The present invention comprises formulations comprising at least one pesticide and at least one co-polymer comprising (a) a N-vinylamid comonomer a) of formula (I) wherein R1 and R2 are independently of one another hydrogen or C1-C4 alkyl, preferably hydrogen or R1 and R2 represent together a —(CH2)x moiety, which forms together with the nitrogen and the carbonyl-moiety a 5-8 membered ring, and (b) at least one comonomer b) selected from the group consisting of vinylpyrridin, vinylpyrridin derivatives and N-vinlyimidazole in polymerized form, methods of combating harmful insects and/or phytopathogenic fungi, a method of controlling undesired vegetation and methods of improving the health of plants based on the afore-mentioned formulations.
