that would also work they sell screw in type 1/4' barbs get 1/2' pvc with some 4 way tees then ball valves at each side of the tee then more pvc with and end cap then drill the holes for the drips in between the ball valve and the end caps then you can regulate each row. The bonus to that would be no worring about clogged drippers. I think a pro pump like the one I use would do all 72 they run about $85