The invention relates to an attachment for attaching to a harvesting machine, comprising a number of picking devices (2) distributed adjacent to one another over the working width, said picking devices having at least a first and a second picking rotor (10a, 10b), which can be driven in counterrotation. The drawing edges (14) on the drawing bodies (12) on the first and second picking rotors (10a, 10b) are arranged in relation to one another in such a way that, during rotary movement of the first and second picking rotors (10a, 10b), two adjacent drawing edges (14) of the first picking rotor (10a) hold, in the range of action of said drawing edges into the downward movement path of a plant stalk (8), the plant stalk (8) temporarily against the drawing edges (14) of the second picking rotor (10b) preceding and lagging behind the two adjacent drawing edges (14) of the first picking rotor (10a) and clamp the plant stalk (8), by means of the four contact points (26) of the plant stalk (8), against the drawing edges (14) of the first and second picking rotors (10a, 10b) into an arc shape approximating the enveloping circle (16) of the first picking rotor (10a), and on the second picking rotor (10b) a knife blade (20) is arranged between the preceding and lagging drawing edges (14) of the second picking rotor (10a), which knife blade cuts into the outside of the plant stalk (8) clamped in an arc shape.