By Mark A. Ritenour
The U.S. and other countries set maximum residue limits (MRLs) on fresh produce for various chemicals, including pesticides that might be used preharvest or postharvest. These materials must be labeled for use on the crop of interest and used only according to label instructions.
While it is unlikely for U.S. MRLs to be exceeded when label instructions are followed, other countries representing important export markets for Florida citrus set their own MRLs. When those MRLs are lower than U.S. MRLs, then use of those pesticides may need to be modified or discontinued to keep from exceeding the country’s tolerances. Violations may lead to rejected loads of product, restrictions on future shipments and even increased requirements for the entire industry to a given market.
Of particular concern over the past year, Korean MRLs for numerous pesticides expired at the end of 2021. This is especially true for grapefruit, with the MRLs of about 30 compounds dropping to essentially the level of detection. Take note when considering which blocks are suitable for shipping to this important market as pesticide residues can remain detectable in crops for several months after their application, depending on the chemical. The registrants for some of these materials (e.g., imazalil and glyphosate) have submitted applications for Korean import tolerance, but it is unclear when such MRLs will come into effect. Unfortunately, some registrants have indicated they will not apply for a Korean MRL because of the cost or other factors.
Visit the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) postharvest resources website for the most current list of MRLs (in parts per million) for various chemicals used on fresh Florida citrus destined for the United States and important export markets. This website also includes links to MRL databases for select countries and to BCGlobal (providing a comprehensive list of maximum residue limits for all commodities and markets). Because MRLs for the various export markets are continually changing, this information is intended as an initial reference source, and no guarantee is made to its accuracy. Always verify these values with other knowledgeable sources within specific markets of interest.
Mark A. Ritenour is a professor at the UF/IFAS Indian River Research and Education Center in Fort Pierce.
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