Kuybyshevskiy Jubilee

Introduced by V.A. Molchanov and A.N. Minin at the Samara Botanical Garden and Samara Regional Experimental Station for Horticulture by sowing seeds from open-pollinated seedling No. 4. Distributed as saplings among gardeners in the Middle Volga region. Registered in the State Register for the Middle Volga region in 2005.

Large tree, up to 6 m tall. Sparse, broad-pyramidal crown. Fruit set primarily on spurs and cluster branches. Branches are thick, poorly branched. Bark on trunk and main branches is cracked, gray-brown, hard. Shoots are thick, knotted, green, with reddish tint on sun-exposed side. Leaves are large, broadly egg-shaped, dark green, with strongly tapered apex. Leaf blade slightly concave, smooth, matte. Leaf margin straight, doubly serrated. Flowers are white-pink, large.

Fruits are medium-sized, roughly cylindrical, averaging 22 g. Fruit shape is round. Apex is rounded. Base has a depression, with inconspicuous cavity. Fruit stalk is short, medium thickness, good detachment from branch, weak attachment to stone. Stone is medium-sized, loose, rough. Fruit color is orange, slightly flushed with red on sun-exposed side. Lenticels absent. Skin is thin. Flesh is orange, slightly fibrous, juicy. Juice is colorless. Flavor is sour-sweet, with pleasant aroma. Taste rating — 4.4 points. Appearance — 4.5 points. Fruits contain 12.5% dry matter, 8.86% sugars, 1.88% acids, 10.31 mg/100g vitamin C, 2.08 mg/100g carotene, 1.18% pectin. Primary use is universal.

Flowering — May 1–3. Fruit ripening period is medium. Harvesting period — July 20–25. Fruits should be harvested before full maturity. Commercial and consumer qualities of fruits are high. Transportability is good.

Partially self-fertile. Best pollinators: Kuybyshevskiy Early, Karlik, Samarskiy.

Enters fruiting at 4 years. At 6–7 years, trees yield 12–15 kg; at 12–13 years — up to 40–50 kg. Annual fruiting. Fruits remain well attached on tree, but some drop during ripening.

Highly winter-hardy. Withstood severe winters of 1968/69, 1978/79, and 1986/87. Greatest damage to yield occurs during alternating thawing and freezing in late winter, leading to significant loss of flower buds. Resistant to bark cracking. Moderate drought tolerance. In dry years, fruit size decreases and fruits drop. Resistant to diseases and pests.

Propagated by grafting onto seedling rootstocks of cold-resistant plum varieties: Skorospelka Krasnaya, Ternosliwa Kuybyshevskaya, Vengerka Oktyabrskaya, and clonal rootstock OP-15-2.

Young trees require formative pruning; during full fruiting, regular annual pruning is needed. In older trees, rejuvenating pruning is necessary, involving removal of skeletal and semi-skeletal branches within the crown.

Advantages of the variety: high winter hardiness of wood and flower buds, large and high-quality fruits.

Disadvantages of the variety: fruit damage by moniliosis in wet years.