I have a question about a week ago I sprayed RM43 herbicide in my gravel driveway to kill and prevent the weeds in the center strip. I thought I read the directions correctly to stay out of the drip line of any wanted trees. Well I have come to find it twice the distance of the drip line. I have a mature sugar maple tree off to the side of the driveway the drip line is about right on the line of driveway. When I mixed the spray I mixed it 3.5 oz to the gallon in a 2 gallon hand pump sprayer. Now I am worried I have made a serouis mistake and great injured if not killed my tree. Is there anything that can be done at this point, what are the chances of that the tree dies? Thanks for any help.
Question about R43 herbicide
- Thread starter Adamoh
- Start date
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smokey7
jack of a lot ace of a few
Is the tree showimg signs of being wounded by the spray dope? How long ago did you spray the drive? On that size tree id doubt the roots are under the drive yet.
I think you’ll be OK. RM43 is predominately glyphosate with a little Imazapyr to aid in control of brushy plants.
Maple trees are sensitive to Imazapyr by foliar absorption, and the absorption of the herbicide through the roots is dependent on the pH of the soil.
To limit the soil mobility of Imazapyr, you could raise the pH of the soil by applying lime to the treated area.
That said, I think the risk to your trees is low. Glyphosate deactivates in the soil quickly, and brushy plants are really only controlled by foliar applications in the Fall.
Here’s some additional information you might find useful.
https://pace.oregonstate.edu/course...-and-preventing-herbicide-injury-to-trees.pdf
Maple trees are sensitive to Imazapyr by foliar absorption, and the absorption of the herbicide through the roots is dependent on the pH of the soil.
To limit the soil mobility of Imazapyr, you could raise the pH of the soil by applying lime to the treated area.
That said, I think the risk to your trees is low. Glyphosate deactivates in the soil quickly, and brushy plants are really only controlled by foliar applications in the Fall.
Here’s some additional information you might find useful.
https://pace.oregonstate.edu/course...-and-preventing-herbicide-injury-to-trees.pdf
I sprayed the driveway just over a week ago. I’ve seen a few leaves on the outside of tree look to be cupped and burnt on edges. It’s a small percentage of the leaves maybe 5-10%.
Thank you for the information, makes me feel better about the survival chances of the tree.
