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John E. Erwin

Professor & Chair

Professor & Chair

Plant Science & Landscape Architecture 2104 Plant Sciences Building 4291 Fieldhouse Drive College Park, MD 20742-4452


  • B.S. Ornamental Horticulture Delaware Valley College of Science and Agriculture (1983)
  • M.S. Horticulture Michigan State University (1986)
  • PhD. Horticulture Michigan State University (1989)

My research aims to 1) reduce negative impacts of high temperature on crop yield by accelerating high temperature tolerant crop development through molecular and traditional breeding techniques, to 2) reduce chemical, energy and labor crop production inputs while increasing postharvest life, and to 3) introduce new drought and/or heat tolerant crops.For instance, Additional work I am involved in focuses on temperature and lighting requirements to maximize vegetable and fruit crop production in controlled environment agriculture systems to maximize yield and nutritional value.


Some Research Outcomes:  

- Developed novel temperature manipulation techniques to reduce stem elongation in controlled environments (referred to as DIF, DROP and DIP) to reduce chemical and energy use.

- Identified photoperiodic flowering requirements of ornamentals and herbs (>80 species) used to control flowering throughout North America to increase sales and reduce inputs.  

- Determined photosynthetic and flowering heat tolerance is associated with stomatal closure and the plant growth hormone abscisic acid synthesis and/or response in Arabidopsis and tomato.

- Determined photosynthetic responses of ornamental, leafy greens, tomatoes and peppers to irradiance, CO2 and temperature to maximize photosynthesis and yield and minimize energy inputs.

- Determined how temperature, irradiance and daylength impact flowering of >78 cacti/succulent species that has facilitated commercialization of cacti and succulents throughout North America.

- Developed novel fungicide/pesticide application techniques that have/are dramatically reduced chemical and labor inputs and environmental impacts while increasing efficacy.


Recent work focuses on 1) how microbial media inoculation can increase the nutritional value of foods produced in controlled environment systems, 2) how to induce natural plant defenses to decrease pesticide use and increase beneficial insect efficacy in controlled environment agricultural systems, and 3) whether inoculation with high-temperature tolerant microbes can enhance root heat tolerance (important in containerized production) to increase crop growth and yield.



Professional Work

2019-present          Professor and Chair, Department of Plant Science & Landscape Architecture

1986–present         Controlled Environment and Ornamental and Crop Production Consultant

2007-2019               Professor, Department of Horticultural Science, University of Minnesota.

2010-2017               Elected Citywide Minneapolis Park and Recreation Board Commissioner (2 terms; 8 years)

1997–2007              Associate Professor, Department of Horticultural Science, University of Minnesota.     

2002-2005               Elected Citywide Minneapolis Park and Recreation Board Commissioner (1 term; 4 years)

1989-1996               Assistant Professor, Department of Horticultural Science, University of Minnesota.

1983–1989              Graduate Research Assistant, Department of Horticulture, Michigan State University.

1983-1989               Owner, Erwin Landscaping Service (Lansing, MI)

1976-1983                Landscaper, Nursery Manager, County Line Landscape Nursery (Harleysville, PA).


My research efforts revolve around: 

-  1) the environmental physiology of thermomorphogenesis and high temperature effects on flowering,

-  2) on environmental manipulation and production strategies in controlled environments to maximize photosynthesis and yield, reduce production time, increase sales and reduce chemical, energy and labor inputs in ornamental and greenhouse vegetable production, 

-  3) identification of and development of production strategies for new heat/drought tolerant ornamental crops (especially cacti and succulents), and 

-  4) environmental and microbial impacts on edible crops in controlled environment systems (CEA) to increase yield and pest and disease tolerance.


Research Findings:

My work showed diurnal temperature fluctuations affect plant morphogenesis broadly and that ABA is associated with and high temperature tolerance in flowering in Arabidopsis and tomato.   

As part of that work we developed novel temperature management techniques (DIF, DROP, DIP) to reduce chemical growth retardant use and production strategies to reduce pesticide/fungicide application.  

