Planter plates or seed plates are an integral part of row crop planters, especially for corn. They
are round plates or disks with indentations, slots, or holes evenly spaced around their outer edge.
Each row unit of a planter requires a planter plate. The planter plate precisely meters seeds flowing from a seed box into the seed tube which delivers seeds into the soil. Planter plates can be changed depending on the size and type of seed.
As the planter moves, the plate within each row unit rotates, picking up seeds in each slot and dropping them at a constant rate into the seed tube. This rotation can be ground-driven, where the plates turn as the planter’s wheels do; or either hydraulically or electronically-driven.
In newer planters, seed plates are positioned vertically. The seeds are held in place by air pressure or vacuum until they are released into the seed tube.
In older planters, plates were positioned horizontally and seeds were held in the plates by gravity.