METHOD OF ENHANCING BIOLOGICAL EFFECTIVENESS OF PLANT TREATMENT COMPOSITIONS

A method of eliciting biological activity of an anionic exogenous chemical substance, for example the herbicide glyphosate, is provided. This method comprises preparing a plant treatment composition having the anionic exogenous chemical substance dissolved or dispersed in water, together with (a) an alkylether surfactant component consisting of one or more surfactants each having the formula: R -O-(CH2CH2O)n((CHR)2O)m-R wherein R is an aliphatic saturated or unsaturated hydrocarbyl group having about 16 to about 22 carbon atoms, n is an average number of about 5 to about 100, m is an average number of 0 to about 5, one R in each-((CHR)2O)-group is hydrogen and the other R is methyl, and R is a hydrogen, C1-4 alkyl or C2-4 acyl group; and (b) an amine surfactant component. The weight ratio of the alkylether surfactant component to the amine surfactant component is about 1:10 to about 10:1; and the alkylether and amine surfactant components are present in total in an adjuvant amount of about 0.05 to about 0.5 parts by weight per part by weight of the anionic exogenous chemical substance, expressed as acid equivalent. The method further comprises applying the plant treatment composition to foliage of the plant within a short period prior to rain or activation of overhead irrigation on the plant.