A low-cost, highly maneuverable cotton harvester (10) with a row unit (26) that effectively follows the ground contour includes frame structure (30) pivotally connected to the two lower links (22) of a tractor three-point hitch (14). A picking unit (26) is connected by a linkage structure (52) to the frame (30) and is closely coupled behind a rear drive wheel (16) of the tractor (12). A lift arm (98) extends forwardly and downwardly from an end (99) pivotally connected to the linkage structure (52a). The lower forward end of the lift arm includes a non-steerable gauge wheel (44) generally aligned with the tractor axle (44a), and a hydraulic cylinder (100) pivots the lift arm (98) relative to the linkage structure to adjust row unit operating height and to raise and lower the row unit to and from the field operating position. The gauge wheel axis (44a) is aligned with the axis (16a) of the drive wheel (16). A variable speed pulley assembly (90) synchronizes picker drum speed to ground speed.
