Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/6235
Title: Evaluation of chemicals for aquatic plant control
Authors: Steward, Kerry K.
Keywords: Aquatic plant control
Herbicides
Aquatic weeds
Hydrilla
Chemicals
Chemical control
Chemcontrol
Waterhyacinth
Evaluation
Weed control
Aquatic Plant Control Research Program (U.S.)
Publisher: U.S. Army Engineer Waterways Experiment Station
Series/Report no.: Miscellaneous Paper (Aquatic Plant Control Research Program (U.S.)) ; no.Miscellaneous Paper A-79-3
Abstract: The purpose of this project was to expand evaluation research on the use of chemicals for aquatic weed management in an attempt to discover new herbicides or growth regulators. Several experimental formulations of fenac were screened for efficacy against waterhyacinth, hydrilla, and southern naiad. All ten were effective against waterhyacinth, four were effective against hydrilla, and three were effective against southern naiad. The growth retardant EL-509 effectively inhibited hydrilla regrowth from clipped stems for 24 weeks in outside aquaria. Combinations of fenac and organic copper complex more effectively controlled hydrilla in outside aquaria than either herbicide when used alone. Hexazinone had controlled hydrilla in outside aquaria for nearly a year when the experiment was dismantled. No regrowth occurred from rootstocks nor from propagules since production of propagules had been prevented by treatments. Phytotoxic residues were detected by bioassays 8 months after treatments. Field evaluation of hexazinone under DuPont's experimental use permit produced control of hydrilla for over 12 months at 3.4-kg/ha treatment rate but for only 4 months at the 6.7-kg/ha rate. A 2.0-mg/l treatment of fenac to a 4.1-ha area within a 9.7-ha lake in Broward County, Florida, has controlled hydrilla throughout the lake for 10 months and has eliminated cattails in shallow areas and along the lake margin. Both hexazinone and terbutryn controlled green alga Chara spp. in outside aquaria at concentrations of 0.2 mg/l. An experimental herbicide from Kalo Laboratories was effective in controlling waterhyacinth in greenhouse tests but ineffective against submersed weeds hydrilla, southern naiad, and Chara spp. in the laboratory. Metribuzin and RH-2915 were not effective against torpedograss in field trials.
Description: Miscellaneous Paper
Gov't Doc #: Miscellaneous Paper A-79-3
Rights: Approved for public release; distribution is unlimited
URI: http://hdl.handle.net/11681/6235
Appears in Collections:Miscellaneous Paper

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