress emergence of various plant species. Application of pythiacious-specific mefenoxam to B. napus and S. alba treated soils results in significant increases in emergence of wheat, pigweed and hairy vetch. These data suggest that BSM-induced control of specific soilborne pathogens and weeds results in part, through the capacity to stimulate certain elements of the resident soil microbial community.