Abstract: The invention relates to new plant growth regulating compositions, which contain as active agent 0.001 to 95% by weight of one or more compound(s) of the general formula (I), ##STR1## wherein R.sup.1 and R.sup.2 each represent hydrogen atom, a C.sub.1-5 alkyl group, a C.sub.5-7 cycloalkyl group, an aryl group, a halogen-substituted aryl group, an aralkyl group, a C.sub.2-5 alkenyl group or a C.sub.2-5 alkynyl group, orR.sup.1 and R.sup.2 form, together with the adjacent nitrogen atom, a morpholino, pyrrolidino, piperidino or perhydroazepinyl group, andR.sup.3 stands for hydrogen or a C.sub.1-5 alkyl group,together with an inert, solid, liquid and/or gaseous carrier or diluent, and optionally one or more additives, such as surfactants or other substances of plant biological activity.The compounds of the general formula (I) in which R.sup.1 is hydrogen and R.sup.2 stands for hydrogen, C.sub.1-3 alkyl, aralkyl or C.sub.3-5 alkenyl group, furthermore in which R.sup.1 and R.sup.3 are hydrogen and R.sup.