Zhoushan Pomelo

Zhoushan Pomelo

Zhoushan Pomelo is a protected geographical indication product.

Zhoushan Pomelo is a certified geographical indication trademark.

Zhoushan Pomelo is a registered geographical indication for agricultural products.

　　In 1994, the town of Zhoushan in Liangzihu District, Ezhou, introduced the Changshan pomelo and began trial planting, which was quickly scaled up. In 1997, local agricultural experts confirmed that Zhoushan shares the same geographical latitude and natural climate as Changshan, making it suitable for cultivating pomelos.

　　After years of careful cultivation, this golden-colored, sweet-and-sour fruit has taken root in Zhoushan, continually bringing surprises to fruit farmers—

　　In 2004, Zhoushan Pomelo was rated as a high-quality fruit of Hubei Province;

　　In 2006, testing by the National Ministry of Agriculture’s Food Supervision and Inspection Center found that the “soluble solids content in Zhoushan Pomelo juice” (commonly referred to as sugar content) exceeded 10%, surpassing other pomelo varieties on the market;

　　In 2007, Zhoushan Pomelo was certified as a Green Food product by the China Green Food Development Center, authorized to use the Green Food label;

　　In March of this year, Zhoushan Pomelo successfully obtained the Geographical Indication Certification Trademark registration certificate issued by the State Administration for Industry and Commerce. This marks the first case of a national forest and fruit origin certification trademark for Ezhou City.

　　Currently, the planting area of Zhoushan Pomelo has exceeded 50,000 mu, with 20,000 mu bearing fruit. The total annual yield from mature trees reaches 22.4 million jin. Eighty percent of households in Zhoushan Town grow pomelos.

　　In recent years, many fruit dealers and processing companies from Changshan have come to Zhoushan—not only to purchase fresh fruit for direct sale but also to seek stable supply sources through joint ventures.

　　Geographical Scope

　　The geographical indication area for Zhoushan Pomelo covers three towns and one district (Liangzi Island Ecotourism Zone), encompassing 26 administrative villages: Conglin, Hupiao, Tongyou, Shaofeng, Fanxiong, Hongnei, Yangjing, Yongtang, Niushan, Qiaoke, Zhoushan, Xiake, Xiaozui, Niushan East, Chenjiazui, among others. In 2001, the municipal Party committee and government made the decision to vigorously develop pomelo cultivation and optimize the fruit variety structure, initiating regional planning focused on a 50,000-mu core zone centered on Zhoushan Town. This zone consists of three areas: the roadside pomelo high-yield belt along the road from Fanxiong to Taihe in Zhoushan, the hilly pomelo high-yield belt centered on Donggou Town and Changling, and the hilly pomelo high-yield belt centered on Hongnei and adjacent villages. By 2007, the construction goal for the 50,000-mu pomelo base core zone had been achieved. The Zhoushan Pomelo production area lies between 114°30′–115°05′ east longitude and 30°01′–30°36′ north latitude, with the highest elevation at 418.4 meters and the lowest at 11.7 meters. It borders Xianning to the south, Jiangxia to the west, and Daye to the east. The production area spans 700 hectares, with an annual output of 60,000 tons.

　　Natural Ecological Environment and Humanistic Historical Factors

　　(1) Soil and Topography: The terrain in the Zhoushan Pomelo production area slopes from east to west and from south to north, featuring mid-to-high hills, ridges, valleys, plains, and Liangzi Lake. Hills account for 44.4%, plains for 36.4%, and hilly uplands are a key topographical feature of Liangzi Lake District, making them ideal for establishing pomelo production bases. The soil is rich in selenium, predominantly red-yellow loam, fertile, with organic matter content exceeding 1%. The soil layer is deep, with active soil layers over 60 cm, groundwater levels below 1 meter, and soil pH ranging between 5.5 and 7.5. Additionally, the pomelo production area…

　　…is close to Liangzi Lake. During spring and summer, the evaporation from the lake creates frequent fog, which is highly conducive to pomelo growth and fruit setting.

