A regulator valve includes an inlet coupled for receiving a spray solution delivered by a fixed displacement pump coupled to a solution tank. Located in the valve body so as to divide the solution received at the inlet between a bypass or tank port of the regulator valve, and a boom port is a ball valve in the form of a hollow sphere having a first circular opening in register with said inlet, a second circular opening in register with said boom port and an elongate, wedge-shaped opening in register with said bypass port. The ball valve is mounted for rotation about an axis which is coaxial with the first circular opening and includes a stem coupled to an electric motor for actuating the valve, the motor being coupled for receiving a control signal for causing the motor to position the ball for dividing the flow so as to achieve a desired solution application rate.