Lighting applications for greenhouses and controlled environments; light-emitting diodes; greenhouse energy conservation; crop production in controlled environments
My research group focuses on the environmental physiology of ornamental and herbaceous specialty plants (such as leafy greens) grown in controlled environments. In particular, we are investigating how environmental factors, particularly light (quantity, quality, and duration) and temperature, influence growth and development of annual bedding plants, herbaceous perennials, leafy greens, and potted flowering plants. Three underlying objectives of this research are: 1) to improve the production efficiency and/or quality of crops currently grown; 2) to minimize production inputs – with an emphasis on lighting optimization and energy efficiency; and 3) to introduce “new” greenhouse crops to the industry to replace or supplement the production of other, less profitable crops. See below for more information on my research and extension/outreach activities, or watch the video below about current lighting research projects for my group and the group of my colleague, Dr. Roberto Lopez.
I collaborate with faculty at Clemson Univ., North Carolina State Univ., Univ. of Florida, Univ. of Minnesota, and Texas A&M Univ. and researchers at the USDA-ARS in Toledo, Ohio. Together, we have formed the Floriculture Research Alliance, a partnership with industry stakeholders and the USDA-ARS in which we develop science-based solutions to floriculture sustainability issues.
There are two primary types of lighting applications in the production of greenhouse crops: low-intensity lighting to create long photoperiods, and high-intensity (supplemental) lighting to increase photosynthesis and thus plant growth. Long days can promote flowering in some crops (long-day plants) or inhibit flowering in others (short-day plants). We are evaluating plant responses to different photoperiodic lighting strategies, including different lighting intensities, durations, and spectral characteristics. Recent grower articles on lighting can be found on the MSU Floriculture production website.
One research project is in partnership with Osram and Osram Opto Semiconductors in which we are growing floriculture and vegetable seedlings indoors in controlled environments under different light spectra created from LEDs. Plant morphology and growth is dependant on the light spectrum, and identifying desirable ratios of red, blue, green, and/or far-red light can assist in the development of plant lighting regimens for sole-source or supplemental lighting applications. Currently, I am in the midst of developing the Controlled-Environment Lighting Laboratory that consists of two independently controlled and refrigerated growth rooms, each with 12 deep-flow hydroponic shelves and customized LED lighting.
A project that ended in 2015 focused on using light-emitting diodes (LEDs) to improve our understanding of how the red and far-red light ratio, as well as blue light, influence flowering of photoperiodic crops This research was part of a USDA SCRI-funded project on enabling specialty-crop growers working in protected environments to successfully transition from traditional horticultural lighting sources to LED technologies. For more information, visit our website Developing LED Lighting Technologies and Practices for Sustainable Specialty-Crop Production.
I recently served as co-convener of the volume 1134 of Acta Horticulturae., held under the auspices of the International Society for Horticultural Science (ISHS). This symposium was held on the Michigan State University campus in May, 2016. The edited proceedings has been published as
In an attempt to save on greenhouse heating costs, some growers have lowered their temperature setpoints. A lower greenhouse temperature delays crop timing, but surprisingly little information is available on how temperature controls the rate of development of many economically important bedding and perennial plants. We are performing studies to determine how temperature and daily light integral (DLI) regulate plant development during the plug or liner stage and the finish stage. Effects on plant quality, including flowering characteristics, are also being determined. These studies will enable us to predict how changing the greenhouse temperature influences crop timing. For more information on greenhouse energy, please visit our Greenhouse Energy Cost Reduction Strategies website.
A constant challenge for many greenhouse growers is to properly manage plant height and architecture of their crops. For the past several years, we have been quantifying how the timing, method, and rate of application of various PGRs influence growth and development of bedding plants, perennials, and potted plants. Research continues on products that are currently on the market and on chemicals that are being considered for use with ornamentals. Information on the use of plant growth retardants on greenhouse crops can be found on our Plant Growth Regulator Research website.
