The present invention relates to a method of controlling undesired vegetation, and/or phytopathogenic fungi and/or undesired insect attack and/or regulating the growth of plants, which comprises the steps of A) preparing an aqueous tank mix which has a tank mix acidity of at least pH 5.0 comprising contacting a pesticide formulation, water, a base, and optionally an auxiliary; and B) allowing a pesticidal effective amount of said tank mix to act on crops, their habitat, on the undesired vegetation, on the respective pests, and/or on seed of said crops. It also relates to a use of a base for preparing an aqueous tank mix as defined in any of claims 1 to 10 which a tank mix acidity of at least pH 5.0.