When did glyphosphate stop killing roots?
It never had been effective at killing the root system of a trees and most other perennials. I can post a lot of real life pictures tonight but all it will do is clog the mans thread up. If you want to believe it is effective at permeant killing of trees and some other perennials that is fine. It is effective on most annuals. It is too late in the year for you to try this but you can next year. Go select four similar sized trees that you would like to kill. Spray 25, 50,75and 100percent of them respectively. See what the results are. You will see the respective amounts appear to die but the untouched will live. Select a fifth tree and cut it down then spray the stump. In 2024 go back and look at the results. The four uncut but sprayed trees will be alive and the stump applied one will be sprouting shoots depending on species. Another quicker trial is to spray a small section of grass early in the spring. It will appear to die but then as the season progresses you will see the grass come back. This is one of the reasons when no till farming you have to spray a second application of Glyphosate as the first application burns everything down but does not kill the roots of the perennials such as grasses. It does kill grasses such as corn because corn is an annual.
Since you are in the PNW with a different growing season how did those plants look like 90 days 120 days, 240 days and 360 days later after a single application? Are your no-till farmers using a single application for lifetime control? If so that is great as one application to a perennial is lifetime control with no more control needed. Then no one would ever need to buy Glyphosate again for perennial. . So on woody stem and basal bark applications no one uses the most effective treatments of Picloram or Triclopyr ? The poster asked about killing a woody stem from a cut stump and Glyphosate is ineffective at that task. You can believe what you want but real life experience by millions is hard to refute. I guess you want to believe it I am not going to argue with you. I just want to help the poster find an effective method of permanently solving the issue and not a "band-aid" for a few months or a year. In 30 years of using Picloram I have never had to treat a stump twice and no one that I have ever talked with has either. You can believe what you choose. If you do not believe me then go do the experiment I suggested. It will be quicker in your growing season. I am very interested in the findings.
He must be thinking of some other chemical.
I have never used it but have heard it is effective. The active ingredient is imazapyr.
What he said!
We used it in a hand sprayer at 10% Tordon 22k with Basal Oil + DYE for spraying stumps on small scale. Needs to be sprayed soon after cut so the so the cambium area takes up chemical, can also add 2-4D to the mix for better control.
I have always just used the RTU but last winter I looked into getting the 22K because I needed a huge amount. I got conflicting answers from some folks on how to mix it. Some said 2 gallons of diesel with one gallon each of 22K and 24D. Others said to use water. So if I understand you correctly you are using the 22K as only 10 percent of your solution. If so how much 24D
Glyphosate foliar spray will get to the roots, need to allow it to transfer from foliage before cutting. Can also paint fresh cut stumps/vines with concentrate.
