With the models 7000/7100 planters, JD had to type of meters: plate and plateless. Here we will discuss the plateless. Plateless planters have what is called a corn finger pick up unit for metering corn. It is much more accurate for corn than a plate planter. Another plus is that one corn meter plants all shapes and sizes of corn whereas a plate planter has many different plates for the different sizes and shapes of corn seed. The corn meter will also plant sunflowers. The corn meter can be replaced with a soybean meter and soybean cup for planting soybeans. Within the same bean meter the bean cup can be replaced with a milo or sorghum cup for planting milo or sorghum. The bean and milo cups will also plant similar sized and shaped seeds. Takes about a minute per row to switch meters. Summary: Pros- Plateless planters are much more accurate planting corn. Cons- Pretty much limited to corn, sunflowers, soybeans, and milo with the correct meters.

The JD model 1250's had plate type seed meters. With the models 7000/7100 planters, JD had two type of seed meters: plate and plateless. Here we will discuss the plate meter. Plate planters have what is called a plate in the bottom of the seed hopper. This is a round disc with notches or cells for metering the seeds.   To change plates, unlatch box and turn bottom side up.  Loosen wing nut that holds plate lid in place.  Flip hinged lid over and pull out plate.  It is rather simple and takes less than a minute per box.  I carry corn milo and soybean plates on hand and sell for $5 each.  You can buy new plates for about $14 each for many different seeds.  You can plant a larger variety of seeds or crops with plate planters. In fact you can purchase blank plates and make your own plates for specific seeds.  When it comes to corn, a plate planter has a harder time achieving accuracy than a plateless planter. All corn plates will plant corn, but to get the accuracy you need the plate that has the right size and shape of cell for the corn. Sometimes it can be hard to do. With the right plate, it does a good job. If you are planting food plots and not going for yield, than it is not a big deal. Any corn plate will do.

Summary: Pros- Plate planters plant a larger variety of seeds. Plates are inexpensive compared to plateless meters.  Cons- Not quite as accurate for corn as a finger pick up meter found in plateless planters.
ksfarms
corn   soybean   milo
plates​
seed box with plate meter
seed box with plate meter
p l a t e    m e t e r
p l a t e l e s s     m e t e r
corn finger pickup meter
soybean meter with soybean cup
box with corn finger pu meter
seed box with plateless
​ meter removed