Tolclofos-methyl is primarily used as a fungicide in agriculture and aquaculture. It effectively controls a wide range 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, tolclofos-methyl is used to treat fungal infections in fish, particularly on fish eggs, where it prevents the spread of water molds like Saprolegnia. This helps improve hatch rates and supports healthier fish populations in breeding facilities. The compound is valued for its systemic action, meaning it is absorbed and distributed within plant tissues or adheres effectively to aquatic surfaces, providing longer-lasting protection. It is often formulated as a solution for easy application through soil drenching, spraying, or direct addition to water in fish hatcheries.