Effects of different light intensity on the growth of tomato seedlings in a plant factory

Abstract

Light-emitting diodes (LEDs) were the best artificial light source for plant factories. Red lightemitting diodes (LEDs, R) and blue light-emitting diodes (LEDs, B) were used to obtain different light intensities of uniform spectra, and the greenhouse environment was considered as a comparison. The results showed that root dry weight, shoot dry weight and stem diameter were superior in plant growth under 240 μmolm-2s-1, additionally, the Dixon Quality Index (DQI) was also best. Under 240 μmolm-2s-1, the net photosynthesis rate (Pn) was consistent with the greenhouse s treatment, superior to other experimental groups. The results implied that the PPFD was more suitable for the cultivation of tomato seedlings under the condition of 240 μmolm-2s-1, and can replace the greenhouse conditions so as to save energy and reduce emissions.