Napa cabbage
On August 15, 1945, Korea won its independence; Dr. Woo resigned from his positions at the Takiyi research farm and Tokyo University, and prepared his own place near a Buddhist temple. In Korea, farmers were left no seeds to plant because trade between Korea and Japan ceased, and the seeds were produced only in Japan. The policy was aimed to hinder Koreans from obtaining technological knowledge and to profit from selling the seeds to Koreans at a high price. As a result, after the liberation, there were neither people nor companies in Korea which could produce vegetable seeds such as radish and Napa cabbage, and seeds could not be imported from Japan. In accordance to a suggestion by Kim Jong-yi to resolve this problem, President Yi Seung-man sponsored a campaign to urge for Dr. Woo's return; Dr. Woo complied, and a team was established to allow Dr. Woo to work as soon as he returned to Korea. The team worked to gather money and resources, and established the "Hanguk Nong'eop Gwahak Yeonguso" (한국 농업 과학 연구소) or Korean Agricultural Science Research Institute near the city of Busan.