Aconitum: effects of environmental conditions and tuber size on growth, flowering and tuber production

Citation
Aa. Watad et al., Aconitum: effects of environmental conditions and tuber size on growth, flowering and tuber production, SCI HORT A, 81(2), 1999, pp. 135-147
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
SCIENTIA HORTICULTURAE
ISSN journal
0304-4238 → ACNP
Volume
81
Issue
2
Year of publication
1999
Pages
135 - 147
Database
ISI
SICI code
0304-4238(19990601)81:2<135:AEOECA>2.0.ZU;2-M
Abstract
Aconitum (Aconitum napellus) is a hardy geophytic herbaceous perennial, wit h a tall leafy stem bearing violet or blue flowers on long, packed racemes. Although aconitum was introduced as a new commercial cut-flower crop almos t 20 years ago, it is produced on a rather limited scale, because of low fl owering percentages and low flower quality. The aim of this work was to stu dy the factors responsible for these drawbacks. Growth curves of the differ ent organs showed that daughter tubers reach their final weight ca. 4-6 wee ks after flowering, when the tuber's central bud starts to elongate. At thi s stage, there is no flower differentiation. Flowering was highly dependent on tuber weight: 30- to 40 g tubers gave flowers of optimal quality, where as plants derived from tubers of 5 g or less did not flower. Plants from la rger tubers produced more tubers, whereas smaller ones had a higher growth rate. Treating the tubers with 200 ppm GA(3) enhanced sprouting of dormant tubers. Plants did not develop from tubers at 27 degrees C or higher, where as at 22 degrees C or below the tubers sprouted and developed vigorous plan ts. Long-day conditions, begun when plants were 10 cm high and continued un til harvest, increased plant height and flower quality. Spraying 10 cm plan ts once with 100 ppm GA(3) resulted in enhanced stem and raceme elongation. Failure to flower resulted from both internal and environmental factors: s mall tuber size, limited solar radiation and small root-system volumes resu lted in low flowering percentages. (C) 1999 Elsevier Science B.V. All right s reserved.