Autumn variety, developed in the USA by breeder P. Kieffer in 1868 from seeds of the Ussuri or Chinese sand pear, whose flowers were reportedly accidentally pollinated by pollen from the 'Bere Anjou' variety, or by pollen from the 'Williams' variety.
Approved for cultivation in the North Caucasus region. Also grown in Ukraine, Moldova, Georgia, and the republics of Central Asia.
Medium-sized tree with a dense, pyramidal crown. Main scaffold branches emerge from the trunk at an angle of 25-30°. Bears fruit on spur-bearing branches and 3-4-year-old wood.
Shoots are straight, above average thickness, greenish-brown with a reddish tint, hairy at the upper part. Buds are small, elongated, light-brown. Buds are small, acute, dark brown, pressed against the stem. Leafiness is good. Bark on the trunk is gray with cracks, on scaffold branches dark gray. Leaves are above average size and large, thick, leathery, shiny, dark green, egg-shaped with a gradual transition to a long, sharp tip. Leaf blade is curved upward, edges with broad-toothed serrations. Petiole is thin, short, burgundy-colored.
Blooms very early and requires pollinators.
Fruits are medium-sized, sometimes large, cube-shaped or barrel-shaped, bumpy. Skin is thick, dry, rough to the touch; light green when picked, golden-yellow when ripe, with numerous large scattered brown spots. Occasionally a brownish-red blush appears on the sun-exposed side. Blossom end is narrow, small, with bumps along the edges. Fruit stalk is straight, short, thick with swellings at both ends. Depression in the calyx cup is small, shallow, bumpy, often rusted. Calyx is open, medium-sized, sepals small.
Flesh is yellowish-white, very juicy, sweet, slightly coarse, with a noticeable specific flavor, acceptable in taste. Under Kuban conditions, fruits contain 13.5% dry solids, 8.1% sugars, 0.3% titratable acids, 8.5 mg/100g ascorbic acid, and 68.0 mg/100g raw mass of P-active catechins.
Harvesting ripeness occurs from September 20-30. Storage life extends until December.
Fruits set in clusters within inflorescences and remain firmly attached to the tree. Transportability is good. Fruits are eaten fresh and are well-suited for canning.
Begins bearing fruit from 5-6 years of age. Annual and very high yield. In the central part of Kuban, 16-19-year-old trees of this variety yield 180-200 centners/ha; in the foothill zone, 24-26-year-old trees yield 200-250 centners/ha; under favorable agronomic conditions, individual mature trees may produce up to 300 kg of fruit.
Kieffer variety is resistant to scab and drought-tolerant, but winter hardiness is not sufficiently high. Recovery ability is moderate.
Advantages of the variety: low soil requirement, high yield, early fruiting, disease resistance.
Disadvantages of the variety: weak winter hardiness of trees, mediocre fruit flavor.
Widely used in breeding as a source of disease resistance. In the North Caucasus NIIIGIPS, with its involvement, the variety 'Nart' (Kieffer Seedling Ch Lesnaya Krasavitsa + Bere Ardanpon + Bere Bosk) was developed.
