Berry Irrigation Water Research: A Study on the Food Safety Risks Using Surface Water for Irrigation

What were the goals of this study?

• To identify whether E. coli can be transferred to strawberries from irrigation water
• To measure the survival of E. coli on strawberries, when the E. coli originates from irrigation water.

How did we conduct the study?

• Research took place on a farm
• Researchers applied water to strawberries using an overhead irrigation system
• Irrigation water exceeded the Canadian Council for Ministers of the Environment (CCME) guideline for generic E. coli in agriculture water (100 colony forming units/100 mL of water)
• Researchers followed randomized complete block design (8 replications)
• Sampling of water and strawberries took place before irrigation, just after irrigation, and hourly after irrigation.

What did we find?

• Irrigation water that exceeded the CCME guidelines for generic E. coli did contaminate strawberries with E. coli
• Extending the time between irrigation and harvesting reduced the number of strawberries that test positive for E. coli.

Our recommendations

• Test your irrigation water for E. coli
• When water exceeds the CCME guidelines, reduce the risk by:
  • Extending the time between irrigation and harvesting
  • Limiting irrigation water contact with the fruit. For example:
    - Install drip irrigation
    - Avoid using sprinklers after fruit has formed.