More recently, we developed lighting/temperature strategies to schedule flowering to maximize sales.  

Temperature and lighting standards we developed are now being used to maximize leafy green and herb nutritional value and yield (photosynthesis) in controlled environment production systems.

Current work focuses on UV-A, -B and -C light effects on nutritional value of edible crops, post harvest life of ornamental crops and pest and disease proliferation.


My undergraduate teaching efforts primarily focus on using experiential learning utilizing techniques grounded in science to teach horticulture crop production techniques in controlled environment systems.  

As part of that work I teach coursework focusing on hydroponic and/or aquaponics systems in controlled environment agricultural systems utilizing new LED lighting technologies.  

My most recent teaching efforts focus on two courses

-  ‘Growing the Guilty Pleasures’, and

-  ‘Backyard Farmer:  The Science to Food Production and Preservation’ 

with appeal to a more general audience and to attract non-majors to the plant sciences.  

My graduate teaching efforts have focused on teaching whole plant photosynthesis, flowering physiology, and consulting methods.


My extension program is the only program that focuses on 1) controlled environment agriculture, 2) greenhouse production of ornamental and edible crops, and 3) outdoor ornamental crop production in North America.   As such, I strive to be a national, regional and local extension resource.  All extension articles and recent presentations can be found on my website: .

My extension activities are grounded in a strong belief in the importance of the Lang-Grant mission to Maryland residents and industry as well as the regional and national industries.  

I use a broad array of communication and outreach tools to address industry needs, however, my outreach efforts are increasingly web-based (websites, video conferencing, email, etc.).  These tools allow for outreach to growers on the Eastern Shore and Western Maryland as well as a broader national and international audience. 

Research Publications

Books Chapters:

