 UGET didn’t like the idea of having two international seminars so close to each other.However, several careful and diplomatic dialogues per mail, and a meeting in Leiden (the Netherlands) on 15–16 March 1957, resulted in a cooperation and a tight friendship between Tahar Belkhodja (president of UGET) and R. van den Berg (president of NSR).The NSR decided to cancel its congress in Wageningen in favour of the one in Tunis and to cooperate intensively with UGET.