PROBLEM TO BE SOLVED: To provide a raising seedling tray structure to hold and transport raising seedling root balls without the need of pots, to provide a method for making the raising seedling tray structure, and to provide a composite tray used for the method. SOLUTION: The composite tray has a raising seedling tray connected with an upwardly opened basket container in which root balls are to be held, and an upwardly opened surrounding container detachably attached to the outside of the basket container, surrounding the side and the bottom of the basket container. The raising seedling tray structure comprises the raising seedling tray connected with the upwardly opened basket container and root balls held in the basket container without through a pot. The method for making the raising seedling tray structure comprises a process of preparing the composite tray, a process of attaching the surrounding container to the raising seedling tray, a process of filling a medium in the surrounding container, a process of letting seedlings take root in the filled medium and a process of removing the surrounding container from the tray. COPYRIGHT: (C)2005,JPO&NCIPI
