Synonyms: sodium 2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoate (IUPAC); 'Grass-short' (Kumiai); 'Ectran' (IPESA); 'Nominee' (Bayer CropScience, Kumiai); 'Paladin' (Baocheng); 'Short-keep' (Riken Green); 'Sunbishi' (Sundat). 'Regiment' (Kumiai, Valent); 'Velocity' (Valent)
CAS No.: 125401-75-4
Molecular Weight: 452.35507
Molecular Formula: C19H17N4NaO8
Form White: odourless powder.
M.p. 223–224 °C
V.p. 5.05 × 10-6 mPa (25 °C)
Kow logP = –1.03 (23 °C)
Henry 3 × 10-11 Pa m3 mol-1 (calc.)
Solubility In water 68.7 g/l (20 °C, distilled water). In methanol 25 g/l (20 °C); in ethyl acetate 6.1 × 10-2, n-hexane 8.34 × 10-3, acetone 1.4, toluene <1.0 × 10-6, dichloromethane 1.3 (all in mg/l, 25 °C).
Stability Decomposes at 223 °C.
Hydrolysis DT50 >1 y (pH 7 and 9, 25 °C), 88 d (pH 4, 25 °C).
Aqueous photolysis DT50 42 d in natural water, 499 d in distilled water (both 25 °C, 1.53 W/m2, 260–365 nm). pKa 3.35 (20 °C)
A selective, systemic post-emergence herbicide, absorbed by foliage and roots. By inhabiting branched chain amino acid synthesis, bispyribac sodium is used to control grasses, sedges and broad-leaved weeds, especially Echinochloa spp., in direct-seeded rice, at rates of 15–45 g/ha. Also used to stunt growth of weeds in non-crop situations.
100g/l SC, 200g/l SC, 400g/l SC
20% WP, 25% WP
20% WDG, 40% WDG, 80% WDG
pouch, bottle, drum
Risks and Safety Information
Bispyribac sodium is a Class 9, Environmentally hazardous herbicide
LD50 Oral Acute for male rats 4111 mg/kg, female rats 2635 mg/kg, Birds LD50 Oral Acute for bobwhite quail >2250 mg/kg. LC50 (96 h) Acute for rainbow trout and bluegill sunfish >100 ppm. Animals >95% of dose applied to rats was excreted in urine and faeces within 7 d. Plants Following application to foliage and soil at 5-leaf stage of rice plants, c. 10% of carbon label was distributed between straw and roots at harvest. Soil/Environment In soil, DT50 <10d