Broadleaf Weed Killers for Pasture-What are the Products with No Grazing Restrictions

[millerra]

I personally would not and will not allow 2,4D to be used on my farm.

It has a very long life time in the environment, and under the right conditions can break down into toxic compounds and or estrogen mimics.

Round up is better from a chemical standpoint because it has a short life span in the environment and breaks down into relatively biologically friendly products.

There is a significant difference between acute toxicity and short term safety and long term, low level exposure, toxicity and life time/breakdown products of a compound in the environment.

[FYI - I am not a internet chicken little or a rabble-rouser - I am by trade a chem prof (biochem) and teach envir chem. This is just my opinion, having looked at the science…]

[ladyfarrier]

"…It has a very long life time in the environment, and under the right conditions can break down into toxic compounds "

Millera, what sort of conditions could cause the aforementioned to happen?

I appreciate your knowledge and would like to learn more about this…

Thanks.

[Ridge_Runner]

Millera,

I’d also like to know more about 24D and long term use issues. Any thoughts on some of the other products like Cimmarron? I have used Roundup but mainly along fencelines and such. It would never work with mass spraying of the pasture obviously as it will kill everything including my grass.

[millerra]

off the top of my head (at home after a clinic) - UV light (sunlight) and oxygen (O2) especially if the 2,4D is relatively concentrated will cause 2,4D to react with itself. I will look more specifically on Tues, if still interested. As a sprayed on chemical, it would be come relatively dilute but since it stays around, there will be a long term baseline concentration that will slowly build if used consistently.

Again, this is off the top of my head and I will look into my papers on Tues when back at work (spring break and all) but this is what I remember:

Originally 2,4 D and 2,4,5 T were the active ingredients of agent orange. The potent toxins in agent orange were the dioxins - a contaminant due to a reaction w/ O2 during the synthesis. They have since cleaned up the dioxins from the original 2,4 D products BUT it is the dioxin formation that is one of the primary concerns when it hangs around in the environment… Horses are extremely sensitive to some of the dioxins (race track incident in the ?30s?)

Due to the chlorines on the aromatic ring - it is not a microbe friendly compound and therefore 2,4D lasts a very long time.

[Tamara_in_TN]

[QUOTE=Daydream Believer;4751682]
Tothenines…I’m completely with you and up to this year, I’ve resisted spraying my fields at all…but I have a terrible infestation of buttercups and they are impeding the growth of grass. I’m the last person to be liberal with chemicals.

killing them before 3-4 inches is your only shot of being rid of them…and then DON’T overgraze again…that is how they came to be with the “good” greenery being cropped out

slay them all, the Lord will know if own

Tamara in TN

[Ridge_Runner]

Good heavens Millerra! Is there any chemical for broad leaf weed control that is safe…truly safe? I appreciate your looking that up for us. I really don’t want to add potentially harmful chemicals to my pastures if I can avoid it!

[twofatponies]

[QUOTE=Daydream Believer;4757937]
Good heavens Millerra! Is there any chemical for broad leaf weed control that is safe…truly safe? I appreciate your looking that up for us. I really don’t want to add potentially harmful chemicals to my pastures if I can avoid it![/QUOTE]

There’s always the hoe and the trowel!

We had neighbors when I was a kid who spent each afternoon on their knees digging out the weeds by hand. Their lawn was amazing. They were an elderly Japanese couple, which may have been a contributing factor. Everyone else either ignored the weeds or used ChemLawn.

[Ridge_Runner]

@twofatponies;4757944

There’s always the hoe and the trowel!

We had neighbors when I was a kid who spent each afternoon on their knees digging out the weeds by hand. Their lawn was amazing. They were an elderly Japanese couple, which may have been a contributing factor. Everyone else either ignored the weeds or used ChemLawn.

I’m not talking a “lawn” but about 20 acres of pasture! Nice idea but not practical!

[deltawave]

Nothing is “truly safe”, in all honesty. You have to make the calculation if potential risk outweighs potential benefit. Ideally with the best possible facts in hand.

[millerra]

It’s exactly as DW has said…

One has to weigh risk vs benefits.

The problem with chemicals and toxicity - as we have been learning over the last 50 years - is that there is a difference between acute, high dose exposure and long term, very low dose, chronic exposure. It is very difficult to scientifically quantify the latter until, perhaps, the damage is already done (eg asbestos, benzene).

Hence, the problem with things like 2,4 D, PCBs, etc…

Since 2,4D is available, it is clearly one’s choice to use it or not. My choice is not.

