Replanting of the hillside

In 2022, Son La is the province with the largest longan acreage in the country, with 20,000 hectares and a production of almost 100,000 tons. A year earlier, the National Intellectual Property Office (Ministry of Science and Technology) issued the decision to issue a certificate of trademark registration “Son La Label” as an endorsement for tropical fruits on the hillside.

However, few people know that about five years ago, when the province’s new fruit tree development project took shape, longan trees had to arouse many doubts from the people. The main concern of farmers in general is the question: “Fruit is in season, where will it be eaten?”

An urgent requirement for farmers and scientific researchers is to spread the harvest over thousands of hectares of longan so that the longan does not ripen at the same time. In addition, it is the selection of longan varieties with strong growth, high yield and good fruit quality to diversify the structure of longan varieties.

Since 2010, the Fruit and Vegetable Research Institute has been researching, selecting and testing T6 longan varieties in the northern provinces. During the five-year test period from 2014 to 2019 at three sites in Dai Thanh Township (Quoc Oai District, Hanoi City), An Vi Township (Khoai Chau District, Hung Yen Province) and Yen Hung Township (Song Ma District, Province) . ). Son La), the institute has produced T6 longan with strong growth ability, large, slightly twisted leaves, shiny leaf surface and dark green color.

The flowering time of the variety is around February and is almost similar to the flowering time of the main longan variety Huong Chi. The yield of T6 longan at the trial sites reached 31.5-33.7 kg/tree at 6 years of age. The variety has good fruit quality, the Brix value is 21.3 – 22.5%, the portion ratio is 66.8 – 68.6%. The strain’s concentrated harvest time is usually earlier than the peak longan season. Since 2019, the Ministry of Crop Production has recognized the longan variety T6 and allowed trial production in the northern provinces.

The family of Pham Thi Thanh, one of 17 members of Hung Loc Agricultural Service Cooperative, Song Ma District, has been breeding T6 longan for three years. Before that, her family, like many other households, planted local longan varieties on an area of ​​more than 1 ha. However, since it coincides with the time of the longan harvest in Hung Yen’s peak season, the family’s profit is almost negligible.

On the advice of some members of the cooperative, her family learned to fell and graft decades-old longan trees with the Fruit and Vegetable Research Institute’s T6 variety. Half believing, half doubting, Ms. Thanh’s family was convinced of the yield and quality of the new longan.

“My family often sells longan early, around June, at a value many times higher than the official seasonal longan. At the peak, the price of longan reached 60,000 VND/kg, which helped the family earn about 350 million VND,” she said.

Not far from Ms. Thanh’s house, Hoa Muoi Agricultural Service Cooperative of Chieng Khoong Township also boldly converted 13/30 hectares of Mien Thiet Longan to transplant T6 Longan. From the second year, members of the cooperative are impressed by the profitability that the early ripening longan brings.

Director Luong Van Muoi said the hardest part about advising co-op members to switch to early maturing longan varieties was that the longan crop was stable and suddenly cut off, resulting in all two crops being lost and not harvested .

“Not only does the cultivation technique need to be strictly followed and requires a lot of effort, but people also need to closely monitor the growth of the longan tree while timing based on the weather to cut branches that stimulate the plant to bloom,” Herr shared Muoi with.

Thanks to the determination and consensus of the members, the early-ripening longan variety produced by the cooperative was represented at the Song Ma district exhibition stand at the OCOP Vietnam Fruit and Products Festival in 2022. was born in the town of Son La at the end of May 2022.

Currently, the harvest time of early-ripening longan varieties in Son La is usually 1-2 months earlier than the main varieties. Since then, farmers here have better conditions in terms of product consumption while avoiding the “depreciation season” situation as before.

Promote the early ripening of longan

In the north, Longan is concentrated in a few provinces, including Lao Cai, Son La, Thai Nguyen, Bac Giang, Hai Duong, Hung Yen and Hanoi. Son La and Hung Yen are the two provinces with the largest acreage and the largest annual harvest.

According to the Research Institute of Vegetables, northern longan varieties are more focused on late-ripening tea, with varieties HTM1 and HTM2 being grown in Hanoi, while varieties PHM99-1.1 are mainly grown in Son La and Hung Yen. For early-ripening tea, only the PHS2 variety is cultivated on a small scale in Khoai Chau District, Hung Yen Province. In addition, prior to the announcement of the T6 variety, the main crop of mature longan tea was not the focus of research and only the longan variety Huong Chi was selected.

In order to extend the harvest time, a suitable variety structure for each tea is required in addition to technical measures. Therefore, the Research Institute of Fruit and Vegetables is actively coordinating the transfer of the technical process of grafting to replace local varieties in production. So far, the process of grafting, improving and replacing varieties is repeated on 5,000 ha of longan in Song Ma and Mai Son districts of Son La province.

associate Prof. Dr. Nguyen Quoc Hung, director of the Fruit and Vegetable Research Institute, said that during the testing process, the yield of the longan varieties at all three planting sites gradually increased with the age of the trees. In particular, the yield of the selected longan strain T6 was over 15% higher than that of the control variety. Some criteria for evaluating the fruit quality of the selected T6 longan line, such as sugar content, vitamin C, etc., are equal or higher than the same evaluation criteria of the control variety.

“Harvest time is one of the indicators of the characteristics of the variety and partly determines the economics of production. “The monitoring results show that the T6-selected longan line at the Son La trial site has a harvest time about ten days earlier than at the Hanoi and Hung Yen planting sites,” Hung said. This is also considered to be one of the criteria to help the T6 Longan variety become more hybridized in the Northern Mountain Province.

According to Mr. Nguyen Van Phuong, vice chairman of the Song Ma District People’s Committee, the district currently has more than 7,500 hectares of longan cultivation area, of which about 300 hectares are early maturing longans, concentrated in Chieng Khoong, Chieng Khuong and Na Nghiu communities. In order to achieve the goal of 1,000 hectares of early-ripening longan by 2030, Song Ma District directs the specialized district agencies and community people’s committees to actively coordinate with the Fruit and Vegetable Research Institute, conduct propaganda, and encourage farmers to transplant early-ripening longan Guide varieties for propagation, improve yields and increase income for longan growers.

“The expansion of the early maturing longan area helps promote the application of scientific and technical advances in production, especially the introduction of new varieties of high economic value into production, thereby successfully completing the task of spreading the agricultural crop,” said Phuong.

Song Ma’s early-ripening longan not only features high yield, but also features delicious quality and beautiful design, and has been ordered by many merchants inside and outside the province.

Since 2017, the Song Ma District People’s Committee has regularly organized the “Song Ma Longan Festival”. This is an opportunity for local people to promote the Song Ma brand to a large number of domestic and foreign tourists.