Abstract: A process is provided for enhancing the reliability and consistency of effectiveness of an exogenous chemical substance applied to foliage of a plant, involving application of a phenyl-substituted olefin compound to the foliage, either sequentially or simultaneously with the exogenous chemical substance. Also provided are plant treatment and concentrate compositions comprising an exogenous chemical substance and a phenyl-substituted olefin compound.

Abstract: Aqueous concentrate herbicidal compositions are provided comprising a herbicidally effective amount of ammonium salt of N-phosphonomethylglycine wherein the molar ratio of ammonia to N-phosphonomethylglycine provides a pH of about 6 to about 7, and a herbicidal efficacy enhancing amount of one or more surfactants. Compositions of the invention are storage-stable over a wide range of temperatures. Also provided is a method of killing or controlling vegetation comprising diluting a composition of the invention in water and applying the diluted composition to foliage of the vegetation.