  1. Erwin, J.  2019.  Environmental physiology of ornamental crops.  In:  M. Reid, ed., Advances in Ornamental Horticulture.  Cambridge Press. (in press; anticipate 2020).
  2. Currey, C., D. Kopsell, N. Mattson, R. Lopez and J. Erwin.  2016.  In: Runkle, E. & R. Lopez, Lighting Up Profits:  Chapter 15 – Supplemental and sole-source lighting of leafy greens, herbs, and microgreens.  2nd. Ed., Meister Pub., Willoughby, OH. pp.
  3. Erwin, J., N. Mattson & R. Warner.  2016.  In: Runkle, E. & R. Lopez, Lighting Up Profits:  Chapter 10 – Light effects on annual bedding plants.  2nd. Ed., Meister Pub., Willoughby, OH. pp. 
  4. *Ascough, G., J. Van Staden, and J. Erwin.  2006.  In: Watsonia.  A. Teixeira da Silva (Ed.), Floriculture, Ornamental and Plant Biotechnology: Advances and topical issues, Global Science Books, London. pp.
  5. Erwin, J.E.  2006. Factors affecting flowering in ornamental plants.  In.  Flower Breeding and genetics:  Issues, challenges. Anderson, N. Ed. 7-48.
  6. Erwin, J.E. 2005.  Flower induction in ornamental plants.  In.  Flower Seeds:  Biology and technology.  Ed. M.B. McDonald and F.Y. Kwong. CABI Publishing, Cambridge, MA , USA.  Pp. 87-116.
  7. Erwin, J.E.  2004.  Using Day length to control flowering.  In: Lighting up your profits.  Eds Runkle, E. and R. Lopez.  Greenhouse Grower Press.
  8. Erwin, J., N. Matteson, and R. Warner.  Light effects on bedding plants.  In:  Light Management in Controlled Environments. Eds. Runkle, E., and R. Lopez.  Greenhouse Grower Press.  pp. 1-13.
  9. Warner, R., and J.E. Erwin.  2001.  Temperature.  In Tips on regulating growth of floriculture crops.  C.A. Buck and S.A. Carver Eds, Ohio State Univ. Pub., pp. 10-17.
  10. Erwin, J.E., and R.M. Warner 1999.  Temperature.  In Tips on Growing Bedding Plants, Ed. Harry Tayama, 4th. Ed., Ohio State Univ. Pub. pp. 69-82.
  11. Heins, R.D. and J.E. Erwin.  1999.  Non-chemical control of bedding plant growth.  In Tips on Growing Bedding Plants, Ed. Harry Tayama, 4th Ed., Ohio State Univ. Pub. pp. 105-109.
  12. Erwin, J.E. 1997.  Fuchsia, In:  Tips on Growing and Marketing Specialty Potted Plants.  Ohio Florists Association, Columbus, OH.  pp. 66-70. 
  13. Erwin, J.E.  1996.  Light and Temperature, In:  Tips on Growing and Marketing Garden Mums.  Ohio Florists Association, Columbus, OH, pp. 36-42.
  14. Erwin, J.E.  1995.  Temperature and light effects on New Guinea impatiens growth.  In New Guinea Impatiens:  A Ball Guide, Ball Publishing, Batavia, IL, pp. 41-54.
  15. Erwin, J.E.  1994.  Asexual propagation of bedding plants.  In Bedding Plants IV, Ed. J. Holcomb. Ball Publishing, pp. 363-378.
  16. Barrett, J., and J.E. Erwin.  1994.  Controlling bedding plant height.  In Bedding Plants IV, Ed. J. Holcomb, Ball Publishing, pp. 197-214.
  17. Erwin, J.E. 1993.  Temperature effects on bedding plant growth.  In Tips on Growing Bedding Plants, Ed. Harry Tayama, 3rd. Ed., Ohio State Univ. Pub. pp. 77-91.
  18. Heins, R.D. and J.E. Erwin.  1993.  Non-chemical control of bedding plant growth.  In Tips on Growing Bedding Plants, Ed. Harry Tayama, 3rd Ed., Ohio State Univ. Pub. pp. 106-111.
  19. Erwin, J.E.  1993.  Poinsettia height control.  In Poinsettias:  Growing and Marketing. Ed. J. Martens and K. Pyle.  Ball Publishing, Batavia, IL, pp. 22-30.
  20. Erwin, J.E., and R.D. Heins.   1992. DIF:  Control plant growth with temperature.  Meister Publishing, Cleveland Ohio. (in Japanese).
  21. Erwin, J.E., and R.D. Heins.   1992. DIF:  Control plant growth with temperature.  Meister Publishing, Cleveland Ohio. (in English).
  22. Erwin, J.E., R.D. Berghage, and D.A. Hopper. 1991. Light and temperature effects on geranium growth, In Geranium Tips, 2nd Ed., Ed. H Tayama, Ohio State Univ. Pub. pp. 23-26.
  23. Erwin, J.E., and R.D. Heins.  1991.  Environmental effects on geranium growth.  In. Geraniums IV, Ed. John White.  Ball Pub. Inc., pp. 55-63.
  24. Erwin, J.E.  1991.  Nephrolepis exaltata 'Bostoniensis'.  In:  GrowerTalks on crop culture.  Geo. J. Ball. Pub., Chicago, IL. pp. 155-156.
  25. Erwin, J.E., and R. Heins.  1990.  Research Update:  Don't use B-Nine on your vegetable plugs-it's illegal.  Try temperature for height control.  In GrowerTalks on Plugs, Geo J. Ball, Pub., West Chicago, IL., pp. 99-100.


Refereed Journal Articles (total: 64)