We till up our hay field every few years, let it regrow, spray w/ round up, and plant w/ our grass/alfalfa mix. Now we’re waiting for a alfalfa/grass seed mix that is round up ready

Of course, there is a risk using round up ready plants- primarily, IMHO, the spread of the round up resistance gene to weeds. That, in my opinion, is a bad thing.

sorry I don’t have any better advice…

[millerra]

FYI

From my stuff:

2,4D is less likely to form dioxins then other compounds, such as the PCBs, when it is in low concentrations (e.g. sprayed on field).

However,

It does break down over time into 2,4 dichlorophenol (2.4 DCP) which is very stable (loses the acetic acid group linked by an O).

2,4 DCP is an endocrine disruptor and a suspected carcinogen and teratogen (a compound suspected to cause birth defects).

So, short term - it’s a “relatively” safe compound. Long term, chronic low dose exposure that would occur due to repetitive spraying of pasture land w/ concomitant water contamination, I would still “just say no”.

[Ridge_Runner]

Millerra…thanks for that info. Do you have any information on the product called Cimarron Max?

I copied this off the label…Thanks!

Active Ingredients By Weight
Metsulfuron Methyl* Methyl 2-[[[[(4-methoxy-6-methyl -1,3,5-triazin-2yl)amino]carbonyl] amino]sulfonyl]benzoate . . . . . . . . . . . . . . . . . . .0.75%
Dimethylamine salt of dicamba (3,6-dichloro-o-anisic acid)** . . . . . . . . . . . . . .12.25%
Dimethylamine salt of 2,4-dichloro- phenoxyacetic acid*** . . . . . . . . . . . . . . . . . . . .35.25%
Inert Ingredients . . . . . . . . . . . . . . . . . . . . . . . . .51.75%
TOT AL 100.0%

[Ridge_Runner]

Also Cimarron Plus? I hope you don’t mind my asking but the kind of information you have is not easy to find on line. Thanks!

This one did not copy over as well unfortunately.

Active Ingredient
Metsulfuron Methyl Methyl 2-[[[[(4-methoxy-6-methyl -1,3,5-triazin-2yl)amino]carbonyl] amino]sulfonyl]benzoate 48%
Chlorsulfuron 2-Chloro-N-[(4-methoxy-6-methyl- 1,3,5-triazin-2-yl)aminocarbonyl] benzenesulfonamide 15%
Inert Ingredients
By Weight 37%
TOTAL 100%

[millerra]

I will have to look up the first incredient as I am unfamiliar w/ it. The first one you posted definitely contains a form of 2,4 D.

The second I suspect contains atrizine (also not one of my favs but only because it lasts forever and is suspected as a estrogen mimic.)

Will get back by tomorrow…

[ToTheNines]

WOW millerra, thank you so much. I have been suspicious, but not very scientific about it. I do not use herbicides, and my one of my favorite morning exercises is walking my fields with a maddox to unroot weeds. Mowing and chopping – takes time but it pays off.

[Ridge_Runner]

Thanks also Millera. I really appreciate your insight and sharing your information with us.

[CL_Moonriver]

Please don’t hang me. But despite all the bad press that glyphosate has been getting lately, it is practically non-toxic in the doses your horses would be exposed to.

The bigger concern with using herbicides (and I suspect this applies to all herbicides) on weeds in your pasture is not the toxicity of the herbicide itself, but the fact it can cause chemical changes in some plants that make them more attractive to horses. In other words, a poisonous plant that horses normally do not eat can become attractive to them after herbicide application. And then it’s the fact that the plant itself is toxic that poses a danger to them, rather than any toxicity from the herbicide.

[Bluey]

That was a spammer bumping this 8 year old thread up.

Reported.

[CL_Moonriver]

@Bluey

That was a spammer bumping this 8 year old thread up.

Oops. Good catch. I didn’t realize how old the thread was and that the last person who responded was a spammer.

[Where_sMyWhite]

FWIW, since the Brash Herbicide was responsible for reactivating

I would double check to confirm if a license is required to apply Brash Herbicide in your state.

NB on pre-emergents… normally they need to be watered in within 2-3 days of application to be effective. Pre-emergents keep seeds from germinating, all seeds, so think about what you might be sowing (grass seed) in the pasture if you choose to treat with a pre-emergent.

I’m on the glyphosate (aka Roundup) bus. As far as herbicide goes, one of the less harmful to the environment with a fairly fast breakdown in the soil. Reasonably easy to spot treat. Yes, weeds (unwanted plants) are starting to develop glyphosate resistance (I’m not talking about the “Round-up Ready” crops that have been modified so glyphosate doesn’t kill them.)