Michigan is the nation’s third largest producer of floriculture crops, with a reported wholesale value of $406 million in 2014. Michigan is one of the nation's largest producers of young plants, herbaceous perennials, and bedding plants. In total, floriculture is the fourth largest agricultural commodity in the state behind milk, corn, and soybeans.
My overall outreach objective is to disseminate research-based information and provide educational opportunities for the greenhouse industry in Michigan and beyond. I have developed the MSU Floriculture website, which provides production information and outreach activities targeted for the floriculture industry in Michigan and beyond. Some of the floriculture outreach activities and sources of information for commercial greenhouse growers are briefly described below.
This page contains links to MSU research-based information on plant production strategies, management of the environment, greenhouse energy conservation, control of plant pathogens, the Greenhouse *A*Syst module, and other topics. Visit the MSU Greenhouse Crop Production Articles website, which contains many recent grower articles that have appeared in popular trade magazines and newsletters. Topics include bedding plant production, herbaceous perennial production, light, plant growth regulators, potted plant production, propagation of cuttings, and temperature. Information is also available on educational programs, including the Michigan Greenhouse Growers Expo and .
This electronic newsletter is available free and contains short articles about emerging disease and insect pests, crop culture guidelines, height control strategies, educational events, and other greenhouse production topics. Articles are primarily written by MSU faculty and MSU Extension educators and outreach specialist with floriculture expertise, but educators with related expertise also contribute.
The Michigan Greenhouse Growers Expo is held jointly with the Great Lakes Fruit, Vegetable and Farm Market EXPO at the DeVos Place Convention Center in downtown Grand Rapids, Michigan. The last Expo was on December 5-6, 2017. This Expo is planned by the MSU Floriculture Team in coordination with the Western Michigan Greenhouse Association and the Metropolitan Detroit Flower Growers Association. The greenhouse education sessions are open to everyone attending the Great Lakes Fruit, Vegetable and Farm Market EXPO. Sessions present research-based information focused on greenhouse production issues, pest management, marketing, profitability, energy conservation, new production technologies, and more.
In late July and early August of each year, we partner with several leading young plant producers in the state for a coordinated open house featuring plant displays in landscapes and containers. The 2017 Tour ran from July 24 to August 4. The objective of the Tour is to educate growers and industry professionals about new and existing plant selections and how they perform in different settings. The MSU Plant Trial Field Day is an annual grower meeting that consists of tours of the Horticulture Demonstration Gardens and presentations targeted for managers and staff of retail and wholesale greenhouses, garden centers, and landscape companies.
|Cathy Whitman||Floriculture Research Technician||2001-present|
|Nate DuRussel||Floriculture Greenhouse Technician||2013-present|
|Yujin Park||Ph.D. student||2014-present|
|Qingwu (William) Meng||Ph.D. student||2015-present|
|M.S. student (conferred)||2014-2016|
|Roberto Lopez||Visiting scholar, Purdue University||2014-2015|
|Qingwu (William) Meng||M.S. student (conferred)||2012-2014|
|Heidi Wollaeger||M.S. student (conferred)||2011-2013|
|Mike Olrich||Floriculture Greenhouse Technician||2001-2013|
|Fumiko Kohyama||Visiting scholar, Kyoto University||2012-2013|
|Yoon Jin Kim||Post-doctoral Research Associate||2012-2013|
|Tasneem Vaid||M.S. student (conferred)||2010-2012|
|Daedre Craig||M.S. student (conferred)||2008-2012|
|Matthew Blanchard||Post-doctoral Research Associate||2010|
|Matthew Blanchard||Ph.D. student (conferred)||2005-2009|
|Wook Oh||Post-doctoral Research Associate||2007-2009|
|Linsey Newton||M.S. student (conferred)||2006-2008|
|Sonali Padhye||Post-doctoral Research Associate||2006-2008|
|Kyungchul Han||Visiting professor, Cheongju Natl. Univ. Edu.||2007-2008|
|Roberto Lopez||Ph.D. student (conferred)||2003-2007|
|Ki Sun Kim||Visiting professor, Seoul National Univ.||2004-2005|
|Matthew Blanchard||M.S. student (conferred)||2003-2005|
|Roberto Lopez||M.S. student (conferred)||2001-2003|
|Lee Ann Pramuk||M.S. student (conferred)||2001-2003|
Lopez, R. and E.S. Runkle. 2017. Light Management In Controlled Environments. 180 pp. Meister Media Worldwide, Willoughby, OH.
