Emerson's enhancement effect revisited: increasing photosynthetic rate and quantum yield of photosystem II with far-red LEDs (Shuyang Zhen)

ISHS Secretariat
Shuyang Zhen

Shuyang Zhen received her BSc in Landscape Gardening at Huazhong Agricultural University, China in 2011. Shuyang then went to graduate school at the University of Maine, USA and completed an MSc in Horticulture in 2013. Her Master's research, under the direction of Dr. Stephanie Burnett, focused on improving irrigation efficiency for the production of ornamental plants. Shuyang is currently studying for her PhD under the direction of Dr. Marc van Iersel (lab website: http://hortphys.uga.edu) at the University of Georgia. Her aim is to improve the efficiency of supplemental lighting for horticultural crop production in controlled environments. Greenhouses commonly use high power lamps to supplement sunlight to enhance photosynthesis and increase crop quality and growth under low light conditions, especially in winter. Crop production costs increase substantially because of the high electrical consumption of these lamps. Light use efficiency could be improved by providing plants with light levels and quality (spectral distribution) that result in the greatest plant biomass production. Part of her work examined the use of chlorophyll fluorescence measurements to quantify how efficiently plants use light to produce biomass under different light intensities, and thus develop more efficient lighting protocols for a range of plant species. Another part of Shuyang's work focused on developing improved light spectra for more effective photosynthetic lighting using light emitting diodes (LEDs). Certain light wavelengths are absorbed and utilized more efficiently by plants for photosynthesis than others, and combining the optimal combination of narrow spectrum lights may have a positive synergistic effect on photosynthesis. Her results indicated that the light from commonly used white or red/blue LEDs can be used more efficiently if they are supplemented with far-red light. An LED company in Athens, GA, USA, has already revised the design of their LED lights based on these findings.

Shuyang Zhen won an ISHS student award for the best poster at the VIII International Symposium on Light in Horticulture in USA in May 2016.

Shuyang Zhen, Department of Horticulture, University of Georgia, 1111 Miller Plant Science Building, Athens GA 30602, USA, e-mail: syzhen@uga.edu

Emerson's effect
far-red LEDs
Student Award Winners