bingo, yer a winner!!
this is a hard 1. the herbacides work best when the laeves are young and reddish in color... this'll need multiple applications of round-up etc. cutting the vine and directly coating w/ round-up works ok too...
maybe do this: cut the vine- pull half off the silo, other half outta the ground. lay the vines in a safe place to be baked by the sun. DO NOT bury- it'll grow... things to know-remember: the oil in PI or P oak, urshoil (sp?) stays active in the plant for five years after cutting.... never wash with hot water sinc hoy h2o opens your ores and lets the oil in...
personally, i'd let the vines stay until winter, then attack when dormant and the oils not actively running...
good luck, be careful!!!!!!!!!!!1