Kozai, T., K. Fujiwara, and E.S. Runkle. 2016. LED Lighting for Urban Agriculture. 454 pp. Springer, Singapore.
Currey, C.J., R.G. Lopez, and E.S. Runkle. 2016. VIII International Symposium on Light in Horticulture (Acta Hort. 1134). 452 pp. East Lansing, MI.
Blanchard, M.G., E.S. Runkle, and Y.-I. Lee. 2010. Proceedings of the First International Orchid Symposium (Acta Hort. 878). 487 pp. Taichung, Taiwan.
Fisher, P. and E. Runkle. 2004. Lighting Up Profits: Understanding Greenhouse Lighting. 98 pp.
Heins, R., A. Cameron, W. Carlson, and E. Runkle. 2000. Firing Up Perennials: The 2000 Edition. 142 pp. Meister Media Worldwide, Willoughby, OH.
Meng, Q. and E.S. Runkle. 2016. Control of flowering using night-interruption and day-extension lighting, p. 191-201. In: T. Kozai et al. (eds.). LED Lighting for Urban Agriculture. Springer, Singapore.
Runkle, E.S. 2016. Recent developments in plant lighting, p. 233-236. In: T. Kozai et al. (eds.). LED Lighting for Urban Agriculture. Springer, Singapore.
Mitchell, C.A., M.P. Dzakovich, C. Gomez, R. Lopez, J.F. Burr, R. Hernández, C. Kubota, C.J. Currey, Q. Meng, E.S. Runkle, C.M. Bourget, R.C. Morrow, and A.J. Both. 2015. Light-emitting diodes in horticulture, p. 1-88. In: J. Janick (ed.). Horticultural Reviews vol. 43. John Wiley & Sons, Hoboken, NJ.
Blanchard, M. and E. Runkle. 2011. Temperature, p. 67-81. In: J. Nau (ed.). Ball Redbook, 18th ed., vol. 2. Ball Publishing, Chicago, IL.
Blanchard, M.G., J.A. Chong, J.E. Faust, and E.S. Runkle. 2006. Temperature and light, p. 51-60. In: J.M. Dole and J.L. Gibson (eds.). Cutting Propagation: A Guide for Propagating and Producing Floriculture Crops. Ball Publishing, Batavia, IL.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 2002. Manipulating day length to flower perennials, p. 79-83. In: R. Blanchette (ed.). GrowerTalks on Perennials. Ball Publishing, Batavia, IL.
Heins R.D., A.C. Cameron, W.H. Carlson, E. Runkle, C. Whitman, M. Yuan, C. Hamaker, B. Engle, and P. Koreman. 1997. Controlled flowering of herbaceous perennial plants, p. 15-31. In: E. Goto et al. (eds.). Plant Production in Closed Ecosystems. Kluwer Academic, Netherlands.
Poel, B.R. and E.S. Runkle. 2017. Spectral effects of supplemental greenhouse radiation on growth and flowering of annual bedding plants and vegetable transplants. HortScience 52:1221-1228.
Meng, Q. and E.S. Runkle. 2017. Investigating the efficacy of white light-emitting diodes at regulating flowering of photoperiodic ornamental crops. Acta Hortic. 1170:951-957.
Both, A.J., B. Bugbee, C. Kubota, R.G. Lopez, C. Mitchell, E.S. Runkle, and C. Wallace. 2017. Proposed product label for electric lamps used in the plant sciences. HortTechnology 27:544-549.
Park, Y. and E.S. Runkle. 2017. Far-red radiation promotes growth of seedlings by increasing leaf expansion and whole-plant net assimilation. Environ. Exp. Bot. 136:41-49.
Poel, B. and E.S. Runkle. 2017. Seedling growth is similar under supplemental greenhouse lighting from high-pressure sodium lamps or light-emitting diodes. HortScience 52:388-394.
