"After 20 years of research, and promotion by the Institute, we found that Yunnan's unique geography and climate can supply blueberries to the market all year round, and people can eat fresh blueberries in all seasons," according to Yang Zhengsong, a researcher at the Alpine Fruit Innovation Team of the Institute of Alpine Economic Botany, Yunnan Academy of Agricultural Sciences.
Yunnan is located on a low-altitude plateau, and 94% of the area is mountainous. It has the advantages of a large temperature difference between day and night, long sunlight time, and abundant water resources. It is very suitable for the cultivation of blueberries. The blueberries produced here have good hardness, high sweetness, appropriate sugar-acid ratio, and high anthocyanin content, which are deeply loved by customers. Yunnan has become the first choice for international berry giants such as the United States, Australia, the United Kingdom, Chile, Spain, and France to deploy.
Since 2002, the Institute of Alpine Economic Plants, Yunnan Academy of Agricultural Sciences has successively introduced 88 blueberry varieties from home and abroad for cultivation research, and screened out 13 excellent blueberry varieties suitable for early, mid-and late-maturing production areas, and realized excellent varieties. Especially in the rapid propagation of blueberry seedlings, the one-step seedling method of blueberry tissue culture has been established. Compared with the conventional seedling cultivation method, the rooting time of new seedlings has been shortened from 150 days to 30 days, the survival rate and the quality of new seedlings have been improved, and the seedling breeding cycle has been shortened, which has promoted the rapid development of blueberries in Yunnan Province. By the end of 2021, the blueberry planting area in Yunnan is about 6666 hectares, with an output of about 45,000 tons, ranking sixth in China in terms of planting area and output.
According to Yang, based on the climate of Yunnan and the growth performance of different blueberries, the blueberry industry in Yunnan is divided into early-ripening, mid-ripening and late-ripening blueberry producing areas. The early-ripening blueberry producing areas are mainly 900-1,500 meters above sea level, rich in light and heat resources, long frost-free periods, and even frost-free every year. Generally, the lowest temperature is above 5 ℃ in tropical and subtropical regions. Therefore, the varieties with low cooling demand are selected for planting, and the fruiting period is from late October to April of the following year.
The mid-ripening blueberry production area is located in a temperate zone with an altitude of below 2,500 meters, a large temperature difference between day and night, and a long light time. The fruiting season is from May to July every year. The altitude of the late-ripening blueberry production area is above 2,500 meters. The high-altitude area with cold winter and long frost period can meet the long-term low-temperature demand of the late-ripening varieties. The blueberry growth period is more than 1 month longer than the conventional growth period. Nutrient accumulation takes a long time, and the fruit quality is good. The fruiting period is from August to October every year, making it the latest producing area in China.
"The different ripening stages of blueberries in Yunnan's early, middle and late-ripening blueberry producing areas enable Yunnan to have blueberries on the market all year round, and people can eat fresh blueberries in all seasons," said Yang.