Horticultural Sciences Department

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Biographical Sketch

Education:

2005 Ph.D., Horticultural Science. North Carolina State University. Raleigh, NC 27695.

2001 M.S., Horticultural Science Minor: Soil Science. North Carolina State University. Raleigh, NC 27695

1989 B.S., Fine Arts, Clemson University. Clemson, SC 29634.

Professional Positions:

2011 - present Associate Professor. Horticultural Sciences, University of Florida. Organic and Sustainable Vegetable Production.

2005 - 2011 Assistant Professor. Horticultural Sciences, University of Florida. Organic and Sustainable Vegetable Production.

Professional Activities & Service:

2008 – 2011 Chair, Chair-elect, and Secretary, Organic Agriculture Working Group,Amer. Soc. Hort. Sci.

2007 – present Leadership Team Member and Cover Crops Topic Area Leader eOrganic, an eXtension Community of Practice.

2007 – present Member, Southern Region Amer. Soc. Hort. Sci. Awards Committee: Julian Miller, Sr. Distinguished Research Award

2005 – present Member, Florida State Hort. Soc.

2000 – present Member, Southern Region Amer. Soc. Hort. Sci.

2000 – present Member, Organic Agriculture Working Group, Amer. Soc. Hort. Sci.

2000 – present Member, Pi Alpha Xi

2000 – present Member, Gamma Sigma Delta

2000 – 2005 Member, National Sweetpotatoes Collaborators Group

1999 – present Member, Amer. Soc. Hort. Sci.

Instruction:

HOS 3281 – Beginning Organic and Sustainable Crop Production

Content. This was a new course that I developed and taught in Fall 2006. The goal of this course was to introduce students to science from a number of disciplines relevant to sustainable and organic crop production and to foster an appreciation of the interdisciplinary nature of farming.

Role. Required for students enrolled in the Interdisciplinary Minor as well as the Organic Horticulture Major.

HOS 4905C – Beginning Organic and Sustainable Crop Production

Content. This was a new course that I developed and taught in Spring 2007. The intent of this course is to further develop the concepts learned in HOS 3281 and to critically evaluate relevant agricultural issues that affect the industry, the environment, and society. Students received two hours of classroom lecture and six hours of field laboratory exercises each week.

Role. This capstone course is required for students enrolled in the Organic Horticulture Major.

Mentoring/Advising:

My philosophy of teaching is to provide students with the tools and information they need to create a level of understanding that fosters new ideas. I believe students learn best when they enjoy their work, take pride in their accomplishments, and have well-defined and attainable professional goals. My goal is to facilitate learning in an environment that is creative, challenging, and fulfilling, and feel this is best achieved by having high expectations and a course structure that fosters success for all learning types.  

High school student mentoring includes those students enrolled in Science and Technology Program (SSTP) summer research program for high school students. Each student designed, managed, collected and analyzed data and reported on their own research project.

  • Emily Greene 2009. Topic: Potassium uptake in cover crops.
  • Déina Bossa 2009. Topic: Rhizobium nodulation in legumes. Best Poster and Award of Distinction, SSTP Final Competition.
  • Joey Elsakr 2008.Topic: Potassium uptake in Crotalaria juncea ‘Tropic Sunn’ L.Best Paper and Award of Distinction, SSTP Final Competition. Co-author of Florida State Proceedings Paper.

Undergraduate student mentoring includes the following:

  • Terry Byatt, Independent Study (BS Horticultural Sciences). 2011. Topic: Extension program development and evaluation for the FL Small Farms Conference.
  • Lauren Coleman, Independent Study (BS Botany) 2010. Topic: Organic greenhouse lettuce production. She completed an EDIS publication on her research now in revision.
  • Bill Lester, Undergraduate Honor’s Thesis (BS Horticultural Sciences) 2008-2009. Topic: Efficacy of a biological miticide. In collaboration with Oscar Liburd, Entomology and Nematology.
  • Rachel Ben-Avraham, Undergraduate University Scholar (BS Horticultural Sciences) 2006-2007. Topic: nitrogen mineralization. Awarded 2nd place in the Undergraduate Speaking Competition, Southern Region American Society for Horticultural Science, February 2007 and presented at UF’s Undergraduate Symposium, March 2007. 

Chaired Graduate Committees

Applicant’s Role

Student

Research Topic

Home Dept.

