Tolclofos-methyl is primarily used as a fungicide in agriculture and aquaculture. It effectively controls a broad spectrum of fungal pathogens, especially those causing root and soil-borne diseases in crops. It is commonly applied in the cultivation of vegetables, fruits, and ornamental plants to prevent damping-off and root rot caused by fungi such as Pythium and Phytophthora species. In aquaculture, it is used to manage fungal infections in fish eggs and larvae, helping to improve survival rates in hatcheries. Its systemic action allows it to be absorbed by plant tissues, providing both preventive and curative effects. Due to its effectiveness at low application rates and relatively low toxicity to non-target organisms, it is considered a valuable tool in integrated pest management programs.