Ömerli Karfoki Grape

Ömerli Karfoki grape is a table and raisin grape variety cultivated in the Ömerli district of Mardin Province, Türkiye, belonging to the local “Karfoki” type. The green-yellow colored fresh berries turn a brownish amber hue when dried, a characteristic that easily distinguishes them from other dried grapes. The clusters are branched and loosely berried, with large, round berries that are typically single-seeded. This grape variety, with its gene center in Ömerli, is grown on its own roots in the region using dry farming methods and generally without the use of fertilizer.

Morphological Characteristics

The upper surface of young leaves of the Ömerli Karfoki grape is glossy light green, with sparse procumbent hairs between the main veins and very sparse erect hairs. Mature leaves are five-lobed and pentagonal in shape, of medium size and relatively compact. The terminal lobe is slightly inwardly curved along the main vein axis. The upper leaf surface varies between dark green and green, with no anthocyanin pigmentation observed. The teeth are long and straight on both sides. The petiole sinus is U-shaped; the petiole is short and bears sparse procumbent and very sparse erect hairs on the lower surface. In autumn, the leaves change color from yellow to brown.

Canes develop with medium vigor, and shoots are semi-erect. One-year-old canes have a cylindrical cross-section and a brown corky texture. Dark brown continuous lines are present along these canes. The flowers are hermaphroditic and form clusters on the second to fourth nodes of summer shoots.

Cluster and Berry Characteristics

Clusters are branched-conical in shape, of medium length, and loosely berried. Berries are large, round, and uniform in form, with an average length of 16 mm and width of 14 mm. The skin is thin and green-yellow in color. The average berry weight is 2.4 grams, and the average cluster weight is approximately 180 grams. The berry stalk is short and detaches easily from the cluster; berries are mostly single-seeded. Transverse grooves on the dorsal surface of the seed are not prominent. Average yield per cane is about 2.4 kg.

Phenological Development and Climate Requirements

Budbreak occurs between March 30 and April 5. Full bloom coincides with May 20–25, while fruit set occurs between August 15 and 20. The variety requires an Effective Temperature Sum (ETS) of 227.5°C-days during bloom and 1755.0°C-days during fruit set. The climatic conditions of Ömerli district meet these phenological requirements.

Ecological Conditions and Agricultural Practices

Ömerli district lies at an elevation of 800–1100 meters, with annual rainfall ranging between 400 and 670 mm. These environmental conditions enable the grape to reach the target high dry matter content (92.5%) in just 7–10 days during drying. The vineyards in the district are typically 50–80 years old, and dry farming methods are widespread. Phylloxera infestation is absent. The absence of fertilization contributes to the high antioxidant capacity of the product.

Ömerli Karfoki grape is grown on its own roots. Pruning follows the “goble” system, with winter pruning carried out in a short-mixed style. Propagation is performed using hardwood cuttings and layering.

Drying Process and Distinguishing Features

Fresh grapes are dipped in a potash solution containing potassium carbonate. The solution consists of 0.5% sunflower oil, 5–6% potassium carbonate, and water. The use of sunflower oil is a key distinguishing feature that differentiates this grape from other dried grapes treated with olive oil. Upon drying, the berries turn a brownish amber color, a hue that enables easy identification of the product.

Monitoring and Protection

Monitoring of the product is conducted by a supervisory body comprising experts from the Ömerli District Directorate of Agriculture and Forestry and the Ömerli Chamber of Agriculture, under the coordination of the Ömerli District Governorship. During inspections, ampelographic characteristics and the color/shape criteria of the dried grape are specifically evaluated. In addition to annual inspections, additional inspections may be carried out upon complaint or need. Reports are submitted to the Turkish Patent and Trademark Office under Law No. 6769 on Industrial Property.