Winter apple variety of intensive type, selected by the North Caucasus Regional Research Institute of Horticulture and Viticulture. The variety was identified in 1970 as a low-growing bud mutation of the Delicious variety, induced by cesium-137 radiation. Breeder S. N. Artiukh.
In 1997, the variety was introduced into the State Register of Selection Achievements of Russia and recommended for commercial and hobby orchards in the North Caucasus region. The variety is present in North Caucasian orchards and has begun spreading to orchards in southern Russia and Ukraine, replacing the Delicious variety.
Main clonal variation — suppression of growth processes, resulting in a 25-35% reduction in height and diameter compared to the Delicious variety. Due to this variation, the tree enters fruiting earlier — on the 4th-5th year, without the periodicity characteristic of the original variety, and the fruit appearance has improved due to more intense coloring. Sugar and P-active substances content increased in the fruits. But the main feature of the induced clone — yield increased by 25% and more, depending on tree density and orchard cultivation technology.
Trees are medium- and low-growing, with oval crowns in youth, broadly oval in fruiting, branches diverge from the trunk at a sharp angle, slightly curved at the base, with dark-gray bark, mixed fruiting, predominantly with rings on multi-year wood, beginning from two-year-old branches.
Shoots are relatively thick, weakly branched, dark-red with a steel sheen, sparsely hairy, with numerous very small tubercles. Leaves are broadly oval, with a rounded base and moderately elongated apex and pointed tip, doubly toothed edges, slightly curved and moderately lobed. Upper leaf surface — dark green, glossy, lower — light, with weak pubescence on young leaves, absent on older ones. The leaf forms an acute angle with the stem. Petiole is long, with a red stripe on the underside (in the original variety — only at the base), stipules are medium-sized, lanceolate.
Flowers are large, cup-shaped, pink, with red outer petal edges, long hairy stigmas, with stigmas positioned above and below the anthers. Buds are red.
Fruits (see fig.) are large, similar in shape to the Delicious variety. They differ in skin coloration: it is significantly more intense, bright orange-red. Only the shaded part of the fruit up to 25% is characterized by a blurred streaked pattern of skin coloration. Skin is rough, very dense, smooth, with whitish large subcutaneous dots, and gray dots on the shaded surface. Weak waxy bloom intensifies during storage. Rim and cup walls remain green. Seeds are light-brown, flat-round with blunt tip. Cup tube is funnel-shaped. Seed chambers are half-open with a narrow slit into the mid-open central chamber.
Flesh is greenish-white when picked, cream-colored when stored, very sweet, with a "Delicious" spicy aroma, dense and juicy — very tasty. Chemical composition of the fruit: dry matter — 13-16.2%, sugars — 10-14.5%, titratable acids — 0.2-0.35%, ascorbic acid — 5-7.7 mg/100g, P-active substances — 140-280 mg/100g.
Typical harvest period — second and third decades of September. If left too long after picking, fruits drop off. Fruits can be stored until April. During storage, skin color intensity increases. Fruit transportability is good. Fruit marketability is high — 90%.
Fruits are consumed fresh, in processing — juices, chips.
The variety requires pollinators. Best pollinators are varieties: Renet Simirenko, Kuban Renet, Prizubansky. Flowering is medium-late.
Winter and drought resistance of Delicious Spur is significantly higher than that of Delicious. For example, during the winter of 1993-1994, in orchards of the Prizubansky and Stepny regions of the Krasnodar Krai, where trees of Renet Simirenko, Delicious and its clonal introduced varieties died, Delicious Spur trees showed partial damage to bark and wood on the north-eastern side of 1-2-year-old wood. Tolerant to diseases. Requires protection only in epidemic years.
Advantages of the variety: good ecological adaptability of intensive type, high yield, high marketability and dessert quality, vitamin content of fruits, aroma.
Disadvantages of the variety: fruit drop if harvesting is delayed, need for protection against scab during epidemics.
In breeding, the Delicious Spur variety is a donor of high marketability and vitamin content of fruits.
