Blueberry plant named ‘Colossus’

Abstract

‘Colossus’ is a new and distinct southern highbush blueberry (Vaccinium corymbosum L.) variety distinguished at least by a low chilling requirement, vigorous, semi-bushy to semi-upright growth habit, good field disease resistance, and large, firm fruit that are sweet with a touch of acidity and exhibit small, dry picking scars and are suitable for mechanical harvest.

Claims

1. A new and distinct variety of southern highbush blueberry plant named ‘Colossus’, as illustrated and described herein.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) ‘Colossus’ is illustrated in the accompanying photographs, which show the plant's flowers, fruit, leaves, and form. Colors shown are as true as can be reasonably reproduced by photographic procedures and may differ from those cited in the detailed description, which accurately describe the colors of ‘Colossus’.

(2) FIG. 1—Shows clusters of opening ‘Colossus’ flowers.

(3) FIG. 2—Shows clusters of ‘Colossus’ berries during the fruit ripening season.

(4) FIG. 3—Shows a close-up of harvested ‘Colossus’ berries.

(5) FIG. 4—Shows a close-up of mature ‘Colossus’ leaves with a scale bar.

(6) FIG. 5—Shows a close-up of mature ‘Colossus’ fruit with a scale bar.

(7) FIG. 6—Shows 5-year-old ‘Colossus’ plants during February, with their vigorous, semi-upright architecture.