　　(2) Hydrology: The water sources for planting, processing, and irrigation of Zhoushan Pomelo come from the Liangzi Lake water system. Water is derived from natural rainfall and groundwater, primarily relying on water stored in the Yangtze River and Liangzi Lake for irrigation. The water quality meets the NY/T5016-2001 standard, and the excellent water source and quality provide innate conditions for producing high-quality Zhoushan Pomelo.

　　(3) Climate: The climate in the Zhoushan Pomelo production area is subtropical monsoon, characterized by distinct seasons, abundant rainfall, ample sunlight, and a long frost-free period. The average annual temperature is 17°C, with an absolute minimum temperature ≥ -7°C, January average temperature ≥ 4°C, accumulated annual temperature ≥ 10°C exceeding 5000°C, annual precipitation of 1282.8 mm, frost-free period of 266 days, annual sunshine duration of 2003.8 hours, and total solar radiation of 110.3 kcal/cm².

　　(4) Humanistic and Historical Factors: The registered Zhoushan Pomelo product has a history of over ten years. In 1993, our town introduced and trial-planted it in the Zhoushan Forest Farm from Changshan, Zhejiang. By 1996, it was verified that the pomelo was a new fruit variety well-suited to Liangzi Lake, with product quality superior to other local fruits. In 1997, after evaluation by Ezhou’s forestry and fruit experts, it was concluded that the pomelo is a high-quality fruit with high economic returns, suitable for development in Liangzi Lake at the time. In the same year, it was gradually promoted across the district and city with positive results and social recognition. In 2003, the Municipal Agriculture Bureau organized relevant local units to apply for Hubei Province’s Pollution-Free Agricultural Product certification, which was approved (certificate number: WNCR-HB03-00017). In 2004, Zhoushan Pomelo won the Best-Selling Product Award at the Hubei (Wuhan) Agricultural Expo and was also named a High-Quality Citrus by the Hubei Provincial Department of Agriculture, receiving a certificate. The “Zhoushan Brand” pomelo was successfully registered. In 2006, after review by the China Green Food Development Center, the product met Grade A Green Food standards and was certified as a Green Food product (label number: LB-44-0411171988A).

　　Thanks to years of effort, in 2007, the Zhoushan Pomelo base was designated as the core pomelo production zone of Ezhou City. In March of the same year, it was recognized by Hubei Province as a Pomelo Sector Construction Base.

　　Production Technical Requirements

　　(1) Site Selection: Zhoushan Pomelo is suitable for planting on wind-sheltered, sun-facing hills and ridges facing south.

　　The soil should be weakly acidic or neutral. Adequate moisture is required during the growing season, but waterlogging must be avoided as it can cause root rot and plant death. Zhoushan Pomelo is mainly planted in 26 villages in Zhoushan Town, including Conglin, Hupiao, Tongyou, Shaofeng, Fanxiong, Hongnei, Yangjing, Yongtang, Niushan, Qiaoke, Zhoushan, Xiake, Xiaozui, Niushan East, and Chenjiazui. The environmental quality of the production site must comply with the requirements of the “Technical Conditions for Green Food Production Areas” (NT/T391-2000).

　　(2) Variety Selection: Zhoushan Pomelo is a natural hybrid of pomelo and citrus. In 1993, our town introduced it from the Changshan Citrus Research Institute in Zhejiang and planted it in the Zhoushan Forest Farm. Scions were taken from superior individual plants and grafted onto rootstocks, with the resulting saplings planted across the 26 administrative villages. All Zhoushan Pomelo saplings must be sourced from the base and be free of pests and diseases.