  1. Erwin, J., Hussein, T. & D.J. Baumler.  2019.  Pepper photosynthesis, stomatal conductance, transpiration and water use efficiency differ with variety, indigenous habitat and species of origin.  Hortscience 54(?): (in press). 
  2. Erwin, J., & J. Hensley.  2019.  Evaluation of species with horticultural attributes foe green roofs in a cool, dry climate.  Hortscience. 54(?):. (in press).
  3. Lahijani, M., M. Kafi, A. Nezami, J. Nabati, J.E. Erwin.  2019.  Effect of CO2 enrichment on gas exchange, biochemical traits, and minituber yield in potato (Solanum tuberosum L.) cultivars.  Journal of Agricultural Science and Technology, 21(4), 883-894.
  4. Lahijani, M., Kafi, M., Nezami, A., Nabati, J., Mehrjedi, M., Shankoomahally, S., and Erwin, J. E.  2018. Variations in assimilation rate, photo assimilate translocation, and cellular fine structure of potato cultivars (Solanum tuberousa L.) exposed to elevated CO2. Plant Physiology and Biochemistry, 130, 303-313. doi: 10.1016/j.plaphy.2018.07.019
  5. Lahijani, M., Kafi, M., Nezami, A., Nabati, J., & Erwin, J. E. 2018. Effect of 6-benzylaminopurine and abscisic acid on gas exchange, biochemical traits, and minituber production of two potato cultivars (Solanum tuberosum L.). Journal of Agricultural Science and Technology, 20(1), 129-139.  
  6. Lahijani, M., Kafi, M., Nezami, A., Nabati, J., & Erwin, J. E.  2018. Sprouting, plant establishment, and yield improvement of potato (Solanum tuberosum L.) minituber cultivars by foliar application of benzylaminopurine and abscisic acid. doi: 10.22069/EJCP.2018.12071.1929
  7. Erwin, J., and E Gesick.  2017.  Photosynthetic responses of Swiss chard (Beta vulgaris), kale (Brassica oleracea and napus pabularia) and spinach (Spinacea oleracea) to irradiance and carbon dioxide.  HortScience, 52(5): 706-712.
  8. Erwin, J., K Altman, and F Esqueda.  2017.  Temperature impacts on cactus and succulent development rate.  HortTechnology, 27(1):65-68.
  9. Erwin J., R. O’Connell, and K. Altman. 2016. Photoperiod, irradiance and temperature affect Echinopsis ‘Rose Quartz ‘flowering.  HortScience 51(12): 1494-1497.
  10. Boldt, J., M.H. Meyer, and J.E. Erwin.  2014.  Foliar anthocyanins:  a horticultural review.  Horticultural Reviews.  42:209-252.
  11. Cave, R.L., Hammer, G.L., McLean, G., Birch, C.J., Erwin, J.E., Johnson, M.E.  2013.  Modelling temperature, photoperiod and vernalization responses of Brunonia australis (Goodeniaceae) and Calandrinia sp. (Portulacaceae) to predict flowering time.  Annals of Botany, 111(4):629-639.
  12. Fisher, PR, Runkle ES, Blanchard MG, Erwin JE, MacKay B.  2012.  FlowersOnTime: A computer decision-support tool for floriculture crop producers.  Journal of Extension, 50(5): 5TOT5.
  13. Currey CJ, Erwin JE. 2012.  Foliar applications of plant growth regulators affect stem, elongation and branching of 11 Kalanchoe species.  HortTechnology, 22:338-344. 
  14. Cave RL, Birch CJ, Hammer GL, Erwin JE, Johnston ME. 2011. Juvenility and flowering of Bruonia australis(Goodeniaceae) and Calandrinia sp. (Portulacaceae) in relation to vernalization and daylength. Annals of Botany, 108:215-220.
