Second year hop stopped growing at 7'

Well here's the deal i got back from my deployment and my hop had already started growing. It is in one of those big black containers 20-25 gal.? (about 18" tall and about 14 inches across)
It was growing rapidly and i dint trim any of the shoots there's about 20 shoots i just decided to let it take its course this year. well anyway it just decided to stop growing one day last week. some of the lower leaves are yellowing so i added nitrogen and alittle p. not urine. lol. i took a closer look and i see some roots growing from the drainage holes. So me thinks i am prolly root bound. what do you guys think?

If you have a place to plant it, put it in the ground. Root bound may not be the reason it stopped growing though. It should be flowering by now or starting to, they pretty much stop growing once they start to flower. Regardless, if you keep it in that pot you'll never see the full potential.

very true. the pot is so big and the bines so attached to there twine i am kinda apprehensive to take it out of the pot for fear of breaking something

Transplant it in the fall then so it can overwinter and take off first thing come spring.

You might want to drill out a few more holes on the bottom of the pot to make sure that it's draining well. If the water isn't coming out of the bottom then you could be drowning the plants. I grow hops both in the ground and in pots with success in N. San Diego County. I can get three or four years of growth in a pot before I'll take it out, divide rhizomes, and start over. Currently, I have three, second-year Chinook plants in pots and they are 20' tall and flowering like mad. They get watered more often (pretty much every day) and require more food then the in-ground ones but do very well. My guess is the roots stopped up your drain holes, so double check that water flows out the bottom when you water and, perhaps, drill a few 1/2" to 1" holes in the bottom of your pots to be sure you have adequate drainage.

I will drill some holes for now then replant in fall, this was my strongest plant last year so it could be that the roots are pretty massive. the root that was coming out of the drain hole was at-least a 1/4" dia.. thank you for the responses ill up date on what happens.