Doctorate She Received at the Age of 70
Especially, the natural bioactivator developed by her and her research group increases the crops' resistance to environment and photosynthetic capacity and effectively keeps off the harmful insects.
In Juche 106(2017), the World Intellectual Property Organization recognized the natural bioactivator as the world's natural green pollution-free organic compound fertilizer and awarded the invention medal to its developers.
During her more than 40-year-long scientific researches, Yu Son Ok was advised many times by experts to write a doctoral thesis.
But she postponed writing it again and again, saying she is pleased if her invention contributes to increasing the agricultural production of the country and the people get benefits from it.

She was awarded a doctorate according to a decision of the State Commission for Conferment of Academic Degrees and Titles of the DPRK at the age of 70 in February this year for her great contribution to solving urgent sci-tech problems arising in the agricultural practice.