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A systems approach for producing greenhouse tomatoes free of human pathogens and plant pathogens.
M. LEWIS IVEY (1), S. Ilic (2), F. Baysal-Gurel (3), J. T. LeJeune (4), S. A. Miller (4). (1) Agcenter, Louisiana State University, Baton Rouge, LA, U.S.A.; (2) The Ohio State University, Columbus, OH, U.S.A.; (3) The Ohio State Univ., Wooster, OH, U.S.A.; (4) The Ohio State University, Wooster, OH, U.S.A.

There is renewed interest in tomato greenhouse production in the US due to increased demand for year-round locally produced tomatoes. Risk factors such as plant diseases, insects and water quality are inherent to greenhouse tomato production sustainability and profitability. The risk of human pathogen contamination in the production system is not well understood. Many production practices are potential risk factors for the introduction and dissemination of pathogens through the system. A systems approach was implemented to identify and confirm critical points for pathogen entry and dissemination, and economical preventative strategies to mitigate risk. A production flow diagram was developed based on 26 site evaluations of small, medium and large greenhouses. In terms of economic consequences, industry ranked bacterial canker and <i>Botrytis</i> grey mold as major plant disease hazards. The Delphi Process was used to elicit the opinions of 46 plant pathologists and food safety experts to confirm practices that are critical points for pathogen entry and dissemination. Irrigation water, crop debris, production equipment, and workers were identified as common risk factors for both plant and human pathogens. Eight greenhouses were sampled over time to determine the relevance of each of the identified sources within the production system. Critical entry/dissemination points were identified for <i>Botrytis </i>grey mold, bacterial canker and <i>Listeria</i> <i>monocytogenes</i>.

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