Halosulfuron Methyl 75% WG (water-dispersible granule) herbicide works by inhibiting the enzyme acetolactate synthase (ALS) in plants. This enzyme is responsible for the production of essential amino acids needed for plant growth. By disrupting amino acid synthesis, halosulfuron methyl inhibits weed growth and development. It primarily targets broadleaf weeds while having minimal impact on grasses. Halosulfuron Methyl 75% WG is applied post-emergence, after the weeds have appeared, and it suppresses root and shoot growth, leading to the eventual death of susceptible plants.