Not Getting Systemic kill from Roundup

hankhill – posted 24 July 2006 03:54

I’ve been experimenting will killing variousweeds by wiping and spraying the foilageabove the grass level with Roundup, but Idon’t ever seem to be getting a systemickill down to the roots. It just kills theleaves where the spray hit them, and that’sit. Am I doing something wrong?

I’m using Roundup in the “ready to use plus”spray bottle (blue & white). Active ingredientsare glyphosate and pelargonic acid.

Grassguy – posted 24 July 2006 14:33

at what rate are you mixing,

SuperTurF – posted 24 July 2006 20:04

While attacking any broadleaf weed you probally need a stout adjuvent to stick. The cuticle that the weed has repels(or beeds off) most of the liquid form matieral. Be advised that total kill will never occur without following up with a pre-emerge at the specific time. Once the plant feels under attack or stressed it will put out seeds. Check your rate for the certain plant you are focused on then consider a good adjuvent.

jr – posted 25 July 2006 15:30

What makes you say you aren’t getting a systemic kill? Roundup would not just kill the leaves and not the roots, because thats not how it works. It kills the roots and in turn the leaves die. That’s why it can take a week or more to see results. There is no contact action, unless you have bought one of these new mixes they have with roundup and some contact killer like reward or scythe.

SuperTurF – posted 25 July 2006 20:00

Thats correct Roundup attacks the green pigmentation in the plant called…..yes thats right cloraphll (F for spelling)

hankhill – posted 25 July 2006 23:08

Folks, as I mentioned, I’ve got the “ready to use”bottle. There’s no “rate” or mixing, I justwhip it out and spray, like a Windex bottle.It’s called Roundup “ready to use plus” andis sold at Lowes in a white & blue bottle.

jr, I saw the browning/dead leavetops myself,so it did quickly kill that part of the plant. I willkeep an eye out to see whether it will kill theplant’s roots, but as of 3-4 days later, ithasn’t happened.

Perhaps I need a different Roundup formula.

[This message has been edited by hankhill (edited 25 July 2006).]

jr – posted 26 July 2006 17:46

I didn’t question whether the leaves were dead or not. You said they were, fine. What I asked was how do you know the roots aren’t dying as well.

hankhill – posted 27 July 2006 00:21

I guess we’ll have to wait and see on that! 🙂

Alex_in_FL – posted 20 August 2006 07:24

The pelargonic acid chemically burns the plant thus it is fast and has no lasting mode of action. The glyphosate is the systemic killer.

Remember, Roundup has to travel to the root (so figure 1-2 days transport time). Then it blocks the plant’s ability to convert material to food. So in effect it staves the plant. Starvation is a slower process.

If you are killing a tuber plant (like sedges) then it will take multiple uses to kill as the tuber provides nurishment. My guess is roundup used every two weeks for 12 or 14 weeks might kill nutsedge – but no promises.

Also, wiping on may not get the roundup in all the pores like spraying does – but that is speculation on my part.

One hint. Roundup is more effective when used around mid day (better than early morning or late afternoon).

Hope this helps!!!

[This message has been edited by Alex_in_FL (edited 20 August 2006).]