 From 1967 to 1995 he worked as a professor at the university.From 1978 to 2000 he was director and head of the Max Planck Institute for Plant Breeding Research (Institut für Züchtungsforschung) at the Max-Planck-Gesellschaft in Cologne, Germany.He received many prizes, among which were the Francqui Prize in 1979, the Wolf Prize in Agriculture in 1990, and the Japan Prize in 1998, which he shared with Marc Van Montagu.