Research conducted at Cornell University has found that if produce farmers wait 24 hours to harvest their crops after a rain, the food they produce will be safer for people to eat. The USDA has proposed rules allowing farmers to apply “wait periods” after irrigation water, to let “potentially dangerous microbes die off”.
Any water applied to a field creates conditions more hospitable to the Listeria monocytogenes bacteria. Researchers tested fields in several locations in New York state. They found that after rains, the chances of finding Listeria dropped dramatically 24 hours after a rain, to levels similar to the baseline.
Farmers would use weather data, GIS technology and data driven information to take a “systems approach” to managing food safety and their crops.
Listeria outbreaks have been linked to apples and cantaloupe, and recalls for this contamination have been issued for peaches, nectarines, and plums, among other produce. Listeria is especially problematic on produce since there is often no cooking, or “kill step” on these items before they are consumed.
This research is being conducted to help set rules, standards, and guidelines for the Food Safety Modernization Act of 2011. The research was published in the Journal Applied and Environmental Microbiology. The Center for Produce Safety funded the research.