My dad fell and hit his head and he has an open wound like an inch long but it is not bleeding, should we take him to the e.r?

Yes: I don't want to alarm you, but there are several issues that should probably be checked out. This gash may need to be washed out with irrigation and sutured back together. He may need to be evaluated for brain or neck trauma from the fall. He may need to be observed overnight to make sure that his condition doesn't deteriorate, but most likely, if he looks good he can go home with you.

Yes, don't delay: Even though it's not bleeding, it likely needs to be stitched-up or stapled closed, so it doesn't get infected & heals properly with a minimal scar. After that has been done, wash it gently with antibacterial soap & water daily & then cover it with neosporin anti-biotic ointment for 2 weeks. Tylenol (acetaminophen) for pain if needed. He'll be fine, don't worry ;).