Management of Fungicide Residues on Processing Tomatoes. R. J. Precheur, Associate Professor, Department of Horticulture, The Ohio State University, Columbus 43210. M. A. Bennett, R. M. Riedel, K. L. Wiese, and J. Dudek. Assistant Professor, Department of Horticulture, Professor, Department of Plant Pathology, Assistant Professor, Department of Food Science and Technology, The Ohio State University, Columbus 43210; and Technical Coordinator, National Food Laboratory, Washington, DC 20005. Plant Dis. 76:700-702. Accepted for publication 12 January 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0700.

In 1988 and 1989, residues of ethylenebisdithiocarbamate, chlorothalonil, and anilazine on raw, unwashed, unpeeled processing tomatoes from field experiments were 16–25% of the Environmental Protection Agency tolerance levels. Decreasing fungicide rates early in the season resulted in an additional 33–53% reduction in residues without adverse effects on fruit yield or quality. The total amount of fungicide applied during the growing season, and not just the last applications before harvest, seems to determine residue levels. Ethylene thiourea, chlorothalonil, and anilazine residues were at or below detection limits in tomato juice processed from field-grown tomatoes in both years of the study.

Keyword(s): anthracnose.