A mechanical harvester for harvesting a produce with a stem/core planted in a field includes a chassis, and a cutting device and a transport assembly connected to the chassis. The cutting device is configured to cut the stem/core of the produce. The transport assembly is configured to transport the produce using a movable first belt with a first set of produce grippers and a movable second belt with a second set of produce grippers. When the produce is held between the first set and second set of produce grippers, a portion of the first set of produce grippers opposes a portion of the second set of produce grippers. The opposing produce grippers are configured to compress and exert a force on the produce to hold the produce between the movable first and second belts.