Aquatic Plant Control Research Program. Evaluation of Endothall/Adjuvant Mixtures in Flowing Water

摘要

Four endothall/adjuvant formulations (inverts Asgrow 403 and I'vod and polymers Nalquatic and Poly Control) were evaluated for endothall release profiles and control of Eurasian watermilfoil (Myriophyllum spicatum L.) at flow velocities of 1.5 and 3 cm/sec. Endothall release profiles from the adjuvant formulations were compared with release profiles from conventional, liquid endothall formulations. All of the endothall/adjuvant formulations released endothall for longer periods than did the conventional endothall formulation at the 1.5-cm/sec flow velocity. The polymer formulations released endothall for longer periods (72 to 84 min posttreatment) than the invert formulations (36 to 48 min posttreatment). At the 3-cm/sec flow velocity, endothall residues were below detection (0.01 mg/l) by 12 min posttreatment when using all of the endothall formulations. In comparison, endothall release profiles were 12 to 132 min shorter than 2,4-dichlorophenoxyacetic acid profiles obtained from a previous study using identical adjuvants an flow velocities. The extended release profiles of the polymers Nalquatic and Poly Control make these adjuvants the most promising of those tested for use with endothall in stands of Eurasian watermilfoil where foil velocities are <3 cm/sec.