Controlled Environments Horticulture

Controlled Environment Horticulture is the production of specialty crops under indoor production systems with the technology to control the environment such as greenhouses, vertical farms/plant factories, tissue culture and post-harvest. In this field of study, we use the science of plant eco-physiology to understand plant responses to the different environmental factors. We then use that knowledge to maximize plant growth rate, development, morphology, physiology and ultimately improve crop yield, phytochemical content, and flavor.

The research in this program is directly translated to indoor production in greenhouses, high-tunnels, tissue culture, and plant factories/vertical farms. The main environmental components to optimize plant responses are light (intensity and quality), temperature, air movement, humidity and CO2 concentration. With the recent improvement of Light Emitting Diodes (LEDs), our work is currently focused on the effect of light quality (spectrum), light intensity, and the interaction of light with other environmental factors.

Overall, our objective is to improve horticultural indoor production while increasing sustainability of current systems.

[Return to Top]


Principal Investigator: Ricardo Hernández

Environmental Optimization to Increase Phytochemicals in non-commercial plant species

Lead Scientist: 

Luis Morales Suarez, Ph.D

This research program will increase the affordability of Vertical farm products by providing more nutritionally dense produce by significantly increasing the phytochemical contents and biomass accumulation while reducing the resource inputs. We expect for exotic germplasms grown under optimized indoor conditions to have a greater content of beneficial phytochemicals than commercial cultivars. In other words, we plan to use CE research to find the baseline information to create plant-based nutraceutical farms.

Dynamic light recipes to improve lettuce growth rate and quality (morphology and phytochemical content) in indoor production systems

Funded by:

USDA NIFA, project [1007454] Lead Student: Hans Spalholz, Ph.D.

Most research has focused on characterizing plant responses when exposed to a single light recipe (static spectrum). However, research that identifies the matching spectrum to the different plant growth stages (lag, log, and plateau) to maximize output (nutrient, flavor, growth) is lacking, we called this the dynamic spectrum. This research project is focused on finding dynamic light recipes to improve lettuce growth and quality.


Interactions between Daily Light Integral (DLI) and CO2 concentration to improve propagation efficiency of grafted vegetable seedlings

Lead Student:

Brandon Huber, Ph.D.

Indoor nursery using electrical lighting is a standard commercial technology for pre- and/or post-grafting processes in Asian and European countries that have advanced nursery technologies. The advantages include 1) uniform plant growth, 2) higher density production, 3) highly contained environment, 3) complete independence from outside climate, and 5) conditioned flowering for earliness; yet the disadvantages are 1) high capital costs, and 2) limited availability of systems.

The objective of this project is to maintain high plant quality while reducing electricity demands from electrical lighting  by increasing concentration of supplemental CO2 in order to increase plant grow efficacy (g per kWh).


strawberry nursery production in controlled environments

Optimization of strawberry nursery production in full controlled environment systems

Lead Student:

Xiangnan Xu, Masters of Science

The current open-field strawberry nursery production system is a multi-year and multi-location operation and limited to select regions in the U.S. The current system has inherit risks. For example, disease contamination of strawberry nursery material; and lack of plant uniformity and supply due to variable environmental conditions.

In this research project, we aim to designing precision indoor propagation (PIP) tools to optimize strawberry nursery production and to develop disease-free propagation material. PIP is defined as the production of propagation material under fully controlled environments and under the exemption of natural sun light. The project main objective is to optimize the environment to increase runner/tip production while reducing production cost. Current efforts are focused on photoperiod, light intensity, and temperature optimization.


Optimizing site-specific solar radiation modelling for its application in the horticultural, agricultural and photonics industries

Lead Scientist:Titta Kotilainen, PhD

The objective of this project is to measure irradiance conditions under a range of structural materials, different locations, sites, and times of day/year. Measurements will be performed with partners, in Finland, the US, UK and mainland Europe. The objective of the project is to predict light quality inside the greenhouse based on outside irradiance using modelling. Validation of models is done by measuring under various scenarios and comparing measurements to models of what the irradiance is predicted to be.

This project, funded by Academy of Finland, is a joint effort between University of Helsinki, Department of Biosciences, Division of Plant Biology; NCSU, Department of Horticultural Sciences; Stockbridge Technology Centre (UK); Kauppapuutarhaliitto (association for Finnish growers); and Photonics Finland.


Photoperiodic responses of LED supplemental lighting in the greenhouse to improve growth and development of tomato transplants and lettuce

Lead Scientist:

Cristian Collado
Lead Students: Kai Rundquist and John Calero

While maintaining the same Daily Light Integral (DLI) using supplemental LED lighting in the greenhouse, we intent to improve plant morphology and quality by adjusting the photoperiod.

