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Close Details
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Session Time :
8/5/10 1:00 PM - 8/5/10 4:00 PM
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Content Area : Plant Pathology Kelman Scholars
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Student Presenters :
Kari Amber Peeden Biological Sciences
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Mentors and/or Co-Authors :
Frank Louws
Plant Pathology
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Abstract Title : Role of soil boilogy in strawberry plant productivity
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Abstract :
Soil fumigation using methyl bromide (MB) is used as a pre plant treatment to control a range of pathogens in crop production systems. The grower at Rudd Strawberry Farm located in Greensboro noted that MB suppressed strawberry plant growth in one field compared to adjacent non-fumigated areas, an unusual phenomena and opposite of expectations. We hypothesized this was a biologically mediated process. Treated (MB) or nontreated (NT) soils were collected in a pair-wise sampling design in the spring at peak harvest 7 months after soil treatment and 6 months after planting. Strawberry leaf dry weights were 10.4 g/plant from MB treated rows and 29.8 g/plant in non-treated rows (P<0.001). Soil and strawberry roots were tested for the presence or absence of pathogenic (completed) and beneficial microbes (in process). Soil microbial numbers were counted using grow-out dilution assays. Fungal populations were dramatically suppressed to 1175 and 3255 Pythium colony forming units per gram of dry soil (cfu/gds) in MB compared to NT soils, respectively, and 1096 and 10058 Fusarium cfu/gdw (P-value<0.001). Culturalable bacterial populations were not affected. Therefore, MB treatment effectively reduced pathogen populations. Further work is underway to understand why MB treated plants had reduced growth, despite less plant pathogens. We are performing biological and molecular assays to determine if beneficial microbes play a role. If so, we will ask the question “Can these microbes be used in future farming systems not dependent on broad spectrum biocides and pesticides?
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