Halosulfuron-methyl

Halosulfuron-methyl is a sulfonylurea post-emergence herbicide used to control some annual and perennial broad-leaved weeds and sedges (such as nutsedge/nutgrass) in a range of crops (particularly rice), established landscape woody ornamentals and turfgrass. It is marketed under several tradenames including Sedgehammer and Sandea.

It is systemic and selective, and acts as an inhibitor of acetohydroxyacid synthase (AHAS, also known as acetolactate synthase) restricting the biosynthesis of the essential amino acids, valine and isoleucine, thus restricting plant growth. Symptoms take several weeks to develop and include general stunting, chlorosis, and necrosis of the growing points. It typically does not affect other major annual and perennial weed grasses and broadleaves such as spurge, dandelions, lambsquarters, and oxalis.