  15. Currey CJ, Erwin JE. 2011. Photosynthetic daily light integral impacts growth and flowering of several Kalanchoespecies. HortTechnology, 21:98-102.
  16. Thompson DI, Mtshali NP, *Ascough GD, Erwin JE, Van Staden J. 2011. Flowering control in Watsonia: effect of corm size, temperature, photoperiod and irradiance. Scientia Horticulturae, 129:493-502.
  17. Cave RL, Birch CJ, Hammer GL, Erwin JE, Johnston ME. 2011. Cardinal temperatures and thermal time for seed germination of Bruonia australis (Goodeniaceae) and Calandrinia sp. (Portulacaceae). Hortscience, 46:753-758.
  18. Currey CJ, Erwin JE. 2011. Photoperiodic flower induction of several Kalanchoe species and ornamental characteristics of flowering species. Hortscience, 46:35-39.
  19. Rohwer, C.L. and J.E. Erwin. 2010.  Spider mites (Tetranychus urticae) perform poorly and disperse from plants exposed to methyl jasmonate. Entomologia Experimentalis et Applicata, 137(2):143-152.
  20. Currey, C. & J.E. Erwin.  2010.  Variation among Kalanchoe species flowering responses to day/night length and short-day cycle number.  Journal of Horticultural Science and Biotechnology, 85(4):350-354.
  21. Cave, RL, CJ Birch, GL Hammer, JE Erwin, ME Johnson. 2010.  Floral ontogeny of Brunonia (Goodeniaceae) and Calandrinia sp. (Portulacaceae).  Australian Journal of Botany, 58: 1-9.
  22. Ascough, G., J.E. Erwin, and J. van Staden.  2009.  Micropropagation of Iridaceae – a review.  Plant Cell Tissue and Organ Culture. 97 (1):1-19.
  23. Ascough, GD., O Navak, A Pencik, J Rolick, M Strand, JE Erwin, and J van Staden.  2009.  Hormonal and cell division analysis in Watsonia lepida seedlings.  Journal of Plant Physiology.  166(14):1497-1507.
  24. Ascough, G.D., J. van Staden, & J.E. Erwin.  2008.  In vitro storage organ formation on ornamental geophytes.  Hort. Reviews.  Ed. Jules Jannick. Wiley Press.  34:417.
  25. Ascough, G.D., J.E. Erwin, and J. van Staden.  2008.  Reduced temperature, elevated sucrose, continuous light and gibberellic acid promote corm formation in Watsonia vanderspuyiae.  Plant Cell Tissue and Organ Culture. 95:275-283.
  26. Ascough, GD, J.E. Erwin, and J van Staden.  2008.  Effectiveness of colchicine and oryzalin at inducing polyploidy in Watsonia lepida N.E. Brown.  Hortscience, 43(7):2248-2251.
  27. Rohwer, C.L. and J.E. Erwin. 2008. Horticultural application of jasmonates: a review.  Journal of Horticultural Science and Biotechnology. 83:283-304.
  28. Ascough, G.D., J. Erwin, and J. van Staden.  2007.  In vitro propagation of four Watsonia species.  Plant, Cell, Tissue and Organ Culture, 88:135-145.
  29. Ascough, JE Erwin, J Van Staden.  2007.  Botanical nepotism – keeping storage organ formation in the family.  South African Journal of Botany, 73(2):277.
  30. Ascough, G.D., J.E. Erwin, and J van Staden.  2007.  Temperature-dependent seed germination in Watsonia species related to geographic distribution.  South African Journal of Botany. 73(4):650-653.
  31. Warner, R., and J.E. Erwin.  2006.  Prolonged High Temperature Exposure Differentially Reduces Growth and Flowering of Twelve Viola × wittrockiana Gams. cultivars. Scientia Horticulturae. 108:295-302.
