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Virginia Tech

Use of Plant Growth Regulators to Increase Branching of Clematis Spp.

Abstract

dc:description.abstract

Clematis spp. L. is a twining vine covered in showy blooms. Typical growth of hybrids is from the main leader, producing a thin, unbranched plant with one cyme. Apical dominance is released by cutting back the vine during production. Cutting back, or pinching, of a plant is labor intensive and compromises bloom for vegetative growth at time of sales. The purpose of this project was to eliminate manual pinching by treating young plants with chemical plant growth regulators (PGRs) that enhance branching without removal of the apical meristem. The first project evaluated the use of Atrimmec (dikegulac sodium), Fascination (BA+GA4+7), Florel (ethephon), and Dropp 50 (thidiazuron) on Clematis cultivars Ernest Markham, and Hagley Hybrid, and Clematis viticella 'Polish Spirit.' Plants treated with 800 mg·L-1 Atrimmec, or 800 or 1200 mg·L-1 Fascination experienced an increase in branch numbers. The second experiment manipulated the ratio of the components of Fascination, 6-BA and GA4+7, to reduce phytotoxicity experienced in the first experiment. The optimal ratio to enhance branching was 1:1, which is the stock solution for Fascination. All ratios produced phytotoxic symptoms. A third experiment tested lower rates of thidiazuron and added CPPU (forchlorfenuron) to the list of PGRs to test. The last experiment took the most effective PGR treatments, Atrimmec at 800 mg·L-1, and Fascination at 800 or 1200 mg·L-1, and compared them to the current production practices of pinching. Large flowering cultivars of clematis were used, including 'Comotesse de Bouchard,' 'Ernest Markham,' and 'Hagley Hybrid.' Atrimmec increased branch numbers and suppressed leader lengths without a mechanical pinch. Results from Fascination varied by cultivar.

Degree

thesis:*
Name thesis:degree_name
Master of Science
Level thesis:degree_level
masters
Discipline thesis:degree_discipline
Horticulture
Department dc:contributor.department
Horticulture
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
2002

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Puglisi, Sadie Erica
Chairs dc:contributor.committeechair
  • Latimer, Joyce G.
  • Scoggins, Holly L.
Committee member dc:contributor.committeemember
  • Eaton, Gregory K.

Subjects

dc:subject × 7

Rights

dc:rights
Statement dc:rights
  • In Copyright

Identifiers

dc:identifier.*
Dc Identifier Other
etd-09102002-174147
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/35000

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Puglisi, Sadie Erica. Use of Plant Growth Regulators to Increase Branching of Clematis Spp.. masters thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/35000