　　(3) Production Process Management: The production process of Zhoushan Pomelo must strictly follow the “Zhoushan Pomelo Production Operation Procedures.” The use of pesticides and fertilizers during production must comply with the “Green Food Pesticide Use Guidelines” (NT/T393-2000) and the “Green Food Fertilizer Use Guidelines” (NY/T394-2000). To ensure the quality characteristics of Zhoushan Pomelo, particular attention must be paid to the following aspects: A. Soil, Fertilizer, and Water Management ① Deep Plowing and Soil Improvement: From July to August, dig trenches 30 cm inward from the outer edge of the tree canopy’s vertical projection, 50–100 cm wide and 60–80 cm deep, in a semi-circular shape. Apply ample manure inside the trench, then refill with surface soil. Change the digging direction annually and gradually expand outward to create favorable conditions for root growth. ② Rational Fertilization: Along with deep plowing, apply 300 kg of farmyard manure per adult Zhoushan Pomelo tree annually. During peak flowering, spray 300-fold diluted borax once to improve fruit set. During the growing season, spray 0.5% potassium dihydrogen phosphate to enhance fruit coloration and quality. ③ Timely Irrigation: Irrigate once before flowering each year to protect blossoms and fruit. In late October to early November, irrigate once with freezing water to ensure the trees safely survive winter and prevent frost damage. Adjust irrigation according to soil moisture during the growing season. B. Pruning Zhoushan Pomelo mainly uses a pagoda or open-center tree form to ensure a full tree structure, strong light penetration inside and outside the canopy, uniform fruiting, high yield, and good quality. The tree structure includes: a trunk height of 50–60 cm, 5–6 main branches, arranged in 2–4 layers with 0.3–0.5 m spacing between layers, 3–4 lateral branches per main branch, and a tree height of 3.5–4.5 m. Pruning characteristics: in addition to shortening main and lateral branches, upright, overly dense, and water sprout branches should be heavily pruned or removed, while horizontal and oblique branches should be retained to promote flower bud formation. C. Flower and Fruit Management Manually thin flowers and fruit, preferably when flowers are just opening or still closed, maintaining a flower-to-leaf ratio of 1:15. Thinning fruit typically occurs from late May to early June, about ten days after full bloom: leave one fruit every 20–25 cm, with weaker branches bearing fewer fruits and stronger trees slightly more.

　　(2) Variety selection: Zhoushan Huyou is a natural hybrid of pomelo and citrus. In 1993, our town introduced the variety from the Changshan Citrus Research Institute in Zhejiang Province and planted it at the Zhoushan Forest Farm. The scions were taken from superior individual plants, and the resulting saplings were planted across 26 administrative villages in the town. All Zhoushan Huyou saplings planted must come from the base and be free of pests and diseases.

　　(3) Production process management: The production process of Zhoushan Huyou must strictly follow the "Zhoushan Huyou Production Operation Procedures." The use of pesticides and fertilizers during production must comply with the "Green Food - Pesticide Application Guidelines" (NY/T 393-2000) and the "Green Food - Fertilizer Application Guidelines" (NY/T 394-2000). To ensure the quality characteristics of Zhoushan Huyou, particular attention must be paid to the following aspects. A. Soil, fertilizer, and water management. ① Deep plowing and soil improvement. From July to August, dig trenches 30 cm inward from the inner edge of the vertical projection of the tree canopy, with trench width of 50–100 cm and depth of 60–80 cm, in a semi-circular shape. Apply ample manure inside the trenches, then refill with surface soil. Change the digging direction annually and gradually expand outward to create favorable conditions for root growth. ② Rational fertilization. Along with deep plowing and soil improvement, apply 300 kg/year of farmyard manure per mature Zhoushan Huyou tree. During the full bloom period, spray a 300-fold solution of borax once to improve fruit set rate. During the growing season, spray a 0.5% potassium dihydrogen phosphate solution to enhance fruit coloration and quality. ③ Timely watering. Water once before flowering each year to protect flowers and fruit. In late October to early November, water once as a freeze-prevention measure to ensure the safe overwintering of trees and prevent frost damage. Water appropriately during the growing season based on soil moisture conditions. B. Rational pruning. Zhoushan Huyou mainly adopts a pagoda or open-center tree form to ensure a full tree structure, strong light penetration both inside and outside the canopy, uniform fruiting, high yield, and good quality. The tree structure includes: a trunk height of 50–60 cm, 5–6 main branches arranged in two to four layers (with 0.3–0.5 m spacing between layers), 3–4 lateral branches retained on each main branch, and a total tree height of 3.5–4.5 m. Pruning characteristics of Zhoushan Huyou: In addition to shortening the main and lateral branch tips, upright branches, overly dense branches, and water sprouts should be heavily pruned or removed. Horizontal or slightly angled branches should mostly be left to grow to encourage flower bud formation. C. Flower and fruit management. Manual thinning of flowers and fruits is practiced, with the best time for flower thinning being when flowers have just opened or are still closed, maintaining an optimal flower-to-leaf ratio of 1:15. Fruit thinning is generally done from late May to early June, about ten days after full bloom: leave one fruit every 20–25 cm, leaving fewer fruits on weaker branches and slightly more on stronger trees.

