What to use on the brush ???

I cleaned up 8 acres of woods over the winter. Got rid of most of the brush & left a lot of oaks. The brushy plants & a lot of Virginia creeper is coming back now. I'll take the tractor thru there with the broadcast nozzle & the hand gun. What's the most cost effective herb To use ? Dont want to kill grasses or the mature oak trees.maby a strong dose of LV-4 ?

What to use on the brush ???