Question
Recently just put a spade through black poly in the flower zone, fixed that problem, went to run the sprinklers through ever zone, all came on but zone 4 stays on throughout, the only way I can shut water off is to turn main valve to sprinklers off. the main controller board(HUNTER) has no power over that zone at all! Stumped in NJ

Answer
Chances are you cut through the mainline and a bit of debris got into the pipe. The debris ended up in the valve that is stuck on. You'll need to locate the valve and open the top of it and flush out the problem.
If you need help on this procedure, let me know the model # of the valve, Hunter has a few different ones.

Matt