  32. Warner, R., and J.E. Erwin.  2005.  Naturally-occurring variation in high temperature induced floral bud abortion across Arabidopsis thaliana accessions. Plant, Cell and Environment. 28:1255-1266.
  33. Warner, R., and J.E. Erwin.  2005.  Prolonged high temperature exposure and daily light integral impact growth and flowering of five herbaceous ornamental plant species. Journal of the American Society of Horticultural Science, 130(3):319-325.
  34. Mattson, N., and J.E. Erwin.  2005.    The impact of photoperiod and irradiance on flowering of several herbaceous ornamentals.  Scientia Horticulturae. 104:275-292.
  35. Van Gaal, T., and J.E. Erwin.  2005.  Diurnal variation in thigmotropic inhibition of stem elongation.  Hortechnology, 15(2):291-294.
  36. Warner, R., and J.E. Erwin.  2003.  Effect of photoperiod and daily light integral on flowering of five Hibiscus L. spp.  Scientia Horticulturae. 97:341-351.
  37. Warner, R., and J.E. Erwin.  2003. Effect of plant growth retardants on stem elongation of Hibiscus species.  HortTechnology. 13(2):293-295.
  38. Erwin, J.E., A. Smith and R. Warner.  2002.  Vernalization, photoperiod and GA3 interact to affect flowering of Japanese radish (Raphanus sativus ‘Chinese Radish Jumbo Scarlet’).  Physiologia Plantarum. 115:298-302.
  39. Warner, R., and J.E. Erwin.  2001. Variation in floral induction requirements of Hibiscus spp.  Journal of the American Society of Horticultural Science. 126:262-268.
  40. Cutlan, A., J. E. Simon, L. Bonilla, and J.E. Erwin.  2000.  Intra-specific variability of feverfew:  correlations between parthenolide. Morphological traits and seed origin.  Planta Medica. 66:612-617.
  41. Erwin, J.E.  1998.  Temperature and light effects on plant stem elongation.  Journal of the Japanese Society of Horticultural Science. 67(6):1113-1120.
  42. Erwin, J.E. and G. Engelen-Eigles. 1998. Influence of simulated shipping and rooting temperature and production year on Easter lily (Lilium longiflorum Thunb.) development. Journal of the American Society for Horticultural Science.123:230-233.
  43. Engelen-Eigles, G., and J.E. Erwin.  1997. A model plant for vernalization studies.  Scientia Horticulturae. 70:197-202.
  44. *Reese, Cheryl R., and J.E. Erwin.  1997.  The effect of day/night temperature on Pharbitis nil Chois flowering.  HortScience. 32:1046-1048.
  45. Erwin, J.E.  1997.  Factors affecting propagation of Clematis by stem cuttings.  HortTechnology. 7:408-410.
  46. Erwin, J.E., Glomsrud, N., T. Vikor, R. Moe, and P. Etzel.  1997.  Cutting position, leaf removal and time of year affects Rosa axillary shoot development.  Scientia Horticulturae, 68:157-170.
  47. Moe, R., J. E. Erwin, and W. Carlson.  1996.  Factors affecting Gerbera jamesonii early seedling branching and mortality.  HortTechnology, 6(1):59-61.
  48. Hopper, D.A., G.W. Stutte, A. McCormack, D.J. Barta, R.D. Heins, J.E. Erwin, and T.W. Tibbitts.  1997.  Plant growth chamber handbook.  North Central regional Research Publication.  340:217-225.
  49. *Hellewell, K.B., D.D. Stuthman, A.H. Markhart III, and J.E. Erwin.  1996.  Day and night temperature effects during grain filling in oat.  Crop Science, 36:624-628.
