Dr. and Associate Prof. Ri Tong Jo is Merited Scientist and a teacher of thremmatology in the agrobiology faculty of Pyongyang University of Agriculture. He is usually nicknamed “master of stevia.”

He has devoted nearly 40 years of his career to the research on breeding a new kind of high-yielding stevia suitable to the climatic and soil conditions in the country and the cultivation, seed-gathering and processing of the plant. Thus he has rendered a tangible service to solving the sugar problem.

He was born of a peasant in December 1938 when his country was under the Japanese imperialists’ military occupation. In the 1960s he learned biology at Kim Il Sung University and then finished the postgraduate course summa cum laude before starting his career as a teacher in the university.

Working as the dean of a faculty at Pyongyang University of Agriculture since 1982, he buckled down to the research into stevia which would be of great importance in solving the sugar problem in the country.

Harvested usually in August, it is a natural sweetening plant which belongs to a stevia kind of the aster family.

Stevia had long been under research in the country, but it failed to win the public favour owing to its aftertaste of bitterness and plant smell.

In the days of breeding a new variety, Ri, while giving lectures, pushed ahead with his breeding project in an experimental farm dozens of kilometres away from the university.

His nearly-20-year-long painstaking efforts bore fruit. He succeeded in cultivating a new kind of stevia which is better in leaf yields, content of sugar and sweet taste.

In the course of this, he presented scores of papers including those on studies of hereditary polymorphism of stevia and on the farming of a good kind of stevia. He also wrote a lot of books and reference books while training dozens of stevia scholars.

Later, he intensified the research on cultivation and processing techniques of stevia and promoted the work for introducing the plant across the country.

A scientist should set the problem the country wants to solve as his research project and carry it through to the end. And only when it produces good economic results can it be said to be a success. This is Ri’s belief.

This belief has served as the motive force for him to travel across the country to solve sci-tech problems arising in the cultivation, introduction and processing of stevia even when he is well over 80.

Today the stevia sugar powder and solution are in wide use in foodstuff, pharmaceutical, cosmetics and other industries.