novel 2 - vinyl - 1 - cyanocyclopropane - 1 - carboxylates and 2 - vinyl - 1 - arylcyclopropane - 1 - carboxylates useful as herbicides , pesticides and chemical intermediates are provided . the invention also relates to a method of modifying plant growth by the application of vinylcyclopropane derivatives wherein the carboxylate group contains an amine or quaternized amine moiety .