  50. Erwin, J.E.  1996.  Temperature and photoperiod affect cactus scion necrosis.  HortTechnology. 6:393-396.
  51. Erwin, J., and R. Heins.  1995. Thermomorphogenic responses in leaf and stem development.  Hortscience. 30:940-949.
  52. Erwin, J.E., P. Velguth, and R.D. Heins.  1994.  Day/night temperature environment affects  Lilium  longiflorum cell morphology.  Journal of Experimental Botany. 45:1019-1025.
  53. Erwin, J.E., R.D. Heins, and J. Faust. 1993.  Thermomorphogenic and photoperiodic responses of  Nephrolepis exaltata cv 'Dallas Jewel'.  Hortscience, 28(3):182-184. 
  54. Erwin, J.E., R.D. Heins, W. Carlson, and S. Newport.  1992.  Mini Review:  Diurnal temperature fluctuations and mechanical manipulation affect plant stem elongation.  PGRSA Quarterly, 20(1):1-17.
  55. Erwin, J.  1992.  Physiological basis for day/night temperature regime (DIF) effects on stem elongation.  Nordiska Jordbruksforskares Forening, NJF-Utredning/Rapport NR 77:  Regulering av plantenes morfogenese.
  56. Erwin, J.E., R.D. Heins, and R. Moe.  1991.  Temperature and photoperiod effects on  Fuchsia x hybrida morphology. Journal of the American Society of Horticultural Science. 116(6):955-960.
  57. Moe, R., R.D. Heins, and J.E. Erwin. 1991.  Stem elongation and flowering of the long-day plant Campanula isophylla Morettii. in response to day and night temperature alterations and light quality.  Scientia Horticulturae, 48:141-151.
  58. Erwin, J.E., and R.D. Heins.  1990.  Temperature effects on lily development rate and morphology from the visible bud stage until anthesis.  Journal of the American Society of Horticultural Science. 115:644-646.
  59. Berghage, R.D., R.D. Heins, M.G. Karlsson, J. Erwin, and W. Carlson.  1989.  Pinching technique influences lateral shoot development in poinsettia.  Journal of the American Society of Horticultural Science. 114(6):909-914.
  60. Erwin, J.E., R.D. Heins, and M.G. Karlsson.  1989.  Thermomorphogenesis in Lilium longiflorum, Thunb., American Journal of Botany. 76:47-52.
  61. Karlsson, M.G., R.D. Heins, *J.E. Erwin, R.D. Berghage, W.H. Carlson, and J.A. Biernbaum.  1989.  Irradiance and temperature effects on time of development and flower size in chrysanthemum.  Scientia Horticulturae. 39:257-267.
  62. Karlsson, M.G., R.D. Heins, *J.E. Erwin, and R.D. Berghage.  1989.  Development rate during four stages of chrysanthemum growth determined by preceding and prevailing temperatures.  Journal of the American Society of Horticultural Science. 114(2):234-240.
  63. Karlsson, M.G., R.D. Heins, *J.E. Erwin, R.D. Berghage, W.H. Carlson, and J.A. Biernbaum.  1989.  Temperature and photosynthetic photon flux influence Chrysanthemum shoot development and flower initiation under short day conditions.  Journal of the American Society of Horticultural Science. 114:158-163.
  64. Karlsson, M.G., R.D. Heins, and *J.E. Erwin.  1988.  Quantifying temperature controlled leaf unfolding rates in Lilium longiflorum Thunb. 'Nellie White'. Journal of the American Society of Horticultural Science.  113:70-74.



