Spectral Control: Impacts of Broad and Narrow LED and Legacy Lighting Spectra on Plant Morphology and Yield
Wednesday, March 01, 2017: 4:00 PM - 4:30 PM
The increasing outputs, efficiencies and affordability of solid state lighting (SSL) in horticultural applications are creating opportunities for growers to increase yields, decrease electrical costs, and control plant morphology by manipulating the delivered light spectrum to plants. Ongoing research at West Virginia University regarding the impacts of light quality on key growing and operational variables are examined here with an emphasis on broad and narrow spectrum SSL. In preliminary tests with tomatoes, basil and petunias and extensive testing of lettuce and kale, typical narrow band grow lights resulted in reduced biomass and length with the darkest pigmentation. Non-LED light sources, such as high pressure sodium, with predominantly green-yellow output, produced more elongated plants with less pigmentation but higher biomass than narrow band LEDs. Broad spectrum volumetric LED grow lights typically produced the greatest biomass with pigmentation and compactness levels in between that of narrow band lights and the other lights.