Vegetation Control in Fish Ponds with Terbutryn (Igran 80W)

Najas, Chara, and several filamentous algae species were controlled or eliminated by a single 0.1 mg!l (active ingredient) application of the herbicide Igran 80W, an 80% wettable powder formulation of terbutryn (2-tert-butylamino-4-ethyl-amino-6-methyl-thio-s-triazine), a commercial product registered for control of terrestrial vegetation but not now approved by the United States Environmental Protection Agency for use in ponds or other waters. The chemical, applied in summer, eliminated target plants within 2 weeks of application. The chemical is relatively nontoxic to fish at concentrations recommended for vegetation control.