The present invention relates to the use of certain hydrophobically modified cationic polymers, prepared by polymerising an alkyl ester of acrylic acid or an alkyl ester of methacrylic acid, a nitrogen containing monomer and an associative monomer as deposition enhancers for pesticides and crop production chemicals, such as plant growth regulators, fertilizers and micronutrients, in aqueous solutions an aqueous composition comprising these polymers and one or more pesticides and/or crop production chemicals, a process for preparing said aqueous composition, and the use of said composition for treatment of plants.