Scientist Develops Stevia Variety 300 Times Sweeter Than Cane Sugar

With 26 new crop varieties, many of which have been recognised as national varieties, Prof. & Acad Tran Dinh Long, President of the Vietnam Seed Association, is recognised as one of scientists who has made significant contributions to Vietnamese agriculture. Behind these scientific achievements lies a lifelong journey driven by his love for the field and his aspiration to enhance the value of Vietnam's agricultural products.

Prof. & Acad. Tran Dinh Long, President of Vietnam Seed Asociation. Photo: Mai Loan.

THE JOURNEY TO CREATE VIETNAM’S FIRST STEVIA VARIETY OF “Mr. STEVIA”

Talking with Knowledge and Life, Prof. & Acad. Tran Dinh Long shared that among the many crop varieties that he and his colleagues have successfully developed, stevia remains one of his most memorable accomplishments.

According to Prof. & Acad. Tran Dinh Long, in 1988, during an official visit to the Americas, General Vo Nguyen Giap brought stevia to Vietnam and assigned the Ministry of Agriculture and Rural Development to research and develop the plant, which was later entrusted to the Vietnam Academy of Agricultural Sciences.

Prof. & Acad. Tran Dinh Long inspects the ST77 stevia variety in Nam Dinh. Photo: NVCC.

Prof. & Acad. Tran Dinh Long felt the pressure when accepting the task. At the time, he knew almost nothing about stevia and initially imagined it to be a plant similar to sugarcane. Given the limited research facilities, simply keeping the plant alive was difficult, while propagating it posed an even greater challenge.

The biggest challenge was that the plant did not flower, making seed propagation impossible. Only after two years of cultivation in Da Lat did the plant finally begin to bloom, allowing researchers to reproduce it through sexual propagation.

Starting with a single original plant, the research team spent five years isolating tissues and conducting tissue culture before successfully developing the ST88 stevia variety. In 1995, ST88 was officially recognized as a national crop variety. ST88 contains a high concentration of natural sweetening compounds, making it approximately 300 times sweeter than cane sugar while providing no calories. As a result, it has been widely used in medicine, as it is suitable for people with diabetes and obesity.

With this foundation, the research team later successfully developed ST99 and ST77, which contain approximately 25% more sweetening compounds than ST88.

For Prof. & Acad. Tran Dinh Long, the greatest source of pride is not merely the scientific achievement but the economic benefits stevia has brought to farmers. Many households in Hung Yen, Bac Giang, Hai Duong, Bac Ninh, Nam Dinh, and Hoa Binh have improved their incomes and living standards by cultivating the crop. Therefore, local farmers fondly call him "the Academician of Farmers" or "Mr. Stevia."

"Whenever I visit farmers, they are delighted and even nicknamed me 'Mr. Stevia.' I feel happiest when they tell me that growing stevia has enabled them to buy a TV and improve their lives. Rather than awards or honors, that is what truly brings me happiness," Prof. Long said.

A LIFELONG COMMITMENT TO VIETNAMESE AGRICULTURE

Born in 1941 in Cam Khe, Phu Tho, Prof. & Acad. Tran Dinh Long grew up in Vietnam's midland countryside, surrounded by palm hills, tea plantations, and green rice fields. Raised in a farming family, his childhood nurtured a deep affection for crops and inspired his lifelong ambition to improve farmers' livelihoods, which led him to pursue agricultural research.

After graduating from Hung Vuong High School (Class of 1958–1961, alongside renowned poet Pham Tien Duat), he studied at Kishinev State University (KGU) in the former Soviet Union. Upon returning to Vietnam, he taught at Hanoi Agricultural University I and Agricultural University II, while holding numerous important positions in agricultural research and education.

VUSTA leaders, staff members, and invited guests congratulate Prof. & Acad. Dang Vu Minh and Prof. & Acad. Tran Dinh Long on being honored by the Russian Academy of Sciences (RAS).

Throughout nearly a lifetime devoted to science, Prof. & Acad. Tran Dinh Long has left an enduring legacy in crop breeding. He is the creator of 26 new crop varieties, including 10 soybean varieties, 6 peanut varieties, and 4 mung bean varieties. Many of these have been officially recognized as national crop varieties. These varieties have helped increase farmers' incomes by 15-20% compared with older varieties. Two notable examples are the L23 peanut and DT26 soybean, which have been granted Plant Breeders' Rights Certificates.

Besides scientific research, he has also authored numerous books and academic publications on agriculture that are highly regarded within the scientific community.

Prof. Long believes that agriculture remains the backbone of Vietnam's economy. He expressed satisfaction that Vietnam has mastered the development of many high-quality crop varieties, including internationally acclaimed ones such as ST25 rice. Notably, Ho Quang Cua, the engineer and Hero of Labour who developed ST25 rice, was once his student.

Nevertheless, Prof. Long argues that Vietnam's greatest agricultural challenge today is to promote deep processing, organic farming, and circular agriculture. He advocates reducing the use of chemical fertilizers and pesticides while replacing them with organic fertilizers and biological crop protection products to restore soil health and produce safer, higher-value agricultural products.

According to him, once Vietnam succeeds in developing deep processing, integrated value chains and strong agricultural brands, the country's agricultural, forestry, and fisheries exports will reach even greater milestones.

"My greatest concern is how to help Vietnamese agriculture reach the global stage. To compete globally, our agricultural products must have higher value. To achieve that, we need value-chain production and deep processing. These are absolutely essential," he emphasized.

This article is part of the "Portraits of Scientists" series published to celebrate the 9th National Congress of VUSTA for the 2026–2031 term.