Complete Date

Chair,

2 Ph.D.

Friedman, Seth

Effects of biochars in varying management contexts on mycorrhizae and nutrient cycling.

Horticultural Sciences

5/2013

Valle, Alvaro

Cover crop species with high phosphatase activity and facilitative root architecture to increase plant available phosphorus in vegetable cropping systems.

Horticultural Sciences

Accepted a position in industry

Co-Chair,

1 Ph.D.

Goldman, Maggie (with Peter Andersen)

Rhizosphere ecology changes over time during transition to organic production. 

Horticultural Sciences

12/2014

Chair,

4 Masters

Sarah Taber

The effect of Si on powdery mildew in cucumber 

Horticultural Sciences

12/2011

Sanon, Dakson

Summer cover crop management effects on fall cabbage 

Horticultural Sciences

12/2013

Beyer, Allison

Cultivar selection and fertility management of organic colored bell peppers in the greenhouse.

Horticultural Sciences

12/2011

Davies, Libby (Name change to Libby Rens as of 06/2010)

Chlorine dioxide as a water sanitizer for greenhouse bell pepper with a recirculated irrigation system.

Horticultural Sciences

05/2011

Sierra, Augustinas

Nutrient release and availability from individual and blended nutrient sources for organic transplant production. http://etd.fcla.edu/UF/UFE0021484/sierraaugustinas_i.pdf

Horticultural Sciences

08/2007

Chair,

2 DPM

Vega, Rafael A.

N/A

Doctor of Plant Medicine

12/2011

Taber, Sarah

N/A

Doctor of Plant Medicine

12/2011

Graduate Committees, Member

 Role

Student

Research Topic

Home Dept.

Complete Date

Member, 2 M.S. Committees

Emmanuel Torres-Quezada

TBD

Horticultural Sciences

05/2013

Poh, Bee Ling

Effect of irrigation pressure on water movement in crop root zone and crop yields of drip-irrigated tomato. http://etd.fcla.edu/UF/UFE0042605/poh_b.pdf

Horticultural Sciences

12/2011

Cho, Alyssa

Evaluation of sunn hemp (Crotalaria juncea L.) production for seed in the Southeastern United States as an economically profitable cover crop. http://etd.fcla.edu/UF/UFE0042214/cho_a.pdf

Horticultural Sciences

08/2010

Member,

4 Ph.D. Committees

Weiss, Stuart

Applying agroecological principles and sustainable organic agriculture practices to low-external-input farming in the Caribbean.

Horticultural Sciences

12/2011

Gill, Harsimran

Integrated management of soil surface insect community by soil solarization and mulching. http://etd.fcla.edu/UF/UFE0042015/gill_h.pdf

Entomology and Nematology

08/2010

Bhan, Manish

Weed population response to increasing crop diversity in organic vegetable production. http://etd.fcla.edu/UF/UFE0041224/bhan_m.pdf

Horticultural Sciences

05/2010

Tyson, Richard

Reconciling water quality parameters impacting biofiltration and cucumber (Cucumis sativus) in an aquaponic system with perlite biofilter root growth medium. http://etd.fcla.edu/UF/UFE0019861/tyson_r.pdf

Horticultural Sciences

05/2007

Member,

6 DPM* Committees (non thesis)

Tatiana Sanchez

N/A

DPM

08/2015

Johnson, Ken

N/A

DPM

08/2012

Weiss, Liron

N/A

DPM

05/2011

Merritt, Joyce

N/A

DPM

05/2010

Krueger, Romy

N/A

DPM

12/2009

Palenchar, Jessica

N/A

DPM

05/2009

Canova, Eduardo

N/A

DPM

12/2008

Publications (in reverse chronological order)

Refereed Journal Articles:

Treadwell, D.D., G.J. Hochmuth, R.C. Hochmuth, E.H. Simonne, S.A. Sargent, L.L. Davis, W.L. Laughlin, and A. Berry. 2011. Organically-managed greenhouse basil and spearmint respond differently to fertilizer source and analysis in a trough system. HortTechnology. 21(2):162-169. 

