Abstract: Disclosed is a method and apparatus for lifting and stacking cartons onto a bed attached to a truck bed, especially in an agricultural field. The lifting apparatus includes two endless parallel belts to lift the cartons from the field onto a first conveyor. Variations in carton size or alignment may be accommodated by a pivoting loading frame or by lateral movement of the loader, which lateral movement is compensated for by a self-alignment mechanism. Cartons are transported to an elevator via a first and second conveyor. The elevator lifts the cartons to the level of a palletizer with a false floor wherein a reciprocating and pivoting transfer head removes the cartons from the elevator and deposits them onto the prestacking area of the palletizer false floor. Cartons may be selectively rotated into a transverse loading position by the transfer heads. Upon assembly of a first row of cartons, a tamping bar extends to position the cartons against the truck tailgate or against previously stacked cartons.