Adapazarı White Chestnut Squash

Adapazarı White Chestnut Squash is a winter squash variety belonging to the species Cucurbita maxima. The product is cultivated in the agricultural areas of Sakarya province and along the banks of the Sakarya River, and 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”.

Product Description and Distinctive Characteristics

Adapazarı White Chestnut Squash 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 0.5–1 cm, while the thickness of each lobe varies between 5–10 cm. The flesh is orange in color and contains 14–16% water-soluble dry matter.

The plant exhibits a prostrate growth habit and spreads laterally 3–10 meters. Plant height is approximately 70–80 cm. Male and female flowers display clearly defined morphological features such as 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 2,500 to 5,000 kg per decare.

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

Adapazarı White Chestnut Squash (AA)

Production Method

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, composted fertilizer (50 kg/da) in spring, and urea or ammonium nitrate (10 kg/da) during the second weeding.

Sowing: Sowing is carried out at a depth of 4–5 cm in raised beds during late March to early April. The pit method is used, with pits spaced at 2x2 m or 3x2.5 m intervals. Three to four seeds are planted in each pit. Thinning is performed when plants reach the 5–6 leaf stage.

Irrigation and Pest Control: The crop is generally grown without irrigation; however, 1–2 irrigations may be necessary during dry periods. Mechanical and chemical methods are employed for weed and pest control. Protective measures are taken against pests such as aphids, spider mites, and thrips. Appropriate plant protection products are applied to manage diseases.

Harvesting and Storage: Fruits are harvested after reaching full maturity, 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 temperatures below 10 °C and 60–70% relative humidity.

^{Adapazarı White Chestnut Squash} (AA)

Geographical Boundary and Monitoring

The geographical boundary is limited to Sakarya province. Monitoring is carried out 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.