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Evaluation of Pesticide Solutions in the Transmission of Pathogenic Bacteria to Horticultural Crops


This study is based on a premise that introduction of bacterial pathogens such as Salmonella, Listeria, E. coli and Shigella by liquid pesticides applied to horticultural crops, could increase the risk of food-borne illness to individuals who consume such products. An overall objective of this study is to evaluate the potential of food safety associated risks with the spraying of pesticides, prepared using on-farm water of unknown bacteriological quality, onto horticultural crops.
The study will involve a laboratory assessment of the ability of Salmonella, Listeria, E. coli or Shigella to grow in selected, recommended pesticides used on Ontario horticultural crops, and conditions affecting growth of pathogens in pesticides: time, temperature, concentration of pesticide (water volume), and presence of competing microorganisms. A small plot field trial will be carried out with the objective to assess the potential risk of applying pesticides if pathogen growth has occurred, one pesticide shown to promote pathogen growth will be inoculated with a mixture of two pathogens, and applied onto a horticultural crop (e.g. tomatoes).

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Expected Impact of Project Outcomes on Food Safety in Ontario: The outcomes of this research will allow for identification of possible risk factors associated with the use (including storage) of on-farm water (especially surface waters) in mixing pesticides applied to commercial fruit and vegetable crops. They also will enhance knowledge and scientific information pertaining to the identification of on-farm critical control points and a contribution of information to pesticide education programs.

In addition, pesticides requiring special handling or caution with respect to mixing and storing will be identified, as well as future research needs in this area. <P> For more information, please visit the <a href="; target="_blank">Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA) Food Safety Research Program</a>.

Holley, Richard
University of Manitoba
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