Y Higuchi et al. /Journal of Plant P energy requirement to abolish flowering. Alternatively, red-light exposure during the daily photoperiod may have induced desen- sitization of the bluelFR-sensing receptor during NB. We believe that the latter hypothesis is more likely because, under SD with blue, red, or blue red photoperiods, flowering was not promoted by red-light supplementation compared to that with monochro- matic blue light-in fact, it was slightly delayed in monochromatic rod light(Tablo 1