Abstract: There is provided a concentrate composition, suitable for foliar application to a plant to elicit a biological activity therein, comprising (a) about 20% to about 90% by weight of a plant treatment compound that is an acid having a solubility in deionized water at 25° C. of less than about 50 g/l and is present predominantly in the acid form, and (b) a surfactant of formula R—O—(CH2CH2O)n—H wherein R is a straight or branched chain aliphatic hydrocarbyl group having about 24 to about 60 carbon atoms and n is an integer having an average value of about 5 to about 100. The weight ratio of the surfactant to the plant treatment compound is about 1:2 to about 1:30. In a particular embodiment, the composition is a liquid suspension concentrate having a continuous aqueous phase and a discontinuous particulate phase comprised predominantly of the plant treatment compound. The plant treatment compound can be a herbicide, for example glyphosate.