Section 18 Label Renewal Approved for Use of Mertect (Thiabendazole) for Control of Sweetpotato Black Rot Postharvest in Domestic Markets

— Written By

Written by Camilo H. Parada-Rojas and Dr. Lina M. Quesada-Ocampo

The United States (U.S.) Environmental Protection Agency (EPA) renewed the section 18 emergency label, originally obtained in 2016, for the use of Mertect (thiabendazole) postharvest to control black rot (caused by the fungus Ceratocystis fimbriata) in sweetpotatoes. 

This means the extended label is valid for use in 2021 and will expire on July 2, 2022. Growers planning to export sweetpotatoes to the European Union should avoid using thiabendazole on any sweetpotato roots. While thiabendazole is approved for U.S. domestic use, its use on sweetpotato exports remains limited to a MRL of 0.01ppm. More details regarding the status of MRLs can be found on the BCGlobal website

For any questions, please contact your local N.C. Cooperative Extension agent or the NC State University Vegetable Pathology Lab. Thiabendazole remains an effective tool to be used by sweetpotato packers and growers to control black rot, but should be used as part of an integrated pest management program that includes cultural practices described in our Black Rot of Sweetpotato publication

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