Southern Crisp-Sweet Pomelo

Southern Crisp-Sweet Pomelo

The southern crisp-sweet pomelo is a product with geographical indication.

　　The southern pomelo, also known as the crisp-sweet pomelo, is an early-maturing, high-quality variety of citrus in the pomelo family. It features an attractive shape, large size, thin rind, crisp and tender texture, balanced sweet-and-sour flavor, rich aroma, high soluble solids content, abundant juice, few seeds, rich nutrition, unique taste, and excellent quality — all of which have made it highly popular among consumers. In 1989, it participated in the National Quality Fruits Evaluation, ranking third only after Wenzhou pomelo and Mi-zhou pomelo, earning the title of High-Quality Product from the Ministry of Agriculture. In 1993, it was awarded the UN Technology Information System China National Sub-Centre's Science and Technology Star Award for Invention and Creation.

　　Geographic Scope

　　The geographical indication area for the southern crisp-sweet pomelo includes 33 townships such as Laoya Town, Panlong Town, Qunlong Township, Pingqiao Township, and Mawang Township. The production area lies between 105°27′–106°24′ east longitude and 31°04′–31°40′ north latitude, at elevations ranging from 300 to 450 meters. It borders Yilong County and Peng’an County to the east, Yanjing County and Zitong County to the west, Shunqing District and Xichong County to the south, and Jiange County and Langzhong City to the north.

　　Natural Ecological Environment and Humanistic-Historical Factors

　　(1) Soil and Topography: The terrain in Nanbu County is higher in the northwest and lower in the southeast, with the Daba Mountain and Jianmen Mountain ranges extending east-west. Elevations range from a minimum of 290 meters to a maximum of 880 meters. The production area for the southern crisp-sweet pomelo lies between 300 and 450 meters in elevation, and the landscape is primarily low mountains and hills, with shallow and flat dam areas accounting for 9%. The soil type is purple soil, with a clayey loam texture. It contains over 1% organic matter, 0.116% total nitrogen, 78 ppm available nitrogen, 9 ppm available phosphorus, 67 ppm available potassium, and a pH value between 6.8 and 7.8. The distinctive topography and landforms of the production area provide essential conditions for the formation and maintenance of the unique qualities of the southern crisp-sweet pomelo.

　　(2) Hydrology: Nanbu County is rich in water resources. The Jialing River flows from north to south through the county, covering a length of 116 km and a drainage area of 2,236 km². The Xi River, a first-level tributary, runs 175 km east-west through the region, covering a drainage area of 1,779.9 km². The Shengzhong Reservoir, the largest water conservancy hub in Southwest China, is located within Nanbu County, with a total capacity of 1.339 billion m³, providing gravity irrigation for 40,000 hectares of farmland in the county. The county has groundwater reserves of 62.66 million m³, with water quality classified as soft or slightly hard, temperatures between 10–27°C, and no color, odor, or taste. The water conservancy projects, natural river systems, and high-quality groundwater resources offer favorable conditions for the production of the southern crisp-sweet pomelo and the formation of its unique qualities.

　　(3) Climate: The production area of the southern crisp-sweet pomelo lies within a subtropical warm and humid monsoon climate zone. The Qinling and Daba Mountains form a natural barrier, resulting in mild winters, a temperate climate, distinct seasons, significant monsoon influence, and abundant rainfall. The annual average temperature is 16.8°C, with extreme highs reaching 42.4°C and extreme lows dropping to -5°C. The accumulated temperature above 10°C ranges from 5,226 to 5,624.3°C, the annual average sunshine duration is 1,293.2 hours, the frost-free period spans 316 days, the average annual rainfall is 970.2 mm, and the relative humidity of the air is 78%.

　　(4) Humanistic-Historical Background: The development of the southern crisp-sweet pomelo — from introduction and selective breeding to promotion and cultivation — has spanned over 30 years. In 1978, the county fruit tree technology extension station introduced the variety from Cangxi County for trial planting but found issues with varietal mixing and quality degradation. Starting in 1980, professional technicians organized efforts based on theories of fruit tree genetics and breeding, using bud mutation principles. They conducted clonal selection and regional trials using local pomelos as rootstock. By 1986, the variety was selected and shaped, winning first place in the Nanchong Region Quality Fruit Evaluation. Its early maturity, high yield, storability, and internal quality were significantly superior to similar products. The southern crisp-sweet pomelo becomes edible in early October and fully matures by late October. Comparative tests showed a 3% increase in juice content, a 1.7% decrease in acidity, a 1.31% increase in sugar content, a 0.3% rise in soluble solids, and a 3.5% boost in vitamin C.

　　In 1990, taking advantage of the southern crisp-sweet pomelo’s recognition as a “High-Quality Agricultural Product” by the Ministry of Agriculture, the county Party committee and government designated it as a priority project for agricultural restructuring and began large-scale, locally adapted promotion across the county. During this promotion, a relatively high rate of fruit cracking occurred. In response, the county fruit tree technology extension station launched a three-year research effort to prevent cracking, developing a comprehensive production system that included cross-pollination, plastic mulching, formula fertilization, and regulated water management with initial promotion and subsequent control. This significantly reduced the incidence of cracking across large growing areas. After going through trial planting, selective breeding, and cracking prevention research, the southern crisp-sweet pomelo ultimately became a high-quality fruit with unique regional characteristics. Following its first national evaluation win in 1989 — the “Ministry of Agriculture High-Quality Agricultural Product Award” — it went on to receive many accolades including the “Silver Award at the Thailand Quality Agricultural Products Expo” in 1993, the “UN Science and Technology Invention Creation Star Award,” the “Gold Awards” at the 2nd, 3rd, 4th, and 5th National Pomelo Cooperation Conferences, the “Gold Award at the 2nd China Agricultural Expo” in 1995, and the “Gold Award at the China Western (Chengdu) Agricultural Expo” in 2005. Research and development on the quality improvement and integrated supporting technologies of the southern crisp-sweet pomelo won the “Third Prize for Scientific and Technological Progress” from the Sichuan Provincial People’s Government, while the cracking prevention research and its promotion earned the “Second Prize for Scientific and Technological Progress” from the Nanchong Municipal People’s Government.

　　The current planted area of crisp-sweet pomelos is 2,666.7 hectares, of which 2,000 hectares have been certified as pollution-free production bases and 266.7 hectares recognized as provincial standardized production demonstration areas. Annual production reaches 33,000 tons, all of which have obtained pollution-free product certification. The fruit is sold in more than 10 provinces and cities including Xinjiang, Gansu, Shanxi, Shaanxi, and Chongqing. Currently, large-scale planting is underway in the 33 suitable townships, with plans to develop a 10,000-hectare southern crisp-sweet pomelo advantage industry belt.