Fake Glyphosate?

[Susco]

I bought some Glyphosate to kill the tall grass and weeds around my perimeter wall.

 

Done this a few times in the past, and usually after 3-4 days it would die off.

 

This time after 5 days the weeds are just some kind of lighter green. It hasn't rained since I sprayed

 

I always buy from the same large farm supply shop, I don't buy the Monsanto but those at 450 Baht/4 liter, and add 200ml to 15 liter water.

 

Product is manufactured 1 year ago.

 

This make me think the stuff on the market lately is just fake product from China.

 

Anyone else experienced this?

 

 

 

 

[cooked]

In the dry season when things are hardly growing, it can take two weeks to show.

I'm sure you'll get some rain soon and you'll get results. I often spray a second time anyway, as heavy growths of grass etc prevents as yet smaller plants being properly attacked.

[tifino]

I always scribble in texta onto the bottle the date applied...

 - and it always works out about 7-10 days minimum fpor the desired effects to begin 

 

[drtreelove]

59 minutes ago, cooked said:

In the dry season when things are hardly growing, it can take two weeks to show.

I'm sure you'll get some rain soon and you'll get results. I often spray a second time anyway, as heavy growths of grass etc prevents as yet smaller plants being properly attacked.

This is a good point. Two weeks is not uncommon. There are variables, soil and plant moisture content has a lot to do with translocation.

 

"Tall grass" will be harder to control than if you apply to younger, actively growing grass and other young weeds.

 

The glyphosate you purchased may not be fake, it may very well be what it says it is, but it may not contain the surfactants that make it more effective. That's what the RoundUp label products have perfected, and why they have been so popular,  the most effective surfactants. But beware, the surfactants are what can volatilize into a gaseous drift and contaminate nearby crops, landscape plants and water, especially with high temperatures.  

 

Another factor is the condition of the water for your tank mix. Alkaline, hard water will not allow the most effectiveness. Condition the water prior to mixing in the glyphosate concentrate. 

 

"Always add ammonium sulfate (21-0-0) to glyphosate mixtures. Ammonium sulfate should be added at a minimum of 1.0 pound per acre if using greater than 12 gallons per acre of spray volume or 4 to 6 pounds per 100 gallons of spray mixture (lbs/100 gal) If water hardness is greater than 1600 ppm apply minimum of 8.5 to 17 lbs/100 gal."

"In order for Glyphosate to be effective
it needs to be absorbed into the plant.
In soft water Glyphosate has no problems in being absorbed,
however; in hard water Glyphosate will be "tied up"
and not be absorbed as readily.
This is known as "hard water antagonism".
Hard water contains high concentrations of the soluble salts, calcium (Ca++) and magnesium (Mg++).
When these are present in your spray water
the Glyphosate, which is negatively charged,
will combine with them to form Glyphosate-Magnesium
and Glyphosate-Calcium compounds.
These compounds are not as easily absorbed by the plant
and the result is poor uptake and poor weed control.

So how can growers increase the efficacy of
their Glyphosate treatments?
A common practice has been
to add a surfactant to the spray tank,
this allows the Glyphosate spray solution
to spread across the leaf surface better
and the result is greater absorption into the leaf.
Some Glyphosate products
now have the surfactant in them such as "Roundup Ultra".
Roundup Ultra does not solve the hard water antagonism problem by the addition of a surfactant though,
as the surfactant alone does not address this problem.

The hard water problem is best solved by
adding 17 pounds of ammonium sulfate per 100 gallons
to the spray water before the Glyphosate is added.

Urea - Ammonium Nitrate (28% liquid nitrogen)
will also improve the efficacy of Glyphosate,
but not as well a the Ammonium sulfate.

The addition of this compound to the spray water does two things.
First, the sulfate ions tie up the calcium and magnesium ions
by forming conjugate salts and
secondly, some of the Glyphosate ends up as
a Glyphosate-Ammonium compound
which some species of weeds preferentially absorb
into their leaf tissue over Glyphosate alone."

 

 

[Susco]

10 minutes ago, drtreelove said:

secondly, some of the Glyphosate ends up as
a Glyphosate-Ammonium compound
which some species of weeds preferentially absorb
into their leaf tissue over Glyphosate alone."

Thanks for the comprehensive explanation.

 

The bottle actually says Glyphosate - isopropylammonium

 

Usually it takes about 3-4 days to show results on the same application, and I always read that applying on a hot day will give best results, so that is why I expected quicker result this time.

 

Seems that is not really correct then, as I recall that with previous applications it usually rained within the next 24 hours, sometimes shortly after the application.

[drtreelove]

13 minutes ago, Susco said:

Thanks for the comprehensive explanation.

 

The bottle actually says Glyphosate - isopropylammonium

 

Usually it takes about 3-4 days to show results on the same application, and I always read that applying on a hot day will give best results, so that is why I expected quicker result this time.

 

Seems that is not really correct then, as I recall that with previous applications it usually rained within the next 24 hours, sometimes shortly after the application.

Hey, product quality is always a question in my mind. I've had some fails with pesticides and fertilizers that I was sure was due to poor quality, or outright fraud.  

In 2005 I attended all three days of a regional "Pesticides in Southeast Asia" conference in Chiang Mai. It was sponsored by the Rockefeller Foundation and the presenters were scientists and researchers from universities and organizations from all over the region.  It was shocking to hear of some of the extreme health and environmental issues that are a result of local practices, old generation harsh chemistry pesticides and contaminated materials.  More than one presenter told of inconsistencies in product formulations, contamination and undisclosed toxic substances in products from China and India where a lot of Thailand's chemicals come from.