Meng, Q. and E.S. Runkle. 2017. Moderate-intensity blue radiation can regulate flowering, but not extension growth, of several photoperiodic ornamental crops.
Blanchard, M.G. and E.S. Runkle. 2016. Investigating reciprocity of intensity and duration of photoperiodic lighting to regulate flowering of long-day plants. Acta Hortic. 1134:41-48.
Park, Y. and E.S. Runkle. 2016. Investigating the merit of including far-red radiation in the production of ornamental seedlings grown under sole-source lighting. Acta Hortic. 1134:259-266.
Oh, W. and E.S. Runkle. 2016. Flowering and morphological responses of petunia and pansy as influenced by lamp type and lighting period to provide long days. Korean J. Hortic. Sci. Tech. 34:207-219.
Craig, D.S. and E.S. Runkle. 2016. An intermediate phytochrome photoequilibria from night-interruption lighting optimally promotes flowering of several long-day plants. Environ. Exp. Bot. 121:132-138.
Meng, Q. and E.S. Runkle. 2015. The role of blue light in night-interruption lighting of petunia. Acta Hort. 1107:101-105.
Vaid, T. and E.S. Runkle. 2015. Low temperature diminishes the photoperiodic flowering response of three petunia cultivars. Acta Hort. 1104:185-190.
Wollaeger, H.M and E.S. Runkle. 2015. Growth and acclimation of impatiens, salvia, petunia, and tomato seedlings to blue and red light. HortScience 50:522-529.
Newton, L.A. and E.S. Runkle. 2015. Effects of benzyladenine on vegetative growth and flowering of potted Miltoniopsis orchids. Acta Hort. 1078:121-127.
Meng, Q. and E.S. Runkle. 2015. Low-intensity blue light in night-interruption lighting does not influence flowering of herbaceous ornamentals. Sci. Hort. 186:230-238.
Kim, Y.J., D.J. Yu, H. Rho, E.S. Runkle, H.J. Lee, and K.S. Kim. 2015. Photosynthetic changes in Cymbidium orchids grown under different intensities of night interruption lighting. Sci. Hort. 186:124-128.
Meng, Q. and E.S. Runkle. 2014. Controlling flowering of photoperiodic ornamental crops with light-emitting diode lamps: A coordinated grower trial. HortTechnology 24:702-711.
Kohyama, F., C. Whitman, and E.S. Runkle. 2014. Comparing flowering responses of long-day plants under incandescent and two commercial light-emitting diode lamps. HortTechnology 24:490-495.
Wollaeger, H.M. and E.S. Runkle. 2014. Growth of impatiens, petunia, salvia, and tomato seedlings under blue, green, and red light-emitting diodes. HortScience 49:734-740.
Vaid, T.M., E.S. Runkle, and J.M. Frantz. 2014. Mean daily temperature regulates plant quality attributes of annual ornamental crops. HortScience 49:574-580.
Zhu, C., P. Unachak, J.R. Llera, D.B. Knoester, E.S. Runkle, L. Xu, and E.D. Goodman. 2014. Robust multi-objective evolutionary optimization to allow greenhouse production/energy use tradeoffs. Acta Hort. 1037:525-532.
Wollaeger, H.M. and E.S. Runkle. 2014. Producing commercial-quality ornamental seedlings under sole-source LED lighting. Acta Hort. 1037:269-276.
Wollaeger, H.M. and E.S. Runkle. 2013. Growth responses of ornamental annual seedlings under different wavelengths of red light provided by light-emitting diodes. HortScience 48:1478-1483.
Currey, C.J., R.G. Lopez, V.K. Rapaka, J.E. Faust, and E.S. Runkle. 2013. Exogenous applications of benzyladenine and gibberellic acid inhibit lower-leaf senescence of geraniums during propagation. HortScience 48:1352-1357.
Vaid, T.M. and E.S. Runkle. 2013. Developing flowering rate models in response to mean temperature for common annual ornamental crops. Sci. Hort. 161:15-23.
