Abstract: The invention relates to new bicyclo(2.2.1)heptane derivatives of the general formula I ##STR1## wherein R represents a C.sub.1-12 alkyl group optionally substituted by a lower alkoxy group, a C.sub.2-4 alkenyl group or a phenyl-(lower alkyl) group optionally substituted on (I), phenyl ring by one or more lower alkoxy groups or halogen atoms.The invention relates further to plant growth regulating compositions comprising as active agent 0.001 to 95% by weight of a racemic and/or optically active compound of the general formula I, wherein R has the above defined meanings, along with a conventional organic or inorganic, solid and/or liquid carrier and/or filler and/or diluent and/or surfactant.