In April 2009, the National Academies of Science, at the request of the Florida Department of Citrus, formed the National Research Committee on Strategic Planning for the Florida Citrus Industry: Addressing the Citrus Greening Disease (Huanglongbing). At the same time, the forward-looking citrus industry in Florida initiated the Citrus Research and Development Foundation (CRDF). When the National Research Council’s report was published in March, 2010 it included a recommendation that one organization be identified and empowered to have oversight responsibility over HLB research and development efforts. The organization selected was CRDF.
CRDF is a non-profit corporation organized under Florida State laws as a Direct Support Organization of the University of Florida. It’s Mission is to “Advance disease and production research and product development activities to ensure the survival and competitiveness of Florida’s citrus growers through innovation and research.”
The organization is headed by a 13-member Board of Directors, ten of whom are required by statute to be growers. The others are from academia and government. The COO handles the day-to-day management of business affairs, and Project Managers oversee the research and commercial product delivery project portfolios.
CRDF Mission Statement
CRDF Bylaws (apprvd 9-26-2023)
Conflict of Interest Policy (6-10-2012)
Business Plan (as revised 5-17-2023)
Morgan McKenna is a fourth generation Florida Citrus grower. After graduation, Morgan spent seven years with Syngenta Crop Protection in various roles from AgriEdge Specialist to Sales Representative and assisting in the management of their Citrus Intern Program. In late 2020 she returned to her family business of citrus caretaking and harvesting in Polk, Highlands, Hardee, and Hendry counties. At McKenna Brothers, Morgan takes pride and enjoys working alongside her dad, uncle, & cousin to help produce & harvest quality oranges that are used to make delicious Florida Orange Juice.
In addition to serving on the Citrus Research & Development Foundation board, Morgan is a member of Class XI Wedgworth Leadership Institute and sits on the Polk Citrus Advisory Committee and UF’s AEC Advisory Council.
Director of Agronomy, Alico, Inc.
Fort Myers, Florida
Ron Mahan is vice president and chief financial officer of Tamiami Citrus LLC, a citrus production company with groves in Collier, Desoto, Hardee, and Highlands counties, owned by affiliates of Collier Enterprises. He joined Collier’s Agribusiness Group in 1988, serving in various roles for the company’s operations based in Immokalee. He was part of the team that created Consolidated Citrus LLC and served on its board of directors. Mahan played key roles in Collier’s acquisition and operation of Orange-Co, which was subsequently sold to Alico in 2014. Mahan is a member of the Processed Orange Advisory Board to the New Varieties Development & Management Corporation, Chairman of the Citrus Crop Estimates Advisory Committee to the USDA, a member of the Citrus Administrative Committee, and President and Board Member of Gulf Citrus Growers Association. He holds B.S. and M.S. degrees from the University of Florida and is an alumnus of the Harvard executive education program.
George F. Hamner, Jr. returned to Florida to join the family citrus business in 1978, taking over operations in 1985. He remains the President and CEO of Indian River Exchange Packers, Inc., which owned and operated a modern full service fresh fruit packing company shipping fruit around the world. The packing house has recently been sold, but various ongoing operations continue. Mr. Hamner is also President and CEO of Vero Producers, Inc. where he oversees the production and marketing of the fruit produced on the family’s 1200+ acres of citrus groves. He continues to serve on numerous industry related boards, as well as civic, business, and public committees. He is the past Chairman and President of the Indian River Citrus League, past President of Florida Citrus Mutual, past President of Florida Citrus Packers and currently Chairman of the Citrus Administrative Committee which along with the Department of Citrus regulates fresh Florida grading and shipping standards.
Mostly though, he just likes to quail hunt and bonefish which he does as often as his wife will allow.
Dr. Christopher Gunter, chair of the University of Florida department of Horticultural Sciences. Dr. Gunter would replace Dr. Robert Gilbert as an appointee recommended by the University of Florida and would become the Board of Trustees’ appointee to the board. His term would conclude upon recommendation from the University of Florida.
