Erik Runkle

Contact Me

Professor
Department of Horticulture

Phone:
(517) 353-0350

Email:
runkleer@msu.edu

Quick Links: Research Extension Publications Lighting Laboratory

Joined Department

January, 2001

Appointment

50% Extension
50% Research

Education

B.S. University of Illinois at Urbana-Champaign, Ornamental Horticulture, 1993
M.S. Michigan State University, Horticulture, 1996
Ph.D. Michigan State University, Horticulture, 2000

General Information

My research group focuses on the environmental physiology of herbaceous specialty plants grown in controlled environments. In particular, we are investigating how environmental factors, especially 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, high value specialty crops to replace or supplement the production of less-profitable crops.

Honors

American Society for Horticultural Science (ASHS) Fellow, 2023
ASHS Vegetable Publication Award (most outstanding paper on vegetable crops), 2021
Kenneth Post Award for Graduate Research in Floriculture (most outstanding paper on floriculture crops), 2006, 2013, 2014, 2018
ASHS Outstanding Extension Publication Award: Book, 2005, 2018; Fact Sheet, 2013; Website, 2008; Newsletter, 2008
American Society for Agricultural and Biological Engineers Blue Ribbon Award, 2005, 2018
State, Regional, and National Learning Module Awards, National Association County Agricultural Agents, 2016
AmericanHort Alex Laurie Award (most outstanding research paper), 2006, 2012, 2014
USDA Agriculture Research Service Technology Transfer Award, 2012
Excellence in Technology Transfer, Federal Laboratory Consortium for Technology Transfer, 2012
Outstanding Extension Specialist, Michigan Association of Extension Agents, 2011
Research Fellow, Japan Society for the Promotion of Science, Kyoto University, 2009
Outstanding Extension Specialist, Michigan Extension Specialist and State Staff Assoc., 2008

Research

Lighting Applications in Specialty Crop Production

There are three primary types of lighting applications in controlled-environment production of crops: low-intensity lighting to create long days, high-intensity (supplemental) greenhouse lighting to increase photosynthesis and thus plant growth, and sole-source lighting of plants indoors. Recent grower articles on plant lighting can be found on the MSUE Floriculture & Greenhouse Crop Production website.

Indoor Production of Leafy Greens. One research project, supported by the USDA Specialty Crops Research Initiative, is entitled "Improving the profitability and sustainability of indoor leafy-greens production". This project is in collaboration with researchers at Michigan State, Ohio State, Purdue, Arizona, and the USDA, as well as commercial indoor producers of leafy greens, lighting companies, horticulture suppliers, and others in the space. To facilitate this research, I developed the Controlled-Environment Lighting Laboratory (CELL), which consists of two independently controlled and refrigerated growth rooms, each with 12 deep-flow hydroponic shelves and sophisticated, customized LED lighting. Below is a video showing CELL, developed by former Ph.D. student Qingwu Meng.

Indoor Production of Floriculture Transplants. My research team also utilizes CELL to better understand how different radiation wavebands (from UV to far-red) influence growth, flower initiation, and quality of floriculture transplants. This research has been supported in part by the American Floral Endowment and OSRAM. Results from these studies have been published in trade magazines, which are available here.

I also collaborate with faculty at Clemson, Florida, Maryland, 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 in which we develop science-based solutions to floriculture sustainability issues. Our current projects focus on techniques to increase plant resilience of floriculture crops.

Managing the Greenhouse Environment for Energy Conservation

In an attempt to save on greenhouse heating costs, some growers have lowered their temperature setpoints. A lower greenhouse temperature delays crop timing, but until recently, little information was available on how temperature controls the rate of development of many economically important bedding and perennial plants. We have performed studies to determine how temperature and daily light integral (DLI) regulate plant development and quality characteristics during the plug or liner stage and the finish stage. 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 website.

Plant Growth Regulators (PGRs) on Greenhouse Crops

A constant challenge for many greenhouse growers is to properly manage plant height and architecture of their crops. 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 flowering plants. Research continues on products that are currently on the market and on chemicals that are being considered for registration. See articles on Height Management of Ornamentals for more information.

