Adapazarı White Chestnut Squash

Adapazarı Beyaz Kestane Kabağı is a winter squash variety belonging to the species Cucurbita maxima. The product is cultivated in the province of Sakarya and along the agricultural lands extending alongside the Sakarya River. It was officially registered on 26 June 2020 under the Industrial Property Law No. 6769 by the Turkish Patent and Trademark Office as a “Geographical Indication”.

Adapazarı Beyaz Kestane Kabağı has a dark whitish-gray color and a large, elliptical shape when viewed from above. Its thick rind and firm flesh make it suitable for long-term storage. Morphologically, the fruits are 8–12 lobed, with a diameter of 30–35 cm and a height of 20–27 cm, weighing on average 10–25 kg. The depth of the lobes ranges from 0.5 to 1 cm, while the thickness of each lobe varies between 5 and 10 cm. The flesh is orange and contains 14–16% water-soluble dry matter.

The plant exhibits a prostrate growth habit and spreads laterally 3–10 meters. Plant height reaches approximately 70–80 cm. Male and female flowers display clearly defined morphological features including sepals, pedicels, and pistils. The plant is sensitive to drought and high temperatures. Plant density is 175–300 plants per decare, with each plant producing 2–3 fruits. Yield ranges from 2500 to 5000 kg per decare.

The region-specific ecological factors include alluvial, slightly alkaline and organic-rich soils found in the Sakarya River basin, along with an annual rainfall of 800 mm, an average humidity of 72%, and an average temperature of 14.4 °C. These factors play a decisive role in determining the physical properties of the product.

^{Adapazarı Beyaz Kestane Kabağı} (AA)

Soil Preparation and Fertilization: Fields are deeply plowed in autumn. In spring, they are worked with disc harrows and cultivators. Burnt barn manure (2–3 tons/da) is applied in autumn, compost fertilizer (50 kg/da) in spring, and urea or ammonium nitrate (10 kg/da) during the second hoeing.

Sowing: Sowing is carried out at a depth of 4–5 cm in raised beds between late March and early April. The pit method is used, with pits spaced 2x2 m or 3x2.5 m apart. Three to four seeds are planted in each pit. Thinning is performed when plants reach five to six leaves.

Irrigation and Pest Control: The crop is generally grown without irrigation; however, one or two irrigations may be necessary during dry periods. Mechanical and chemical methods are used to control weeds and pests. Protective measures are taken against specific pests such as aphids, mites, and thrips. Appropriate plant protection products are applied to manage diseases.

Harvesting and Storage: Fruits are harvested after reaching full maturity and once the vines have completely dried. The produce is stored in warehouses before the onset of cold weather. It can be stored for up to six months in a well-ventilated environment at a temperature below 10 °C and a relative humidity of 60–70%.

^{Adapazarı Beyaz Kestane Kabağı} (AA)

The geographical boundaries are limited to the province of Sakarya. Monitoring is conducted by a three-member commission composed of representatives from the Sakarya Corn Research Institute and the Sakarya Provincial Directorate of Agriculture and Forestry, under the coordination of the Sakarya Chamber of Commerce.