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Publication #SL431

Phytophthora Identification and Sampling in Citrus Nurseries1

Jamie D. Burrow, Diane B. Bright, Tim D. Riley, Evan G. Johnson, and James H. Graham2

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Phytophthora species are important soilborne, fungus-like pathogens that attack the root systems, trunk, and fruit of citrus trees at any age. The front of this identification sheet includes images of healthy and infested roots and descriptions of leaf and root symptoms. The back lists sampling procedures: soil collection, soil testing, and diagnosing phytophthora.



This document is SL431, one of a series of the Plant Pathology Department, UF/IFAS Extension. Original publication date July 2015. Revised July 2019. Visit the EDIS website at


Jamie D. Burrow, Extenion program manager, Citrus Research and Education Center; Diane B. Bright, senior biological scientist, Citrus REC; Tim D. Riley, plant pathologist, Citrus Health Response Program, USDA APHIS PPQ; Evan G. Johnson, assistant research scientist, Citrus REC; and James H. Graham, professor emeritus, Soil and Water Science Department, Citrus REC; UF/IFAS Extension, Gainesville, FL 32611.

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.