Whitman, C.M. and E.S. Runkle. 2013. Flowering of newly introduced herbaceous perennial ornamentals in response to photoperiod and low-temperature treatments. Acta Hort. 1000:353-360.
Craig, D.S. and E.S. Runkle. 2013. A moderate to high red to far-red light ratio from light-emitting diodes controls flowering of short-day plants. J. Amer. Soc. Hort. Sci. 138:167-172.
Fisher, P.R., E.S. Runkle, M.G. Blanchard, J.E. Erwin, and B. MacKay. 2012. FlowersOnTime: A computer decision-support tool for floriculture crop producers. J. Extension 50(5):5TOT3.
Miller, W.B., N.S. Mattson, X. Xie, D Xu, C.J. Currey, K.L. Clemens, R.G. Lopez, M. Olrich, and E.S. Runkle. 2012. Ethephon substrate drenches inhibit stem extension of floriculture crops. HortScience 47:1312-1319.
Whitman, C.M. and E.S. Runkle. 2012. Determining the flowering requirements of two Aquilegia cultivars. HortScience 47:1261-1264.
Runkle, E.S., M.G. Blanchard, and J.M. Frantz. 2012. Using flowering and heat-loss models for improving greenhouse energy-use efficiency in annual bedding plant production. Acta Hort. 957:99-106.
Craig, D.S. and E.S. Runkle. 2012. Using LEDs to quantify the effect of the red to far-red ratio of night-interruption lighting on flowering of photoperiodic crops. Acta Hort. 956:179-186.
Runkle, E.S., S.R. Padhye, W. Oh, and K. Getter. 2012. Replacing incandescent lamps with compact fluorescent lamps may delay flowering. Sci. Hort. 143:56-61.
Blanchard, M.G., E.S. Runkle, A.-J. Both, and H. Shimizu. 2012. Greenhouse energy curtains influence shoot-tip temperature of New Guinea impatiens. HortScience 47:483-488.
Runkle, E.S., S.R. Padhye, M.G. Blanchard, and W. Oh. 2011. Energy-efficient greenhouse lighting of ornamentals. Acta Hort. 907:53-59.
Blanchard, M.G., E.S. Runkle, and P.R. Fisher. 2011. Modeling plant morphology and development of petunia in response to temperature and photosynthetic daily light integral. Sci. Hort. 129:313-320.
Blanchard, M.G., E.S. Runkle, and J.M. Frantz. 2011. Energy-efficient greenhouse production of Petunia and Tagetes by manipulation of temperature and photosynthetic daily light integral. Acta Hort. 893:857-864.
Blanchard, M.G. and E.S. Runkle. 2011. The influence of day and night temperature fluctuations on growth and flowering of annual bedding plants and greenhouse heating cost predictions. HortScience 46:599-603.
Blanchard, M.G. and E.S. Runkle. 2011. Quantifying the thermal flowering rates of eighteen species of annual bedding plants. Sci. Hort. 128:30-37.
Padhye, S.R. and E.S. Runkle. 2011. Use of compact fluorescent lamps to provide a long-day photoperiod to herbaceous perennials. Acta Hort. 886:197-205.
Blanchard, M. and E. Runkle. 2010. Effects of emerging shoot size, temperature, and benzyladenine on growth and flowering of Zygopetalum Redvale 'Fire Kiss'. Acta Hort. 878:302-309.
Runkle, E. 2010. Environmental and hormonal regulation of flowering in Phalaenopsis orchids: A mini review. Acta Hort. 878:263-267.
Newton, L.A. and E.S. Runkle. 2010. Effects of paclobutrazol sprays on inflorescences of three potted moth orchid clones. HortTechnology 20:892-895.
Oh, W., E.S. Runkle, and R.M. Warner. 2010. Timing and duration of supplemental lighting during the seedling stage influence quality and flowering in petunia and pansy. HortScience 45:1332-1337.
Blanchard, M.G. and E.S. Runkle. 2010. Influence of NIR-reflecting shading paint on greenhouse environment, plant temperature, and growth and flowering of bedding plants. Trans. ASABE 53:939-944.
