Duckweed treatmwent for pond?

[Tollster]

Has anyone successfully treated it? I have a small pond and have a hard time figuring surface acreage.

After some research I found Diquat Dibromide to be highly successful, but there are strong safety precautions that should be adhered to, per the MSDS.

Has anyone used this stuff?

The MSDS suggest a paper suit and particulate filter. I have a half mask 3M, I use for painting, do ya'll think this will suffice, with safety glasses?

I have tried other stuff, such as copper sulfate and an aquatic herbicide used in farm ponds with restricted water use for the first two weeks. None of it could touch it and it seems to only grow worse each year.

 

[Coyote machine]

Can you post some pics of your pond?
You could contact your local ag dept of you state university to assist you in deciding how to tackle the problem.

 

[Fossil Farm]

Duckweed is a tough one. Copper sulfate has never been labeled for it, and as you found out will not touch it. Not sure what is still on the market, but Reward and a formulation of Sonar were labeled for duckweed. Be sure to follow the application times and rates closely to get a good kill. Surface acreage is length times width. An acre is 43,560 square feet. Good luck.

 

[Bigfoot62]

Try Karmex (diuron) herbicide. Click on the link for a description. It's a dry granule and I just sprinkle it around the edges.
Note: it is a total kill herbicide. It gets ALL of the vegetation, but won't hurt your fish or livestock.

 

[farmgirl19]

You can sell duckweed in the aquarium and tropical fish circles, as long as not to certain states. With more moderate climates, it becomes more invasive. Also most carp love to eat it, so could control it that way.

 

[3v0]

I hope this is old news: The duckweek is problem because the pond has high nutrient levels. Duckweed is one of natures tools to deal with the nitrates etc.

How many gallons is the pond ?

 

[traveling fisher]

Duckweed is tough but I had Watermeal which is worse. A combination of Sonar and Reward were the solution and it worked. 1/2 acre pond.
Sonar works when the plants bob below the surface and get in contact. I sprayed Reward manually. When the plants blow to the corner of the pond, I would spray them. Sometimes infrequently, other times multiple days in a row. Eventually the plants disappeared. It takes time and attention but eventually works. Good luck

 

[RobertBrown]

Duckweed is the fastest growing plant there is.
But it's bot as bad as it looks. Some cultures eat it and I've read that it makes good chicken feed, up to 20% protein. It cleans the water, doesn't take oxygen from the water and will keep the water cooler cutting down on evaporation and oxygen depletion. My pond water is much clearer since the duckweed invasion and it provides a significant protein source for the fauna that habituates the pond.
I've decided to forgo the herbicides for now.

 

[murphy1244]

try sonar*a.s.

 

[sshaw]

I've been using Sonar from SePRO (fluridone) to control Hydrilla in my 4 acre pond. Sonar is also supposed to be very effective for duckweed. The liquid form would be very easy to use. Just pour the proper amount in the pond and it will spread throughout the water. It's crazy expensive, but might not be too bad if your pond is small.

See this page from SePRO for more info:
https://www.lakelawnandpond.com/DuckweedBasics.aspx

 

[WaterDoc]

If you contact the plant expert at the Penn State Univ Ag Extension Office, that person should be able to give you an ID and a treatment for the pest. Here is the contact info: 702 Sawmill Road, Suite 102; Bloomsburg, PA 17815-7727; Phone: 800-851-9710; Fax: 570-784-5769; NorthumberlandEx@psu.edu; Office Hours: Monday-Friday 8:00 a.m. - 4:00 p.m.

Do any of these look like the weed you have in your pond?
Common Duckweed Lemna minor


Spirodela spp; Giant Duckweed


Hydrilla verticillata; Looks like Elodea


This link gets you to an article from Penn State on killing duckweed in ponds. http://extension.psu.edu/pubs/xh0014‎

If the herbicides you plan on using are regulated, you need to fill out the paperwork required by the commonwealth. It looks like the two best herbicides are regulated, Sonar (fluridone 41.7%) and Reward (diquat dibromide). DO NOT use Diuron granules for treating ponds or waterways unless the commonwealth approves it. That is an extra-label use and is illegal. Bigfoot62 is using it on soil which is ok. But if you use it to treat the pond and it runs off into Teresa Tree Huggers garden you could be in some serious trouble because the garden will look like it got hit by a West Texas drought. Diuron granules work excellent to treat weeds in soil.

If there are fish in the pond and the plants have grown aggressively, then the fish may die when you treat the pond with the herbicide. Oxygen levels are depleted as the dead plants decompose and the fish will suffocate. You may be able to prevent fish death by aeration of the pond before, during and after treatment, just like you aerate an aquarium. This also will help prevent future growth of the duckweed if you continue to aerate the pond.

Follow label directions on whichever herbicide you use. You should wear a respirator for organic vapors, eye protection (minimum of safety glasses, better to use goggles without vents) and gloves. I personally wear a full-face respirator, hat and gloves, old pants and long sleeve shirt, then throw the pants and shirt away if they get really wet with herbicide otherwise I simply wash them twice in strong laundry detergent. Then I take a good long shower. Good Luck.

 

[bcjmmac]

Have you tried putting bales of straw in the pond? The straw will soak up nutrients & help keep algae, other plants, in check so might be worth a try without poisoning everything.

 

[Tollster]

My pond is only about 1/3 acre or less, about 60' by 30-40' at most, spring fed. Its a mature pond and has been here since the early 70's.
I have tried raking it on windy days as well. Its common duckweed, and very resistant to most anything. I will give Sonar or diquat bromide a shot perhaps, and treat a little at a time until I get the upper hand.
Thanks for all ya'lls help and replies.
~ Tol