Relationships between water chemistry and herbicide efficacy of Eurasian watermilfoil management in Wisconsin lakes

Frater P, Mikulyuk A, Barton M, Nault M, Wagner K, Hauxwell J, Kujawa E. 2017. Relationships between water chemistry and herbicide efficacy of Eurasian watermilfoil management in Wisconsin lakes. Lake Reserve Manage. 33:1-7.Eurasian watermilfoil (EWM) is an invasive aquatic plant with the potential to disrupt native aquatic plant communities, decrease property values, and affect recreational uses of lakes. Much time, effort, and money is put forth every year to combat the spread of this invader. We examined the long-term efficacy of EWM management using herbicide and derived an empirical equation to quantify long-term treatment success for the lakes in this study. We found that lakes with lower pH (<7.5), conductivity (<0.1 mS/cm), and total dissolved solids (TDS <0.1 g/L) exhibited more successful long-term management. Our results suggested that lake water chemistry may play a role in long-term herbicide management success of EWM.