Fig 1. The spectra of nine lighting treatments.

Lighting treatments consisted of blue (B, 400–500 nm), green (G, 500–600 nm), red (R, 600–700 nm), and far-red (FR, 700–800 nm) light delivered by light-emitting diodes. The value that follows each waveband indicates its photon flux density in μmol∙m⁻²∙s⁻¹.