Margaret Improved


Denomination: 'Margaret Improved'
Trade name: Dahlietta Margaret
Botanical Name: Dahlia
Applicant/Holder: Ball Horticultural Company
622 Town Road
West Chicago, Illinois
United States of America
Breeder: Francois Van Hee, PanAmerican Seed Europe, Enkhuizen, Netherlands
Agent in Canada: BioFlora Inc.
38723 Fingal Line
R.R. #1
St. Thomas, Ontario
N5P 3S5
Tel: 519-631-6241
Application Date: 2001-07-19
Application Number: 01-2793
Grant of Rights Date: 2006-10-14
Certificate Number: 2624
Date rights surrendered: 2010-11-25

Variety Description

Variety used for comparison: 'Margaret' (Dahlietta Margaret)

Summary: 'Margaret Improved' is a dahlia variety which has no stem anthocyanin colouration, whereas 'Margaret' has medium anthocyanin on the stems. The leaves of 'Margaret Improved' are narrower than those of 'Margaret' and the ray florets are wider. 'Margaret Improved' has uniformly coloured yellow flowers, while 'Margaret' has irregularly bicoloured flowers that have a deep yellow main colour with yellow brown secondary colour, mostly on the outer ray florets. The lower side of the ray florets of 'Margaret' have streaks of red pink, which are not present in 'Margaret Improved'.


'Margaret Improved' is a dahlia variety which has an upright, compact growth habit. The stems are light green with no anthocyanin colouration. The leaves are simple and dark green in colour with a medium number of shallow incisions on the margins. The texture of the upper surface of the leaf is weakly rugose and the veins on the upper surface are raised.

The peduncle of 'Margaret Improved' has no anthocyanin colouration. The flowers are located at the same level as the foliage or moderately above it. The flowers are decorative, double and yellow. The ray florets are densely arranged and straight along the longitudinal axis. In cross section at the mid-point the ray florets of 'Margaret Improved' are strongly concave (U-shaped). The lateral margin of the ray floret is flat and the tip is rounded and dentate.

Origin & Breeding History: 'Margaret Improved' was selected as a single seedling among the seedlings originating from the open pollination of Dahlia variabilis plants in a controlled breeding program during September 1997, at Enkhuizen, The Netherlands. The initial selection was made in September 1998. Asexual propagation since that time has been through the use of vegetative cuttings.

Tests & Trials: Tests and trials for 'Margaret Improved' were conducted in a polyhouse during the spring/summer of 2005 in St. Thomas, Ontario. The trial included a total of 15 plants of each variety. All plants were grown from rooted cuttings, transplanted into 15 cm pots on April 28, 2005. Observations and measurements were taken from 10 plants of each variety on June 14, 2005. All colour measurements were made using the 2001 RHS Colour Chart.

Comparison tables for 'Margaret Improved' with reference variety 'Margaret'

Leaf length (including petiole) (cm)

  'Margaret Improved' 'Margaret'
mean 9.7 11.1
std. deviation 1.30 1.02

Leaf width (cm)

  'Margaret Improved' 'Margaret'
mean 4.5 7.9
std. deviation 0.42 0.80

Width of ray floret (mm)

  'Margaret Improved' 'Margaret'
mean 19.6 13.3
std. deviation 3.43 1.06

Colour of upper side of ray floret (RHS)

  'Margaret Improved' 'Margaret'
main 1A 2A
secondary N/A 167C (outer florets)

Colour of lower side of ray floret (RHS)

  'Margaret Improved' 'Margaret'
main 1B 4A-B
secondary N/A 51C-D
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