Dr. Christopher Gunter was named professor and chair of the UF/IFAS Horticultural Sciences department in June 2021. Dr. Gunter is an expert in vegetable production and he was previously a faculty member at North Carolina State University and director of graduate programs. Horticultural Sciences has experts and programs that break new ground in research, plant breeding and genetics, fruit and vegetable production and related disciplines that continue to shape the future of food in Florida and around the world.
Aaron Himrod is a third generation Florida Citrus Grower who is growing the Florida Citrus industry one plant at a time.
As a third generation Florida Citrus Grower in Hardee county and a member of the Peace River Valley Citrus Growers Association, Himrod has a passion for growing the Florida Citrus industry. At Himrod Citrus Nursery, he grows multiple kinds of young citrus plants that will eventually make it into the groves and replace underperforming trees. Trees stay in Himrod’s nursery for about 18 months where he grafts two different kinds of citrus trees together to produce a more robust, healthy tree that will ultimately produce a better variety of Florida Orange Juice.
With people like Himrod working in the Florida Citrus industry, the future has never looked brighter.
Vice President, Rolling Meadow Ranch Groves LLC
Lake Wales, Florida
Associate Vice President for Operations, UF's Institute of Food and Agricultural Sciences
Jeanna Mastrodicasa is the Associate Vice President for Operations with UF’s Institute of Food and Agricultural Sciences. Her appointment follows more than a year as chairperson of the advisory board of the Center for Public Issues Education. Dr. Mastrodicasa earned an ABJ in public relations and a J.D. in law from the University of Georgia, an M.S. in college student personnel from the University of Tennessee, and a Ph.D. in higher education administration from the University of Florida. She first joined UF in 1997 as an academic advisor in the College of Liberal Arts and Sciences, a position she held for two years before being named Assistant Dean of Students. She was Associate Director of the Honors Program at UF for seven years, where she directed the campus undergraduate research program University Scholars, advised student Fulbright grant applicants, and managed several duties including admissions, orientation, and advising efforts within the Honors Program. She served as Assistant Vice President for Student Affairs for nearly eight years before her appointment to IFAS. In addition to her work at the University of Florida, Dr. Mastrodicasa served the Gainesville community-at-large as a City Commissioner from 2006 to 2012, during which time she served as Mayor Pro-Tem from 2010-2011 and chaired the city’s Public Safety Committee for five years and the Gainesville Community Redevelopment Agency from 2009 to 2010; She also served on several committees for six years represented the city on the Alachua County Tourist Development Council. Dr. Mastrodicasa is the co-chair of the Assessment, Research, and Evaluation Knowledge Community with the National Association of Student Personnel Administrators (NASPA) and frequently presents on issues related to millennial college students, their use of technology, and generations in the workforce. She co-authored the book “Connecting to the Net.Generation: What Higher Education Professionals Need to Know about Today’s Students” (NASPA 2007).
Trevor A. Murphy is a third generation Florida Citrus grower. He partnered with the late Marvin Kahn in 2015 and owns/manages groves in Desoto, Hardee, Highlands and Polk counties. He holds B.S. and M.A degrees from the University of Florida. He currently serves as a board member for the Highlands County Citrus Growers Association, United Way of Central Florida Highlands County Division, Leadership Highlands and Highlands Gator Club, in addition to serving as President of the Highlands County Farm Bureau.
Chief of the Bureau of Methods Development and Biological Control, FDACS
Dr. Eric Rohrig serves as the Chief of the Bureau of Methods Development and Biological Control, part of the Florida Department of Agriculture and Consumer Services, Division of Plant Industry. His main focus is the advancement of approaches to control invasive plants and invertebrates. The development of biological control programs, such as air potato, cactus moth, and Asian citrus psyllid are a major part of his activities. Additionally, bureau actions support numerous statewide eradication programs including giant African land snail and various fruit fly species. He holds Masters and Doctorate degrees in Entomology with an emphasis on insect behavior and biological control from the University of Florida. He has dedicated the past 20 years to supporting Florida agriculture and natural areas having been employed by both FDACS and previously the United States Department of Agriculture, Agricultural Research Service. His experience includes laboratory and field research as well as administrative duties managing numerous statewide programs aimed at controlling invasive plants, snails, and insects.