Blanchard, M.G. and E.S. Runkle. 2010. Intermittent light from a rotating high-pressure sodium lamp promotes flowering of long-day plants. HortScience 45:236-241.
Blanchard, M.G. and E.S. Runkle. 2009. Influence of short-term storage temperature and duration of canna rhizomes on subsequent greenhouse forcing. Acta Hort. 847:313-319.
Blanchard, M.G. and E.S. Runkle. 2009. Use of a cyclic high-pressure sodium lamp to inhibit flowering of chrysanthemum and velvet sage. Sci. Hort. 122:448-454.
Runkle, E.S., S.J. Allen, T.A. Dudek, J.M. Himmelein, and D.M. Krauskopf. 2009. The Floriculture College of Knowledge: A certificate program for greenhouse growers. Acta Hort. 832:195-202.
Newton, L.A. and E.S. Runkle. 2009. High-temperature inhibition of flowering of Phalaenopsis and Doritaenopsis orchids. HortScience 44:1271-1276.
Oh, W., I.H. Cheon, K.S. Kim, and E.S. Runkle. 2009. Photosynthetic daily light integral influences flowering time and crop characteristics of Cyclamen persicum. HortScience 44:341-344.
Blanchard, M.G. and E.S. Runkle. 2009. Effects of a new cyclical lighting system on flower induction in long-day plants: A preliminary investigation. Acta Hort. 813:623-630.
Lopez, R.G., M.G. Blanchard, and E.S. Runkle. 2009. Propagation and production of Zamioculcas zamiifolia. Acta Hort. 813:559−564.
Blanchard, M.G. and E.S. Runkle. 2008. Increasing stem elongation and bract size of poinsettia ‘Freedom Red’ with gibberellins and benzyladenine. Acta Hort. 774:209-215.
Lopez, R.G. and E.S. Runkle. 2008. Photosynthetic daily light integral during propagation influences rooting and growth of cuttings and subsequent development of New Guinea impatiens and petunia. HortScience 43:2052-2059.
Lopez, R.G. and E.S. Runkle. 2008. Low temperature storage influences morphological and physiological characteristics of nonrooted cuttings of New Guinea impatiens (Impatiens hawkeri). Postharvest Biol. Technol. 50:95-102.
Oh, W., Y.H Rhie, J.H. Park, E.S. Runkle, and K.S. Kim. 2008. Flowering of cyclamen is accelerated by an increase in temperature, photoperiod, and daily light integral. J. Hort. Sci. Biotech. 83:559-562.
Blanchard, M.G. and E.S. Runkle. 2008. Temperature and pseudobulb size influence flowering of Odontioda orchids. HortScience 43:1404-1409.
Blanchard, M.G. and E.S. Runkle. 2008. Container opacity and media components influence rooting of potted Phalaenopsis and Doritaenopsis orchids. Acta Hort. 788:115-120.
Rapaka, V.K., J.E. Faust, J.M. Dole, and E.S. Runkle. 2008. Endogenous carbohydrate status affects postharvest ethylene sensitivity in relation to leaf senescence and adventitious root formation in Pelargonium cuttings. Postharvest Biol. Technol. 48:272-282.
Blanchard, M.G. and E.S. Runkle. 2008. Benzyladenine promotes flowering in Doritaenopsis and Phalaenopsis orchids. J. Plant Growth Regul. 27:141-150.
Lopez, R.G. and E.S. Runkle. 2008. Effect of temperature and pseudobulb maturity on flowering of the orchid Miltoniopsis Augres ‘Trinity’. Acta Hort. 766:273-278.
Glady, J.E., N.S. Lang, and E.S. Runkle. 2007. Effects of ethephon on stock plant management of Coreopsis verticillata, Dianthus caryophyllus, and Veronica longifolia. HortScience 42:1616-1621.
Blanchard, M.G. and E.S. Runkle. 2007. Dipping bedding plant liners in paclobutrazol or uniconazole inhibits subsequent stem extension. HortTechnology 17:178-182.