Extension and Outreach

Michigan is the nation’s third largest producer of floriculture crops, with a reported wholesale value of $711 million in 2022. 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. The MSU Floriculture website provides production information and communicates outreach activities targeted to the greenhouse industry in Michigan and beyond. Some of our outreach activities are described below.

Greenhouse Production Information

This page contains links to MSU research-based information on plant production strategies, management of the environment, greenhouse energy conservation, and other topics. Topics include bedding plant production, herbaceous perennial production, plant lighting, plant growth regulators, temperature management, and more. Information is also available on educational programs, including the Online College of Knowledge for floriculture/greenhouse crop production.

MSUE News

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 MSUE educators and outreach specialists with floriculture expertise.

Michigan Greenhouse Growers Expo

The annual 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 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.

Team Personnel

Nate DuRussel	Greenhouse research technician	2013-present
Jiyong Shin	Ph.D. student	2021-present
Charlie Smith	M.S. student (co-advised with Roberto Lopez)	2023-present
Bridget Knight	M.S. student	2023-present
Devin Brewer	Floriculture research technician	2024-present
Avery Tucker	M.S. student	2024-present
Eric Stallknecht	Ph.D. student (conferred)	2019-2023
Nathan Kelly	Ph.D. student (conferred)	2019-2023
Cathy Whitman	Floriculture research technician	2001-2020
Yoon Jin Kim	Visiting research scholar, Seoul Women's University	2019-2020
Viktorija Vastakaite-Kairiene	Visiting research associate, Lithuanian Research Center for Ag. and Forestry	2019-2020
Yujin Park	Post-doctoral research associate	2018-2019
Mengzi Zhang	M.S. student (conferred)	2016-2018
Qingwu (William) Meng	Ph.D. student (conferred)	2015-2018
Yujin Park	Ph.D. student (conferred)	2014-2018
Daegeun Choe	Short-term scholar	2018
Brian Poel	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) Lindberg	M.S. student (conferred)	2011-2013
Mike Olrich	Floriculture greenhouse technician	2001-2013
Fumiko Kohyama	Visiting scholar, Kyoto University	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

Refereed Publications

Books (Edited)

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. Meister Media Worldwide, Willoughby, OH.

Heins, R., A. Cameron, W. Carlson, and E. Runkle. 2000. Firing Up Perennials: The 2000 Edition. 142 pp. Meister Media Worldwide, Willoughby, OH.

Refereed Journal Publications & Conference Proceedings

Shin, J. and E.S. Runkle. 2024. Considerations of utilizing far-red light in the production of leafy-green vegetables indoors. Eur. J. Hortic. Sci. 89(3):1-9.

Kohler, A.E. and E.S. Runkle. 2024. Sole-source lighting of lettuce that increased yield had no negative effect on postharvest longevity. HortScience 59:903-909.

Smitley, D., C. Oneil, E. Hotchkiss, E. Runkle, and J. Studyvin. 2024. Evaluation of the most popular annual flowers sold in the United States and Europe indicates low visitation rates by pollinators and large variation among cultivars. J. Econ. Entomol.:toae084.

Stallknecht, E.J., C.K. Herrera, T.D. Sharkey, R.R. Lunt, and E.S. Runkle. 2023. Growth of snapdragon under simulated transparent photovoltaic panels for greenhouse applications. J. Environ. Hort. 41:170-179.

Kelly, N. and E.S. Runkle. 2023. Ultraviolet A and blue light transiently regulate total phenolic and anthocyanin concentrations in indoor-grown red-leaf lettuce. HortScience 58:1595–1602.

Stallknecht, E.J. and E.S. Runkle. 2023. Opportunities and challenges with advanced greenhouse glazing materials. Acta Hortic. 1377:205-218.

Abedi, M., X. Tan, E.J. Stallknecht, E.S. Runkle, J.F. Klausner, M.S. Murillo, and A. Bénard. 2023. Incorporating the effect of the photon spectrum on biomass accumulation of lettuce using a dynamic growth model. Front. Plant Sci. 14:1106576.

