The present invention relates to a method of applying an aqueous, pesticide-comprising dispersion of a polyurethane which is a reaction product of at least one polyol (A) and at least one polyisocyanate (B) to plants or plant parts. The invention furthermore relates to an aqueous pesticide-comprising dispersion of a polyurethane which is a reaction product of at least one polyol (A) and at least one polyisocyanate (B). Furthermore, it relates to the use of the dispersion for controlling phytopathogenic fungi and/or undesired plant growth and/or undesired insect or mite attack and/or for regulating the growth of plants, by allowing the dispersion to act on the respective pests, their environment and/or the plants or plant parts to be protected from the respective pests, the soil and/or on undesired plants and/or the use plants and/or their environment.