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Publication #PP275

Quick Reference Guide for Foliar Fungicides1

Megan M. Dewdney2

This document is best viewed as a pdf.

This reference guide provides quick access to foliar fungicide recommendations from the Florida Citrus Production Guide. Also included are guidelines for fungicide resistance management.

Fungicide Resistance Management

Fungicide resistance is now problematic in Florida citrus groves, with documented strobilurin resistance causing control failure of Alternaria brown spot. These guidelines apply to all fungicide applications within a season and all fungal diseases.

  • Make no more than the recommended number of sequential applications of any fungicide without alternating to another fungicide with a different mode of action (FRAC codes). To conserve fungicide efficacy, it is recommended to rotate modes of action with each application.

  • Do not make more than the maximum number of applications of any fungicide class combined in a year for all diseases, and never exceed maximum label rates per acre per year.

  • Control measures should begin before disease development and continue as indicated by recommended disease management practices. For guidance, consult the Florida Citrus Production Guide (



This document is PP275, one of a series of the Plant Pathology Department, UF/IFAS Extension. Original publication date May 2010. Revised July 2019. Visit the EDIS website at


Megan M. Dewdney, associate professor, Plant Pathology Department; UF/IFAS Citrus Research and Education Center Lake Alfred, FL 33850.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication do not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer's label.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.