NICOSULFURON

Common name:Nicosulfuron

Chemical name:

2-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-N,N-dimethylnicotinamide

2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-N,N-dimethyl-3-pyridine carboxamide

Trade name: Accent(Brand name of DuPont Crop Protection)

Molecular formulae:C₁₅H₁₈N₆O₆S

Chemical structure:

Physical and Chemical properties:

Molecular weight:410.4g/mol; Physical form: Colourless crystals. Density:0.313 (bulk); Melting point:169-172℃; Flash point:>200℃ (Cleveland open cup); Vapour pressure:<8 × 10-7 mPa (25 ℃); Henry constant:<4.68 × 10-9 Pa m3 mol-1 (25 ℃); Partition coefficient(n-octanol and water): logP = -0.36 ( pH 5), -1.8 ( pH 7), -2 ( pH 9); pKa:4.6 (25℃); Solubility: In water 0.07 g/l. In acetone 18, ethanol 4.5, chloroform, dimethylformamide 64, acetonitrile 23, toluene 0.370, hexane <0.02, dichloromethane 160 (all in g/ kg, 25 ℃).; Stability: Hydrolysis DT50 15 d ( pH 5); BBR> 7 & 9.

Purity: 95%, 98%

Mode of actions:

Nicosulfuron is absorbed by the leaves of treated plants and translocated to the meristematic tissue causing growth inhibition, discoloration, necrosis and, eventually, plant death. The product is most effective against grasses when applied between emergence and tillering. Broadleaf weeds are most effectively controlled when treated at the 2-3-leaf stage. Split applications can improve the efficacy of the product. Nicosulfuron is rainfast within six hours. DuPont recommends the use of adjuvants such as non-ionic surfactants or crop oil concentrates to enhance the activity of its granular product. Nicosulfuron has no residual activity, being quickly metabolised by plants.

Nicosulfuron shows high selectivity to maize, but treatment of maize crops with some soil insecticides sensitises the crop to nicosulfuron, resulting in crop damage. DuPont and ISK report that nicosulfuron is safe to soybeans planted in rotation with maize.

Crop use:

Selective post-emergence control in maize of annual grass weeds, broad-leaved weeds and perennials grass weeds.

Toxicology:

Oral: Acute oral LD50 for male and female rats and mice >5000 mg/ kg.

Percutaneous: Acute percutaneous LD50 for male and female rats >2000 mg/kg. Moderate eye irritant; not a skin irritant (rabbits); not a skin sensitiser (guinea pigs). The 75% formulation is not an eye irritant. Inhalation: LC50 for rats (4 h) 5.47 mg/l.

Environmental profile:

Bobwhite quail LD50 >2,000 mg/litre Rainbow trout [96 hrs] LC50 >1,000 mg/litre Bluegill sunfish [96 hrs] LC50 >1,000 mg/litre Bee [contact] LD50 >20 mg/bee Fate in soil:

The half-life of nicosulfuron in soil is 7-20 days. Fate in aquatic systems:

Nicosulfuron is degraded by hydrolysis and by microbial action. It has a half-life of between 20 and 60 days.

Transportation information:

Signal Word: CAUTION; Hazard Class: III(Slightly hazardous)

Other products:

Straight formulated products: Nicosulfruon 75% WDG; Nicosulfuron 80% WP; Nicosulfuron 8%, 40g/L, 60g/L OD.

Mixtures:

Metsulfuron-methyl+nicosulfuron Nicosulfuron+atrazine+rimsulfuron Nicosulfuron+dicamba+diflufenzopyr Nicosulfuron+rimsulfuron Nicosulfuron+thifensulfuron-methyl Nicosulfuron+atrazine Dicamba+Nicosulfuron Nicosulfuron+Atrazine+Mesotrione Fluroxypyr+Nicosulfuron+Atrazine