Moccaldi, L.A. and E.S. Runkle. 2007. Modeling the effects of temperature and photosynthetic daily light integral on growth and flowering of Salvia splendens and Tagetes patula. J. Amer. Soc. Hort. Sci. 132:283-288.
Runkle, E.S. 2007. Innovative production systems for ornamental potted plants: A case study for Phalaenopsis orchids. Acta Hort. 755:55-59.
Blanchard, M.G., L.A. Newton, E.S. Runkle, D. Woolard, and C.A. Campbell. 2007. Exogenous applications of abscisic acid improved the postharvest drought tolerance of several annual bedding plants. Acta Hort. 755:127-132.
Rapaka, V.K., J.E. Faust, J. Dole, and E.S. Runkle. 2007. Diurnal carbohydrate dynamics affect postharvest ethylene responsiveness in portulaca (Portulaca grandiflora ‘Yubi Deep Rose’) unrooted cuttings. Postharvest Biol. Technol. 44:293-299.
Rapaka, V.K., J.E. Faust, J. Dole, and E.S. Runkle. 2007. Effect of time of harvest on postharvest leaf abscission in lantana (Lantana camara L. ‘Dallas Red’) unrooted cuttings. HortScience 42:304-308.
Blanchard, M.G. and E.S. Runkle. 2006. Temperature during the day, but not during the night, controls flowering of Phalaenopsis orchids. J. Exp. Bot. 57:4043-4049.
Lopez, R.G. and E.S. Runkle. 2006. Temperature and photoperiod regulate flowering of potted Miltoniopsis orchids. HortScience 41:593-597.
Runkle, E.S. and R.D. Heins. 2006. Manipulating the light environment to control flowering and morphogenesis of herbaceous plants. Acta Hort. 711:51-60.
Lopez, R.G. and E.S. Runkle. 2006. Daily light integral influences rooting and quality of petunia cuttings. Acta Hort. 711:369-373.
Lopez, R.G. and E.S. Runkle. 2005. Environmental physiology of growth and flowering of orchids. HortScience 40:1969-1973.
Pramuk, L.A. and E.S. Runkle. 2005. Modeling growth and development of Celosia and Impatiens in response to temperature and photosynthetic daily light integral. J. Amer. Soc. Hort. Sci. 130:813-818.
Pramuk, L.A. and E.S. Runkle. 2005. Photosynthetic daily light integral during the seedling stage influences subsequent growth and flowering of Celosia, Impatiens, Salvia, Tagetes, and Viola. HortScience 40:1336-1339.
Lopez, R.G., E.S. Runkle, and R.D. Heins. 2005. Flowering of the orchid Miltoniopsis Augres ‘Trinity’ is influenced by photoperiod and temperature. Acta Hort. 683:175-180.
Lopez, R.G. and E.S. Runkle. 2004. The effect of temperature on leaf and flower development and flower longevity of Zygopetalum Redvale ‘Fire Kiss’ orchid. HortScience 39:1630-1634.
Shimizu, H., E.S. Runkle, and R.D. Heins. 2004. A steady-state model for prediction of poinsettia plant shoot-tip temperature. J. Amer. Soc. Hort. Sci. 129:303-312.
Clifford, S.C., E.S. Runkle, F.A. Langton, A. Mead, S.A. Foster, S. Pearson, and R.D. Heins. 2004. Height control of poinsettia using photoselective filters. HortScience 39:383-387.
Lopez, R.G., E.S. Runkle, R.D. Heins, and C.M. Whitman. 2003. Temperature and photoperiodic effects on growth and flowering of Zygopetalum Redvale ‘Fire Kiss’ orchids. Acta Hort. 624:155-162.
Shimizu, H., R.D. Heins, and E. Runkle. 2003. Simulation study of total energy consumption required to produce a mature plant at different greenhouse temperatures. J. Soc. High Tech. Agric. 15:123-129. (In Japanese; abstract in English.)
Runkle, E.S. and R.D. Heins. 2003. Photocontrol of flowering and extension growth in the long-day plant pansy. J. Amer. Soc. Hort. Sci. 128:479-485.
