Oxadiazon is primarily used as a selective pre-emergent herbicide in agriculture to control a wide range of annual grasses and broadleaf weeds. It is commonly applied in crops such as rice, turf, and certain fruit orchards. The chemical works by inhibiting protoporphyrinogen oxidase (PPO), an enzyme involved in chlorophyll and heme biosynthesis, leading to the accumulation of phototoxic porphyrins that damage cell membranes in emerging weeds upon light exposure. This prevents weed seedlings from establishing and competing with desired crops. In rice paddies, oxadiazon is particularly effective in managing weeds during the early stages of crop growth, ensuring better yields. It is also used in non-crop areas like roadsides and industrial sites to maintain weed-free zones. Application is typically done through soil treatment, where it forms a barrier that targets germinating weeds while minimizing impact on established plants. Proper usage and adherence to guidelines are essential to ensure environmental safety and effectiveness.