THE EFFECT OF CO₂, DAYLENGTH AND LIGHT ON THE PRODUCTION AND SUBSEQUENT GROWTH OF BEGONIA X TUBERHYBRIDA CUTTINGS

Stock plants of Begonia x tuberhybrida ‘Karelsk Jomfru’ were subjected to various CO₂ regimes and to different daylength and light intensities.
The experiment was carried out in growth rooms at 19°C. The plants were grown at two CO₂ levels, either 330 or 1100 μl l^-1 and irradiated with either 7 or 15 Wm^-2. One half of the plants were grown at 10 h (SD) and the other half at 24 h (LD) photoperiod.

Yield of cuttings and the after-effects of stock plant treatments on lateral shoot formation and growth of cuttings were studied.

Carbon dioxide enrichment of the stock plants strongly enhanced number of cuttings (23 %). The effect of CO₂ was promoted by LD treatment.
At LD the stock plants produced 41 % more cuttings compared with SD. Number of cuttings were also enhanced by increasing irradiation level (23 %).

Long days to stock plants had a positive after-effect on growth and lateral shoot formation of rooted cuttings.
CO₂ enrichment of stock plants had no after-effects.
Rooted cuttings from stock plants grown at 7 Wm^-2 produced significantly more lateral shoots than cuttings from 15 Wm^-2.

Abbreviations: LD = long photoperiod, SD = short photoperiod.

Symposium on CO2 Enrichment

R. Djurhuus

https://doi.org/10.17660/ActaHortic.1984.162.5