Denomination: 'Yoyukon'
Trade name: Yukon
Botanical Name: Chrysanthemum ×morifolium
Applicant/Holder: Syngenta Crop Protection AG
Schwarzwaldallee 215
Breeder: Wendy Bergman, Syngenta Flowers, Inc., Alva, United States of America
Agent in Canada: BioFlora Inc.
38723 Fingal Line
R.R. #1
St. Thomas, Ontario
N5P 3S5
Tel: 519-631-6241
Application Date: 2004-10-01
Application Number: 04-4434
Grant of Rights Date: 2008-03-03
Certificate Number: 3154
Date rights surrendered: 2014-02-24

Variety Description

Variety used for comparison: 'Yosnowmass' (Snowmass)

Summary: The flowering response time for 'Yoyukon' is seven (7) weeks whereas it is eight (8) weeks for 'Yosnowmass'. 'Yoyukon' has a larger flower head diameter than 'Yosnowmass'. The ray florets of 'Yoyukon' have a longer corolla tube and longer floret than those of 'Yosnowmass'. The curvature of the ray florets along the longitudinal axis is moderately incurved for 'Yoyukon' while it is strongly incurved for 'Yosnowmass'.


PLANT: year round cultivation, pinched plant type, disbud flowering type, potted plant production, seven (7) week response group

LEAF BLADE: broad wedged to truncate base, parallel to overlapping margins of sinus between lateral lobes

FLOWER HEAD: double type, decorative incurve (intermediate) sub-type, self coloured, white colour group
RAY FLORETS: medium incurving along longitudinal axis of majority, concave in cross-section, incurved end, one to two notched tip, white on inner and outer sides
DISC FLORETS: tubular type, massed at centre but not visible

Origin & Breeding History: 'Yoyukon' is a product of a planned breeding program conducted by the breeder, Mrs. Wendy R. Bergman, an employee of Yoder Brothers, Inc. in Barberton, Ohio, USA. It originated from a cross-pollination made in November 1999 between the proprietary Chrysanthemum seedling selection designated 'YB-4699' as the female parent and another prorietary Chrysanthemum seedling selection designated 'YB-4976' as the male parent. The cross took place in Salinas, Califormia, USA. 'Yogolden Gate' was selected in November 2000 in Fort Myers, Florida, USA based on its uniform plant growth habit, desirable inflorescence form, ray floret colours, fast response time and excellent post-production longevity.

Tests & Trials: Trials for 'Yoyukon' were conducted under greenhouse conditions similar to those used in commercial production, during the winter of 2007 at Yoder Canada Ltd. in Leamington, Ontario. Thirty (30) unrooted cuttings of each variety were directly stuck into 15 cm pots, with five (5) cuttings per pot and six (6) pots per variety. Cuttings of the candidate were stuck on December 27, 2006, while those of the reference variety were stuck on December 20, 2006. Plants were spaced 30 cm apart, pinched once prior to short day treatment and later disbudded by removal of lateral buds. Measured characteristics were based on measurments taken from 10 plants or parts of plants. All colour determinations were made using the 2001 Royal Horticultural Society (RHS) colour Chart.

Comparison tables for 'Yoyukon' with reference variety 'Yosnowmass'

Flower head diameter (cm)

  'Yoyukon' 'Yosnowmass'
mean 16.1 11.5
std. deviation 1.21 0.44

Ray floret corolla tube length (cm)

  'Yoyukon' 'Yosnowmass'
mean 5.5 1.5
std. deviation 0.79 0.47

Floret length (cm)

  'Yoyukon' 'Yosnowmass'
mean 6.9 4.1
std. deviation 0.39 0.19

Ray floret colour (RHS)

  'Yoyukon' 'Yosnowmass'
upper & lower sides close to 155C close to 155C

Click on image for larger view
Chrysanthemum: 'Yoyukon' (left) with reference variety 'Yosnowmass' (right)

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