Material control elements carried by the rotor of an axial flow rotary combine separator include inclined blades as well as conventional rasp bars. The inclined blades take various forms but common features include their downstream inclination, (that is in the direction of the axial movement of crop material in the separator) and having a frontal working edge athwart the direction of rotation to engage crop material and deflect or urge it downstream. The orientation and configuration of the blades results in their working edges being their dominating material control feature while the inclined surfaces have a subordinate role in material control, the actual effect of the surfaces depending on the orientation of their line of slope with respect to the rotor axis.