Pesticidal compositions of improved effectiveness are provided, including apesticide (e.g., an insecticide orherbi-cide) together with a copolymer adjuvant or additive selected from thegroup consisting of acid or salt copolymers containingindi-vidual quantities of maleic and itaconic moieties. The compositions ofthe invention provide multiple-fold increases ineffective-ness, as compared with an equal amount of the pesticide in theabsence of the copolymer.
