Abstract: Methods and compositions are disclosed wherein exogenous chemicals are applied to plants to generate a desired biological response. One embodiment of the present invention is a plant treatment composition that comprises an exogenous chemical and a first excipient substance. The first excipient substance is an amphiphilic quaternary ammonium compound or mixture of such compounds, having the formulaR.sup.8 --W.sub.a --X--Y.sub.b --(CH.sub.2).sub.n --N.sup.+ (R.sup.9)(R.sup.10)(R.sup.11) T.sup.-wherein R.sup.8 represents the hydrophobic moiety and is a hydrocarbyl or haloalkyl group having from about 6 to about 22 carbon atoms, W and Y are independently O or NH, a and b are independently 0 or 1 but at least one of a and b is 1, X is CO, SO or SO.sub.2, n is 2 to 4, R.sup.9, R.sup.10 and R.sup.11 are independently C.sub.1-4 alkyl, and T is a suitable anion.

Abstract: A composition is disclosed for application to a plant that comprises an exogenous chemical (for example, a postemergent herbicide), an aqueous diluent, and a first excipient substance that is amphiphilic. The weight/weight ratio of the first excipient substance to the exogenous chemical is between about 1:3 and about 1:100. The aqueous composition forms anisotropic aggregates on a wax layer, and the presence of the anisotropic aggregates can be detected by a test described herein. Compositions of the present invention, when applied to plants, provide enhanced biological activity per unit amount of exogenous chemical, as compared to otherwise similar compositions containing surfactants that do not form anisotropic aggregates. Without being bound by theory, it is presently believed that this enhanced biological activity results from the formation or enlargement of hydrophilic channels through the epicuticular wax of the plant.

Abstract: Methods and compositions are disclosed wherein exogenous chemicals are applied to plants to generate a desired biological response. One embodiment of the present invention is a plant treatment composition that comprises (a) an exogenous chemical; (b) a first excipient substance which is a compound or mixture of compounds having the formulaR.sup.14 --CO--A--R.sup.15wherein R.sup.14 is a hydrocarbyl group having about 5 to about 21 carbon atoms, R.sup.15 is a hydrocarbyl group having 1 to about 14 carbon atoms, the total number of carbon atoms in R.sup.14 and R.sup.15 is about 11 to about 27, and A is O or NH; and (c) a second excipient substance which is an amphiphilic substance having a critical packing parameter greater than 1/3.