Amicarbazone 95%TC

Mode of action: Amicarbazone is a new triazolinone herbicide with a broad spectrum of weed control. The phenotypic responses of sensitive plants exposed to amicarbazone include chlorosis, stunted growth, tissue necrosis, and death. Its efficacy as both a foliar- and root-applied herbicide suggests that absorption and translocation of this compound is very rapid. This new herbicide is a potent inhibitor of photosynthetic electron transport, inducing chlorophyll fluorescence and interrupting oxygen evolution ostensibly via binding to the Qb domain of photosystem II (PSII) in a manner similar to the triazines and the triazinones classes of herbicides. As a result, its efficacy is susceptible to the most common form of resistance to PSII inhibitors. Nonetheless, amicarbazone has a good selectivity profile and is a more potent herbicide than atrazine, which enables its use at lower rates than those of traditional photosynthetic inhibitors.

Properties: Colorless crystals, mp 137.5°. d 1.12. Vapor pressure (Pa): 1.3 ´ 10-6 (20°); 3.0 ´ 10-6 (25°). Log P (octanol/water): 1.18 (pH 4); 1.23 (pH 7); 1.23 (pH 9). Soly in water (20°): 4.6 g/l (pH 4 - 9). LD50 in rats (mg/kg): 1015 orally; >2000 dermally. LC50 in rats (4 hr): 2.242 mg/l air. LC50 in bluegill sunfish, rainbow trout (96 hr): >129, >120 mg/l (Philbrook).

Melting point: mp 137.5°

Log P: Log P (octanol/water): 1.18 (pH 4); 1.23 (pH 7); 1.23 (pH 9)

Density: d 1.12

Toxicity data: LD50 in rats (mg/kg): 1015 orally; >2000 dermally; LC50 in rats (4 hr): 2.242 mg/l air; LC50 in bluegill sunfish, rainbow trout (96 hr): >129, >120 mg/l (Philbrook)

Use: Herbicide.