When the operator of a cultivation air seeder shifts the tractor valve to raise the cultivators and openers from the ground as the seeder prepares to turn around at the end of a field, the operating and control system of the seeder causes the cultivators to be raised first, followed in sequence by the trailing openers. The seed meter turns off as soon as the cultivators leave their lowered position, but the blower stays on so that seeds in the conduits downstream from the meter continue to be delivered to and deposited into the ground by the openers until the cultivators reach their raised position, whereupon the openers are raised. Depending upon the particular seeding mode selected by the operator, the cultivators and openers either lower simultaneously as the operator shifts the tractor valve to the lowering position when starting down the next pass, or the cultivators are lowered first, followed in sequence by the openers. Regardless of the selected seeding mode, the seed meter turns on as soon as the cultivators reach their lowered positions.
