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United States Department of Agriculture

Agricultural Research Service

Research Project: Developing the Logistics for Producing Human Pathogens-free Organic Strawberries in the State of Tennessee

Location: Plant, Soil and Nutrition Research

Project Number: 8062-21000-037-09-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Sep 1, 2013
End Date: Jun 30, 2014

This project addresses two priority areas in the program: 1) Reduce the risk of human pathogens on fresh berries, and 2) Implement meaningful and constructive metrics for strawberry production sustainability. The four objectives of this project are: 1) To determine microbial populations, particularly human pathogens, on organic and inorganic fresh strawberries; 2) To identify the potential points of human pathogen contamination on fresh strawberries during the production and post-harvest handling processes; 3)To demonstrate the feasibility of developing a new detection kit (protein dipsticks) that can rapidly and reliably test the presence of human pathogens on fresh strawberry; 4) To develop science-based modules for sustainable organic strawberry production consisting of the best field management practices, protection and monitoring human pathogen contamination on fresh strawberries, and delivery of new technologies to end users through the extension network across the state of Tennessee.

Eight strawberry growers in four counties in Middle Tennessee will be enlisted and provide plots of organic strawberries. The production areas selected will follow the management guidelines in support of organic strawberry production. Samples of fresh berries will be collected from these study plots and from the nonorganic plots for reference. Fresh berries and those stored for several days at room temperature and 4 °C will be tested for the presence of human pathogenic microbial species using conventional microbial methods. Marker proteins for the detection of those pathogens will be developed using proteome analysis technology. A database will be developed using the results from surveys of consumers, especially the customers of “pick-your-own” establishments, concerning their preference for organic vs. non-organic products and the value they attach to certification of growers for risk-free strawberry production. On-farm demonstration and training of county agents will be conducted during the project. A science-based strategy will be developed for production and storage and marketing of human pathogen-free organic strawberries. Major methods and processes to be used: Organic strawberry field management practices will be modified from what is currently being used in California for organic strawberry production, and still will follow the guidelines defined by the USDAs Organic Food Production Act of 1990; Human pathogens on organic and inorganic strawberries will be determined using the most probably number (MPN) method; Marker proteins for each human pathogenic strain will be identified using the whole proteome analysis approach, and the feasibility of new antibody-based “dipstick” assay tool will be evaluated with a view toward developing a tool that can be used by non-scientists to determine the status of a strawberry crop with respect to pathogen contamination. Technologies developed from this project will be delivered to stake holders through workshop sessions, field demonstration on experimental fields, U-pick strawberry farms, and at area strawberry festivals.

Last Modified: 10/16/2017
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