George1 and I have been discussing some weed issues, and that got me thinking.

Is it an option to mix herbicides? Let's say I want to mix Reward and Rodeo to get a quick plant kill with Rodeo, plus the systemic control of Reward. Would the results be worth it, or should I just stick with one or the other?

I'm assuming they would be mixed at 1/2 rates to get the total effect, but not sure there would be any value to this.

Just curious more than anything else.

Not a good idea without professional advice as some contact herbicides reduce/hinder the ability of the plant to absorb systemic herbicides.

Reward is a liquid diquat formulation that has been effective on ... and is very effective if mixed with a copper compound. It is a contact herbicide. Contact herbicides act quickly and kill all plants cells that they contact.

Rodeo, Aquamaster, Eraser AQ, Touchdown Pro, and AquaNeat are liquid glyphosate formulations and have been effective on .... These are broad spectrum, systemic herbicide. Systemic herbicides are absorbed and move within the plant to the site of action. Systemic herbicides tend to act more slowly than contact herbicides. An aquatically registered surfactant (see the label) will have to be added to the glyphosate solution for good results.

That was my original thought, which prompted the question. If the exposed cells died quickly, then I wasn't sure they wouldn't be able to absorb the systemic herbicide.

Your answer makes sense.

Just thinking today as I was spraying weeds. Is there any reason to use a diquat like Reward or Weedtrine-D at all? The plants covered are about the same as Rodeo, but diquat just seems quicker acting.

Does it boil down to a kill by touch or kill by absorption issue? If so, only using Rodeo would let me cut my chemical cache in half and simplify spraying.

Use the one that kills the weed in question. Not all work on the same plants.

Ditto. Personal choice here, but I'd prefer to use a systemic for longer weed control vs. a contact for quick results.

It depends on the results that you are looking for.

Quick kill risks low DO from a quick burn down of the weeds. Systemic can take 30-90 days to act. Some products are available in granular forms that are easier to apply.

All your answers are exactly what got me thinking about all this to begin with. I've tried to be very diligent and frugal with spraying my lake, and don't mind annual spraying of the same emergent weeds. But, I was trying to figure out a more permanent method of invasive control.

When Bob first came to my lake he warned me about patches of pennywart that had been trapped by my primrose. He said if I kill all the primrose, I would have a mess with the more aggressive pennywart. 2 points for Bob on that observation. He wasn't kidding, and I paid for that.

It's just that my back building is starting to look like a feed store, and I was wanting to simplify my spraying routine.

I know that Reward can be more effective if mixed with coppers, so I was curious how far mixes can go.

Thanks for all your input.