Effects of light quality and photoperiod of light emitting LED on growth and biomass accumulation of shallot

In the present investigation, effects of light quality emitted by light emitting light emitting diodes (LED),  and selected photoperiods on the growth and biomass accumulation of shallot (Allium cepa var. aggregatum) have been studied. Two ratios of red and blue light namely, 2:1 and 1:1 and two photoperiods 16 h dark and 8 h light cycle and 12 h each alternating light and dark cycle were tested. The results showed that the growth of spring shallots and the accumulation of biomass were associated with the ratio of red and blue light as well as on the photoperiod. The plant height growth, growth rate and the accumulation of chlorophyll a were the fastest under an experimental condition of 16 h of illumination with a red and blue light ratio of 2:1. The synthesis of chlorophyll b was the fastest under an experimental condition of 12 h of illumination with a red and blue light ratio of 2:1. Key words: Shallots, light emitting diodes (LED), light, red and blue light quality, biomass.