A chopper assembly for harvesting equipment (20) including a rotary chopper device (50) with a plurality of knives and a cylindrical chopper grate assembly (56) spaced from the rotary chopper to form a passageway for crop residue. The chopper grate assembly (56) includes a plurality of slots (60) extending in the direction of crop residue flow. A knife bank assembly (62) includes a plurality of knife elements (64) aligned with and insertable in the slots (60) with the knife bank assembly (62) being displaceable between a position where the bank knife elements (64) are fully inserted through the slots (60) into the passageway and a position where they are substantially clear of the passageway. A deflector (84) is provided for covering the slots (60) and the deflector (84) is displaceable with the knife elements (64) to uncover the slots (60) as the knife elements (64) are displaced through the slots (60) and into the passageway.
