Karaburnu

Main Characteristics

The grape variety Karaburnu is an ancient representative of the eastern group of table grapes, whose homeland is Asia Minor. According to its morphological characteristics and biological properties, it is included in the ecological-geographic group of eastern table varieties (convar. orientalis Negr.). In terms of technological purpose, it is one of the best and most valuable table varieties in the world assortment. The vegetative period from the beginning of budburst to the onset of harvest maturity under the conditions of southern Ukraine is 152 days, requiring a sum of active temperatures at the level of 2927 °C. The variety belongs to the late ripening group, with the harvesting of berries occurring in late September. The vines are distinguished by vigorous growth and good maturity of one-year-old shoots, reaching an average of 80%. Due to the large bunch weight, the grape variety Karaburnu has a high yield, stably exceeding 100 centners per hectare (at specialized state testing plots, average indicators range from 105 to 157 centners per hectare).

Clusters of this variety are large (length ranges from 18 to 26 cm, width — 11 to 14 cm), have a cylindro-conical or winged shape, and are characterized by a loose structure. The average bunch weight is 343 g. The cluster stem is long (up to 10 cm), herbaceous in its consistency. The berries are very large (length 19–26 mm, width 17–21 mm), oblong or, less frequently, oblong-oval in shape, sometimes with a slight widening in the upper part. At the initial stage, the berries are greenish-white, and upon reaching full maturity, they acquire a beautiful golden-yellow coloration with a light brown tan on the side exposed to the sun. The waxy bloom (pruin) is weakly expressed. The skin is thick, tearing; the pulp is dense, fleshy-juicy, with a pleasant harmonious flavor. The average weight of 100 berries is 570 g, and two large seeds develop inside. The sensory evaluation score of fresh products is very high — 9 points. The sugar accumulation in berry juice fluctuates within 13.8–18.1 g/100 ml with a titratable acidity of 5.8–10.5 g/l.

Morphological Description of the Grape Variety Karaburnu

• Young shoot (tip): The tip of the young shoot has a light green color with bronze leaf edges and is characterized by weak araneose pubescence.
• Young leaves: The first leaf is colored light green with a distinct dark bronze tint and bears weak araneose pubescence. Subsequent leaves also retain a bronze tint and weak pubescence.
• One-year-old mature shoot: It is characterized by a brown coloration with dark brown highlighting of the nodes.
• Formed leaf: Leaves are medium in size, with a 5-lobed structure, deep or medium lobing, and a funnel-shaped curvature of the blade. The surface of the leaf is smooth (glabrous) and shiny. The lower surface of the leaf blade is completely devoid of pubescence.
• Leaf incisions and sinuses: Upper sinuses are deep or medium, closed, with an egg-shaped or narrow-elliptical opening. Lower sinuses are of medium depth or small, open, lyre-shaped with a narrow base or in the form of an incoming angle. The petiole sinus is open, wide, vault-shaped or lyre-shaped, often bordered by veins.
• Teeth: The teeth at the ends of the lobes are large and medium, triangular, straight, with a sharp apex and weakly convex sides. The marginal teeth along the edge of the leaf blade are saw-toothed (serrate), with weakly convex sides.
• Saplings: Saplings are semi-spreading, forming vigorous shoots. The tip of the shoots is bronze, without pubescence. The leaves are shiny and do not differ in appearance from the leaves of mature vines. The autumn color of the foliage is yellow.

Agrotechnical Features

For planting vines of the grape variety Karaburnu, it is recommended to allocate southern and southwestern slopes with fertile, moderately moist soils. The training of the bushes is carried out according to the four-arm fan or double-armed Guyot system, and the Guyot system provides the highest quality of clusters and berries. With the fan system, the load is increased to 35–45 buds and 20–22 shoots after debris removal (shoots thinning), and the canes are pruned long — to 10–12 buds. With the double-armed Guyot system, it is recommended to leave an average of 24–28 buds, and after thinning — 10–14 shoots, with long pruning of canes to 10–15 buds. On the bushes after thinning, it is necessary to leave up to 50% of sterile shoots. The ability to form water sprouts (adventitious shoots) is weakly developed. The grape variety Karaburnu demonstrates excellent compatibility with rootstocks Riparia × Rupestris 101-14, Rupestris du Lot, Chasselas × Berlandieri 41B, as well as Berlandieri × Riparia Kober 5BB and Riparia × Rupestris 3309.

The share of fruitful shoots on a vine is 48%, while the fruitfulness of water sprouts and shoots from replacement buds is low (23%). The fruiting coefficient is 0.48, and the fruitfulness coefficient reaches 1.25. The mechanical properties of the harvest are excellent: the berries are very firm and firmly attached to the pedicels, withstanding a separation force of 351 g and a crushing resistance of 1827 g. Due to this, the harvested grapes tolerate long-distance transportation well and are suitable for long-term storage. The direction of use of the harvest is broad: in addition to fresh consumption, the grape variety Karaburnu is highly valued for the preparation of compotes, marinades, jams, as well as for drying to obtain large-berried raisins.

The variety has a low natural resistance to major fungal diseases: it is significantly affected by downy mildew (mildew) and powdery mildew (oidium), and is also unstable against berry gray rot (botrytis), which requires regular chemical treatments. At the same time, it is less damaged by spider mites than other grape varieties. The frost resistance of the variety is weak; in harsh winters, a significant mortality of vine buds is recorded, reaching 80–90%, which requires mandatory winter covering in most cultivation regions.