Chlortoluron is primarily used as a selective herbicide in agriculture to control a wide range of annual grasses and broadleaf weeds in crops such as winter wheat, barley, and rye. It works by inhibiting photosynthesis in target plants, effectively stopping their growth and leading to their eventual death. Farmers apply it pre-emergence or early post-emergence to ensure crops remain weed-free during critical growth stages. Its effectiveness in cooler temperatures makes it particularly useful in temperate climates. Additionally, it is valued for its residual activity, which provides prolonged weed control, reducing the need for frequent applications. Proper application and dosage are essential to minimize environmental impact and avoid damage to non-target plants.