A weed seed devitalization arrangement for use with a. combine harvester, attached to the combine harvester, towed behind, or standalone. The weed seed devitalization arrangement receives weed seeds entrained in a. portion of the air and material previously discharged from a combine harvester or other crop/lawn cutung apparatus. The weed seed devitalization arrangement includes a roton'stator arrangement including but not necessarily excluding other elements, one or more stationary substantially circular array of weed seed impact members, the members being arranged so as to impact weed seeds being provided into the substantially circular array; and one or more rotatable substantially circular array of weed seed impact members, the rotatable array movable with respect to a stationary substantially circular array of weed seed impact members, the impact members of the rotatable substantially circular array arranged to impact weed seeds being directed through the rotatable substantially circular array. Another element may be a driven rotating clement at or near the central portion of the rotor/stator arrangement for receiving the portion of air and material discharged from the combine harvester entrained with weed seeds and for providing a flow of air and entrained material including weed seed into the arrays of the arrangement.