Stanley Plum

Synonyms: Stanley

Derived from: Prune Agen x Grand Duke

Stanley plum – a cultivar of American origin. Entered into the State Register in 1983 for the North Caucasus region.

It is a medium-vigour tree with a sparse, rounded crown. The trunk is dark gray, straight. The bark is slightly fissured and moderately peeling. Young shoots are slightly spiny, raspberry-purple in color, glabrous. Internodes are of medium length, 30–35 mm. The vegetative bud is conical, small, 2.1–3 mm, appressed, with an acute tip. The leaf blade is medium-sized, rounded with an obtuse-acuminate tip and a rounded base. Length 7.5 cm, width 5.4 cm. Leaves are green, moderately concave, of loose texture. The upper surface of the leaf is glabrous; the lower surface has weak, woolly indumentum along the midrib and lateral veins. Serration uniserial; teeth medium-sized. Petiole anthocyanic, medium-sized, up to 1.9 cm long. Glands sessile, 1–2 in number, yellow-green, of medium size. Stipules lanceolate, 8–10 mm long, pale green.

Blooms late, in mid-April. The cultivar is partially self-fertile. From floral buds 1–2 saucer-shaped flowers develop, up to 31 mm in diameter. Petals large, 13 mm long and 10 mm wide, ovate, white. Petal overlap slight. Corrugation absent, tip rounded, margins undulate. Stamens – 28. Filaments 7–12 mm long, straight. Anthers yellow. Pistil reaches 11 mm in length. Style straight, up to 10 mm long. Stigma positioned above and below the anthers, rounded. Ovary glabrous. Sepals oval, 6 mm long and 3 mm wide, not serrated, glabrous. Calyx bell-shaped, pubescent. Pedicel up to 21 mm long, glabrous.

Begins to bear fruit in the 4th–5th year. Fruits are asymmetric, obovate, very large, 53×40×37 mm and weighing 49 g. Ground color green, covering color dark purple, solid, without bloom. Number of subcutaneous dots medium, brown, without streaks. Skin of medium firmness, covered with a dense waxy bloom, poorly separates from the flesh. Apex rounded, base elongated with a neck. Depth of the cavity medium. Dorsal suture moderately open. Ventral suture medium, central ridge moderately expressed, lateral ridges noticeable. Flesh yellow, firm, granular-fibrous, moderately juicy, of excellent sweet-acid taste. Cavity same color as the flesh. Stone of medium size, acute, well free from the flesh, surface moderately pit-ridged. Fruits ripen in early September. Yield high and regular. Storability/transitability medium.

Tasting scores: frozen fruit – 4.8 points, prunes – 4.5 points, juice with pulp – 4.6 points, preserves – 4.5 points, compote – 5 points.

Fruit composition: sugars – 13.8%, dry matter – 21.6%, acids – 0.72%, pectins – 1.02%, ascorbic acid – 8.9 mg/100 g, polyphenols – 460 mg/100 g. Sugar-acid index 19.17%

Hardiness zone: 4 (down to -34°C).

Location: prefers sunny sites (the tree should receive at least 6 hours of sunlight per day). Soil required: moist loam, well-drained. Drought tolerance medium.

Planting, pruning and care: similar to those for European plum.

Diseases and pests: resistance to sharka and polystigmosis high; to moniliosis – insufficient.

Use: fruits are consumed fresh and used for making jams, preserves, juices, and prunes.