The effect of the colors (wavelengths) of white light on the phototropic growth of vegetable roselle
(hibiscus sabdariffa) has been studied. The results show that green light has the maximum observed
transmitted intensity indicating that chlorophyll and accessory pigments in roselle leaf are good
reflectors of green light (i.e. insignificant amount of the energy of green color is absorbed). Blue and red
colors have low observed transmitted intensities showing that chlorophyll and the pigments are good
attenuators of these colors (i.e. significant amount of the energies of blue and red colors are absorbed).
This means that blue and red components of white light transfer their energies to the electrons of
chlorophyll and the accessory pigments during photoelectron absorption process and the energy
transferred is used in photosynthesis and then finally growth. Similarly the percentage transmittance
(%T) of the colors has been used successfully to explain growth in vegetable roselle.