Trade name(s) Peak

Manufacturer(s) Gowan, Syngenta

Formulation(s) 57% water-dispersible granules

Remarks A selective postemergence sulfonylurea herbicide used at low rates for annual broadleaf weed control in wheat, barley, oats, rye, triticale, grain sorghum, and proso millet. Carefully consider crop rotation plans before using.

Water solubility 87 ppm at pH 5; 43,000 ppm at pH 7.7

Storage conditions Stable.

Acute toxicity LD50 - 4,360 mg/kg

Action in plant Interferes with plant enzyme acetolactate synthase, resulting in rapid cessation of cell division.

Site of action Group 2: acetolactate synthase (ALS) inhibitor

Chemical family Sulfonylurea

Koc 18.56 mL/g for a silt loam with 3% OM and pH 6.5