[Return to Top]

Past Research

Morphology and growth of ornamental seedlings grown under supplemental LED lighting and chemical plant growth regulator

Lead Scientist:

Cristian Collado
For more information contact


Effects of light quality during the healing stage on the morphology and growth of grafted tomato transplants using light emitting diodes and fluorescent lights

Lead Scientist:

Jimmy Byrtus
For more information contact

[Return to Top]

Available Positions


Study Abroad

Sustainability in Emerging Countries (Oaxaca -México)- Summer odd years

Crop Physiology and Production

Crop Physiology and Production in Indoor Environments

(PDF) (greenhouse and vertical farms) – Every Spring

Applied Plant-Light Interactions

Applied Plant-Light Interactions

(PDF) – Light effects on crop yield, morphology and development- Spring even years

[Return to Top]


Principal Investigator

Ricardo Hernández, Ph.D.

NC State University Assistant Professor in the Department of Horticultural Sciences – Growing up in a border city in northern México (Cd. Juárez, Chih), I had no exposure to agriculture, not even gardening. I still remember my backyard, a mere 120 square foot concrete space with an eight-foot tall wall with zero gardening potential. I remember being curious about horticultural production, which as an adult, I now realize that it is not exactly a common curiosity for children. My growing passion for agriculture made me realize that the innate instinct of growing plants runs deep within me. I have always been fascinated with the synergistic integration of technology with plant systems in order to improve food production; and in the science of Controlled-Environment-Horticulture, I found the perfect research field that I now call my passion. I have devoted my academic and professional career to advancing the science of applied environmental physiology (controlled environment horticulture), while educating the next generation of scientists. Even though my passion is to seek new discoveries by designing and executing research, I am also fully committed to translating my findings to real world application through teaching, international exposure, and entrepreneurship. I understand that I am a young scientist with a lot to learn. However, I believe my entire life experience has led me to this point and I am committed to devote all my efforts and energy to keep advancing the science of Controlled Environment Horticulture.

View Curriculum Vitae.

Research Group Manager and Technical Support

Cristian Collado, M.S.

I am an agricultural engineer with intuitive skills for technology and love for research. At the age of one year, for example, I sneaked into a car and figured out how to turn it on. Much later, I graduated with honors from the most important university in Argentina (UBA) in 2011 and was given a grant by the federal government to do research in the domestication of native aromatic plants. At the end of this project and after almost four years of being married, I and my wife decided to move to North Carolina. Currently, I work for the Controlled Environment Horticulture lab at NCSU where I combine my knowledge and experience in plant and soil sciences with environmental technology.

Graduate Students

Hans Spalholz

I became interested in horticulture and botany at a young age where I would spend my free time outside. This interest naturally developed into a passion for horticulture that took me to Cornell University (B.S. Plant Science) that was followed by a cap-stone ethnobotany internship in South America. After my undergraduate studies, I became a Peace Corps volunteer in Senegal working to improve food security at the local level. Following this work, I started a Master’s of Science at the University of Arizona where I studied controlled environment agriculture with my research focusing on vegetable grafting. Upon completion, I went to work at the IGZ (Germany) managing a grafted tomato experiment before attending N.C. State University for PhD studies. In my spare time I like to hike, bike, play soccer, and travel.

Brandon Huber

I grew up in Philadelphia, PA. At the early age of 6, I discovered my passion for growing plants. Growing up in a big city, I learned how to utilize small spaces to garden, and grow plants indoors under lights. It was evident a horticulture career was for me, so I earned a BS at Temple University in Horticulture. During my undergrad and a couple years after I worked in greenhouse production. I then gained interest in research and plant breeding and decided to pursue a MS with a focus in plant breeding at NC State University. After finishing my MS, I decided to broaden my experience and pursue a PhD in plant physiology working in controlled environments. As a hobby I enjoy bowling, reptiles, and growing unusual plants including carnivorous, aroids, gesneriads, and giant pumpkins.

Xiangnan Xu

I was born and raised in Beijing, China, which is a crowded city. I moved to USA to continue my higher education. The life here is so different and people are nice and helpful. I move to NC from Oklahoma in summer 2017. My hobbies are dancing, cooking and drinking traditional Chinese tea. Now I enjoy the life in NC very well. I go practice group dancing and search for new restaurants to try every week. I hope I could become a scientist to help farmers in the future!

Postdoctoral Research Associate

Titta Kotilainen

My work with plants and light started in 2004 and ever since I have been studying solar radiation outdoors, supplemental lighting in horticultural applications and varying plant photobiological responses. When I am not thinking about light, so to say, I go swimming or horseback riding or for a walk to the forest (especially late summer/early autumn, as it is the season to pick berries and mushrooms!). And whatever spare time I have, I read novels or watch sports, ice hockey and soccer in particular.

