Effect of chlorsulfuron on growth of submerged aquatic macrophyte Potamogeton pectinatus (sago pondweed)

Research has been conducted on the effect of chlorsulfuron on non-target plants but little information is available on its effects on aquatic macrophytes. Potamogeton pectinatus (sago pondweed) is an ecologically important submerged aquatic macrophyte found in freshwater bodies. Many species of wildlife use this plant as a food source. The objective of this study was to measure the phytotoxic effects of chlorsulfuron on sago pondweed. P. pectinatus plants were exposed to chlorsulfuron at 0, 0.25, 0.50, 1.0, or 2.0 ppb, in an environmental growth chamber. Plants exposed to 0.25 ppb chlorsulfuron showed a reduction in length (76%), number of leaves (50%), and number of stems (50%), compared to control plants. A reduction (47%) was also observed in the length of stems produced by plants treated with > or = 0.50 ppb chlorsulfuron. Significant reductions in wet and dry weights, and increased mortality were observed on treatments with > or = 1.0 ppb chlorsulfuron.