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Risk Assessment of Salmonella Preharvest Internalization in Relation to Irrigation Water Quality Standards for Melons and Other Cucurbits

Suslow, Trevor
University of California - Davis
Start date
End date
The production of melons, including cantaloupe, honeydew, and watermelon, and other cucurbits (specialty melons, cucumber, and squash) requires ample quantities of irrigation water of appropriate microbiological quality to ensure this essential input does not contribute to food safety risk to consumers. A great deal of uncertainty surrounds the setting of rationale and practical standards for growers to follow to meet these expectations.

In open environments, it is unreasonable to expect that no pathogens of concern will ever be in surface water used for irrigation at some low level. Internalization of pathogens from soil and transfer to edible portions of fruits and vegetables has become a concern in recent years.

The primary purpose of this research is to determine, by greenhouse and open field testing, the threshold level of Salmonella that would be required to represent a risk of fruit contamination by uptake of pathogen-contaminated irrigation water through the root system and subsequent transfer through the vine. We anticipate this threshold will be 10,000's times higher than levels of Salmonella reported in irrigation source water for domestic production of these crops.

Food safety standards for melons and cucurbits will not need to remain preoccupied with the risk of internalization from roots.

Funding Source
Center for Produce Safety
Project number
Sanitation and Quality Standards
Bacterial Pathogens
Risk Assessment, Management, and Communication