　　(4) Product Harvesting and Post-Harvest Processing: Zhoushan Pomelo harvesting begins after October 20th each year. For fresh consumption and processing, fruits must meet the color, flavor, and aroma standards characteristic of the variety and are harvested when fully ripe. Fruits intended for short-term storage are picked at 90–95% maturity, while those for long-term storage are harvested at 80–90% maturity. After harvesting, fruits must be sorted and packaged. Harvesters should trim their fingernails and wear gloves, picking fruits from the outer and middle-lower parts of the canopy first, then moving to the inner and upper parts. The "two-cut method" is used: the first cut removes the fruit along with the stem. Harvested fruits should be placed in a cool, dry area, protected from direct sunlight and rain.

　　(5) Production Record Requirements: To gain practical experience and continuously refine techniques, technical personnel organize educated and experienced fruit growers to maintain detailed records on variety selection, cultivation, soil-fertilizer-water management, pruning and flower-fruit management, pest and disease control, pomelo harvesting, and post-harvest processing. These records serve as written documentation to support expanded planting areas and increased yield and income, later compiled into theoretical best practices.

　　Typical Quality Characteristics and Product Safety Standards

　　(1) External Sensory Characteristics: Zhoushan Pomelo fruits are nearly spherical with a well-formed shape, exhibiting inherent varietal traits. Fruit diameter is ≥85mm, or alternatively ≥80mm or ≥70mm, with color ranging from golden yellow to orange-yellow.

　　(2) Internal Quality Indicators: Mature Zhoushan Pomelo fruits contain higher alcohols, aldehydes, ketones, volatile organic acids, and terpenes in both the peel oil glands and pulp juice sacs, emitting an enticing aroma. The fragrance fills the room when stored, offers a refreshing taste upon eating, and leaves a slightly bitter aftertaste. The juice has a soluble solids content of 11–14%, with an edible rate of ≥55%. Each milliliter of juice contains 7–15g of sugar, 0.3–1.5g of acid, and <35–200mg of vitamin C, along with abundant vitamin B, vitamin C, carotene, calcium, phosphorus, iron, magnesium, potassium, and sodium.

　　(3) Safety Requirements: Zhoushan Pomelo safety and hygiene indicators comply with NY5014 standards.

　　Packaging and Labeling Regulations

　　Zhoushan Pomelo products are graded into first, second, and third levels based on appearance and flesh quality. Grading criteria are: fruit diameter of 85mm for Grade 1, 80mm for Grade 2, and 70mm for Grade 3.

　　Packaging of Zhoushan Pomelo products must be labeled with the agricultural product geographical indication "Zhoushan Pomelo."

　　The packaging of Zhoushan Pomelo products bears the label "Zhoushan Pomelo" as a registered geographical indication of agricultural products.