A planter comprising: a seed meter having a housing adapted to hold a pool of seed to be singulated and delivered sequentially; a seed delivery system to provide at least two different varieties of seed to the meter, the seed delivery system having a switching mechanism to change from a first variety of seed to a second variety of seed being delivered to the meter housing; and a controller adapted to operate the switching mechanism to control which seed variety of the first and second seed varieties is delivered to the meter based on the location of the planter in a field, the controller operation of the switching mechanism based on a programmed quantity of seed wherein the controller is adapted to stop supplying a first seed variety to the meter in advance of supplying a second variety to allow for substantial consumption of the first variety of seed in the seed pool prior to supplying the second variety of seed to the seed meter, wherein the location of the planter in the field where supply of the first variety of seed to the meter is stopped is based on the programmed quantity of seed in the seed pool and the seeding rate, wherein the planter further comprises a seed sensor adapted to count seeds delivered by the seed meter; wherein the seed meter is a pressure differential meter utilizing a pressure differential to meter seed; and characterized in that the controller is adapted to decrease the programmed quantity of seed in the seed pool in the event a measured pressure differential changes after stopping delivery of the first variety of seed to the meter housing before an expected quantity of seed has been delivered from the seed pool.. a seed meter having a housing adapted to hold a pool of seed to be singulated and delivered sequentially; a seed delivery system to provide at least two different varieties of seed to the meter, the seed delivery system having a switching mechanism to change from a first variety of seed to a second variety of seed being delivered to the meter housing; and a controller adapted to operate the switching mechanism to control which seed variety of the first and second seed varieties is delivered to the meter based on the location of the planter in a field, the controller operation of the switching mechanism based on a programmed quantity of seed wherein the controller is adapted to stop supplying a first seed variety to the meter in advance of supplying a second variety to allow for substantial consumption of the first variety of seed in the seed pool prior to supplying the second variety of seed to the seed meter, wherein the location of the planter in the field where supply of the first variety of seed to the meter is stopped is based on the programmed quantity of seed in the seed pool and the seeding rate, wherein the planter further comprises a seed sensor adapted to count seeds delivered by the seed meter; wherein the seed meter is a pressure differential meter utilizing a pressure differential to meter seed; and characterized in that the controller is adapted to decrease the programmed quantity of seed in the seed pool in the event a measured pressure differential changes after stopping delivery of the first variety of seed to the meter housing before an expected quantity of seed has been delivered from the seed pool..