FIGURE 4.

Shoot fresh and dry weights, leaf length, and the a* color space coordinate of lettuce “Rouxai” on day 25. Plants were grown under each of six lighting treatments delivered by warm-white (WW) or mixed blue (B; 400–500 nm), green (G; 500–600 nm), red (R; 600–700 nm), and far-red (FR; 700–800 nm) light-emitting diodes (LEDs) during day 0–11, transferred to all six treatments on day 11, and grown until day 25. The number for each LED type is its photon flux density in μmol⋅m^–2⋅s^–1. Means followed by different letters within each parameter and treatment applied during day 11–25 are significantly different based on Tukey’s honestly significant difference test (α = 0.05). NS, non-significant. Error bars show standard errors.