The Harvester is the primary resource gathering unit (while it's technically a structure) that can be deployed on a field of green Tiberium or blue Crystals. It can be summoned once a level 1 Construction yard has been set up. Harvesters can also be granted an income bonus if they are adjacent to a Tiberium silo. As with all games set in the Tiberium universe, the Harvester is the primary source of income, but unlike the other games, a refinery is no longer required.