The Toxicity of EPTC to Nutsedge

Nutsedge tubers germinated readily in soil treated with EPTC. However, growth was suppressed and emergence delayed, the delay depending on the rate of application. EPTC at 12 and 16 pounds per acre with 8 and 12 weeks exposure was very effective in killing nutsedge tubers as indicated by tuber germination and condition of tubers that did not germinate. The granular formulation of EPTC killed highly significantly more nutsedge tubers than the emulsifiable formulation. Repeat applications of EPTC were significantly better in terms of tubers killed than single applications of the same rate of the herbicide. Thorough incorporation of EPTC to a depth of 5 inches of mechanical means was significantly more effective than incorporation by leaching.