The present invention relates to a composition comprising a first salt, which contains a first anionic pesticide (A1 ) and a cationic polyamine (B), and a second salt, which contains a second anionic pesticide (A2) and a cationic polyamine (B), wherein both salts contain the same cationic polyamine (B), and wherein the cationic polyamine comprises at least two amino groups. It further relates to a method for preparing said comprising the step of contacting the first salt and the second salt. In addition, the invention relates to a method of combating harmful insects and/or phytopathogenic fungi, which comprises contacting plants, seed, soil or habitat of plants in or on which the harmful insects and/or phytopathogenic fungi are growing or may grow, plants, seed or soil to be protected from attack or infestation by said harmful insects and/or phytopathogenic fungi with an effective amount of said composition. It also relates to a method of controlling undesired vegetation, which comprises allowing a herbicidal effective amount of said composition to act on plants, their habitat or on seed of said plants. Finally, the invention relates to seed comprising said composition.La présente invention concerne une composition comprenant un premier sel, qui contient un premier pesticide anionique (A1) et une polyamine cationique (B), et un second sel, qui contient un second pesticide anionique (A2) et une polyamine cationique (B), les deux sels contenant la même polyamine cationique (B) et cette dernière comprenant au moins deux groupements amine. L'invention concerne en outre un procédé de préparation consistant à mettre en contact le premier sel et le second sel. En outre, l'invention concerne un procédé pour combattre les insectes nuisibles et/ou les champignons phytopathogènes, qui consiste à mettre en contact des plantes, des graines, le sol ou l'habitat de plantes dans ou sur lesquelles les insectes nuisibles et/ou les champignons phytopathogènes grandissent ou peuvent gr
