My research focuses on the environmental physiology of herbaceous plants, with an emphasis on commercial floriculture crops.  In particular, our research group is investigating how light (quantity, quality, and duration) and temperature (including vernalization) influence growth and development of ornamental herbaceous annuals and perennials.  Two underlying objectives of this research are: 1) to introduce “new” floriculture crops to the greenhouse industry to replace or supplement the production of other, less profitable crops, and 2) to improve the production efficiency  of crops currently grown.  The five major foci of my research program follow. 

Managing the Greenhouse Environment for Energy Conservation
With the recent rise in energy costs, some greenhouse growers have lowered their temperature setpoints to reduce fuel consumption for heating.  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.  In addition, we’re determining if and when supplemental lighting is a cost-effective strategy to produce garden plants during the plug and finish stages. 
 

Flowering Physiology of Potted Orchids
Orchids represent the second most valuable flowering potted crop in the United States, with an estimated wholesale value of $144 million in 2005. However, with the exception of a few genera, little is known about flower induction and development of orchids. One of my areas of research is to determine how environmental parameters (light and temperature) control growth and flowering of various orchid hybrids. The overall goal is to develop production schedules to predictably flower various orchids for sales at any time of the year.  Visit our Orchid Research and Development website for more information and our recent publications. 
 

Production, Postharvest, and Propagation of Nonrooted Cuttings
We are collaborating with researchers at Clemson University and North Carolina State University to identify ways that propagators can maintain the quality of cuttings from point of harvest to rooting.  Research projects focus on (1) stock plant management so that cuttings have the necessary resources to tolerate stresses once harvested, (2) product handling to minimize cutting stresses during transit, (3) the proper package environment, and (4) appropriately handling cuttings after arrival and management of the propagation environment. 
 

Growth and Development of Herbaceous Perennials
In the past decade, one of the major research thrusts in the Floriculture Group at Michigan State University has been to determine the cultural and environmental requirements for production of flowering herbaceous perennials. One main objective continues to be determining how various species respond to photoperiod, vernalization treatments, daily light integral, growing temperatures, and plant growth retardants.  From this information, we can generate production schedules to flower crops of perennials for a predetermined date.  For more information, visit our MSU Perennial Research website. 
 

Plant Growth Regulators on Greenhouse Crops
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.

Personnel

Major Outreach Programs

The Michigan floriculture industry has steadily increased in size and scope since the early 1990's, with a 37% gain in value from 2001-2005.  Michigan has become the nation’s third largest producer of floriculture crops, with a reported wholesale value of over $384 million in 2005.  Michigan produces the nation’s second largest bedding plant crop, is second largest producer of young plants (plugs and liners), and is the third largest producer of herbaceous perennials.  In total, floriculture is the fourth largest agricultural commodity in the state behind milk, soybeans, and corn.   

I provide research-based information and educational opportunities to the floriculture industry in Michigan and beyond.  Many of my outreach activities and recent grower publications are available on the Floriculture Area of Expertise Team’s website.  Some of the floriculture outreach activities in which I provide leadership are briefly described below. 

The College of Knowledge
The Floriculture College of Knowledge is a greenhouse grower career certificate program that is comprised of 12 four-hour educational courses. This program has been developed for greenhouse growers that want to improve their knowledge and skills in the production of floriculture crops. In 2005, we developed a Business College of Knowledge, which consists of four modules focused on business management of horticultural companies. 

Michigan Greenhouse Energy Cost Reduction Strategies
In collaboration with horticulturists, agricultural economists, and agricultural engineers, we have developed this website resource that contains production strategies and technologies that greenhouse growers can use to consume less energy and improve production efficiency. 

Greenhouse Crop Advisory Team (CAT) Alert
This electronic newsletter is published twice monthly from late December through early May of each year.  Research-based articles are written by members of the Floriculture AoE Team and discuss emerging disease and insect pests, cultural guidelines, height-control strategies, extension activities, and other production-related topics. 

The Michigan Garden Plant Tour
Each year (late July to mid-August), we partner with several leading young plant producers in the state for a coordinated open house featuring plant displays in landscapes and containers.

The MSU Garden Plant Showcase (held in early August each year) is an annual grower meeting that consists of self-guided tours of the Horticulture Demonstration Gardens and presentations for retail and wholesale greenhouse companies and garden plant centers. 

Please visit the MSU Greenhouse Crop Production Articles website, which contains many recent grower articles that have appeared in popular trade magazines and newsletters. 

Articles for Greenhouse Growers

For reprints of some recent publications, please click here. 

For a full listing of grower articles, please click here. 

Books 

Fisher, P. and E. Runkle. 2004. Lighting Up Profits: Understanding Greenhouse Lighting. 98 pp.  Meister Media Worldwide, Willoughby, Ohio. 

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

Book Chapters 

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, Ill. 

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, Illinois. 

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 Publishers, Netherlands. 

Refereed Journal Publications 

Pramuk, 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.

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.

• Paper received the Alex Laurie Award as the most outstanding research paper published in the ASHS journals in floriculture in 2005 (tie with paper below).

• Paper received the Kenneth Post Award as the most outstanding floriculture research paper published in ASHS journals in 2005

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.

• Paper received the Alex Laurie Award as the most outstanding research paper published in the ASHS journals in floriculture in 2005 (tie with paper above).

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. in Agric. 15:123-129. (In Japanese.) 

Runkle, E.S. and R.D. Heins. 2003.  SEQ CHAPTER \h \r 1Photocontrol of flowering and extension growth in the long-day plant pansy. J. Amer. Soc. Hort. Sci. 128(4):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. Scientia 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 Newsletter 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. Scientia 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. 

DEPARTMENT OF HORTICULTURE
Michigan State University

Please send your comments to Ms. Sandy Allen allens@msu.edu
This page was last edited in 07/24/07 .