Active ingredient

Rimsulfuron

Chemical name

N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-3-(ethylsulfonyl)-2-pyridinesulfonamide

Classification

Herbicide / Agrochemical

Formulation

25%WDG, 95%TC

Biochemistry

Branched chain amino acid synthesis (ALS or AHAS) inhibitor. Acts by inhibiting biosynthesis of the essential amino acids valine and isoleucine, hence stopping cell division and plant growth. Crop selectivity derives from rapid, selective metabolism by contraction of the sulfonylurea group and ring migration (L. Martinetti et al., Proc. Br. Crop Prot. Conf. - Weeds, 1995, 1, 405) and by hydroxylation on the pyrimidine ring, followed by glucose conjugation (M. K. Koeppe, IUPAC 5E-003 (1998)); see Environmental Fate.

 Mode of action

Selective systemic herbicide, absorbed by the foliage and roots, with rapid translocation to the meristematic tissues.

Usage

Rimsulfuron is a post-emergence sulfonylurea herbicide that effectively controls most annual and perennial grasses and several broad-leaved weeds in maize. Also used in tomatoes and potatoes. The target rate for most situations is 15 g/ha. Rimsulfuron has a wide crop-safety margin under most conditions.

Mammalian Toxicology

Oral: Acute oral LD50 for rats >5000 mg/kg. 

Skin and eye: Acute percutaneous LD50 for rabbits >2000 mg/kg. Non-irritating to skin; moderately irritating to eyes (rabbits). Non-sensitising to skin (guinea pigs). 

Inhalation: LC50 (4 h) for rats >5.4 mg/l air.