SEOUL, May 12 (Xinhua) -- The South Korean government said Monday that it will expand its existing ban on Japanese potatoes to cover products grown on the main island of Honshu.

    According to the Yonhap News Agency, South Korea's National Veterinary Research and Quarantine Service (NVRQS) said the measure which came in response to the discovery of Globodera rostochiensis, or yellow potato cyst nematodes, will take effect on Wednesday.

    The import ban will only affect potatoes from two prefectures in Honshu, the NVRQS said.

    South Korea has banned import of potatoes from Japanese Hokkaido and Kyushu for several years.