What dauber applied full strength herbicide stands to be the most fatal to the tubers of greenbriar when applied to the freshly cut vine 2" above ground? The clip and daub technique is very precise and uses a very small quantity of chemical even though it is full strength. The variety of greenbriar in question puts out a leafless vine 1/4- 5/8" in diameter each spring which grows at the rate of 4-6"/day. Leaves don't emerge until it is high into the tree. The lower section of the vine is well defended with cat like thorns. Both triclopyr and glyphosate, separately and in combination kill the vine itself, but there is regrowth from the tuber in 6-12 months 80% of the time. Tens of thousands of the same tubers have been treated this way annually over the past 4 years on a 75 acre heavily wooded plot in north central Texas. Should I expect any better results from Grazon P+D, or diquat?