Articles
The effects of root zone volume on early bolting in Delphinium × belladonna and Consolida ajacis
Article number
1453_28
Pages
203 – 208
Language
English
Abstract
Early bolting under high temperature conditions is a serious problem in the production of high-quality cut flowers in Delphinium, which are high-temperature and long-day plants.
Seedlings of D. grandiflorum grown under root-restricted conditions show reduced rates of early bolting, even in summer in Japan.
Early bolting under high-temperature conditions is also a problem in D. × belladonna and larkspur (Consolida ajacis) but the effects of root restriction have not been studied.
In this study, we investigated the effects of root volume restriction in D. × belladonna and larkspur by growing seedlings in cell trays with different cell sizes.
In D. × belladonna, early bolting of seedlings grown in trays with 288 cells (root zone volume approximately 9 mL) was suppressed more than in other root zone volumes.
There was no significant difference among cell trays in cut flower quality after transplanting.
Trays with 288 holes were also effective in suppressing early bolting in larkspur.
Early bolting rate in trays with 288 holes was 34.0% in ‘Cannes Blue Picotee’ and 5.9% in ‘DelQIS Deep Blue’. There was also no significant difference among cell trays in cut flower quality of larkspur after transplanting.
Cut flower length was greater than 70 cm in each treatment except for cell trays with 200 holes (root zone volume approximately 12 mL) in ‘Cannes Blue Picotee’. It is suggested that early bolting of D. × belladonna and larkspur might be controlled by root zone volume, and cell trays with 288 holes are the most suitable to suppress early bolting.
Seedlings of D. grandiflorum grown under root-restricted conditions show reduced rates of early bolting, even in summer in Japan.
Early bolting under high-temperature conditions is also a problem in D. × belladonna and larkspur (Consolida ajacis) but the effects of root restriction have not been studied.
In this study, we investigated the effects of root volume restriction in D. × belladonna and larkspur by growing seedlings in cell trays with different cell sizes.
In D. × belladonna, early bolting of seedlings grown in trays with 288 cells (root zone volume approximately 9 mL) was suppressed more than in other root zone volumes.
There was no significant difference among cell trays in cut flower quality after transplanting.
Trays with 288 holes were also effective in suppressing early bolting in larkspur.
Early bolting rate in trays with 288 holes was 34.0% in ‘Cannes Blue Picotee’ and 5.9% in ‘DelQIS Deep Blue’. There was also no significant difference among cell trays in cut flower quality of larkspur after transplanting.
Cut flower length was greater than 70 cm in each treatment except for cell trays with 200 holes (root zone volume approximately 12 mL) in ‘Cannes Blue Picotee’. It is suggested that early bolting of D. × belladonna and larkspur might be controlled by root zone volume, and cell trays with 288 holes are the most suitable to suppress early bolting.
Authors
T. Goto, M. Kawai, T. Matsuura, K. Yasuba
Keywords
cell tray, cut flower quality, high temperature, root restriction, seedling
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