Help with roundup mixing.

[ponytug]

Thank you Peter, I do have hard water but there is a tap outside I can get soft water.

You are welcome. If you have hard water, I would bet that the lack of efficacy was probably that. You can add AMS to soft water as well as it does improve the efficacy.

All the best,

Peter

 

[Cougsfan]

What is the school of thought regarding spraying herbicide such as glyphosate early in the morning when dew is present on the target species? Seems like I read some time ago that the dew will dilute the chemical and reduce the effectiveness.

I don't think that dew affects the application of herbicides much. Rain that washes the herbicide off the plant immediately after spraying will hurt, but dew will usually just evaporate, leaving the herbicide in place. Spraying herbicides early in the morning when it is cool is actually better as less herbicide will evaporate and drift, and more will be absorbed by the plant. That is especially important with dicamba which is prone to drifting.

Sounds like the op expects Glysophate to start killing the plant immediately. It doesn't. As previously mentioned, it takes a week for it to show any effects and two weeks to show a lot of effect. If you want immediate results add an equal amount of 2-4d with your glysophate and the broadleafs will die quicker (it is kind of waste to apply the double mixture though.) I mix 2.5 oz per gallon of any generic 41% glysophate in water with 1 oz. of surfactant (even if it supposedly comes with a surfactant pre-added, they are usually quite inadequate) and have excellent results on most every weed. People underestimate the need for surfactant, especially later in the year when the weeds are more mature and waxy. It will not only save a lot of expense in herbicides, it will also significantly increase the effectiveness of any herbicide.

One trick I do is I add a few drops of blue food coloring to any non-selective weed killer I mix (glysophate), and red food coloring to selective herbicides (2-4d, dicamba, milestone, etc) so I won't accidentally confuse what is in the sprayer and use the wrong stuff in the right place.

Dishwashing soap (Joy, Dawn, etc) will work as a surfactant if you have nothing else, but a commercial surfactant is considerably more effective.

 

[ultrarunner]

I always mix to label and have found two additions that work for me.

First mentioned already is sufficant... I bought a bottle years ago and still have some...

Second is I never use cold water... always very warm... a biologist gave me the tip.

Ambient temp and growth stage also important...

 

[Cougsfan]

You are right, warm water will definitely increase the absorption of herbicide but it will also increase the potential for herbicide drift to neighboring plants that aren't a target, so be careful. Another trick when spraying around flowers and shrubs is to cover the flower or shrub with a bucket, blanket, or whatever before you spray herbicides in close proximity to it.

 

[dodge man]

Just to clarify my original post what alerted me to something being wrong was the fact the concentrate of roundup I mix myself wasn‘t working near as well as the ready to spray roundup. After doing a little more reading I’m pretty sure my hard water is the problem. I’ve been spraying roundup for a lot of years, not as a farmer but homeowner so I know what to expect.

 

[Complete Turf Care]

I have been a certified commercial applicator for about 40 years. I have sold (to farmers) and applied thousands of gallons of glyphosate and I still use it on a regular basis as a commercial applicator.

Several things I have learned with glyphosate are:
1. glyphosate is not very good on woody plants such as poison ivy, honeysuckle, trees and brush. Tryclopyr is better on this type of plant.
2. Glyphosate is 100% neutralized the instant it touches soil. This soil can be dust on the leaves of the target plants, or dirty water used to mix.
3. Glyphosate has 0 residual activity because it is neutralized instantly when it touches soil.
4. I use 2 oz. per gallon of the original formulation. (41% glyphosate)
5. I will cut that down a bit when I use a stronger concentration.
6. I do not add surfactant if it is already in the formulation, unless I am tank mixing with other products that do require surfactant.
7. The time of day for application does not affect the activity. Rainfall immediately after application will reduce activity. Rainfall 2-3 hours after application will not significantly reduce activity.
8. Young, fast growing plants are easier to kill.

 

[jaxs]

I have been a certified commercial applicator for about 40 years. I have sold (to farmers) and applied thousands of gallons of glyphosate and I still use it on a regular basis as a commercial applicator.

Several things I have learned with glyphosate are:
1. glyphosate is not very good on woody plants such as poison ivy, honeysuckle, trees and brush. Tryclopyr is better on this type of plant.
2. Glyphosate is 100% neutralized the instant it touches soil. This soil can be dust on the leaves of the target plants, or dirty water used to mix.
3. Glyphosate has 0 residual activity because it is neutralized instantly when it touches soil.
4. I use 2 oz. per gallon of the original formulation. (41% glyphosate)
5. I will cut that down a bit when I use a stronger concentration.
6. I do not add surfactant if it is already in the formulation, unless I am tank mixing with other products that do require surfactant.
7. The time of day for application does not affect the activity. Rainfall immediately after application will reduce activity. Rainfall 2-3 hours after application will not significantly reduce activity.
8. Young, fast growing plants are easier to kill.

Thank you for posting what experience has taught you,there is no better substitute.

 

[npalen]

Just to clarify my original post what alerted me to something being wrong was the fact the concentrate of roundup I mix myself wasn‘t working near as well as the ready to spray roundup. After doing a little more reading I’m pretty sure my hard water is the problem. I’ve been spraying roundup for a lot of years, not as a farmer but homeowner so I know what to expect.

The hard water issue is interesting. Sounds like I need to try some RO (Reverse Osmosis) filtered water. It does make me wonder, however, how large scale applicators deal with hard water.

 

[duffer]

The hard water issue is interesting. Sounds like I need to try some RO (Reverse Osmosis) filtered water. It does make me wonder, however, how large scale applicators deal with hard water.

The farmers use AMS added to the tank to soften the water. They also use room temp water as they normally have it stored in a large tank outside, before using it in their sprayers. It's warmer than us guys who pull it right out of the ground.

 

[old and tired]

I didn't read all responses, sorry if this was already said... Plants need to be actively growing to be able to absorb RoundUp. As for how rain-fast it is, I've had great results after a 30 minute drying time, I think it waters it down into the roots faster. You would have had better results if you watered the weeds first.

Also, you want a slow kill with RoundUp, you want it to reach all parts of the plant (mainly roots) before it does it's thing. Kill it too fast and the weed will just sprout back from the roots that didn't get RoundUp trans-located to. DON'T soak the leaf surface, a light mist is all you need (if the plant is growing). Middle of the summer, hot and dry, you are wasting chemicals.

If you spray under shallow rooted plants like dogwood trees, you can kill it if it gets watered down in the root zone. As for it killing everything, there's about 48 weeds that are resistant to RoundUp.

You want quick death, Paraquat is great (not for home owners). We use about $8k worth of Liberty herbicide at $95/gallon on our research farm. That kills the weeds that RoundUp can't kill.