Sarah Spinosa is fifth generation agriculturalist from Gramling, South Carolina. She holds a bachelor’s degree in Agricultural Education from Clemson University. While studying at Clemson, she met her husband, Christian. After graduating Spinosa moved to central Florida to pursue a career in agricultural marketing for the Florida Department of Citrus. For over six years Spinosa marketed Fresh Florida Grapefruit and Florida Orange Juice to key international markets throughout Europe, Asia and North America. Spinosa’s most recent endeavor is raising her son, James, and being more hands-on in her family’s citrus and beef cattle operation. She served as the Vice President of the Polk County Young Farmers and Ranchers Committee and continues to be an active member. Currently, Spinosa serves on the Polk County 4-H Foundation Board of Directors and the AgAmerica Foundation Board.
Lake Wales, FL
Rob is well known in the industry and served on the executive committee of the Florida Citrus Production Manager’s Assn. He has presented at the Florida Citrus Industry Annual Conference’s Educational Session and impressed the crowd with his drone videos. Rob is committed, sharp and is among the leaders who are testing and adopting tools to survive with HLB, including investing in new strategies with new plantings. He currently serves on the CRDF Executive, Finance and Audit, and Governance Committees, and is well respected by his peers. Rob would most directly represent the SW region of the state. Rob served on the CRDF Board from 2018 through 2023.
After receiving a Bachelor of Science degree in agriculture from the University of Florida in 1986, David began work in citrus land development and grove production for Metropolitan Life Insurance Company, and then Dole Citrus Inc. For the last 25 years, he has been directing agricultural and land management efforts for Graves Brothers Company which is based in Vero Beach. David is active in the Citrus Production Managers Association, participates in RMC and CPDC Committees of CRDF, a member of USDA, APHIS HLB MAC as Florida Grower Representative. He is one of four Florida grower representatives of the Citrus Subcommittee who sets priorities for the SCRI Citrus Disease Research and Education Program. David and his company are dedicated to survive HLB, and manage groves in all three regions of the state (not just the Indian River). David has a command of the situation in the industry as evidenced by his presentation at the Bonita Springs Grower Panel, and is well aware of CRDF programs, goals and challenges. David served on the CRDF Board from 2018 through 2023.
John Updike, of Babson Park, is a third generation citrus grower and the president of Alcoma Properties, Ltd. and Updike Enterprises, Inc. Updike has a bachelor’s degree in commerce from Washington and Lee University and an Education for Ministry from the School of Theology at the University of the South. Updike has served on the Polk County Farm Bureau Board, Polk County Board of Adjustment and Polk County Code Enforcement Board. He is a former member of the “No Name Group” and the Ridge Runners. He presently serves on the CRAFT Foundation’s Board of Directors, is the Secretary of the CRDF Board of Directors, and the Chairperson for the CRDF Commercial Product Delivery Committee. He has five children and 11 grandchildren. John served on the CRDF Board from 2018 through 2023.
Rick Dantzler is a third-generation Floridian who grew up in Winter Haven. He attended Polk County public schools from kindergarten through the 12th grade, and the University of Florida for undergraduate and law school.
In 1982, at the age of 26, he was elected to the Florida House of Representatives where he served for eight years. In 1990, he was elected to the Florida Senate where he served until resigning in 1998 to run for the office of Governor of Florida. Later that year he became the nominee for Lieutenant Governor.
After leaving elected office, Dantzler worked as a lawyer and mediator. In early 2013, he accepted an appointment from President Obama to serve as the State Executive Director of the Farm Service Agency within the USDA. At the end of President Obama’s administration, Dantzler went back to practicing law before becoming the COO of CRDF in August of 2018.
