... . pKa:4.3, weak base. APPLICATIONSBiochemistry: Photosynthetic electron transport inhibitor at the photosystem II receptorsite.Mode of action: Selective herbicide, absorbed ... the apical meristems.Uses: Used pre-emergence in winter cereals, at 1-2 kg a.i./ha, to control blackgrass and annual ... .w.Fish: LC50 (96 h) for rainbow trout 1.1, bluegill sunfish 1.3, carp 1.4.Daphnia: LC50 (48 h) 2.66 mg ...