I just finshed weighing all my frozen Isons I have picked, plus added in what I gave away, and my total so far is 200lbs of grapes from 2 Ison vines that each are 20ft long. I still have approx 60-80lbs left on the vines. This is my best year so far considering that I even cut off many fruiting spurs in the spring because I was afraid they were too crowded.