Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2004
Publication Date: June 1, 2004
Citation: Mazzola, M., Cohen, M.F., Fazio, G. 2004. Impact of soybean and rapeseed seed meal on microbial populations and growth of apple in replant orchard soils. Phytopathology. 94:S68. Interpretive Summary: Abstract only.
Technical Abstract: Soybean meal (SBM) and rapeseed meal (RSM) amendments elicited differential effects on elements of orchard soil microbial communities. While application of either amendment resulted in increased total bacterial populations, SBM enhanced while RSM diminished fluorescent Pseudomonas spp. populations. Streptomyces spp. populations were significantly higher in RSM-treated than in either SBM-treated or non-treated soils. Both amendments suppressed lesion nematode root populations, and RSM but not SBM significantly depressed infection of apple roots by Rhizoctonia solani. In field trials, RSM amendment in conjunction with metalaxyl soil drench significantly increased growth and yield of Gala/M26 apple. The level of disease control and growth of all rootstocks achieved in response to RSM/Metalaxyl treatment was superior to that obtained by pre-plant Telone C35 fumigation. However, relative increase in tree caliper varied among rootstocks, ranging from 263% (M7) to 561% (G16). Rootstocks supporting higher Streptomyces spp. rhizosphere populations trended toward the higher range of growth promotion in response to RSM amendment.