A New Irrigation Technique for Control of Pathogens on Internal Surface of Green Leaves Produce

<p>NON-TECHNICAL SUMMARY:<br/> Contamination of produce eaten raw has been increasingly implicated in foodborne outbreaks in the USA. The study has shown that an E. coli outbreak resulted in illness and deaths, and $37 to 74 million losses for the California produce industry. The major cause of the E. coli outbreak is the contamination of the internal surface and tissue of the plants (internalization). The fresh produce can be contaminated with human pathogens like E.coli, which is shed in the feces of healthy cattle and other farm or wild animals, and can persist in the environment over extended periods. The studies have shown that internalization of E. coli in growing lettuce or spinach occurred. Postharvest sanitizer wash is intended to reduce microorganisms on the produce surface, but will not be effective if microbes are inside the tissues. The advanced irrigation
technique is suggested to prevent microbes growth on the internal surface and inside the tissues. The proposal describes the irrigation method that prevents microbiological growth of enteric pathogens in plant tissues, plant surface and root zone. The disinfectant solution is safe to use on foods and will leave no chemical or environmental residue. A low-cost automated system generates and injects the disinfectant to the irrigation water. Monitoring and control of the parameters of water, soil and plants (surface and tissue) will be conducted.<p>
APPROACH: <br/>New irrigation technique will provide low ozonated water on lettuce surface over the growth cycle. Plants will be grown in soil and growth medium (hydroponic). Plants will be periodically inoculated/contaminated by E. coli during the growth cycle. Plants with and without tissue damages (root damage, leaves creaks and cuts) will be investigated. Two methods of irrigation (spray and drip irrigation) will be applyed. Ozonated water will be used as disinfect solution at different dissolved ozone concentrations (low, medium and high). Ozone generation-injection device will connect directly into irrigation line. The device will inject the determined amount of ozone in the irrigation water. Ozone concentration and oxidation-reduction potential (ORP) of water will be monitored and controlled by an inline ozone and ORP sensors. Water, soil, growth medium, and plant
tissue will be analyzed to determine disinfection effect.</p><p>
PROGRESS: <br/>2013/06 TO 2014/02 <br/>Target Audience: Our target audiences initially were the leafy green vegetable growers in California, who have sustained great economic hardship from food born contamination. There are two areas of the state of California (Imperial Valley and Central Valley) that are responsible, in 2012, for approximately 80% of California’s 6.8 billion in vegetable crops gross revenue. We felt this would be a natural starting point for our search for collaborating partners. The FDA has put out a proposal, which at this moment is under review and open for comment. This proposal would require all agricultural operations that irrigate food products for human consumption to test their water on a weekly basis for possible E-coli contamination. The consequences, for operations that are found to have E-coli contaminations, as of this moment are yet
undetermined. Most growers that we have talked to feel they could have very serious consequences for their business. The thought that there may be an irrigation method that could reduce and/or eliminate E-coli contamination could be huge. We have contacted and discussed our plans to move forward with a more thorough study with field trials and were looking for partners to collaborate with. We spoke with Kay Pricola, the manager of the Imperial Valley Vegetable Growers Association in Imperial Valley, and she expressed interest in collaboration on field trial research. We have also made contact and discussed with individual growers (1) Larry Fox of Fox Farms Vegetables in Brawley and (2) Ralph Strahm a large farmer in El Centro. A couple of the reason we contacted individuals in the Imperial Valley area where, that their proximity to our facility and because in this area there is very high
Hispanic minority population as their labor force working for minimum wage. From the success of our Phase I trials, where we achieved such a high pathogen reduction with our irrigation method, we have expanded our projected target market scope to include all agricultural operation that irrigate food products for human consumption. This includes not only California but all of the United States from, the individual grower and the growers associations, to the FDA and the federally funded state crop advisors. <br/>Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? We have contacted and discussed our plans to move forward with a more thorough study with field trials and were looking for partners to collaborate with. We spoke with Kay Pricola,
the manager of the Imperial Valley Vegetable Growers Association in Imperial Valley, we have also made contact and discussed with individual growers (1) Larry Fox of Fox Farms Vegetables in Brawley and (2) Ralph Strahm a large farmer in El Centro. Growers and managers expressed interest in collaboration on field trial research during the Phase II. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported.</p>