Tyson, R.V., D.D. Treadwell, E.H. Simonne. 2010. Opportunities and challenges to sustainability in aquaponic systems. HortTechnology. 21(1):6-13

Simonne, E., C. Hutchinson, J. DeValerio, B. Hochmuth, D. Treadwell, A. Wright, B. Santos, A. Whidden, G. McAvoy, X. Zhao, and T. Olczyk. 2010. Keeping water and nutrients in the root zone of vegetables. HortTechnology. 20(1):143-152

Gill, H., R. McSorley and D. Treadwell. 2009. Comparative performance of different polyethylene films for soil solarization. HortTechnology. 19(4):769-774. 

Treadwell, D.D. , N.G. Creamer, G.D. Hoyt, J.S. Schultheis. 2008. Nutrient management with cover crops and compost affects development and yield in organically managed sweetpotato systems. HortScience. 43(5):1423-1433

Tyson, R.T., E.H. Simonne , D.D. Treadwell, J.M. White, and A.H. Simonne. 2008.  Reconciling pH for ammonia biofiltration and cucumber Yield in a recirculating aquaponic system with perlite biofilters. HortScience 43:719-724.

Tyson, R.V., E.H. Simonne , M. Davis, E.M. Lamb, J.M. White, and D.D. Treadwell. 2007. Effect of nutrient solution, NO 3-nitrogen concentration and pH on nitrification rate in perlite medium. J. Plant Nutr. 30: 901-913.

Treadwell, D. D., N. G. Creamer , J. R. Schultheis, and G. D. Hoyt. 2007. Cover Crop Management Influences Weed Suppression in Organically Managed Sweetpotato Systems. Weed Technology 21:1039-1048.

Treadwell, D. D. , G. J. Hochmuth, R. C. Hochmuth, E. H. Simonne, L. L. Davis, W. L. Laughlin, S. A. Sargent, Y. Li, T. Olczyk, R. K. Sprenkel, and L. S. Osborne. 2007. Nutrient Management for Organic Greenhouse Culinary Herbs: Where Are We Now? HortTechnology. 17:461-466.

Treadwell, D.D ., D.E. McKinney, N.G. Creamer. 2003. From philosophy to science: A brief history of organic horticulture in the United States. HortScience. 38: 1009-1014.

Book Chapters:

Treadwell, D.D. 2007. Introduction to Organic Vegetable Production. Chapter 24, pp.127-140. In: S.M. Olson and E. Simonne (Eds.) 2007-2008 Vegetable Production Handbook for Florida, Vance Pub., Lenexa, KS. Revision of previous version (2006-2007)

Proceedings:

Treadwell, D.D., C.A. Chase, A. Cho, M. Alligood, and J. Elsakr. 2009. Potential for Sunn Hemp (Crotalaria juncea L.) to utilize soil potassium. Proc. Fla. State Hort. Soc. Vol 122:243-246

Treadwell, D.D., A.H. Simonne , T.P. Nkambule, R.C. Hochmuth, W.L. Laughlin, T. Olczyk, C. Peavy, and C. Rogers. Yield, chemical composition and eating quality of heirloom tomatoes grown in the subtropical climate of Florida. Proc. Fla. State Hort. Soc. Proc. Fla. State Hort. Soc. Vol. 121:170-174.

Simonne, E., C. Hutchinson, J. DeValerio, B. Hochmuth, D. Treadwell, A. Wright, B. Santos, A. Whidden, G. McAvoy, X. Zhao, and T. Olczyk. 2008. Keeping water and nutrients in the root zone of vegetables, pp. 173-203, In: T. Obreza, E. Simonne and B. Boman (Eds.) Proceedings of the 2008 Workshop on BMP Research and Education Priorities for Horticultural Crops, May 20-21, Apopka, FL.

Hochmuth, R.C. , D.D. Treadwell, E.H. Simonne, L.B. Landrum, W.L. Laughlin and L.L. Davis. 2008. Growing bell peppers in soilless culture under open shade structures. Amer. Soc. Plasticulture. Proc 34 th Natl. Agr. Plastic Congress 32:46-50.

Treadwell, D. D . 2007. What’s new with eXtension? eOrganic. Proc. Fla. State Hort. Soc. 120:181-183.

