The knife head mounts to the sickle to hold a plurality of knife sections thereon while allowing removal of the knife sections individually without major disassembly for ease of in field repair and replacement. A knife pin of the knife head connects to a knife arm driven by the sickle drive mechanism and is removable from above also without major disassembly. The knife pin connection provides a vertical self adjustment capability to accommodate sickle wear and vertical misalignment between the sickle and drive. And the knife arm is streamlined for cut plant material flow thereabout and is also adapted for ease of removal and field repair.
