Treflan needs to be incorporated into the soil at the time of planting. I would think you have waited too late to use it. You can still control weeds with an over the top spraying. Clethodim or Poast will control grass; you can use Milestone or 2,4-DB to handle broadleaf. I would wait and see if I had a decent stand before deciding what to do.

It should be coming up ok by now, but the soil in my area has only recently got warm enough for chufa to come up. I'd wait another week and see if comes up better. Good luck!