Olczyk, T. , Y. Qian, K.W. Migliaccio, Y.C. Li, G.H. Hochmuth, R.C. Hochmuth, E.H. Simonne, D.D. Treadwell, L.S. Osborne, and R.K. Sprenkel. 2007. Nutrient Management for greenhouse production of container grown organic herbs. Proc. Fla. State Hort. Soc. 120:178-180

Treadwell, D. D . 2006. A review of cover crop research in Florida: Contributions to nutrient cycling in vegetable production. Proc. Fla. State Hort. Soc. 119:255-257

Hochmuth, R.C ., G.J. Hochmuth, R.K. Sprenkel, E.H. Simonne, D.D. Treadwell, L.S. Osborne, T.W. Olczyk, and Y. Li. 2006. Adopting new plasticulture techniques to grow organic herbs in Florida greenhouses. Proc 33 rd Natl. Agr. Plastic Congress 31:11-15.

Abstracts:

Treadwell, D.D., C.A. Chase, A.H. Cho and M. Alligood. 2010. Residue Quality and Decomposition Rate of Terminated Sunn Hemp Grown for Seed. HortScience. 45(8):138

A. H. Cho, C. A. Chase, D. D. Treadwell and R. L. Koenig.2010. Evaluation of Phenotypic Characteristics of Sixteen Accessions of Sunn Hemp in Florida. Amer. Soc. Hort. Sci. Annual Meeting. Electronic Abstract: http://ashs.confex.com/ashs/2010/webprogram/Paper3686.html

Davies, L.R.R., D. D. Treadwell, D. J. Cantliffe, J. A. Bartz and M. R. Alligood. 2010.  Vigor Response of Greenhouse Bell Pepper Due to Chlorine Dioxide Sanitized Irrigation Water. HortScience. 45(8):S97  

Cho, A., C.A. Chase, R. Koenig and D. Treadwell. 2010. Evaluation of Sixteen Accessions of Sunn Hemp (Crotalaria juncea) for Seed Production Potential in Florida. HortScience. 45(8):S240

Weiss, S., D. Treadwell, C.A. Chase, R. Ben-Avraham. 2009. Effect of Cover Crop and Green Manure Systems for Sustainable Management of Soil Nitrogen and Organic Matter in Low-External-Input (LEI) Organic Crop Production in the Caribbean. 2009 Agron. Soc. Amer. –Crop Sci. Soc. Amer. –Soil Sci. Soc. Amer. Annual Meeting. Electronic Abstract: http://a-c-s.confex.com/crops/2009am/webprogram/Paper54491.html

Treadwell, D.D., C.A. Chase, A. Cho, M. Alligood and J. Elsakr. 2009 Potential for Sunn Hemp (Crotalaria juncea L.) to Utilize Soil Potassium. Fla. State Hort. Soc. 122:243-247

Treadwell, D.D. , M.A. Alligood, C.A. Chase, M. Bhan. 2008. Soil nitrogen responses to increasing crop diversity and rotation in organic vegetable production systems. HortScience. 43:1107.

Tyson, R., E. Simonne , J. White, D. Treadwell, A. Simonne, and E. Lamb. 2008. Sustainability of recirculating aquaponic systems is influenced by system water pH. HortScience. 43:1086

Treadwell, D. D. , G. J. Hochmuth, R. C. Hochmuth, S. A. Sargent, E. H. Simonne, L. L. Davis, W. L. Laughlin, A. Berry, Y. Li, T. Olczyk, R. K. Sprenkel and L. S. Osborne. 2007. Organic Greenhouse Production of Basil and Spearmint: Nutrient Uptake and Postharvest Quality. HortScience 42:868

Sierra, I.A., D.D. Treadwell , E. Simonne and D. Graetz. 2007. Nitrogen mineralization from organic amendments approved for use in organic production. HortScience 42:458-459.

Treadwell, D.D ., G.J. Hochmuth, R.C. Hochmuth, E.H. Simonne, S.A. Sargent, L.L. Davis, W.L. Laughlin, Y. Li, T. Olczyk, R.K. Sprinkel, and L.S. Osborne. 2006. Nutrient management or organic greenhouse culinary herbs. HortScience 41(4):957-958.

Chase , C.A. , O.S. Mbuya, and D.D. Treadwell. 2006. Living mulches for weed suppression and enhanced water infiltration in fall broccoli. HortScience 41(4):998

Creamer, N. G ., D. D. Finney and D. D. Treadwell. 2005. Organic prog rams at the Center for Environmental Farming Systems. Proc. 15 th Annual IFOAM Organic World Congress 15:57

Electronic Extension Publications:

Taber, S., D. Treadwell, R. Tyson and E. Simonne.2010. Foliar micronutrients in closed aquaponics systems: Maintaining healthy levels and sourcing appropriate supplements. EDIS, HS408. http://edis.ifas.ufl.edu/hs408

Treadwell, D. R. Hochmuth, L. Landrum and W. Laughlin. 2010. Microgreens – A New Specialty Crop. EDIS, HS1164. http://edis.ifas.ufl.edu/hs1164

Treadwell, D.D. 2010. Introduction to Organic Vegetable Production. EDIS, CV118/ HS720, http://edis.ifas.ufl.edu/CV118. (Minor revision of original 2006 version, and subsequent revision in 2007.)

