A mower-conditioner has a header equipped with a rotary cutterbar for severing crop and directing it to a crop conditioner spanning a crop discharge opening centered rearwardly of the cutterbar and having a width some-what less than the length of the cutterbar. The cutter discs at the extreme outer ends of the cutterbar are equipped with upright, crop converging drums. For shorter cutterbars, paddles are mounted only to the tops of the cutter discs at the extreme outer ends of the cutterbars for operating in conjunction with the converging drums to move cut crop inwardly and rearwardly to the crop conditioner. For cutterbars of an intermediate length, paddles are also provided on the pair of discs respectively adjacent the discs at the extreme outer ends of the cutterbar and for cutterbars having a longer length, short crop converging drums are mounted to these adjacent discs.