Prunus Tree Rootstock named ‘Piku 4’

Abstract

A new and distinct Prunus rootstock compatible with other Prunus varieties and producing trees with reduced growth, suitable to sandy soil with high productivity.

Description

Classification: Prunus L.

Varietal denomination: ‘Piku 4’.

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct cultivar of hybrid Prunus known by the varietal name ‘Piku 4’. The new variety was discovered in 1976 in a selective breeding program designed to produce growth reducing rootstock for cherry trees in Dresden-Pillnitz, Germany as a cross between an unnamed, unpatented variety of Prunus cerasus (Schattenmorelle) (female parent) and an unnamed, unpatented variety of Prunus “Kursar” (P. kurilensis×P. sargentii) (male parent). The new variety differs from its parents in its growth habit. The following characteristic distinguish the new variety from Prunus avium rootstock varieties:

• • 1. Three-way hybrid.
  • 2. Reduces growth in grafted varieties by 30-40%.
  • 3. Suitable for sandy soil.
  • 4. Precocious crop.
  • 5. Glossiness of upper leaf surface.
  • 6. Growth habit.

The new variety was first asexually reproduced via green cuttings in 1980 in Dresden-Pillnitz, Germany and subsequent propagation therein has confirmed that the characteristics of the new variety are stable and are transmitted to subsequent generations.

DESCRIPTION OF THE DRAWING

The accompanying photographic drawings illustrate the new variety, with the color being as nearly true as is possible with color illustrations of this type.

FIG. 1 shows the tree of the new variety;

FIG. 2 shows a branch with leaves; and

FIG. 3 shows a branch with flower buds;

DESCRIPTION OF THE PLANT

The following detailed description sets forth the characteristics of the new cultivar. The data which defines these characteristics were collected by asexual reproductions via green cuttings carried out in Dresden-Pillnitz, Germany. The color designations were taken outdoors in Dresden-Pillnitz, Germany. Rootstocks were 6 to 7 years old when described. Color designations are noted with reference to standard P. avium rootstock. The new variety prefers dry or sandy soil and is free of PNRV and PDV. As a rootstock, it can be reproduced via softwood cuttings or tissue culture. The new variety anchors adequately with some root sprouts, sufficient compatibility with grafts and exhibits dwarf growth vigor.

TREE

• Size: Small-medium; having an average height of 1.90 m and an average width of 2.00 m.
• Form: Bushy, drooping.
• Trunk:
  • • Surface texture.—Smooth.
    • Bark color.—Dark.
    • Diameter.—5.0 cm, measured at a height of 40 cm.
• Branches:
  • • Surface texture.—Smooth.
    • Bark color.—200A.
    • New growth color.—Light red.
    • Mature growth color.—Brown.
    • Average crotch angle.—60-80°.
    • Internode length.—Medium.
    • Lenticels.—Diameter: 0.05-0.15 cm. Color: 161A. Amount per shoot: >100.
    • Bud.—Medium, round.
• Leaves:
  • • Length.—10.4 cm.
    • Width.—5.0 cm.
    • Surface texture.—Upper side glossy.
    • Form.—Elongated, elliptical.
    • Color.—Upper Surface: 146A. Lower Surface: 146B.
• Petioles:
  • • Length.—1.7 cm.
    • Thickness.—0.15 cm.
• Leaf glands:
  • • Quantity.—1-4.
    • Position.—Under leaf end.
    • Size.—0.20 cm.
    • Color.—Green-red.
• Stipules:
  • • Length.—1.0-1.2 cm.
• Flowers:
  • • Diameter.—2.50 cm.
    • Color.—Upper Surface: N155A. Lower Surface: N155A.
    • Number.—Many.
    • Petals.—Length: Approximately 1.2 cm. Width: Approximately 0.8 cm. Quantity per flower: 5.
    • Sexual characteristics.—Triploid, crop is rare.
    • Stamen number.—>10.
    • Pistil number.—1.

FRUIT

• Maturity date/location: Mid-season in Dresden, Pillnitz.
• Weight: 2 grams.
• Axial diameter: 1-2 cm.
• Fruit stone:
  • • Length.—Approximately 0.6 cm.
    • Diameter.—Approximately 0.5 cm.
• Skin: 187A.
• Flesh color: 187A.

GENERAL

• Weather hardiness: Sufficient tolerance to winter frost.
• Disease resistance: Tolerance to Cytospora.

Claims

1. A new and distinct variety of Prunus rootstock named ‘Piku 4’ substantially as shown and described.