Jm. Vanhuylenbroeck et Pc. Debergh, YEAR-ROUND PRODUCTION OF FLOWERING CALATHEA-CROCATA - INFLUENCE OF LIGHT AND CARBON-DIOXIDE, HortScience, 28(9), 1993, pp. 897-898
Programmed flower induction of Calathea crocata Morr. et Joris is poss
ible under the controlled environmental conditions of a multilayer gro
wing room. A photoperiod of 10 hours for 9 weeks, growth at 18C, and a
photosynthetic photon flux density (PPFD) of 71 mumol.s-1.m-2 induced
flowering in more than 95 % of the plants and in 50 % to 80% of the s
hoots. In the meantime, none of the plants under natural conditions wa
s induced. Significantly more flowers were induced when PPFD during th
e short-day treatment was 71 rather than 56 mumol.s-1.m-2. Flowers bec
ame visible 14 to 16 weeks after the start of the inductive treatment.
Moreover, raising the CO2 concentration to 900 ppm for 5 months incre
ased the leaf area and dry weight by 40%, and resulted in darker leaf
color, longer flower stalks, and significantly accelerated flowering (
10 days).