On May 24, 2018 11.81 acres of Potamogeton crispus-curly leaf pondweed (CLP) were treated with the herbicide endothall at a target concentration of 1.5-2.5 ppm. The water temperature at the time of treatment was between 59 degrees F. A pretreatment survey was conducted on May 8 and a post treatment survey was conducted on June 4, 2018. A chi-square analysis was used to determine the significance of any reductions in frequency of occurrence. The frequency of occurrence from the pretreatment to the post treatment survey showed a statistically significant reduction (from 43.4% to 0%). A comparison of the post treatment survey of 2017 and the post treatment survey of 2018 showed a decrease from 1.2% to 0% which was not significant. Comparing the pretreatment survey of 2017 to the pretreatment survey of 2018 an increase occurred from 61.6% to 43.4%, which was statistically significant. A chi-square analysis revealed a statistically significant reduction in one native plant species. A turion analysis resulted in a mean turion density increase from 2017 to 2018. The mean turion density increased from 7.5 turions/m2 to 10.3 turions/m2.

Chemical permit details

Grant ACEI21118 awarded