The 12th International Conference on Plant Growth Substances was held from 26th to 31st August 1985 in Heidelberg, F. R. G., under the auspices of the IPGSA (International Plant Growth Sub stances Association) and the University of Heidelberg in its 599th year. As many as 750 participants from 40 countries all over the world attended the conference, including guests and staff members of the local organizers. Fine days provided an excellent background for a fruitful and pleasant meeting and all the activities accompanying the scientific programme. During the conference all current aspects...