An apparatus for applying a desired amount of mechanical abrasion to plants and selective cutting of undesirable plant material. The apparatus includes a base, a brush and an elevation device for maintaining the base at desirable height. The base has a first longitudinal axis and a plurality of grooves, the grooves being oriented approximately perpendicular to the first longitudinal axis. The brush has a second longitudinal axis and a plurality of bristles and/or blades extending outwardly from the second longitudinal axis. The brush is attached to the apparatus such that the second longitudinal axis is substantially parallel to the first longitudinal axis and the brush is rotatable about the second longitudinal axis. The brush is spaced from the base such that the plurality of bristles engage the plurality of grooves. The base is adjustable enabling the operator to move the base closer or further from the rotating brush/blades.