Browning, A., D. Smitley, J. Studyvin, E.S. Runkle, Z.Y. Huang, and E. Hotchkiss. 2023. Variation in pollinator visitation among garden cultivars of marigold, portulaca, and bidens. J. Econ. Entomol. 116:872–881.

Kelly, N. and E.S. Runkle. 2023. End-of-production ultraviolet A and blue light similarly increase lettuce coloration and phytochemical concentrations. HortScience 58:525–531.

Kohler, A.E., E.M. Birtell, E.S. Runkle, and Q. Meng. 2023. Day-extension blue light inhibits flowering of chrysanthemum when the short main photoperiod includes far-red light. J. Amer. Soc. Hort. Sci. 148:89-98.

Meng, Q. and E.S. Runkle. 2023. Blue photons from broad-spectrum LEDs control growth, morphology, and coloration of indoor hydroponic red-leaf lettuce. Plants 12(5):1127.

Park, Y. and E.S. Runkle. 2023. Spectral-conversion film potential for greenhouses: Utility of green-to-red photons conversion and far-red filtration for plant growth. PLoS ONE 18(2):e0281996.

Stallknecht, E.J., C.K. Herrera C. Yang, I. King, T.D. Sharkey, R.R. Lunt, and E.S. Runkle. 2023. Designing plant-transparent agrivoltaics. Sci. Rep. 13:1903.

Vaštakaitė-Kairienė, V., A. Brazaitytė, J. Miliauskienė, and E.S. Runkle. 2022. Red to blue light ratio and iron nutrition influence growth, metabolic response, and mineral nutrients of spinach grown indoors. Sustainability 14:12564.

Vaštakaitė-Kairienė, V., A. Brazaitytė, J. Miliauskienė, R. Sutulienė, K. Laužikė, A. Viršilė, G. Samuolienė, and E.S. Runkle. 2022. Photon distribution of sole-source lighting affects the mineral nutrient content of microgreens. Agriculture 12:1086.

Runkle, E.S., Y. Park, and Q. Meng. 2022. High photosynthetic photon flux density can attenuate effects of light quality. Acta Hort. 1337:333-340.

Whitman, C., S. Padhye, and E.S. Runkle. 2022. A high daily light integral can influence photoperiodic flowering responses in long day herbaceous ornamentals. Sci. Hort. (article 110897).

Shen, L., R. Lou, Y. Park, Y Guo, E.J. Stallknecht, Y. Xiao, D. Rieder, R. Yang, E.S. Runkle, and X. Yin. 2021. Increasing greenhouse production by spectral-shifting and unidirectional light-extracting photonics. Nat. Food 2:434–441.

Vaštakaitė-Kairienė, V., N. Kelly, and E.S. Runkle. 2021. Regulation of the photon spectrum on growth and nutritional attributes of baby-leaf lettuce at harvest and during postharvest storage. Plants 10(3):549.

Meng, Q. and E.S. Runkle. 2020. Growth responses of red-leaf lettuce to temporal spectral changes, Front. Plant Sci. 11:571788.

Kelly, N. and E.S. Runkle. 2020. Spectral manipulations to elicit desired quality attributes of herbaceous specialty crops. Eur. J. Hortic. Sci. 85(5):339-343.

Kelly, N., D. Choe, Q. Meng, and E.S. Runkle. 2020. Promotion of lettuce growth under an increasing daily light integral depends on the combination of the photosynthetic photon flux density and photoperiod. Sci. Hort. (article 109565).

Zhang, M., Y. Park, and E.S. Runkle. 2020. Regulation of extension growth and flowering of seedlings by blue radiation and the red to far-red ratio of sole-source lighting. Sci. Hort. (article 109478).

Lopez, R.G., Q. Meng, and E.S. Runkle. 2020. Blue radiation signals and saturates photoperiodic flowering of several long-day plants at crop-specific photon flux densities. Sci. Hort. (article 109470).

Meng, Q., J. Boldt, and E.S. Runkle. 2020. Blue radiation interacts with green radiation to influence growth and predominantly controls quality attributes of lettuce. J. Amer. Soc. Hort. Sci. 145:75-87.

Park, Y. and E.S. Runkle. 2019. Blue radiation attenuates the effects of the red to far-red ratio on extension growth but not on flowering. Environ. Exp. Bot. 168 (article 103871).

