Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2012
Publication Date: 7/1/2012
Citation: Mazzola, M. 2012. Replant disease control and soil system resilience to pathogen infestation in response to Brassicaceae seed meal amendment. Phytopathology. 102:S4.77. Interpretive Summary:
Technical Abstract: A Brassicaceae seed meal (SM) formulation was compared with pre-plant soil fumigation for the ability to control apple replant disease and to suppress pathogen/parasite re-infestation of organic orchard soils. Application of a <i>Brassica juncea/Sinapis alba</i> SM formulation provided disease control and enhanced tree growth in a manner that was comparable or superior to 1,3-dichloropropene/chloropicrin soil fumigation. At the STM orchard both fumigation and SM amendment effectively suppressed components of the causal pathogen complex during the initial growing season. However, at the end of the second growing season, relative to the no treatment control, Jonagold/G11 root infestation by <i>Pratylenchus penetrans</i> and infection by <i>Pythium</i> spp. were significantly elevated in fumigated soil but were suppressed in seed meal amended soils. Correspondingly, tree growth was superior in seed meal treated soil relative to the control and fumigated treatments. At the SR orchard, soil fumigation and seed meal amendment effectively controlled both <i>P. penetrans</i> and <i>Pythium</i> spp. and tree growth was equivalent between these treatments, but significantly greater than the no treatment control. Findings indicate that Brassicaceae SM amendment may modify soil biology in a manner that enhances system resilience, thereby suppressing re-infestation of orchard soils by parasitic nematodes and fungal/oomycete root pathogens; however, the response is likely to be orchard soil specific.