Amidoximes of the formula ##STR1## are disclosed. R represents a hydrogen atom or a hydrogen, lower alkyl (C.sub.1 - C.sub.4) or phenyl; R.sub.1 represents lower alkyl or a metal atom and Ar represents substituted or unsubstituted phenyl or a five-membered substituted or unsubstituted aromatic heterocyclic group where the hetero atom is selected from the group O, S and N. The compounds have phytohormonal activity at low dosages in plants and herbicidal activity at higher levels.