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Lowest toxicity turf herbicide

RigglePLC

LawnSite Fanatic
Location
Grand Rapids MI
Suppose you wanted to apply a herbicide to your customers yards that you could promise was safer than Weed-b-Gone, at the necessary rate per thousand sqft.
For cool season grass, what broadleaf herbicide has the lowest toxicity?
I think I asked the same question 5 years ago, but I could not figure out a good answer.
Suppose a customer asked how many sqft of grass his 50 pound dog would have to eat to risk death?

I am thinking triclopyr would be a good choice.

Nominate your favorite.

And help me do the calculations.
 

greendoctor

LawnSite Fanatic
Location
Honolulu, Hawaii
Turflon Ester Ultra has an LD50 of 3.2 gram per kilogram. A 22.5 kilogram dog would need to ingest and retain 72 grams of concentrated product. Normal application rate of Turflon Ester Ultra is ~20 grams or 3/4 oz per 1000 sq ft. Dog would have to eat and keep down over 3500 sq ft of grass. I know what happens to a dog that eats a few mouthfuls of grass herbicide or no herbicide. Impossible for toxicity to occur. Triclopyr is also not a known or suspected carcinogen.
 
OP
RigglePLC

RigglePLC

LawnSite Fanatic
Location
Grand Rapids MI
Good point, Greendoc!
Thanks for your help with the calculations.
What about Tenacity (mesotrione)?
LD 50 about 5000 or maybe more.
Rate is 4 to 8 ounces per acre.
I converted the 50 pound dog to 800 ounces, and calculated 4 ounces needed to kill the dog.
I concluded he would have to eat about an acre of treated grass to approach a lethal dose.
Probably a half-acre if the 8 ounce Tenacity per acre rate was applied.

Anyone else have a favorite low-tox broadleaf herbicide in mind?
 
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greendoctor

LawnSite Fanatic
Location
Honolulu, Hawaii
Quicksilver and Octane have similar toxicology profiles. In fact, most weeds in a cool season lawn could be handled by a combination of Triclopyr, Tenacity, and Quicksilver or Octane with minimal hazard to dogs.
 
OP
RigglePLC

RigglePLC

LawnSite Fanatic
Location
Grand Rapids MI
Cornell's hazard calculator works swell--however--how do you enter 2,4-D?
And how do you enter Weed-B-Gone?
Or Trimec?--unless you consider them the same.
Is there a way to enter ester as opposed to amine?
When applying a mixture--do you add the risk factors together or average them out?
 

phasthound

LawnSite Fanatic
Location
Mt. Laurel, NJ
Cornell's hazard calculator works swell--however--how do you enter 2,4-D?
And how do you enter Weed-B-Gone?
Or Trimec?--unless you consider them the same.
Is there a way to enter ester as opposed to amine?
When applying a mixture--do you add the risk factors together or average them out?
Those are all good questions. I'm still learning.
Another factor that come into play is how effective is the active ingredient? While one ingredient require 3lb/k another might require 5lb/k. The University of Wisconsin. Can't find the link right now.
By combining the info from both sources you can figure out which products work best with he least negative effects. It's not that easy to figure out. Hopefully there will be more training on how to use the info.
 


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