Runkle, E.S., Q. Meng, and Y. Park. 2019. LED applications in greenhouse and indoor production of horticultural crops. Acta Hort. 1263:17-30.

Meng, Q. and E.S. Runkle. 2019. Far-red radiation interacts with relative and absolute blue and red photon flux densities to regulate growth, morphology, and pigmentation of lettuce and basil seedlings. Sci. Hort. 255:269-280.

Runkle, E.S. 2019. Environmental control of the flowering process of Phalaenopsis orchids. Acta Hort. 1262:7-12.

Zhang, M., C.W. Whitman, and E.S. Runkle. 2019. Manipulating growth, color, and taste attributes of fresh cut lettuce by greenhouse supplemental lighting. Sci. Hort. 252:274-282.

Meng, Q., N. Kelly, and E.S. Runkle. 2019. Substituting green or far-red radiation for blue radiation induces shade avoidance and promotes growth in lettuce and kale. Environ. Exp. Bot. 162:383-391.

Zhang, M. and E.S. Runkle. 2019. Regulating flowering and extension growth of poinsettia using red and far-red light-emitting diodes for end-of-day lighting. HortScience 54:323-327.

Meng, Q. and E.S. Runkle. 2019. Regulation of flowering by green light depends on its photon flux density and involves cryptochrome. Physiol. Plant. 166:762-771.

Lindberg, H.M., R.A. Cloyd, and E.S. Runkle. 2018. Floriculture College of Knowledge online course series: Demographics and impact. J. Natl. Assoc. County Agr. Agents 11(2).

Park Y. and E.S. Runkle. 2018. Spectral effects of light-emitting diodes on plant growth, visual color quality, and photosynthetic photon efficacy: White versus blue plus red radiation. PLoS ONE 13(8):e0202386.

Meng, Q. and E.S. Runkle. 2018. Using radiation to enhance quality attributes of leafy vegetables: A mini-review. Acta Hort. 1227:571-578.

Park, Y. and E.S. Runkle. 2018. Investigating the interaction between photosynthetic photon flux density and far-red radiation in petunia seedlings under sole-source lighting. Acta Hort. 1227:541-548.

Park, Y. and E.S. Runkle. 2018. Far-red radiation and photosynthetic photon flux density independently regulate seedling growth but interactively regulate flowering. Environ. Exp. Bot. 155:206-216.

Llera, J.R., E.D. Goodman, E.S. Runkle, and L. Xu. 2018. Improving greenhouse environmental control using crop-model-driven multi-objective optimization. GECCO '18 Proc. Genet. Evolution Computation Conf. Companion:292-293.

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 Hort. 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. Environ. Exp. Bot. 134:12-20.

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 Hort. 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 Hort. 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.

Shimizu, H., Z. Ma, S. Tazawa, M. Douzono, E.S. Runkle, and R.D. Heins. 2006. Blue light inhibits stem elongation of chrysanthemum. Acta Hort. 711:363-368.

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.

Graduate Theses and Dissertations

Stallknecht, E.J. 2023. Plant growth and development under experimental transparent photovoltaic and red-fluorescent greenhouse coverings. PhD diss., Dept. of Hort., Mich. State Univ., East Lansing, MI.

Kelly, N. 2023. The effects of the photon spectrum on growth and quality attributes of leafy greens produced indoors. PhD diss., Dept. of Hort., Mich. State Univ., East Lansing, MI.

Meng, Q. 2018. Improving yield and quality of indoor food crops with precise light regimens. PhD diss., Dept. of Hort., Mich. State Univ., East Lansing, MI.

Zhang, M. 2018. Manipulating light quality to improve growth attributes of high-value specialty crops in controlled environments. MS thesis, Dept. of Hort., Mich. State Univ., East Lansing, MI.

Park, Y. 2018. Controlling the radiation spectrum of sole-source lighting to elicit desirable photomorphogenic traits and regulate flowering of floriculture seedlings. PhD diss., Dept. of Hort., Mich. State Univ., East Lansing, MI. ISBN 9780355870046.

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.