Ankara Province’s Polatlı district produces a registered agricultural product classified as a long-day dry onion. The product is commonly known among the public as dry onion. It was registered as a geographical indication by the Turkish Patent and Trademark Office on 16.04.2021. Polatlı district is recognized as one of the country’s major onion production centers due to this agricultural potential. Production primarily relies on winter onion cultivation, although summer onion planting is also practiced.
Product Characteristics
Polatlı onion is produced using varieties such as Bonus, Şampiyon, Medusa, Vuaelta, and Karbeyazı, all belonging to the species Allium cepa L. Its distinguishing features include a storage life of up to eight months under suitable conditions and a characteristic pungent onion aroma. These qualities stem from Polatlı district’s ideal sunlight duration, warm climate, and low relative humidity, combined with specialized cultivation methods.
The product exhibits the following key characteristics:
- It generally has a flattened, round shape.
- The bulb diameter ranges between 50–110 mm.
- Its weight varies between 70–450 grams.
- The outer skin color ranges from light yellow to copper-brown tones.
- The interior is white and has a pungent taste.
- The maturation period lasts approximately 140 to 160 days, depending on climate and cultivation conditions.
- It exhibits tolerance to warm climates, pests, and diseases.
- The plant has a strong root system and a distinct sharp odor.
Cultivation Method
The cultivation of Polatlı onion is carried out by direct seeding of seeds into the field.
- Sowing and Field Preparation: Seeds are sown in lines spaced 25–30 cm apart using a seed drill. Sowing depth is recommended at 0.5–1 cm, with in-row spacing of 5–7 cm and between-row spacing of 25–30 cm. Germination typically occurs within 7–10 days. Sowing is conducted between February and mid-April, taking weather conditions into account. The soil is prepared in autumn by plowing 1–2 times and then cultivated and harrowed to achieve a loose, sponge-like texture.
- Crop Rotation: To maintain yield and product quality, it is recommended that onions not be planted in the same field for at least three years, following crop rotation practices.
- Soil and Climate Requirements: Ideal soils are loose, well-draining, humus-rich, and easy to work. The soil pH should be between 6.0 and 6.5. Cool temperatures (average 13°C) are required during the vegetative stage, higher temperatures (average 21°C) during bulb formation, and 24–27°C for maturation.
- Fertilization and Irrigation: Fertilizer requirements are determined by soil analysis. Fertilization is carried out with basal fertilizer in February and March, followed by nitrogenous fertilizer in May. Irrigation by sprinkling is performed approximately 8–9 times before harvest, depending on rainfall patterns. Irrigation is stopped once bulb formation is complete and leaf yellowing begins.
- Plant Protection: Weeding is carried out 2–3 times during the growth period to control weeds and loosen the soil. Approved plant protection methods compliant with regulations are applied against pests and diseases.
- Harvest and Storage: Harvesting takes place from early August to the end of October, depending on bulb maturity. Harvested onions are dried until their outer skins become easily removable. After drying, the tops are cut and cleaned. Onions are sorted by size into small, medium, and large categories and packed separately in sacks. Storage is carried out in dry, cool, clean conventional storages or cold storage facilities under relative humidity conditions of 65–70%.
The cultivation and all stages of production of this product must occur within the geographical boundaries of Polatlı district, Ankara Province.
Geographical Boundary
The registered geographical boundary of Polatlı onion is defined as Polatlı district, Ankara Province. The product’s unique qualities are intrinsically linked to this geographical area’s cultivation potential and production processes.
Monitoring
The monitoring of Polatlı onion is conducted by a monitoring body consisting of at least three members, coordinated by the Polatlı Chamber of Commerce and involving the Polatlı District Directorate of Agriculture and Forestry.
Monitoring is carried out at least once annually, and additional inspections may be conducted upon complaint. The responsibilities of the monitoring body include:
- Verifying the proper use of the geographical indication,
- Inspecting whether harvest, storage, and preservation conditions meet established standards,
- Ensuring compliance with the production stages outlined in the “Production Method” section.
Monitoring results are reported in accordance with Law No. 6769 on Industrial Property and submitted regularly each year to the Turkish Patent and Trademark Office.
