Light and plants expert Tessa Pocock, Ph.D., recently joined the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute as a senior research scientist, leading the development of a new plant physiology lighting program. Her research focuses on plant photosynthesis, and plant development and regulation by light for traditional greenhouse crops and the emerging field of medicinal plants.

Prior to joining the LRC, Dr. Pocock was director of research at Heliospectra, in Sweden, where she designed light-emitting diode (LED) regimes to reduce energy consumption, produce healthier plants, and improve the quality of greenhouse crops. For the last four years, she has been developing a biofeedback system in which the physiology of the plant regulates the spectrum and intensity of LED arrays, in collaboration with Chalmers University of Technology, under a prestigious grant from the Swedish Foundation for Strategic Environmental Research (Mistra).

Light is a powerful regulator of plant physiology, affecting flavor and appearance, as well as nutritional and medicinal value. Each wavelength of light has a different effect on plant physiology. For example,  plants grown under “blue” light are physiologically different than plants grown under “red” light. And each species of plant has an individual response to different wavelengths as well.  

Due to advances in narrowband LED technology, it is now possible to select and deliver a specific wavelength and intensity of light, or different combinations of wavelengths and intensities, resulting in unprecedented control of plant characteristics. A specific wavelength and intensity of light could, for instance, increase the level of antioxidants in salad greens like red leaf lettuce, while a different wavelength and intensity could change the height of poinsettias, or perhaps, increase active compounds in medicinal plants—there are endless possibilities.

“Thanks to recent advances in LED technologies, it is now possible to better elucidate the effects and functions of different portions of the spectrum to manipulate plants with unprecedented control and accuracy,” said Dr. Pocock. “The fine-tuning of light spectra and controlled regulation of plant attributes is adding new sophistication to plant production.”

One of Dr. Pocock’s first projects at the LRC is a study in collaboration with Gotham Greens, a New York City based agribusiness with rooftop greenhouses in Brooklyn. The team will research, evaluate, and model LED and high intensity discharge (HID) greenhouse lighting systems to reduce energy and its associated atmospheric pollution, and improve plant throughput and appearance for higher margins. The study is funded by the New York State Energy Research and Development Authority (NYSERDA), which is providing $500,000 through a research and development program targeting improvements in energy efficiency and crop production for controlled environment agriculture, such as greenhouses. This research will identify optimal lighting to increase leafy vegetable production using energy efficient LEDs compared with existing HID fixtures.

Dr. Pocock earned her diploma in horticulture greenhouse management at Olds Agricultural College in Alberta, Canada, and an honors bachelor’s degree in plant science, master’s degree in plant biochemistry, and doctoral degree in environmental stress biology at the University of Western Ontario, Canada. She then travelled to Sweden on a Marie Curie postdoctoral fellowship to study the effect of climate change on algal photosynthesis and stress responses. She is the author of numerous scientific and technical articles related to plant science and the effect of light and temperature on plants, and has presented at more than 20 national and international conferences.