Weedtrine D

Weedtrine D Thumb
Product Label SDS Sheet

Weedtrine-D is a broad-spectrum liquid aquatic herbicide for use in and around still lakes, ponds, lagoons, ditches, non-crop, or non-planted areas controlling a broad range of filamentous algae and submerged and floating aquatic weeds. Containing 8.53% active diquat dibromide, Weedtrine-D acts as a potent contact killer in plants by disrupting cellular membranes allowing Weedtrine-D to enter plants "short circuit" the plants ability to convert light into energy known as "Photosynthesis".

Effective on many different weeds.

Weedtrine-D is effective anytime live foliage is accessible. Best results occur when applied to reasonably developed foliage, but before growth becomes too dense or weeds flower.

Weedtrine-D is recommended for small ponds less than 1/2 acre with submerged weed and duckweed problems. Weedtrine-D herbicide is quickly absorbed by plants.




1 gallon.
(Treats 4,500 sq. ft.)
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Duckweed Fair
Bladderwort Good
Pondweeds Fair
Cattails Good
Coontail Fair
Eurasian Water Milfoil Fair
Filamentous Algae Fair
Grass Family Good
Milfoil Fair
Water Willow Fair


Water Use Restrictions

Active Ingredients: Diquat dibromide
Weight % Active Ingredient: 8.53
EPA Reg.No. 8959-9
Number of Days
Human Drinking 1 -3
Human Swimming 0
Human Fish Consumption 0
Animal Drinking 1
Turf Irrigation 1 3
Forage Irrigation 5
Food Crop Irrigation 5

To apply, determine the volume of water to be treated in acre-feet. Dilute according to the label directions (dilution rate varies). Spray uniformly over the water surface with a tank or backpack sprayer. Allow material to rain down in coarse droplets for better surface penetration.

One gallon of Weedtrine-D Liquid covers 4,000 sq. ft. of submersed weeds or 8,000 to 10,000 sq. ft. of floating, immersed, or terrestrial weeds. For floating, immersed, or terrestrial weeds, use 2.0 to 6.5 oz. per gallon of water, add Cygnet Plus Liquid and apply with a tank sprayer.

**1 acre = 43,560 sq. ft.

*Consult Label for Exact Doses & Important Application Directions.

We recommend using Weedtrine®-D with the surfactant Cygnet Plus to maximize its effectiveness when applied above water to emergent species. Cygnet Plus reduces the surface tension, allowing the Weedtrine®-D to wet the entire leaf instead of rolling off. Absorption and herbicidal action are usually quite rapid, with visible effects in a few days.

Weedtrine-D Examples:

  • Sample 50ft x 50ft Pond (.057 Acre) * Amount required: .25 to .50 Gallon
  • Sample 75ft x 75ft Pond (.129 Acre) * Amount required: .62 to 1.25 Gallon
  • Sample 105ft x 105ft Pond (1/4 Acre) * Amount required: 1.25 to 2.50 Gallon
  • Sample 148ft x 148ft Pond (1/2 Acre) * Amount required: 2.50 to 5.00 Gallon

For Best Results

Begin application in spring as water temperature warms to 60┬║ F and above. Heavy, out of control growth may require more than one application or physical removal to gain control. For best results, use under conditions of minimal water flow. Apply early on the morning of a calm, sunny day when the plants are actively involved in photosynthesis. The biggest mistake people make is to come home from work and treat vegetation. Contact time should be at least 3 hours.

For algae control best results are achieved when mixing Weedtrine-D with Cutrine Plus or Captain. Dose requirements are less for Duckweed control or shallow waters of less than 2 Feet. For Duckweed control the label recommends adding a non-ionic surfactant. One quart of Cygnet Plus Surfactant is typically enough for most projects. Add Bio Boost Enzyme to the Tank Mix to increase the effectiveness of the algae treatment. Treat heavy infestations in sections to avoid oxygen depletion.


*All pesticides can be harmful to health and the environment if misused. Read the label and follow directions. Consult with your local regulatory agency before applying herbicides and algaecides to public waters. There are herbicides from other states that are either not licensed in Wisconsin or Illinois, or are not recommended by ABI.

A WI DNR Aquatic Plant Control Permit or DATCP Fish Farm License is required in WI in order to apply algaecides or herbicides. In addition ponds and lakes with overflows not contained on the property are required to obtain a WPDES permit. Illinois Residents are required to obtian NPDES permits through the Illinois EPA.

In order to apply chemicals in liquid form within Wisconsin, the applicator must be licensed with the State.

Recommendations of pesticide or treatments for specific algae or aquatic plants are provided for general information purposes only - no warranties are expressed or implied.

* We do not ship EPA registered Algaecides or Herbicides to the following states:

Alaska - California - Connecticut - Delaware -  Hawaii - New Hampshire - New Jersey - New York - Maine - Maryland - Massachusetts  -Oregon - Rhode Island - Washington State - Vermont (for additional information about these restrictions please see shipping or terms and conditions).

Michigan Shipments

Aquathol K, Reward & Weedtrine D can not be shipped without a permit on file.