Nicosulfuron (Nicosulfuron)

Nicosulfuron is a selective herbicide of the sulfonylurea class, widely used in agriculture for the control of annual and perennial grasses, as well as some dicotyledons. It is applied post-emergence and acts systemically, being absorbed by the leaves and roots, with translocation via the xylem and phloem.

Common name (ISO): Nicosulfuron

Synonyms: DPX-V9360 (DuPont development code); HU-195, SL-950, ASC 67041 (development codes);  Accent, Nisshin (commercial product brands).

Gross formula: C15H18N6O6S

Number CAS: 111991-09-4

Chemical class: Sulfonylurea (HRAC Group 2; acts as an inhibitor of the enzyme acetolactate synthase - ALS).

Development history: Nicosulfuron was discovered by ISK Biosciences (now ISK) in the late 1980s as part of an effort to develop selective herbicides for grasses in cereal crops. DuPont de Nemours & Co. took over commercial manufacturing and initial testing, with production in Belle, West Virginia (USA). Field trials began in 1990 in the USA and Canada.

Mode of action: It is a selective systemic herbicide that inhibits the enzyme acetolactate synthase (ALS, also known as AHAS), essential for the biosynthesis of branched-chain amino acids (valine, leucine, and isoleucine) in plants. This disrupts the growth of meristematic cells, leading to chlorosis, necrosis, and plant death within 2–3 weeks. It is rapidly absorbed by the leaves (with some root absorption) and translocated via the phloem and xylem to growing tissues. It is selective for sensitive grasses (e.g., crabgrass, annonigrass), but tolerated by corn due to rapid metabolism by the enzyme glutathione S-transferase.

Patent numbers: US 5411932, CA 2708428 and others.