coupling generally designated 17 is centrally mounted on the front face 15 and includes a first pair of centrally located laterally spaced apart upstanding laterally outer upstanding angle irons 16 and a pair of less spaced apart upstanding central angle irons 18 the angle irons 16 and 18 are coupled to the cross beam 14 via u bolts generally designated 19 spanning the lower ends of the adjacent ones of angle irons 16 and 18 is a pair of lower draw pins 21 to which a pair of laterally spaced apart tractor mounted lower draw hitches 20 are detachably coupled the upper ends 23 of the central pair of angle irons 18 are spanned by a centrally disposed horizontal upper draw pin 22 to which the tractor mounted centrally disposed upper draw hitch 24 is detachably coupled the draw hitches 20 and 24 are frequently referred to as a u201c three point hitch u201d mounted on a tractor t for raising and lowering the frame 12 between a raised inoperative transport position illustrated in fig7 and 9 and a lowered ground engaging operative position illustrated in fig1 dependently mounted on the hollow cross beam 14 is crop residue knock down apparatus generally designated 29 including a relatively heavy transversely disposed drape or curtain 31 made from resilient material such as rubber belting the drape may typically be u00bd u2033 thick and is of sufficient length to span several corn stalk rows r the crop residue knock down apparatus 29 includes a pair of laterally outer upstanding drape mounting angle irons 33 coupled to the front face.