Abstract: A primer system for agricultural product distribution machines, such as an agricultural air seeder, a precision planter, a sprayer, or the like, includes a tank or a bin for holding the product, a distribution system for conveying and distributing the product from the tank and a driving mechanism for driving the product from the tank into the distribution system at a certain rate. The driving mechanism can run automatically or can be selectively operated, based on commands received from a microcontroller. The microcontroller may receive signals from a user interface and from sensing equipment, such as a ground speed detector, a pressure sensor, a flow metre, or the like. In a regular mode of operation, the controller runs the driving mechanism automatically at a rate calculated based on the signals received from the above mentioned systems. Most agricultural machines have the automated mode of operation of the driving mechanism, conditioned by the ground speed of the tractor being higher than a minimum speed.