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Publication #CH201

Scouting for Huanglongbing (HLB; Citrus Greening)1

Jamie D. Burrow, Stephen H. Futch, Tripti Vashisth, and Timothy M. Spann2

This illustrated trifold brochure is best viewed in pdf format. It highlights the purpose of scouting, frequency, methods, grove conditions, tagging suspect trees, scout responsibilities, safety concerns, diagnostics, and what to scout for. Includes contact information for UF/IFAS Extension citrus experts.

Click here to download this brochure.

Purpose of Scouting

The purpose of scouting is to aid in managing HLB by:

  • Identifying HLB-affected trees

  • Planning a management program

When to Scout

  • Symptoms are most visible during the fall and winter months

  • Survey frequency would be determined by incidence and HLB management plan

  • Spring flush makes scouting more difficult

Methods

  • Walking

  • ATVs

  • Tractor- or vehicle-mounted platform

Scout Responsibilities

  • To locate and identify HLB symptoms

  • Operators of platforms and ATVs are responsible for transporting survey crews safely

  • Follow all company procedures for entering and exiting grove

Tagging Suspect Trees

  • Use one color of flagging tape to identify suspect trees

  • Choose colors or designs that cannot be confused with other commonly used flagging tapes

  • GPS or grove map should be used in conjunction with flagging tape to identify positive HLB-affected tree

Grove Conditions

Grove conditions which can hinder a scouting program include:

  • Unmaintained grove middles, tree size, and/or canopy

  • Nutrient deficiencies

  • Non-hedged rows

  • Disease or insect damage

Safety Concerns

  • Safety is a priority when scouting

  • Follow re-entry intervals for chemical applications

  • Be aware of weather, climate conditions, and grove conditions

  • Watch for power lines

  • Always keep a first aid kit in a readily accessible location

  • Employees should be trained in the proper procedures in case of an emergency

What to Scout For

BLOTCHY MOTTLE = GREENING

Yellow veins, vein corking, and green islands are not diagnostic alone. These symptoms should be coupled with blotchy mottle symptoms and a positive diagnostic test to determine a diagnostic test tree.

Figure 14. 

Trees with a yellow appearance, shoot dieback, sparse foliation, and thin canopy.


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Figure 15. 

Blotchy mottle leaves.


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Figure 16. 

Vein corking and blotchy mottle.


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Figure 17. 

Green islands.


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Figure 18. 

Lopsided, misshapen, small fruit.


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Figure 19. 

Yellow veins and/or off-season bloom.


[Click thumbnail to enlarge.]

Diagnostic Labs

Southern Gardens Diagnostic Laboratory
111 Ponce de Leon Ave.
Clewiston, FL 33440
(863) 902-2249
Contact: Mike Irey
msirey@ussugar.com
Florida Division of Plant Industry
PO Box 147100
Gainesville, FL 32614-7100
(800) 282-5153
UF Plant Diagnostic Center
Building 1291, 2570 Hull Rd.
Gainesville, FL 32611
(352) 392-1795

Before sending samples, contact the testing facility to obtain proper sampling procedures, submission guidelines, and fees.

Contacts

UF/IFAS Citrus Research and Education Center
Jamie Burrow
Canker & Greening Extension Education
(863) 956-8648
Megan Dewdney, Ph.D.
Plant Pathologist
(863) 956-8651
Tripti Vashisth, Ph.D.
Horticulturist
(863) 956-8846
Lauren Diepenbrock, Ph.D.
Entomologist
(863) 956-8801
UF/IFAS Southwest Florida Research and Education Center
Ozgur Batuman
Plant Pathologist
(239) 658-3408
Jawwad Qureshi, Ph.D.
Entomologist
(772) 577-7339
UF/IFAS Indian River Research and Education Center
Liliana Cano, Ph.D.
Plant Pathologist
(772) 577-7350
UF/IFAS Extension Offices with Citrus Agents
DeSoto, Hardee, Hendry, Highlands, Lake, Polk, St. Lucie, Sumter
Websites
UF/IFAS Extension Citrus Agents
http://citrusagents.ifas.ufl.edu
UF/IFAS Citrus REC
http://www.crec.ifas.ufl.edu
UF/IFAS Southwest Florida REC
https://swfrec.ifas.ufl.edu/
Local UF/IFAS Extension Office

http://sfyl.ifas.ufl.edu/find-your-local-office/

For more information, please contact the UF/IFAS Citrus Research and Education Center, Lake Alfred (863) 956-1151

Footnotes

1.

This document is CH201, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date August 2008. Revised December 2019. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Jamie D. Burrow, Extension program manager; Stephen H. Futch, Extension agent IV (retired); Tripti Vashisth, assistant professor, Horticultural Sciences Department, UF/IFAS Citrus Research and Education Center; and Timothy M. Spann, former associate professor, Horticultural Sciences Department, UF/IFAS CREC; 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.