The present invention relates to a microemulsion comprising (A) 0.1 to 50% by weight of at least one active ingredient as component A, (B) 0.5 to 40% by weight of at least one solvent which is fully miscible with water, being chosen from the group consisting of esters of acetic acid, of lactic acid, of benzoic acid, of dicarboxylic acids, cyclic esters, cyclic amides, carbonates, sulphur containing solvents, phosphates, ethers and mixtures thereof, as component B, (C) 10 to 40% by weight of at least one nonionic surfactant as component C, (D) 0 to 10% by weight of further additives as component D, (E) 10 to 90% by weight of water as component E and (F) 0.1 to 60% by weight of at least one solvent which is partially miscible with water, as component F, in each case based on the total microemulsion, where the total of the amounts of components A, B, C, D, E and F is 100% by weight and where the microemulsion does not comprise any anionic surfactants, and to a process for the preparation of this microemulsion and to the use of this microemulsion for the treatment of plants.