A header designed for tall crops includes a sickle knife for cutting at the ground, an auger behind the knife, a conditioning system at a discharge for forming a swath and a reel with pivotal bat fingers controlled by a linkage which co-operates with a cam of the reel. An upper auger extends across the header parallel to the cutter knife above and in advance of the reel with its flight driving the crop inwardly. Vertically standing sickle knifes extend between the ends of the frame and the upper auger and each includes forwardly extending top and bottom dividers. The conditioning system includes two fluted rollers and a third parallel roller located behind the nip between the fluted rollers so as to engage the material as it emerges from the nip to force the material round the upper roller to further bend the crop material.