Produce with a core planted in a field can be harvested and decored using a mechanical harvester. The mechanical harvester includes a chassis, a positioning apparatus, a decoring device, and a transport assembly. The method includes moving the mechanical harvester through the row in the field; positioning the produce in the ground using the positioning apparatus; severing a substantial portion of the core of the produce while the produce is in the ground using the decoring device; lifting the produce from the ground; and transporting the produce to a processing unit or a storage unit using the transport assembly.