Depending on what you’re trying to protect, if anything, I’d be cautious using imazapyr. It has soil activity that can last weeks to months depending on the application rate. For general brush control using foliar active herbicides I go with 8 oz of glyphosate, 1 oz of Triclopyr 4 and 1 oz of 80/20 surfactant per gallon on spot spraying. The Triclopyr will kill blackberry and most hardwoods. There’s no reason to apply 2 oz per gallon. That’s a very high application rate.
Thank you for this info! I need to add a lot more glyphosate to my mix from now on.