Program Assistant, CRDF
Office Manager, CRDF
Having moved from Western PA to central Florida in 2005, Audrey’s motto “In Florida, every day is a vacation” has never changed. After 25 years of office management experience in heavy construction in PA, followed by the same the first few years in Florida, she started in 2009 with the FDOC staff contracting CRDF-funded research in the first year while CRDF was being formed and set up as a DSO of the University of Florida. “I remain most appreciative of the opportunities afforded to me during my time with CRDF, enjoy working with the Board and Committees, Growers and CRDF Staff.” In her leisure time, Audrey enjoys time with family and friends, golfing, sewing, and her grandsons’ and Pittsburgh sports.
Project Manager, Horticultural Practices
Originally from California, Jim studied plant ecology at California State Univ., Fullerton, CA, where he earned and a B.A. in 1970 and an M.A. in 1973 in Biology and Plant Ecology. He received a Ph.D. in Biology and Physiological Plant Ecology of desert plant species in 1977 from New Mexico State University, Las Cruces, NM. He then moved to Florida as an Assistant Professor of citrus horticulture research at the University of Florida IFAS, Citrus Research and Education Center. Jim retired as an awarded Full Professor in 2013. His research interests included integration of citrus stress physiology especially interactions with HLB disease, focusing on tree growth, yield and fruit quality. During his career, Jim received many research grants and published over 200 journal articles. In 2014, he was awarded an ISHS Lifetime Achievement Award for “Outstanding Contributions to Research and Education in Fruit Crop Physiology” presented by The Environmental Physiology of Fruit Crops Working Group of the ISHS. Since 2013, he has been a Professor Emeritus with the Florida Citrus Research and Development Foundation as an HLB (Greening) Research Program Manager.
Professor Emeritus Citrus Stress Physiology, University of Florida, CREC, Lake Alfred, FL
Retired in 2013 after 35 years of research at UF/IFAS, CREC on Citrus Horticulture.
2013 to present: HLB Research Program Manager, CRDF, Lake Alfred, FL
Education: Ph.D. 1977, Biology. Physiological plant ecology of desert species. New Mexico State University, Las Cruces, NM.
M.A. 1973 and B.A. 1970, Biology and Plant Ecology, California State Univ., Fullerton, CA.
2014 ISHS Lifetime Achievement Award for “Outstanding Contributions to Research and Education in Fruit Crop Physiology” presented by The Environmental Physiology of Fruit Crops Working Group of the ISHS. March 2014.
2008-2011. University of Florida Research Foundation Professorship awarded from the UF Vice President of Research for “Distinguished Research Performance, Publications, Service & Commitment”.
Research interests: Integration of citrus stress physiology especially interactions with HLB disease.
Tree growth, yield and fruit quality. Effects of light, temperature, mechanical harvesting, drought, salinity, pests and nutrient stress on water, carbon and nutrient budgets of citrus trees.
Recent Publications: (of over 200 lifetime)
2014 Syvertsen, J.P., Garcia-Sanchez, F. 2014 Multiple abiotic stresses occurring with salinity stress in citrus. Environ. Exp. Bot.103: 128-137. PDF
2013 Cimò, Giuseppe, Pedro Gonzalez Blanco, Wije Bandaranayake, Ed Etxeberria, Riccardo Lo Bianco and James Syvertsen. Carbohydrate and Nutritional Responses to Stem Girdling and Drought Stress with Respect to Understanding HLB Symptoms in Citrus. HortScience 48: 920-928. PDF
2013 Caballero, F., F. García-Sánchez, V. Gimeno, J. P. Syvertsen, V. Martínez and F. Rubio. High affinity
Potassium uptake inseedlings of two citrus rootstocks Carrizo citrange (Citrus sinensis [L.] Osb. × Poncirus
trifoliata [L.] Raf.) and Cleopatra mandarin (Citrus reshni Hort. ex Tanaka) Aust. J. Crop Sci. 7(5):538-542. PDF
2012 Gonzalez, P., James P. Syvertsen and Ed Etxeberria. 2012. Sodium distribution in salt-stressed citrus rootstock seedlings. HortScience 47: 1504-1511. PDF
2012 Gimeno V., J.P. Syvertsen, I. Simón, M. Nieves, L. Díaz-López, V. Martínez, F. Garcia-Sanchez. 2012. Physiological and morphological responses to flooding with fresh or saline water in Jatropha Curcas. Environmental and Experimental Botany 78: 47-55. PDF
