A method of protecting plants against damages caused by phytoparasitic pests, such as nematodes by treating a plant, plant part, or a locus thereof with an agrochemical composition comprising an effective amount of dodine or a salt and/or a solvate thereof. An agrochemical composition for controlling phytoparasites comprising an effective amount of dodine or a salt and/or solvate thereof is also described. The agrochemical composition can be used to prevent phytoparasites, including nematodes and nematode progeny, from developing or growing and can be used to kill phytoparasites on plants, plant parts or a locus thereof.