Sargent, S. and D. Treadwell. 2009. Guide for Maintaining the Quality and Safety of Organic Vegetables and Melons during Harvest and Handling Operations. EDIS HS1148. http://edis.ifas.ufl.edu/hs396

Gaul, S.A., R.C. Hochmuth, G.D. Israel, and D. Treadwell. 2009. Characteristics of Small farm Operators in Florida: Economics, Demographics, and Preferred Information Channels and Sources. http://edis.ifas.ufl.edu/WC088

Palenchar, J., D.D. Treadwell, L. Datnoff and A. Gevens. 2009. Cucumber Anthracnose in Florida. http://edis.ifas.ufl.edu/PP266

Stephens, J., S. Park-Brown, D. Treadwell, S. Webb and A. Gevens. 2009. Florida Vegetable Gardening Guide. http://edis.ifas.ufl.edu/VH021

Thralls, E. and D. Treadwell. 2008. Home vegetable garden techniques: Hand pollination of squash and corn in small gardens. http://edis.ifas.ufl.edu/HS3098

Simonne, A. and D. Treadwell. 2008. Minimizing food safety hazards for organic growers. EDIS. http://edis.ifas.ufl.edu/FY1062

Nguyen, T., A. Wysocki, and D. Treadwell. 2008. Economics of the Organic Industry in Florida. EDIS. http://edis.ifas.ufl.edu/FE732

Treadwell, D.D. and M.E. Swisher. 2008. Understanding the ‘USDA Organic’ Label. EDIS. http://edis.ifas.ufl.edu/HS397

Treadwell, D.D., W. Klassen and M. Alligood. 2008. Annual cover crops in Florida vegetable systems. Part I. Objectives: Why grow cover crops? EDIS. http://edis.ifas.ufl.edu/HS387

Treadwell, D.D. W. Klassen and M. Alligood. 2008. Annual cover crops in Florida vegetable systems. Part II. Production. http://edis.ifas.ufl.edu/HS389

Treadwell, D.D. W. Klassen, M. Alligood and S. Shewey. 2008. Annual cover crops in Florida vegetable systems. Part III. Buying and Sourcing. http://edis.ifas.ufl.edu/HS390

Simonne, E.H., R. Hochmuth, J. Bremen, W. Lamont, D. Treadwell and A. Gazula. 2008. Drip-irrigation systems for small conventional vegetable farms and organic vegetable farms. EDIS. http://edis.ifas.ufl.edu/HS388

Treadwell, D. and P. Huang*. 2008. Buckwheat: A cool season cover crop for Florida vegetable producers. EDIS. http://edis.ifas.ufl.edu/HS386

Treadwell, D. and M. Alligood. 2007. Sunn hemp (Crotalaria juncea L.): A summer cover crop for Florida vegetable producers. EDIS, HS376, http://edis.ifas.ufl.edu/HS376

Robert C. Hochmuth , Danielle D. Treadwell, Eric H. Simonne, Linda B. Landrum, Wanda L. Laughlin, and Lei Lani Davis. 2007. Growing bell peppers in soilless culture under open shade structures. EDIS, HS368,http://edis.ifas.ufl.edu/HS368

Sierra, A.*, E. Simonne, y D. Treadwell. 2007. Principios y prácticas para el manejo de nutrientes en la produccion de Hortalizas (Principles and practices of water and nutrient management in horticultural production). EDIS, HS356, http://edis.ifas.ufl.edu/HS356

Migliaccio, K.W., T. Olczyk, Y. Qian, Y. Li, G.J. Hochmuth, R.C. Hochmuth, D.D. Treadwell, E.H. Simonne, L.S. Osborne, and R.K. Sprenkel. 2007. Organic greenhouse container herb production in south Florida: Fertilizer and potting media. EDIS, ABE373, http://edis.ifas.ufl.edu/AE408