2012 Gimeno V, J.P. Syvertsen, I. Simon, V. Martinez, Jose M. Camara-Zapata, Manuel Nieves, F. Garcia-Sanchez.
Interstock of Valencia orange affects the flooding tolerance in Verna lemon trees. HortScience 47:403-409. PDF
2012 Zambrosi, F.C. B., D. Mattos Jr., R.M. Boaretto, J.A. Quaggio, T. Muraoka and J.P. Syvertsen. Contribution of
phosphorus (32P) absorption and remobilization for Citrus growth. Plant & Soil 355:353–362. PDF
2012 Grosser, J.W., Ahmad A. Omar, Julie A. Gmitter and J. P. Syvertsen. Salinity Tolerance of ‘Valencia’ Orange Trees on Allotetraploid Rootstocks. Proc. Fla. State Hort. Soc. 125:50–55. (Refereed Proceedings) PDF
2011 Zambrosi, F. D. DeMattos Jr. and J.P. Syvertsen. 2011. Plant growth, leaf photosynthesis, and nutrient-use efficiency of citrus rootstocks decrease with phosphite supply. J. Plant Nutr. Soil Sci. 174: 487-495. PDF
2011 Melgar, J.C, and J.P. Syvertsen. Oleocellosis Injury of Fruitlets Caused by Late-Season Mechanical Harvesting of Valencia’ Orange Trees After Different Irrigation Treatments Does Not Affect Internal Fruit Quality. HortSci 4 6(3):1-3. PDF
2010 Melgar, J.C, J. Dunlop, L.G. Albrigo and J.P. Syvertsen. 2010. Winter drought stress can delay flowering and avoid immature fruit loss during late season mechanical harvesting of ‘Valencia’ oranges. HortScience 45: 271-276. PDF
2010 Syvertsen, J.P., J.C. Melgar and F. García-Sánchez. Salinity Tolerance and Leaf Water Use Efficiency in Citrus.
JASHS 135: 33-39. PDF
2010 Gimeno, V., J.P. Syvertsen, F. Rubio, V. Martínez and F. García-Sánchez. Growth and mineral nutrition are affected by substrate type and salt stress in seedlings of two contrasting Citrus rootstocks. J. Pl Nutr. 33: 1435–1447. PDF
2010 Melgar, J.C., A.W. Schumann and J.P. Syvertsen. Fertigation frequency affects growth and water and nitrogen use efficiencies of Swingle citrumelo citrus rootstock seedlings. HortScience 45:1255–1259. PDF
2010 Melgar, J.C., J. Dunlop and J.P. Syvertsen. Growth and Physiological Responses of the Citrus Rootstock Swingle Citrumelo Seedlings to Partial Rootzone Drying and Regulated Deficit Irrigation. J of Agr Sci 148: 593-602. PDF
Recent Non-Refereed Publications
2017 Syvertsen, J.P., B. Page, M. Keeley, B. Booker, D. Sutherland and H. Yonce. Soil Microbial Product Interactions with HLB in Valencia/Swingle Trees over Three Seasons at Three Contrasting Sites in Florida. Proc Fla. State Hort. Soc. 130: 2017.
