**3. Discussion**

Mizuna grew faster than lettuce at PPFDs <sup>≥</sup> <sup>125</sup> <sup>µ</sup>mol m−<sup>2</sup> s −1 (Figure 7A). A previous study conducted to identify the effects of photoperiod on leafy greens found much faster growth of mizuna compared to lettuce [18]. The difference in biomass between the two crops increased with increasing PPFD (and shorter photoperiods). The goal of the current study was to determine the underlying reasons for the growth differences between these two crops.
