Used as a selective herbicide in rice cultivation, controlling a broad spectrum of weeds including both annual and perennial grasses, sedges, and broadleaf weeds. It is particularly effective against troublesome species such as Echinochloa crus-galli (barnyard grass) when applied pre- or early post-emergence. Orthosulfamuron inhibits acetolactate synthase (ALS), an enzyme essential for amino acid synthesis in plants, leading to cessation of cell division and plant growth. Due to its soil activity and systemic action, it provides residual control, reducing the need for repeated applications. It is well suited for use in both direct-seeded and transplanted rice systems and is often included in integrated weed management programs to mitigate resistance development.