Photoperiodicity of Baeria chrysostoma

Abstract

1. Baeria chrysostoma is a long-day plant, provided it is grown below 25⚬C. It will grow at light intensities of above 150 f.c., obtained with fluorescent tubes, and responds rapidly to long photoperiods. 2. At least 5 long photoperiods are required for flower initiation, and a 15-hour photoperiod is effective. Plants become sensitive to long photoperiods 5 days after germination; and a few days after the long photoperiodic treatment, microscopic observation shows flower initiation. 3. The intensity of the supplementary light required after an 8-hour photoperiod for flower initiation is above 100 f.c. Both the short and the long wave lengths are effective, but green light is not. The cotyledons and leaves are equally effective in perception of the light effect. 4. No extracts or pure substances induced flowering in plants kept on short photoperiods.