DETAILED BOTANICAL DESCRIPTION

(8) The following detailed description sets forth distinctive characteristics of ‘Colossus’. The data that define these characteristics were collected from asexual reproductions carried out in Florida. The plant history was taken on a plot of plants growing in an experimental trial near Waldo, Fla. Certain characteristics may vary with plant age. ‘Colossus’ has not been observed under all possible environmental conditions, and the measurements given may vary slightly when grown in different environments. Color descriptions are based on The Royal Horticultural Society (R.H.S.) Colour Chart by The Royal Horticultural Society, London, Sixth Edition, 2015. If any R.H.S. color designations below differ from the accompanying photographs, the R.H.S. color designations are accurate. Classification: Family.—Ericaceae. Botanical.—Vaccinium corymbosum L. Common name.—Southern Highbush Blueberry. Cultivar name.—‘Colossus’. Plant: Plant vigor.—Medium to high. Growth habit.—Semi-bushy to semi-upright. Plant height (average).—1.82 m (5-year-old plants). Plant spread (average).—2.13 m (5-year-old plants). Flowers bud density along flowering twigs (number during January).—Medium low. Twigginess.—Medium-low. Tendency toward evergreenness.—Medium-low. Productivity (when hand-harvested in northeast Florida).—2.5 kg/season (5-year-old plants). Chilling requirement.—150 hours below 7° C. Cold hardiness.—Has been grown in temperate climates with extremely cold winter temperatures. Plants have survived winter freezes of −7° C. with minimal damage. Ease of propagation.—Has only been propagated from softwood stem cuttings, where the rooting percentage is greater than 90% and comparable to other varieties. Trunk and branches: Suckering tendency.—Medium-low. Surface texture.—Strong 12-month-old shoots (observed May of 2019): Slightly rough. 3-year-old and older wood: Medium-rough. Color.—New twigs (field): Fan 4 grey group 201 pinkish grey D. 3-year-old, rough textured canes: Fan 4 brown group N200 light brownish grey C. Average internode length (strong, upright shoots measured in June).—12.65 mm. Petiole: Length.—3.21 mm. Width.—1.67 mm. Color.—Fan 3 Yellow-Green Group N144 Strong Yellow-Green D. Texture.—Smooth with no presence of pubescence. Leaves: Length (average).—4.909 cm. Width (average).—2.315 cm. Shape.—Elliptic. Leaf apex.—Acute; with slight falcate. Leaf base.—Elliptic. Margin.—Entire. Surface color.—Upper: Fan 3 green group 137 moderate olive green A. Lower: Fan 3 yellow green group 147 moderate yellow green C. Pubescence.—Upper and lower surfaces and margins: Absent at all. Timing of vegetative bud burst (early, medium, late).—Early. Relative time of leafing versus flowering (without mid-winter hydrogen cyanamide treatment).—Leaving occurs during flowering. Flowers: Arrangement.—Alternately along a moderate length leafing deciduous branch. Fragrance.—None. Shape.—Semi-urceolate, oblong. Flowering period.—50% anthesis at Citra, Fla. on Feb. 15, 2019. Cluster.—Medium-low. Number of flowers per cluster (average).—3. Pedicel.—Length at time of anthesis (average): 5.4 mm. Color at time of anthesis: Fan 3 yellow-green group N144 strong yellow green C, with Fan 4 greyed orange group 166 brownish orange C on the sun exposed side. Peduncle.—Length at time of anthesis (average): 7.52 mm but highly variable. Color at time of anthesis: Fan 3 yellow-green group strong yellow green 144C, with Fan 4 greyed-red group moderate red 181B on sun exposed side. Calyx.—Surface texture: Smooth with slight radiations. Diameter (average): 6.00 mm. Color (outer surface, visible at the time of anthesis without removing the corolla tube): Fan 3 green group 141 strong-yellowish green C to Fan 3 yellow-green group strong yellowish green D on calyx lobes. Corolla.—Diameter (average): 7.68 mm. Length (average, from pedicel attachment point to corolla tip excluding the pedicel): 12.01 mm. Aperture diameter (average): 4.03 mm. Texture: Smooth with slight radiations. Color: Fan 4 white group 155 greenish white C. Anthocyanin coloration in corolla tube: None detected. Reproductive organs: Style.—Length (average, top of ovary to stigma tip): 6.44 mm. Color: Fan 3 yellow-green group 144 strong yellow green B. Location of tip of stigma relative to lip of the corolla: 1.10 mm below. Anthers.—Color: Fan 4 greyed-orange group 163 deep orange yellow A. Pollen: High. Pollen germination: Greater than 90%. Color: Fan 1 yellow group 4 pale yellow green D. Filament length: 3.30 mm. Filament width: 1.15 mm. Self-fruitfulness.—Low to medium. Planting in the field configurations that promote cross-fertilization with other southern highbush varieties is recommended for all southern highbush blueberry plants grown in Florida. Fruit: Mean date of 50% harvest in Citra, Fla.—Week 15. Diameter of calyx aperture (average, mature berry).—0.51 cm. Size and shape of calyx lobes (mature berry).—Absent to very small, erect to slight out curving. Shallow calyx basin. Pedicel length (average, ripe berry).—8.0 mm. Detachment force for ripe berries (easy, medium, hard).—Easy. Fruit cluster density (sparse, medium, dense).—Medium to sparse. Number of berries per cluster (average).—4.2. Fruiting type.—On one-year-old shoots and current season's shoots. Berry: Cluster (tight, medium, loose).—Medium to loose. Weight (average, on well-pruned plants).—Mean of 4.35 g. Height (average).—1.46 cm. Width (average).—2.07 cm. Shape.—Oblate. Surface color of mature berries ripe on plant.—Fan 2 violet-blue group 95 strong purplish blue C. Intensity of fruit bloom.—High. Surface color of ripe berry after polishing.—Fan 4 black group 203 bluish black C. Immature berry color.—With bloom: Fan 3 green group 142 brilliant yellow green B. Without bloom: Fan 3 green group 142 brilliant yellow green B. Flesh color.—Fan 3 yellow green group 145 light yellow green C. Surface wax.—The surface wax on ‘Colossus’ has medium to high surface wax persistence. Pedicel scar.—Small and dry, with an average size of 0.22 cm. Firmness.—Very firm, with average of 261 g/mm. Flavor.—Sweet, with some acid hints. Intensity of fruit sweetness.—Medium. Texture.—Good, with no stone cells present. Fruit storage quality.—Fruit is firm and can be stored without shriveling, mold or loss of firmness for 3 weeks at 4° C. Seeds: Color of dried seeds.—Fan 4 Greyed-Orange group 165 Moderate Brown A. Weight of well-developed dried seeds.—Mean of 2.72 mg. Length of well-developed dried seeds.—Mean of 2.15 mm. Width of well-developed dried seeds.—Mean of 1.25 mm. Use: Produces southern highbush blueberries suitable for hand and machine harvest for the fresh fruit markets. Resistance to diseases, insects, and mites: Has grown vigorously and shows good bush survival in the field. Twig blight (Botryosphaeria spp.) observed but lower than other cultivars, with almost no young plants dying soon after planting. Part of the 3% of selections that survived with over 95% of plants in the plot alive after 8 years in a high disease field planting. Reaction to the various fungal species that cause summer leaf spots (including rust) is lower than those of other southern highbush varieties. Fungicide applications may be needed after harvest to reduce foliar diseases and retain leaves into the fall for maximum flower bud set. Appears to be more tolerant than other southern highbush varieties to spider mites. Susceptibility to typical blueberry insect and mite pathogens such as spotted wing drosophila (Drosophila suzukii), blueberry gall midge (Dasineura oxycoccana), blueberry flower thrips (Frankliniella spp), and blueberry bud mite (Acalitus vaccini) appear similar to other southern highbush cultivars.