Common name nicosulfuron
IUPAC name 2-(4, 6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-N, N-dimethylnicotinamide

APPLICATIONS

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. Maize selectivity derives from selective metabolism (P450-mediated pyrimidine-5-hydroxylation, followed by conjugation with glucose). Mode of action Selective systemic herbicide, absorbed by the foliage and roots, with rapid translocation in xylem and phloem to the meristematic tissues.

Uses Selective post-emergence control in maize of annual grass weeds, including Setaria, Echinochloa, Digitaria, Panicum, Lolium, and Avena spp., broad-leaved weeds, including Amaranthus spp. And Cruciferae, and perennials such as Sorghum halepense and Agropyron repens. Applied at 35-70 g/ha.

ECOTOXICOLOGY

Birds Dietary oral LD50 for bobwhite quail >2250 mg/kg. Dietary LC50 for mallard ducks and bobwhite quail >5620 ppm. Fish LC50 (96 h) for bluegill sunfish and rainbow trout >1000 mg/l. Daphnia LC50 (48 h) >1000 mg/l. Algae NOEC (96 h) for green algae 100 mg/l.

Other aquatic spp. LC50 (14 d) for Lemna gibba 0.0032 mg/l. Bees LD50 (contact) >76 μg/bee; Dietary LC50 (48 h) >1000 ppm. NOEC 500 ppm. Worms LC50 (14 d) for earthworms >1000 mg/kg