Luis Morales Suarez

I am originally from a small town in Pinar del Río near the westernmost tip of Cuba. I grew up surrounded by agriculture, and as a natural “Guajiro” I was always attracted by plants and nature. I hold degrees in plant biology, and I am very passionate about research and promoting plant science in the society. During the last 10 years I have developed a special interest in molecular and physiological events following light perception and signaling. At NC State University I seek to combine my previous expertise and new physiological research to assess plant responses that could have the potential to improve conventional plant production systems. In my free time I enjoy exploring new places with my family, practice tennis, volleyball and badminton, and attempt new recipes as amateur cook.

View curriculum vitae

Undergraduate Students

[Return to Top]


Trade Journals Publications

Book Chapters

Both A.J., Bugbee B., Craver J., Currey C., Dole J., Dorais M., Erwin J., Faust J., Fisher P., Frantz J., Hernández R., Kopsell D.A., Kubota C., Lopez R., Mattson N., Mitchell C., Runkle E., Stutte G., van Iersel M., Warner R., Whitman C. (2017) Light management in controlled environments. Light quality and photomorphogenesis. 105-137. Meister Media Worldwide

Mitchell, C.A., J.F. Burr, M.J. Dzakovich, C. Gómez, R. Lopez, R. Hernández, C. Kutoba, C.J. Currey, Q. Meng, E.S. Runkle, C.M. Bourguet, R.C. Murrow & A.J. Both 2015. Horticultural reviews-light-emitting diodes in horticulture, WILEY Blackwell.

Liu, T. X, Kang L., Lei Z., Hernández, R., (2010). Recent advances in entomological research: hymenopteran parasitoids and their role in biological control of vegetable Liriomyza leafminers (pp. 228-243). Higher Education Press.

Recent Research Publications

Kotilainen T, Robson TM, Hernández R (2018) Light quality characterization under climate screens and shade nets for controlled-environment agriculture. PLOS ONE 13(6): e0199628.

Eguchi, T., R. Hernández & C. Kubota 2016a. End-of-day far-red lighting combined with blue-rich light environment to mitigate intumescence injury of two interspecific tomato Acta Hort, 1134, 163-170.

Eguchi, T., R. Hernández & C. Kubota 2016b. Far-red and blue light synergistically mitigate intumescence injury of tomato plants grown under ultraviolet-deficit light environment. HortScience, 51, 712-719.

Hernández, R., T. Eguchi, M. Deveci & C. Kubota 2016. Tomato seedling physiological responses under different percentages of blue and red photon flux ratios using leds and cool white fluorescent lamps. Sci. Hortic., 213, 270-280.

Hernández, R. and C. Kubota (2016). Physiological responses of cucumber seedlings under different blue and red photon flux ratios using LEDs. Environmental and Experimental Botany.

Hernández, R. and C. Kubota (2015). Physiological, morphological, and energy-use efficiency comparisons of LED and HPS supplemental lighting for cucumber transplant production. HortScience 50(3): 351-357.

Hernández, R., Kubota, C. (2014) Growth and morphological response of cucumber seedlings to supplemental red and blue photon flux ratios under varied solar daily light integrals. Scientia Horticulturae 173C (2014), pp. 92-99

Hernández, R., Kubota, C. (2014). LEDs supplemental lighting for vegetable transplant production: spectral evaluation and comparisons with HID technology. Acta Hortic. 1037, 829-835.

Hernández, R., Dragotakes, A., Kubota, C. (2014). Pulsing effects of supplemental LED lighting on cucumber seedlings. Acta Hortic. 1037, 875-880

Hernández, R., Kubota, C. (2012). Tomato seedling growth and morphological responses to supplemental led lighting red:blue ratios under varied daily solar light integrals. Acta Hortic. 956, 187-194.

Hernández, R., Guo K., Harris M., Liu, T. X, (2011) Effects of selected insecticides on adults of two parasitoid species of Liriomyza trifolii: Ganaspidium nigrimanus (Figitidae) and Neochrysocharis formosa (Eulophidae). Insect Science. Vol 18: 512-520.

Hernández, R., Harris M., Liu, T. X, (2010) Liriomyza and parasitoid species on peppers in the lower Rio Grande Valley of Texas. Southwestern Entomologist Vol 35(1):33-43.

Hernández, R., Harris M., Liu, T. X., (2011) Impact of insecticides on parasitoids of the leafminer, Liromiza trifolii, in pepper in south Texas. Journal of Insect Science. Vol 11:61.

Micheletto S., Rodriguez-Uribe L, Hernández R,. Richins D.R., Curry, J., O’Connell, M.A.(2007). Comparative transcript profiling in roots of Phaseolus acutifolius and P. vulgaris under water deficit stress. Plant Science. Vol 179: 5.

[Return to Top]

[Return to Top]


Dr. Ricardo Hernández

Ricardo Hernández

Office Phone:  919-513-7288

Department of Horticultural Sciences
Campus Box 7609
2721 Founders Drive
Raleigh, NC 27695-7609