Published Conference Proceedings

  1. Cave, R.L., J.E. Erwin, G.L. Hammer, C.J. Birch, and M.E. Johnson.  2010.  An experimental approach for developing seed lines of new Australian native flowering pot plants.  International Symposium on Advances in Ornamentals, Landscape and Urban Horticulture.  Acta Horticulturae. 937:37-43.
  2. Currey, C.J. and J.E. Erwin. 2010. Photoperiodic effects on flowering of Kalanchoe species with ornamental potential. XXVIIIth International Horticultural Congress, Acta Horticulturae 2:137
  3. Zanin, P., and J.E. Erwin.  2008. Responses of Salvia spp. To photoperiod and irradiance at different times in a production cycle.  Acta Horticulturae.
  4. Erwin, J.E.  2007.  Looking for new ornamentals:  Flowering studies.  VI International Symposium on New Floriculture Crops.  Madera Island, Portugal.  Acta Horticulturae.  813:61-66. 
  5. Erwin, J. 2007.  Cacti:  studies on introducing a new group of ornamental plants.  VI International Symposium on New Floriculture Crops.  Madera Island, Portugal. Acta Horticulturae. 813:359-364.
  6. Zanin, P., and J.E. Erwin.  2006.  Photoperiod and irradiance effects on Salvia elegansSgreggii, and Spatensflowering, height and branching.  I International Symposium on Labiatae:  Advances in Production, Biotechnology and Utilization.  Acta Horticulturae. 723:367-374. 
  7. Erwin, J.E., C. Rohwer, and E. Gesick.  2006. Red:far red and photosynthetically active radiation filtering by leaves differs with species.  V. International Symposium on Artificial Lighting in Horticulture.  Lillehammer, Norway.Acta Horticulturae. 711:195-199.
  8. Rohwer, C.L., and J.E. Erwin.  2005.  Irradiance and photoperiod effects on methyl jasmonate synthesis in Artemisiaspp.  V. International Symposium on Artificial Lighting in Horticulture.  Lillehammer, Norway. Acta Horticulturae. 711:375-380.
  9. Mattson, N.S., and J.E. Erwin.  2002.  Temperature affects flower initiation and development rate of impatiens, Petunia, and Viola.  XXVI International Horticulture Congress:  Elegant Science in Floriculture. Acta Horticulturae. 624:191-197.
  10. Erwin, J.E., and R.M. Warner.  2002.  Determination of photoperiodic response group and effect of supplemental irradiance on flowering of several bedding plant species. Acta Horticulturae, 580:95-99.
  11. Warner, R., and J.E. Erwin.  2002.  Estimation of total canopy photosynthetic capacity of roses grown under two canopy management systems. IV. International Symposium on Artificial Lighting Acta Horticulturae. 580:89-93.
  12. Warner, R.M., and J.E. Erwin.  2000.  Photosynthetic responses of heat-tolerant and heat-sensitive cultivars of Impatiens hawkeri and Viola x wittrockiana to high temperature exposures.  IV. International Symposium on Artificial Lighting. Acta Horticulturae.  580:215-219.
  13. Erwin, J.E.  2000.  Variation in photoperiodic responses among commercial species.  IV. International Symposium on Artificial Lighting.  Quebec City, Quebec, Canada. Acta Horticulturae 580:
  14. Wagner, R.  And J.E. Erwin.  2000.  Variation in photosynthetic rate among commercial roses grown under two different management strategies. IV. International Symposium on Artificial Lighting.  Quebec City, Quebec, Canada. Acta Horticulturae 580:
  15. Erwin, J.E., R.M. Warner. 2000.  Determination of photoperiodic response group and effect of supplemental irradiance on flowering of several bedding plant species.  IV International Symposium on Artificial Lighting. Acta Horticulturae580:95-99.
  16. Wagner, R.  and J.E. Erwin.  2000.  Variation in photosynthetic rate among commercial roses grown under two different management strategies. IV International Symposium on Artificial Lighting.  Quebec City, Quebec, Canada.
  17. Wilkins, H.F., and J. E. Erwin.  1996.  Necessary considerations to introduce new taxa.  III International Symposium on New Floriculture Crops.  Perth, Western Australia.  Acta Horticulturae. 454:81-84.
  18. Erwin, J. E.  1992.  Temperature control on stem elongation.  International Society of Horticultural Sciences Symposium on Transplant Technology.  Honolulu, Hawaii. (1992).
  19. Erwin, J.E.  1992.  Thermomorphogenesis.  Scandinavian Horticulture Society Conference on Thermomorphogenesis. Aas, Norway.
  20. Erwin, J.E. 1991.  Control plant growth using temperature.  Proc. Amer. Hydroponics. Soc., 1-6.
  21. Berghage, R.d., J.A. Flore, R.D. Heins, and J.E. Erwin.  1989.  The relationship between day and night temperature influences photosynthesis but not light compensation point or flower longevity of Easter lily, Lilium longiflorum Thunb., ISHS Symposium on Bedding and Pot Plant Culture, 272:91-96.
  22. Berghage, R.D., R.D. Heins, and J.E. Erwin.  1989.  Quantifying leaf unfolding in the poinsettia. ISHS Symposium on Bedding and Pot Plant Culture.  Acta Horticulturae. 272:243-248.
  23. Erwin, J., R. Heins, R. Berghage, and B. Kovanda.  1989.  Temperature effects Schlumbergera truncata ‘Madisto’ flower initiation.  ISHS Symposium on Bedding and Pot Plant Culture 272 Acta Horticulturae. 272:97-102.
  24. Erwin, J., R. Heins, R. Bergahge, and B. Kovanda.  1989.  Thermomorphogenic and photoperiodic responses of Nephrolepis exaltata ‘Dallas Jewel’. Symposium on Bedding and Pot Plant Culture.  Acta Horticulturae. 272:249-254.
  25. Heins, R.D., M.G. Karlsson, J.E. Erwin, M.K. Hausbeck, and S.H. Miller.  1984.  Interaction of CO2 and environmental factors on crop responses.  International Society of Horticultural Sciences Symposium on CO2Enrichment.  Acta Horticulturae, 162:21-28.



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