Articles
FLOWER INITIATION AND DEVELOPMENT IN GARDENIA PLANTS AS AFFECTED BY PHOTOPERIOD AND NIGHT TEMPERATURE
Article number
515_11
Pages
99 – 104
Language
Abstract
Gardenia (Gardenia jasminoides Ellis) young plants were maintained in growth chambers where photoperiods of 8h, 12h or 16h were applied for 4 weeks.
For the following 4 weeks all plants were moved to a photoperiod of 16h and at the end of that time flower bud set was evaluated.
Plants under 8h or 12h for the first 4 weeks showed a definitely higher percentage of visible flower buds as compared to those kept at 16h, proving that short photoperiods promote flower bud initiation in gardenia plants.
In another experiment, photoperiod of 8h was applied to plants for 4 weeks and afterwards they were divided in three groups and placed in 8h, 12 or 16h photoperiod.
It was found from the evaluation that photoperiod of 16h enhanced flower bud development leading to earlier flowering.
In order to define the effect of night temperature on flower bud set in gardenia, plants were placed in growth chambers under 8h photoperiod and 24°C day temperature while the night temperatures were kept at 12°C, 18°C or 24°C. After 4 weeks the night temperature was changed to 18°C for the next 4 weeks for all plant groups.
In two other similar experiments night temperatures of 18°C and 24°C were applied to plants and 4 weeks later each group was divided to three smaller ones and were placed in 12°C, 18°C or 24°C night temperature.
All night temperatures, which were tested, promoted flower bud set and also all six combination temperatures showed a positive effect on flower bud development.
In addition it was noticed that plants with a night temperature of 24°C for both initiation and development stage showed an earlier flowering.
For the following 4 weeks all plants were moved to a photoperiod of 16h and at the end of that time flower bud set was evaluated.
Plants under 8h or 12h for the first 4 weeks showed a definitely higher percentage of visible flower buds as compared to those kept at 16h, proving that short photoperiods promote flower bud initiation in gardenia plants.
In another experiment, photoperiod of 8h was applied to plants for 4 weeks and afterwards they were divided in three groups and placed in 8h, 12 or 16h photoperiod.
It was found from the evaluation that photoperiod of 16h enhanced flower bud development leading to earlier flowering.
In order to define the effect of night temperature on flower bud set in gardenia, plants were placed in growth chambers under 8h photoperiod and 24°C day temperature while the night temperatures were kept at 12°C, 18°C or 24°C. After 4 weeks the night temperature was changed to 18°C for the next 4 weeks for all plant groups.
In two other similar experiments night temperatures of 18°C and 24°C were applied to plants and 4 weeks later each group was divided to three smaller ones and were placed in 12°C, 18°C or 24°C night temperature.
All night temperatures, which were tested, promoted flower bud set and also all six combination temperatures showed a positive effect on flower bud development.
In addition it was noticed that plants with a night temperature of 24°C for both initiation and development stage showed an earlier flowering.
Authors
E.P. Makridou, A.S. Economou
Keywords
Gardenia jasminoides, development, flowering, growth, ornamentals, photoperiod, pot plant, temperature
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