2015 Syvertsen, J.P., T. Minter, Henry Yonce, and W. Bandaranayake. A Single Application of 2,4-D Can Decrease Preharvest Fruit Drop in HLB-Affected ‘Valencia’ Orange Trees. Proc. Fla. State Hort. Soc. 128: 2015
2012 Syvertsen, J.P. and Wije Bandaranayake. 2012. Salinity Tolerance of ‘Hamlin’ Orange Trees on the Hybrid Rootstocks US897 and x639 Is Greater than of Trees on Cleopatra Mandarin. Proc. Fla. State Hort. Soc. 125:56–60. PDF
2008 Ebel, R.C. K. Morgan, P.Newman, J. K. Burns, and J. Syvertsen. Effects of Short-Term Drought Stress of ‘Hamlin’
and ‘Valencia’ Trees and CMNP Application on Fruit Detachment Force, Fruit Drop, and Fruit Quality. Proc. Fla. State Hort. Soc. 121: 65-68.
2008 Schumann, A.W., J.P. Syvertsen, and J.H. Graham. Microbial Soil Amendments do Little to Improve Citrus Tree Performance in Florida Soils. Proc. FSHS 121: 134-139.
As the soil microbiologist at the University of Florida, Citrus Research and Education Center (UF-CREC) with 35 years of experience in citrus production in the Americas, James Graham, Ph.D. researched and extended findings to citrus growers for the most important diseases and pests, including HLB, Citrus Blight, Canker, Phytophthora, Diaprepes root weevil, Asian psyllid, Citrus leafminer. He gained experience with exotic diseases including Leprosis and Citrus Variegated Chlorosis (CVC) most threatening US citrus. Dr. Graham’s research focused on interactions of pathogens and pest epidemics and their management with sustainable horticultural practices including balanced inputs of irrigation and fertilization, judicious use of pesticides and biological control agents. In collaborations with local, national, and international citrus research institutions he conducted research on root health and interactions of pathogens and pests that attack and debilitate roots and decrease tolerance to soil, water, and nutrient stress. Dr. Graham also gained long-term experience with management fruit and foliar diseases that cause economically important fruit losses, tree debilitation which used to exclude fruit from exports markets due to pathogen and pest quarantines.
Stephen H. Futch, PhD is an Extension Agent Emeritus with the University of Florida. He has a BS in agriculture and PhD in Horticultural Sciences both from the University of Florida and an MBA from the University of South Florida. He owned and managed citrus groves in Pasco County, Florida prior to joining UF Extension Service in 1985. He was an Extension Agent for 34 years of which the last 28 years were as the Multi-County Citrus Agent located at the UF Citrus Research & Education Center in Lake Alfred. During his extension career, he authored or co-authored more than 500 articles or research findings. Those articles appeared in trade magazines, professional proceedings, and numerous University of Florida publications. In addition to his citrus extension programs, activities were also directed toward weed control studies, pesticide license classes, agricultural safety programs, Worker Protection Standards trainings, and urban citrus production. He has observed citrus in many regions around the world (Argentina, Australia, Brazil, China, Costa Rica, Cuba, Egypt, Guatemala, Honduras, India, Israel, Jamaica, Mexico, Morocco, Nicaragua, Spain, South Africa, Trinidad, and Uruguay).
University of Georgia, 1971, PhD in Plant Pathology
University of Georgia, 1966, BS in Chemistry
1992-2019 University of Florida, Citrus Research and Education Center and Department of Plant Pathology. J. R. and Addie S. Graves Endowed Chair in Citrus Biotechnology
1991-1992 University of California Presidential Chair in Plant
Dept. of Plant Pathology
Riverside, CA 92521
1984-1991 University of California Professor
Dept. of Plant Pathology
Riverside, CA 92521
1978-1984 University of California Associate Professor
Dept. of Plant Pathology
Riverside, CA 92521
1972-1978 University of California Assistant Professor
Dept. of Plant Pathology
Riverside, CA 92521
Research program primarily focused on being prepared for a next catastrophic disease of citrus, stem pitting caused by Citrus tristeza virus. After entry of HLB into Florida, developed CTV into an expression vector to be used explore potential control measures in the lab and as a tool to deliver anti-HLB genes in citrus groves.
Field Trial Coordinator, CRDF