Runkle, E.S. and R.D. Heins. 2002. Stem extension and subsequent flowering of seedlings grown under a film creating a far red deficient environment. Sci. Hort. 96:257-265.
Runkle, E.S., R.D. Heins, P. Jaster, and C. Thill. 2002. Environmental conditions under an experimental near infra-red reflecting greenhouse film. Acta Hort. 578:181-185.
Runkle, E.S., R.D. Heins, P. Jaster, and C. Thill. 2002. Plant responses under an experimental near infra-red reflecting greenhouse film. Acta Hort. 580:137-143.
Runkle, E., R. Heins, A. Cameron, and W. Carlson. 2001. Minireview of research activity: Horticultural flowering of herbaceous perennials. Flowering Newslett. 31:34-43.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 2001. Photocontrol of flowering and stem extension of the intermediate-day plant Echinacea purpurea. Physiol. Plant. 112:433-440.
Runkle, E.S. and R.D. Heins. 2001. Specific functions of red, far red, and blue light in flowering and stem extension of long-day plants. J. Amer. Soc. Hort. Sci. 126:275-282.
Heins, R.D., B. Liu, and E.S. Runkle. 2000. Regulation of crop growth and development based on environmental factors. Acta Hort. 514:13-22.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 1999. Cold treatment modifies the photoperiodic flowering response of Lobelia ×speciosa. Sci. Hort. 80:247-258.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 1999. Photoperiod and cold treatment regulate flowering of Rudbeckia fulgida ‘Goldsturm’. HortScience 34:55-58.
Runkle, E.S. and Pearson, S. 1998. Phytochrome A does not mediate reduced stem extension from cool day-temperature treatments. Physiol. Plant. 104:596-602.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 1998. Flowering of Phlox paniculata is influenced by photoperiod and cold treatment. HortScience 33:1172-1174.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 1998. Flowering of Leucanthemum ×superbum ‘Snowcap’ in response to photoperiod and cold treatment. HortScience 33:1003-1006.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 1998. Flowering of herbaceous perennials under various night interruption and cyclic lighting treatments. HortScience 33:672-677.
Runkle, E.S., R.D. Heins, A.C. Cameron, and W.H. Carlson. 1998. Flowering of cold-treated field-grown Astilbe. HortTechnology 8:207-209.
Poel, B.R. 2016. Seedling growth is generally similar under supplemental greenhouse lighting from light-emitting diodes or high-pressure sodium lamps. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9781369079869.
Meng, Q. 2014. Investigating use of blue, red, and far-red light from light-emitting diodes to regulate flowering of photoperiodic ornamental crops. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9781321026658.
Wollaeger, H.M. 2013. Growth and morphological acclimation of seedlings to blue, green, and red light from light-emitting diodes. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9781303288968.
Craig, D.S. 2012. Determining effective ratios of red and far-red light from light-emitting diodes that control flowering of photoperiodic ornamental crops. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9781267589828.
Vaid, T.M. 2012. Improving the scheduling and profitability of annual bedding plant production by manipulating temperature, daily light integral, photoperiod, and transplant size. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9781267589361.
Blanchard, M.G. 2009. Manipulating light and temperature for energy-efficient greenhouse production of ornamental crops. PhD diss., Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9781109644616.
Newton, L.A. 2008. Effects of high temperature and plant growth regulators on vegetative growth and flowering of potted orchids. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 978110902817.
Lopez, R.G. 2007. Stock plant and propagation photosynthetic daily light integral and storage influence postharvest performance of herbaceous cuttings. PhD diss., Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9780549239819.
Blanchard, M.G. 2005. Effects of temperature on growth and flowering of two Phalaenopsis and two Odontioda orchid hybrids. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9780542527067.
Pramuk, L.A. 2003. Temperature and daily light integral effects on five bedding plant species. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ProQuest document ID 305327034.
Lopez, R.G. 2003. Effects of photoperiod and temperature on growth and flowering of six orchid hybrids. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI. ProQuest document ID 30532809.