Chennai, Nov 18: Seeking a ban on the field tests of genetically modified paddy varieties in the country, AIADMK chief Jayalalithaa said researchers should focus on seed varieties which protect soil fertility and give more yield. Charging multi-national companies with "selling poisonous BT seeds banned in Japan and European countries", she said these seeds would affect the fertility of the soil. Paddy grown out of genetically modified seeds would harm human beings as well as animals and birds, she said.