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2023–2024 Quick Reference Guide for Foliar Fungicides

Megan M. Dewdney

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.

Figure 1. 
Credit: Hope Norman, UF/IFAS Communications 


Figure 2. 
Credit: Hope Norman, UF/IFAS Communications 


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 (

Publication #PP275

Release Date:July 26, 2023

Related Experts

Dewdney, Megan M.


University of Florida

Related Collections

Part of Citrus Quick Reference Guide Series

Fact Sheet

About this Publication

This document is PP275, one of a series of the Plant Pathology Department, UF/IFAS Extension. Original publication date May 2010. Revised August 2022 and August 2023. Visit the EDIS website at for the currently supported version of this publication.

About the Authors

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


  • Jamie Burrow
  • Megan Dewdney