Mesocosm and field evaluation of Eurasian and hybrid watermilfoil response to endothall in Jefferson Slough, Montana

INTRODUCTION Aquatic plant management decisions and outcomes are influenced by a wide range of variables, such as site-specific hydrology and water quality. [...]genetic variation in the plant species targeted for control can play a role in management outcomes. Given the evident variability in growth and response to herbicide among genotypes, managers would benefit from studies that can help predict whether the specific genotypes present in their water bodies will respond differently to proposed control tactics. [...]in light of other studies demonstrating the potential for differential growth and herbicide response by EWM and HYB, Jefferson Slough managers were interested in determining whether there was any evidence for differences in endothall response by the two different biotypes; in particular, whether hybrids would be tolerant to the proposed endothall treatment.