Denomination: 'Sonnet'
Botanical Name: Prunus avium
Applicant/Holder: Agriculture & Agri-Food Canada, Summerland
Pacific Agri-Food Research Centre
Highway 97
Summerland, British Columbia
V0H 1Z0
Breeder: Frank Kappel, Agriculture & Agri-Food Canada, Summerland, British Columbia
Agent in Canada: Summerland Varieties Corp. (SVC)
105-13677 Rosedale Avenue
Summerland, British Columbia
V0H 1Z5
Tel: 250-494-5164
Application Date: 1998-05-13
Application Number: 98-1400
Grant of Rights Date: 2002-07-08
Certificate Number: 1201
Date rights surrendered: 2016-06-23

Variety Description

Varieties used for comparison: 'Van', 'Lapins' and 'Summit'

Summary: 'Sonnet' is a sweet cherry variety which produces kidney-shaped to flat-round fruit with a bright red skin, compared with the references which all have dark red fruit. 'Van' fruit are a distinct, blocky kidney-shape, while the fruit of 'Lapins' is round and 'Summit' is cordate. The flesh of 'Sonnet' is pinkish white whereas the flesh of the reference varieties is dark red to purple. 'Sonnet' matures with or just slightly after 'Van', just slightly before 'Summit' and about 10 to 12 days before 'Lapins'.


'Sonnet' is a sweet cherry variety which has upright to spreading trees with a moderately dense crown. The one-year-old shoots have a semi-erect attitude, no pubescence and weak anthocyanin colouration on the bud support base. There are very few or no flower buds on the one-year-old shoots. The vegetative buds are conical in shape and held out from the shoot. The current year's shoot of 'Sonnet' has no pubescence and no anthocyanin colouration at the tip. The leaves are elliptical in shape with an acute angle at the tip and rounded base. The leaf apex is cuspidate and the profile in cross section is concave. There is no pubescence on the lower side of the leaf and no variegation or anthocyanin colouration on the upper side. The leaves of 'Sonnet' are medium green with moderately strong glossiness. The leaf margins are biserrate and the indentations are shallow. 'Sonnet' leaves turn green bronze just before leaf fall. The petioles have anthocyanin colouration and usually two to three yellow and red-purple, kidney-shaped nectaries.

'Sonnet' flowers intensely and produces single-type, white flowers in clusters. The flower bud is white. There is no pubescence on the pedicel. The flower petals are round to obovate and are touching or slightly overlapping. The anthers produce pollen. The pistil is normal.

'Sonnet' produces very large, kidney to flat round shaped fruit that is rounded in lateral view. The largest diameter is towards the middle of the fruit. The skin is bright red with small light coloured dots. The suture is moderately prominent. The flesh of 'Sonnet' fruit is pinkish white and moderately firm. The juice is pink. The fruit apex is flat to slightly pointed and the stalk is thin and medium in length. The stone is large, symmetrical and semi-adherent to non-adherent to the flesh. In lateral view the stone is intermediate in shape between spherical and elongate. In front view it is round to ovate and in basal view it is round. The keel is strongly developed.

'Sonnet' produces a low to medium amount of fruit. The variety flowers late and is not self-fertile. The fruit matures mid-season, at about the same time as 'Van' and about 10 to 12 days before 'Lapins' in Summerland.

Origin & Breeding History: 'Sonnet' originated from the cross of 2N-49-2 (a 'Van' x 'Stella' cross from the Summerland breeding program) x 2N-63-31 (a 'Bing' x 'Salmo' cross from the Summerland breeding program). The final cross was made in 1976. The seedling was designated 13S-39-51 in 1981 and was named 'Sonnet' in 1998. Two propagations were made on Prunus avium rootstock and planted out in a trial block at the Summerland Research Centre in 1985. Evaluation on the selection began upon fruiting. The variety 'Sonnet' was selected based on maturity date, fruit size, firmness, resistance to splitting, fruit shape, skin and flesh colour, fertility, luster, productivity and precocity.

Tests & Trials: Tests and trials for 'Sonnet' were conducted in 1998 and 1999 at the Pacific Agri-Food Research Centre of Agriculture and Agri-Food Canada, Summerland, British Columbia. The trials consisted of 5 trees of each variety, on F12/1 rootstock.

Comparison tables for 'Sonnet' with reference varieties 'Van', 'Lapins' and 'Summit'

Average fruit weight (g)

  'Sonnet' 'Van' 'Lapins' 'Summit'
mean 13.8 11.8 11.93 13.7
number measured 50 50 50 50

Length of fruit stalk (mm)

  'Sonnet' 'Van' 'Lapins' 'Summit'
mean 47.7 38.3 55.2 54.3
standard deviation 5.35 3.74 5.92 4.00

Soluble solid concentration

  'Sonnet' 'Van' 'Lapins' 'Summit'
percentage 21.0 22.1 19.6 18.4

Titratable acids (mL NaOH to raise 10mL juice to pH 8.1)

  'Sonnet' 'Van' 'Lapins' 'Summit'
mL/ta 8.2 15.9 11.3 9.8

Susceptibility to rain-induced cracking (%)

  'Sonnet' 'Van' 'Lapins' 'Summit'
percentage 16-26 48 20 24
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