Need to restore Xa Doai orange variety

(Baonghean) -Cam Xa Doai (Nghi Dien, Nghi Loc) is famous for its fragrance and deliciousness. Anyone who has ever eaten Cam Xa Doai will never forget it. When you cut the orange open, you will see a bright yellow color, juicy like drops of solidified honey. Cam Xa Doai is fragrant and delicious, but the concern of the people of Doai commune in particular, the people of Nghe An in general and scientists is that this orange variety is gradually degenerating, leading to a decrease in the area of ​​​​oranges.

Disease-free parent trees used to propagate Xa Doai oranges at the North Central Institute of Agricultural Sciences. Photo: Ngoc Anh

According to the Nghi Dien commune chronicle, about 150 years ago, a French priest who came to this land to preach brought a variety of oranges to plant in the land of the current Xa Doai Bishop's Palace (villages 8 and 9, Nghi Dien commune, Nghi Loc district). After only about 3 to 4 years of planting, the orange tree bore fruit, large, cylindrical, strangely sweet and fragrant, with no seeds or very few seeds. From here, the people of Xa Doai gradually expanded this orange variety into the Xa Doai orange area today. The fragrant and sweet taste of this orange variety quickly spread throughout the world.

Legend has it that, at the fruit competition organized by the Hue court, a man from Doai commune at that time, Mr. Chau, brought oranges to the competition and won first prize. Mr. Chau brought them to the king and unexpectedly, the king granted him the special title of "cuu pham" and from then on, the villagers called him "Mr. Cuu Chau". Not only did the Vietnamese praise Xa Doai oranges for their fragrance and deliciousness, but even priests, missionaries, and Western officials at that time also praised this orange variety. Therefore, Xa Doai oranges were honored to be recorded in the Great French Dictionary and were compared to the specialty mango in Tha Khec, Laos "Xoai Xa Doai Orange - Xoai Tha Khec".

According to Mr. Phan Cong Huong - former Vice Chairman of Nghi Dien Commune People's Committee and currently Chairman of the Association of Restorers of Xa Doai Oranges, the oranges here are delicious first of all because of the good orange varieties, grown on heavy loam soil with a deep cultivation layer and annually deposited with a layer of alluvium from the Le canal. Below the cultivated soil layer, if you dig down about a meter, you will see a layer of shells, mussels, and sea snails that have been and are decomposing. The characteristics of this type of soil along with the good orange varieties have created the famous delicious flavor of Xa Doai oranges.

According to Mr. Phan Cong Huong's calculation, on average, each hectare of land in Nghi Dien commune can grow 500 orange trees. With good investment and care, each orange tree only needs to harvest 100 fruits and sell at the lowest price of 30,000 VND/fruit to earn an income of 1.5 billion VND/ha/year. But sadly, Xa Doai oranges are currently showing signs of biological degeneration. Orange trees show signs of poor growth and development, especially oranges that have no or few seeds now have more and more seeds, smaller fruits and thicker skin. From there, the quality also gradually decreases in sweetness and flavor. Due to the rapid rate of degeneration, the economic efficiency of Xa Doai oranges is gradually decreasing. Many orange gardens have been eliminated to be replaced by other crops. If in 1980, Nghi Dien commune had nearly 70 hectares of oranges, now there are only 6-7 hectares left, planted scattered in hamlets 1, 8 and 9.

Currently, in Nghi Dien commune, the number of households with orange gardens of 30 trees or more is only 10-12. Mr. Nguyen Van Phuc in hamlet 8 - the household with the most beautiful orange garden, said: His family has 30 orange trees, although they are well cared for, but only 10 trees are good, each tree yields an average of 100 fruits, the remaining 20 trees only yield 40-50 fruits. During Tet 2012, the price was 60,000 VND/fruit but there were none to sell.

According to the reflection of most people in Nghi Dien commune, in order to maintain and expand the orange garden, they have implemented the method of selecting branches below the orange tree to graft asexually to plant. This method also does not prolong the fruiting time as much as the original variety. Normally, the fruiting time only lasts for 3-5 years at most and then a new tree must be planted. This is completely true, because grafting branches for planting does not make the tree young from the beginning but it continues to calculate the development stage of the main tree (the tree from which the grafted branches are taken). That is in Nghi Dien commune, the original homeland of Xa Doai oranges. In other localities such as Nghia Dan, Quy Hop, Tan Ky, Con Cuong... (Nghe An); Huong Son, Huong Khe (Ha Tinh)... taking grafted buds of Xa Doai oranges in Nghi Dien and grafting them onto grapefruit tree roots all give many fruits, large fruits, and strong tree shape. But it seems the quality is far inferior to the genuine Xa Doai orange, the fruit is big but the skin is thick, the flesh does not retain its original golden color, the flavor is not fragrant.

To restore or revive the Xa Doai orange variety, it is necessary to have the cooperation and participation of the scientific community as well as the attention and appropriate investment of the locality and related departments. In terms of science, it is necessary to have the right research method with the required purpose of rejuvenating the orange variety from the beginning to prolong the growth and development period from one cycle to another. There must be passionate, enthusiastic people with qualifications, capacity, and a lot of knowledge about orange trees. The investment in terms of time is not 1, 2 or 3 years, but at least 10 years or more.

Regarding the research method, it is not advisable to apply the grafting method, using grafted buds to graft onto the grapefruit tree root, but it is possible to research in two directions: The first direction, select the parent tree, take the seeds from the orange fruit of the parent tree, sow them for planting. Among the dozens of trees planted, select and gradually eliminate trees with deformities of the trunk, branches, leaves, fruit, quality, color, flesh color, flavor of the orange... This method takes a long time and is difficult to implement in production facilities, but should be done at universities or at the Institute of Agricultural Sciences. The second method, also from the parent orange tree, is propagated by the method of cell tissue multiplication. This method is faster and retains the true nature of the variety.

Doan Tri Tue