Diurnal Photosynthesis and Transpiration of Ficus benjamina L. as Affected by Length of Photoperiod, CO2 Concentration and Light Level
Titel:
Diurnal Photosynthesis and Transpiration of Ficus benjamina L. as Affected by Length of Photoperiod, CO2 Concentration and Light Level
Auteur:
Mortensen, Leiv M.
Verschenen in:
Acta agriculturae Scandinavica. Section B, Soil and plant science
Paginering:
Jaargang 42 (1992) nr. 2 pagina's 100-105
Jaar:
1992-06-01
Inhoud:
The diurnal net photosynthesis of Ficus benjamina L., cultivar Cleo, was studied at different daylengths (12, 18 and 24 h day-1), photosynthetic photon flux densities (40 and 120 μmol m-2 s-1 PPFD) and CO2 concentrations (350 and 700 μmol mol-1). Net photosynthesis increased to a maximum after 5-6 and 6-7h of light at 12 and 18h day-1photoperiods, respectively, followed by a decrease towards the end of the photoperiod. At a photoperiod of 18 h day-1 similar diurnal curves were found at 350 and 700 μmol mol-1 CO2, and at 40 and 120 μmol m-2 s-1 PPFD. Five days after the photoperiod was changed from 18 to a 24h day-1the diurnal rhythm disappeared. Transpiration followed the same diurnal rhythm as that for photosynthesis. The water-use efficiency was enhanced by raising the CO2 concentration. A decrease in the CO2 concentration from 700 to 350 μmol mol-1after six days at high CO2 first significantly decreased the photosynthesis, but three days later it reached the same level as that at high CO2.
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